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T cell receptors (TCRS) that have higher affinity for a ligand than wild type TCRs are provided. These high affinity TCRs are formed by mutagenizing a T cell receptor protein coding sequence to generate a variegated population of mutants of the T cell receptor protein coding sequence; transforming the T cell receptor mutant coding sequence into yeast cells; inducing expression of the T cell receptor mutant coding sequence on the surface of yeast cells; and selecting those cells expressing T cell receptor mutants that have higher affinity for the peptide/MHC ligand than the wild type T cell receptor protein. The high affinity TCRs can be used in place of an antibody or single chain antibody.
1. A method for using high affinity TCRs to identify ligands comprising:
labeling high affinity TCRs;
contacting said labeled TCRs with peptide/MHC ligands;
identifying the ligand with which the labeled TCR is bound, wherein said label is selected from the group consisting of: fluorescent compounds, chemiluminescent compounds, radioisotopes and chromophores.
2. A method of using high affinity TCRs to bind to a selected peptide/MHC ligand comprising:
labeling said high affinity TCRs that binds to the selected peptide/MHC ligand with a label;
contacting said labeled high affinity TCRs with cells containing MHC molecules, wherein said label is selected from the group consisting of: fluorescent compounds, chemiluminescent compounds, radioisotopes and chromophores.
3. A method for using high affinity TCRs as diagnostic probes for specific peptide/MHC molecules on surfaces of cells comprising:
labeling high affinity TCRs that binds to specific peptide/MHC ligands with a label;
contacting said TCRs with cells;
detecting said label.
4. A method for using high affinity TCRs that bind to pMHCs for diagnostic tests comprising:
labeling the high affinity TCR with a detectable label;
contacting said labeled high affinity TCR with cells;
detecting the label.
5. The method of
6. The method of
7. The method of
8. A method for using high affinity T Cell Receptors (TCRs) to detect ligands comprising the steps of:
labeling high affinity TCRs;
contacting said labeled TCRs with peptide/MHC ligands;
detecting the presence of the label thereby detecting the ligand to which the labeled TCR is bound wherein the high affinity TCR carries one or more mutations in a CDR.
9. The method of
10. The method of
11. The method of
fluorescent compounds, chemiluminescent compounds, radioisotopes and chromophores.
12. The method of
13. The method of
This application is a divisional of U.S. application Ser. No. 09/731,242, filed Dec. 6, 2000 now U.S. Pat. No. 6,759,243, which is a continuation-in-part of U.S. application Ser. No. 09/009,388, filed Jan. 20, 1998 now U.S. Pat. No. 6,699,658, and wherein this application also claims the benefit of U.S. Provisional Application No. 60/169,179, filed Dec. 6, 1999.
This invention was made with Government support under Contract No. PHS-5-R01-GM55767-03 awarded by the National Institutes of Health (NIH). The Government has certain rights in this invention.
The field of the present invention is molecular biology, in particular, as it is related to combinatorial libraries of immune cell receptors displayed on the cell surface of a recombinant host cell. More specifically, the present invention relates to a library of high affinity T cell receptor proteins displayed on the surfaces of recombinant yeast cells, to soluble high affinity TCR receptor proteins, to high affinity TCR proteins selected for high affinity binding to particular peptide/MHC pairs, to high affinity TCR proteins selected for binding to a particular antigen in the absence of an MHC determinant, and to the use of the selected high affinity TCR derivatives in diagnostic methods and imaging assays, among other applications.
T cell receptors (TCRs) and antibodies have evolved to recognize different classes of ligands. Antibodies function as membrane-bound and soluble proteins that bind to soluble antigens, whereas in nature, TCRs function only as membrane-bound molecules that bind to cell-associated peptide/MHC antigens. All of the energy of the antibody:antigen interaction focuses on the foreign antigen, whereas a substantial fraction of the energy of the TCR:peptide/MHC interaction seems to be directed at the self-MHC molecule [Manning et al. (1998) Immunity 8:413:425]. In addition, antibodies can have ligand-binding affinities that are orders of magnitude higher than those of TCRs, largely because of the processes of somatic mutation and affinity maturation. In their normal cellular context, TCRs do not undergo somatic mutation, and the processes of thymic selection seem to operate by maintaining a narrow window of affinities [Alam et al. (1996) Nature 381:616-620]. The association of TCRs at the cell surface with the accessory molecules CD4 or CD8 also may influence the functional affinity of TCRs [Garcia et al. (1996) Nature 384:577-581]. Despite these differences, the three-dimensional structures of the two proteins are remarkably similar, with the hypervariable regions forming loops on a single face of the molecule that contacts the antigen.
Based on their structural similarities, it is somewhat surprising that there have been significant differences in the success of producing soluble and surface-displayed forms of the extracellular domains of TCRs and antibodies in heterologous expression systems. Many antibodies have now been expressed at high yield and solubility as either intact or Fab-fragment forms or as single-chain (sc) fragment-variable (Fv) proteins. In addition, there are numerous antigen-binding Fv fragments that have been isolated de novo and/or improved through the use of phage-display technology and, more recently, with yeast-display technology [Boder and Wittrup (1997) Nat. Biotechnol. 15:553-557; Kieke et al. (1997) Prot. Eng. 10:1303-1310]. These expression systems for antibody fragments have been key in structural studies and in the design of diagnostic and therapeutic antibodies.
In contrast, the three-dimensional structures of a few TCR molecules were determined only after considerable effort on the expression of soluble, properly folded TCRs [Bentley and Mariuzza (1996) Ann. Rev. Immunol. 14:563-590]. One of the difficulties in exploring the basis of differences between Fab and TCR has been that the extensive sequence diversity in antibody and TCR variable (V) regions complicates efforts to discern what features of the V regions are important for functions other than antigen binding (e.g., V region pairing and association kinetics, stability, and folding). There have been relatively few studies that have compared the V regions of TCRs and antibodies in terms of these properties.
Nevertheless, the TCR from the mouse T cell clone 2C has now been expressed as an sc VαVβ(scTCR) in Escherichia coli [Soo Hoo et al. (1992) Proc. Natl. Acad. Sci. USA 89:4759-4763], as a lipid-linked VαCαVβCβ dimer from myeloma cells [Slanetz and Bothwell (1991) Eur. J. Immunol. 21:179-183], and as a secreted VαCαVβCβ dimer from insect cells [Garcia et al. (1996) Science 274:209-219]. The 2C scTCR had relatively low solubility compared with most scFv, although its solubility is increased about 10-fold by fusion at the amino terminus to thioredoxin [Schodin et al. (1996) Molec. Immunol. 33:819-829]. The difficulty in generating soluble, properly folded VαVβ domains has extended to other TCRs [Udaka et al. (1993) supra; Sykulev et al. (1994) supra; Manning et al. (1998) supra]. The molecular explanation for the apparent differences between TCR and Fv in either solubility or surface-display capability has not been explored adequately. It has been shown that the 2C scTCR can be expressed in a yeast surface-display system after the selection, from a random library, of specific single-site mutations at the Vα/Vβinterface or in a region of the Vβ framework suspected to interact with the CD3ε signal-transduction sub-unit. These mutations, several of which are found naturally in antibody V regions, reflect the significance of these positions in the TCR and provide a basis for further engineering of TCR-binding properties.
The invention provides a combinatorial library of immune T cell receptor polypeptides displayed on the surfaces of recombinant host cells, for example, yeast cells, desirably Saccharomyces cerevisiae. From such a library can be isolated high affinity TCR polypeptides (those that exhibit higher affinity than wild type for the cognate ligand: a complex of peptide bound to a protein of the major histocompatibility complex, pMHC). Desirably, the affinity of the TCR peptide for the pMHC is reflected in a dissociation constant of from about 107 to about 1010, e.g., as measured by methods known to the art. A DNA library comprising nucleic acids encoding soluble high affinity TCRs, wherein said TCRs are made by the method of mutagenizing a TCR to create mutant TCR coding sequences; transforming DNA comprising the mutant TCR coding sequences for mutant TCRs into yeast cells; inducing expression of the mutant TCR coding sequences such that the mutant TCRs are displayed on the surface of yeast cells; contacting the yeast cells with a fluorescent label which binds to the peptide/MHC ligand to produce selected yeast cells; and isolating the yeast cells showing the highest fluorescence is provided. Also provided is a library of T cell receptor proteins displayed on the surface of yeast cells which have higher affinity for the peptide/MHC ligand than the wild type T cell receptor protein, wherein said library is formed by mutagenizing a T cell receptor protein coding sequence to generate a variegated population of mutants of the T cell receptor protein coding sequence; transforming the T cell receptor mutant coding sequence into yeast cells; inducing expression of the T cell receptor mutant coding sequence on the surface of yeast cells; and selecting those cells expressing T cell receptor mutants that have higher affinity for the peptide/MHC ligand than the wild type T cell receptor protein.
The present invention further provides TCR proteins (in cell-bound or in soluble form) that exhibit high affinity binding for the cognate ligand. In the present invention the ligand bound by the TCR protein can be a peptide/MHC complex or because of the selection process, desirably an iterated selection process, it can be a ligand which does not include an MHC component, such as a superantigen. This ligand can be a peptide, a protein, a carbohydrate moiety, or a lipid moiety, among others. These soluble high affinity TCRs may be made by the method comprising: mutagenizing a TCR to create mutant TCR coding sequences; transforming DNA comprising the mutant TCR coding sequences for mutant TCRs into yeast cells; inducing expression of the mutant TCR coding sequences such that the mutant TCRs are displayed on the surface of yeast cells; contacting the yeast cells with a fluorescent label which binds to the peptide/MHC ligand to produce selected yeast cells; and isolating the yeast cells showing the highest fluorescence. The soluble high affinity TCRs are preferably isolated by yeast display.
The present invention further provides methods for detecting the cognate ligand of a high affinity TCR protein, said methods comprising the step of binding the high affinity TCR protein with the cognate ligand, where the high affinity TCR protein is detectably labeled or where there is a secondary detectable protein added, such as an antibody specific for the TCR in a region other than the region which binds the cognate ligand. A preferred method for using high affinity TCRs to identify ligands comprises: labeling high affinity TCRs with a detectable label; contacting said labeled TCRs with ligands; identifying the ligand with which the labeled TCR is bound. Preferably the ligands are those peptide/MHC ligands to which the TCR binds with higher affinity than the wild type TCR. Methods of identifying the ligand are known to one of ordinary skill in the art. Suitable labels allowing for detection of the TCR protein, directly or indirectly, include but are not limited to fluorescent compounds, chemiluminescent compounds, radioisotopes, chromophores, and others.
The high affinity TCR protein can be used in the laboratory as a tool for qualitative and quantitative measurements of a target ligand, in medical, veterinary or plant diagnostic setting or for tissue or plant material identification. Similarly, the high affinity TCRs of the present invention can be used as reagents for detecting and/or quantitating a target material or ligand. Also provided is a method of using high affinity TCRs to bind to a selected peptide/MHC ligand comprising: labeling said high affinity TCRs with a label that binds to the selected peptide/MHC ligand; contacting said labeled high affinity TCRs with cells containing MHC molecules. The high affinity protein of the present invention, where it specifically binds to a tumor cell antigen with high affinity and specificity can be used in diagnostic tests for the particular type of cancer or it can be used in an organism in imaging tests to locate and/or estimate size and number of tumors in an organism, preferably a mammal, and also preferably a human. Methods provided for using high affinity TCRs that bind to pMHCs for diagnostic tests comprise: labeling the high affinity TCR with a detectable label; contacting said high affinity TCR with cells containing the ligand to which the high affinity TCR has high affinity for; and detecting the label. In the method, the label may be chosen to bind to specific peptide/MHC ligands, whereby cells that express specific peptide/MHC ligands are targeted. Preferred methods for using high affinity TCRs as diagnostic probes for specific peptide/MHC molecules on surfaces of cells comprise: labeling high affinity TCRs with a detectable label that binds to specific peptide/MHC ligands; contacting said TCRs with cells; and detecting said label. The detectable label chosen for use depends on the particular use, and the choice of a suitable label is well within the ordinary skill of one in the relevant art. In general, the TCR proteins selected for high affinity binding to a ligand of interest can be used in methods in which antibodies specific for the ligand can be used, with procedural modifications made for the TCR vs. antibody protein, such modifications being known in the art.
The high affinity TCR, desirably a soluble single chain (sc) TCR, can be used to block autoimmune destruction of cells or tissues in autoimmune disease, where the site recognized by the cytotoxic lymphocytes on the surface of the target cell is the same as the site bound by the high affinity TCR. Preferred methods for blocking autoimmune destruction of cells comprise contacting TCRs with high affinity for the site recognized by the T lymphocytes on the surface of a target cell with cells, whereby the autoimmune destruction of cells is blocked.
A soluble, high affinity scTCR can be coupled to a therapeutic compound (e.g., an anticancer compound, a therapeutic radionuclide or a cytoxic protein) where the cognate ligand of the sc TCR is a neoplastic cell surface marker. Alternatively, the binding specificity of the high affinity soluble sc TCR can be a pathogen infected target cell (such as virus-, bacteria- or protozoan-infected) and a toxic molecule can be coupled so that the target cell can be eliminated without further replication of the infective agent. Provided methods of using high affinity TCRs to inactivate pathogens comprise: binding a molecule which is toxic to the pathogen to the high affinity TCR; and contacting said TCR with cells that express said pathogen. "Toxic" means that the pathogen prevents or inhibits replication of the pathogen.
Also provided are methods for using high affinity TCRs to treat disease comprising: coupling a TCR having a high affinity for a neoplastic cell surface marker with a therapeutic compound; and contacting said TCR with cells. Any therapeutic compound that is useful in slowing the progress of the disease that can be coupled with the TCR may be used. Methods of coupling the therapeutic compound with the TCR are known in the art.
Also provided is a method for cloning the gene for a high affinity TCR mutant into a system that allows expression of the mutant on the surface of T cells comprising: mutating TCRs to create high affinity TCR mutants; cloning said TCR mutants into a vector; transfecting the vector into T cells; expressing the high affinity TCR mutant on the surface of T cells. This method may further comprise: selecting those T cells that are activated to a greater extent than other T cells by a peptide/MHC ligand. The transfected/infected T cells may be used for recognition of selected peptide-bearing MHC cells. These transfected/infected T cells are useful in treating disease in patients where T cells from a patient are removed and transformed with the vector that expresses the high affinity TCR mutants and returned to the patient where they are activated to a greater extent by a peptide/MHC ligand than the patient's wild type T cells.
A soluble, high affinity TCR molecule can be used in place of an antibody or single chain antibody for most applications, as will be readily apparent to one of skill in the relevant arts.
In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given to such terms, the following definitions are provided.
A coding sequence is the part of a gene or cDNA which codes for the amino acid sequence of a protein, or for a functional RNA such as a tRNA or rRNA.
Complement or complementary sequence means a sequence of nucleotides which forms a hydrogen-bonded duplex with another sequence of nucleotides according to Watson-Crick base-pairing rules. For example, the complementary base sequence for 5′-AAGGCT-3′ is 3′-TTCCGA-5′.
Downstream means on the 3′ side of any site in DNA or RNA.
Expression refers to the transcription of a gene into structural RNA (rRNA, tRNA) or messenger RNA (mRNA) and subsequent translation of a mRNA into a protein.
An amino acid sequence that is functionally equivalent to a specifically exemplified TCR sequence is an amino acid sequence that has been modified by single or multiple amino acid substitutions, by addition and/or deletion of amino acids, or where one or more amino acids have been chemically modified, but which nevertheless retains the binding specificity and high affinity binding activity of a cell-bound or a soluble TCR protein of the present invention. Functionally equivalent nucleotide sequences are those that encode polypeptides having substantially the same biological activity as a specifically exemplified cell-bound or soluble TCR protein. In the context of the present invention, a soluble TCR protein lacks the portions of a native cell-bound TCR and is stable in solution (i.e., it does not generally aggregate in solution when handled as described herein and under standard conditions for protein solutions).
Two nucleic acid sequences are heterologous to one another if the sequences are derived from separate organisms, whether or not such organisms are of different species, as long as the sequences do not naturally occur together in the same arrangement in the same organism.
Homology refers to the extent of identity between two nucleotide or amino acid sequences.
Isolated means altered by the hand of man from the natural state. If an "isolated" composition or substance occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or a polypeptide naturally present in a living animal is not isolated, but the same polynucleotide or polypeptide separated from the coexisting materials of its natural state is isolated, as the term is employed herein.
A linker region is an amino acid sequence that operably links two functional or structural domains of a protein.
A nucleic acid construct is a nucleic acid molecule which is isolated from a naturally occurring gene or which has been modified to contain segments of nucleic acid which are combined and juxtaposed in a manner which would not otherwise exist in nature.
Nucleic acid molecule means a single- or double-stranded linear polynucleotide containing either deoxyribonucleotides or ribonucleotides that are linked by 3′-5′-phosphodiester bonds.
Two DNA sequences are operably linked if the nature of the linkage does not interfere with the ability of the sequences to effect their normal functions relative to each other. For instance, a promoter region would be operably linked to a coding sequence if the promoter were capable of effecting transcription of that coding sequence.
A polypeptide is a linear polymer of amino acids that are linked by peptide bonds.
Promoter means a cis-acting DNA sequence, generally 80-120 base pairs long and located upstream of the initiation site of a gene, to which RNA polymerase may bind and initiate correct transcription. There can be associated additional transcription regulatory sequences which provide on/off regulation of transcription and/or which enhance (increase) expression of the downstream coding sequence.
A recombinant nucleic acid molecule, for instance a recombinant DNA molecule, is a novel nucleic acid sequence formed in vitro through the ligation of two or more nonhomologous DNA molecules (for example a recombinant plasmid containing one or more inserts of foreign DNA cloned into at least one cloning site).
Transformation means the directed modification of the genome of a cell by the external application of purified recombinant DNA from another cell of different genotype, leading to its uptake and integration into the subject cell's genome. In bacteria, the recombinant DNA is not typically integrated into the bacterial chromosome, but instead replicates autonomously as a plasmid.
Upstream means on the 5′ side of any site in DNA or RNA.
A vector is a nucleic acid molecule that is able to replicate autonomously in a host cell and can accept foreign DNA. A vector carries its own origin of replication, one or more unique recognition sites for restriction endonucleases which can be used for the insertion of foreign DNA, and usually selectable markers such as genes coding for antibiotic resistance, and often recognition sequences (e.g. promoter) for the expression of the inserted DNA. Common vectors include plasmid vectors and phage vectors.
High affinity T cell receptor (TCR) means an engineered TCR with stronger binding to a target ligand than the wild type TCR.
T cells recognize a foreign peptide bound to the MHC product through the αβ heterodimeric T cell receptor (TCR). The TCR repertoire has extensive diversity created by the same gene rearrangement mechanisms used in antibody heavy and light chain genes [Tonegawa, S. (1988) Biosci. Rep. 8:3-26]. Most of the diversity is generated at the junctions of variable (V) and joining (J) (or diversity, D) regions that encode the complementarity-determining region 3 (CDR3) of the α and β chains [Davis and Bjorkman (1988) Nature 334:395-402]. However, TCRs do not undergo somatic point mutations as do antibodies and, perhaps not coincidentally. TCRs also do not undergo the same extent of affinity maturation as antibodies. TCRs as they occur in nature appear to have affinities that range from 105 to 106 M−1 whereas antibodies typically have affinities that range from 105 to 109 M−1 [Davis et al. (1998) Annu. Rev. Immunol. 16:523-544; Eisen et al. (1996) Adv. Protein Chem. 49:1-56]. While the absence of somatic mutation in TCRs may be associated with lower affinities, it has also been argued that there is not a selective advantage for a TCR to have higher affinity. In fact, the serial-triggering [Valitutti et al. (1995) Nature 375:148-151] and kinetic proofreading [Rabinowitz et al. (1996) Proc. Natl. Acad. Sci. USA 93:1401-1405] models of T cell activation both suggest that longer off-rates (associated with higher affinity) would be detrimental to the signaling process. It is also possible that higher affinity TCRs might not maintain the peptide specificity required for T cell responses. For example, peptides bound within the MHC groove display limited accessible surface [Bjorkman, P. J. (1997) Cell 89:167-170], which may in turn limit the amount of energy that can be generated in the interaction. On the other hand, raising the affinity of a TCR by directing the energy toward the MHC helices would presumably lead to thymic deletion during negative selection [Bevan, M. J. (1997) Immunity 7:175-178].
We show that there is not an inherent structural property or genetic limitation on higher affinity of T cell receptor proteins. Higher affinity TCR variants were generated in the absence of in vivo selection pressures by using yeast display combinatorial technology and TCR mutants (e.g., Vα and Vβ CDR3 mutants). Mutants selected for relatively strong binding to the target ligand (a particular p/MHC complex) can have greater than 100-fold higher affinity, i.e., a Kd of about 10 nM for the p/MHC, and these mutants retained a high degree of peptide specificity. A strong preference for TCR proteins with conserved CDR3 motifs that were rich in proline or glycine were also evident. A soluble monomeric form of a high affinity TCR was capable of directly detecting p/MHC complexes on antigen-presenting cells. These findings prove that affinity maturation of TCRs is possible, at least in vitro. Thus, engineered TCR proteins can be used for targeting specific ligands, including particular p/MHC complexes and peptides, proteins or other ligands in the absence of a MHC component.
To examine if it is possible to generate higher affinity TCR that retain peptide specificity, we subjected a characterized TCR to a process of directed in vitro evolution. Phage display technology [Clackson et al. (1991) Nature 352:624-628] has not yet proven successful in the engineering of single-chain TCRs (scTCRs, Vβ-linker-Vα), despite the extensive structural similarity between antibody and TCR V regions. However, we recently showed that a scTCR could be displayed on the surface of yeast [Kieke et al. (1999) Proc. Natl. Acad. Sci. USA 96:5651-5656], in a system that has proven successful in antibody engineering [Boder and Wittrup (1997) supra; Kieke et al. (1997) supra]. A temperature-stabilized variant (called T7) [Shusta et al. (1999) J. Mol. Biol. 292:949-956] of the scTCR from the CTL clone 2C was used in the present study. CTL clone 2C recognizes the alloantigen Ld with a bound octamer peptide called p2Ca, derived from the enzyme 2-oxoglutarate dehydrogenase [Udaka et al. (1993) Proc. Natl. Acad. Sci. USA 90:11272-11276]. The nonameric variant QL9 is also recognized by CTL 2C, but with 10-fold higher affinity by the 2C TCR [Sykulev et al. (1994) Proc. Natl. Acad. Sci. USA 91:11487-11491]. Alanine scanning mutagenesis shows that the CDR3α loop contributed minimal energy to the binding interaction [Manning (1998) supra], even though structural studies have shown that CDR3α of the 2C TCR is near the peptide and it undergoes a conformational change in order to accommodate the pMHC complex [Garcia (1998) Science 279:1166-1172]. Thus, we focused our mutagenesis efforts on the five residues that form the tip of CDR3a.
A library of 105 independent TCR-CDR3α yeast mutants was subjected to selection by flow cytometry with a fluorescently-labeled QL9/Ld ligand [Dal Porto et al. (1993) Proc. Natl. Acad. Sci. USA 90:6671-6675]. After four rounds of sorting and growth, fifteen different yeast colonies were examined for their ability to bind the ligand, in comparison to the scTCR variant T7, which bears the wt CRD3a sequence (
CDR3α sequences of the fifteen mutants all differed from the starting 2C TCR sequence (
In contrast to the isolates that contain glycine, the selection for a proline-rich sequence at the tip of the CDR3α loop is believed, without wishing to be bound by any particular theory, to indicate that these TCR molecules exhibit a more rigid conformation that confers higher affinity. The X-ray crystallographic structures of a germ line antibody of low affinity compared to its affinity-matured derivative showed that the high affinity state may have been due to the stabilization of the antibody in a configuration that accommodated the hapten [Wedemayer et al. (1997) Science 276:1665-1669]. Similarly, the NMR solution structure of a scTCR that may be analogous to the germline antibody showed that the CDR3α and β loops both exhibited significant mobility [Hare et al. (1999) Nat. Struct. Biol. 6:574-581]. Recent thermodynamic studies of TCR:pMHC interactions have also suggested the importance of conformational changes in binding [Willcox et al. (1999) Immunity 10:357-365; Boniface et al. (1999) Proc. Natl. Acad. Sci. USA 96:11446-11451]. Structural and thermodynamic studies of the TCR mutants discussed herein allowed us to examine if the two CDR3α motifs (Gly versus Pro-rich) differ in the mechanism by which they confer higher affinity.
Although the scTCR mutants did not bind the null (irrelevant) peptide/Ld complex MCMV (SEQ ID NO:1)/Ld, it remained possible that the increase in affinity was accompanied by a change in fine specificity. To examine this question, we used QL9 position 5 (Phe) peptide variants which have been shown previously to exhibit significant differences in their binding affinity for the wt 2C TCR [Schlueter (1996) J. Immunol. 157:4478-4485]. The binding of these pMHC to various TCR mutants on the yeast surface and to clone 2C was measured by flow cytometry. As shown in
In order to determine the magnitude of the affinity increases associated with a selected CDR3α mutant, the wild type T7 scTCR and the qL2 scTCR were expressed as soluble forms in a yeast secretion system. Purified scTCR preparations were compared for their ability to block the binding of a 125I-labeled anti-Ld Fab fragments to QL9 or MCMV (SEQ ID NO:1) loaded onto Ld on the surface of T2-Ld cells [Manning (1998) supra; Sykulev et al. (1994) Immunity 1:15-22]. As expected, neither T7 nor qL2 scTCR were capable of inhibiting the binding of 125I-Fab fragments to T2-Ld cells upregulated with the MCMV (SEQ ID NO:1) peptide. However, both T7 and qL2 were capable of inhibiting the binding of anti-Ld Fab fragments to QL9/Ld (
If the soluble scTCR has a high affinity for its pMHC ligand, then it is useful, like antibodies, as a specific probe for cell-surface bound antigen. To confirm this, the soluble T7 and qL2 scTCR were biotinylated, and the labeled-scTCR molecules were incubated with T2-Ld cells loaded with QL9, p2Ca, or MCMV (SEQ ID NO:1). The qL2 scTCR, but not the T7 scTCR, yielded easily detectable staining of the T2 cells that had been incubated with QL9 or p2Ca (
The high affinity receptors described in our study were derived by variation at the VJ junction, the same process that operates very effectively in vivo through gene rearrangements in T cells (Davis and Bjorkman (1988) Nature 334:395-402). The fact that we could readily isolate a diverse set of high affinity TCR in vitro indicates that there is not a genetic or structural limitation to high affinity receptors. This supports the view that inherently low affinities of TCRs found in vivo are due to a lack of selection for higher affinity and perhaps a selection for lower affinity (Sykulev et al. (1995) Proc. Natl. Acad. Sci. USA 92:11990-11992; Valitutti et al. (1995) Nature 375:148-151; Rabinowitz et al. (1996) Proc. Natl. Acad. Sci. USA 93:1401-1405). In this respect, the higher affinity TCRs of the present invention now provide the reagents for directly testing hypotheses about the effects of affinity on T cell responses (Davis et al. (1998) Ann. Rev. Immunol. 16:523-544; Sykulev eta 1. (1995) supra; Valitutti et al. (1995) supra; Rabinowitz et al. 1996) supra).
In summary, we have shown that T cell receptors, which represent a class of proteins as diverse as antibodies, can be engineered like antibodies to yield high affinity, antigen-specific probes. Furthermore, a soluble version of the high affinity receptor can directly detect specific peptide/MHC complexes on cells. Thus, these engineered proteins are useful as diagnostics, for tumor cells, for example. Soluble derivatives of the high affinity TCRs are useful or can be further engineered as high affinity, antigen-specific probes. The soluble TCR derivatives when appropriately labeled (or bound by a detectable ligand for that soluble TCR) can serve as a probe for specific peptide/MCHC complexes on cells, for example, derived surfaces of tumor cells or other neoplastic cells, or antigens diagnostic of virus-infected cells or other diseased cells. Other applications for high affinity TCR cell bound proteins or soluble derivatives include use in diagnosis or study of certain autoimmune diseases. Where a characteristic peptide/MHC or other marker surface antigen is known or can be identified, a high affinity, soluble TCR can be isolated for specific binding to that cell surface moiety and used in diagnosis or in therapy. The high affinity TCR proteins, desirably the soluble derivatives, can be used bound to cytotoxic agents as therapeutics in cancer treatment or other disorders where cells to be desirably destroyed have a characteristic and specific cell surface moiety which is recognized by a high affinity TCR (desirably a soluble TCR protein). Similarly, a soluble high affinity TCR as described herein can be coupled to an imaging agent and used to identify sites within the body where tumor cells reside where the TCR specifically binds a tumor cell marker with high affinity and specificity. A high affinity TCR bound to the surface of a cell or tissue which has been inappropriately targeted for autoimmune destruction can reduce autoimmune tissue destruction by cytotoxic lymphocytes by competing with those cytotoxic lymphocytes for binding to the cell surface of the targeted cells or tissue.
These results can also be considered in the context of an important, basic question in T cell responses. Are the low affinities previously observed for T cell receptors due to the absence of somatic mutations or due to in vivo selective pressures that act on the T cell? The high affinity receptors described in our study were derived by variation at the VJ junction, the same process that operates very effectively in T cells [Davis and Bjorkman (1988) supra]. The fact that we could readily isolate a diverse set of high affinity TCR in vitro indicates that there is no structural or genetic limitation to high affinity receptors. This supports the view that inherently low affinities of TCRs found in vivo are due to a lack of selection for higher affinity and perhaps a selection for lower affinity [Sykulev et al. (1995) Proc. Natl. Acad. Sci. USA 92:11990-11992; Rabinowitz et al. (1996) supra]. In this respect, the higher affinity TCRs now provide the reagents for directly testing hypotheses about the effects of affinity on T cell responses [Davis et al. (1998) supra; Sykulev et al. (1995) supra; Valitutti et al. (1995) supra; Rabinowitz et al. (1996) supra].
It will be appreciated by those of skill in the art that, due to the degeneracy of the genetic code, numerous functionally equivalent nucleotide sequences encode the same amino acid sequence.
Additionally, those of skill in the art, through standard mutagenesis techniques, in conjunction with the antigen-finding activity assays described herein, can obtain altered TCR sequences and test them for the expression of polypeptides having particular binding activity. Useful mutagenesis techniques known in the art include, without limitation, oligonucleotide-directed mutagenesis, region-specific mutagenesis, linker-scanning mutagenesis, and site-directed mutagenesis by PCR [see e.g. Sambrook et al. (1989) and Ausubel et al. (1999)].
In obtaining variant TCR coding sequences, those of ordinary skill in the art will recognize that TCR-derived proteins may be modified by certain amino acid substitutions, additions, deletions, and post-translational modifications, without loss or reduction of biological activity. In particular, it is well-known that conservative amino acid substitutions, that is, substitution of one amino acid for another amino acid of similar size, charge, polarity and conformation, are unlikely to significantly alter protein function. The 20 standard amino acids that are the constituents of proteins can be broadly categorized into four groups of conservative amino acids as follows: the nonpolar (hydrophobic) group includes alanine, isoleucine, leucine, methionine, phenylalanine, proline, tryptophan and valine; the polar (uncharged, neutral) group includes asparagine, cysteine, glutamine, glycine, serine, threonine and tyrosine; the positively charged (basic) group contains arginine, histidine and lysine; and the negatively charged (acidic) group contains aspartic acid and glutamic acid. Substitution in a protein of one amino acid for another within the same group is unlikely to have an adverse effect on the biological activity of the protein.
Homology between nucleotide sequences can be determined by DNA hybridization analysis, wherein the stability of the double-stranded DNA hybrid is dependent on the extent of base pairing that occurs. Conditions of high temperature and/or low salt content reduce the stability of the hybrid, and can be varied to prevent annealing of sequences having less than a selected degree of homology. For instance, for sequences with about 55% G-C content, hybridization and wash conditions of 40-50� C., 6�SSC (sodium chloride/sodium citrate buffer) and 0.1% SDS (sodium dodecyl sulfate) indicate about 60-70% homology, hybridization and wash conditions of 50-65� C., 1�SSC and 0.1% SDS indicate about 82-97% homology, and hybridization and wash conditions of 52� C., 0.1�SSC and 0.1% SDS indicate about 99-100% homology. A wide range of computer programs for comparing nucleotide and amino acid sequences (and measuring the degree of homology) are also available, and a list providing sources of both commercially available and free software is found in Ausubel et al. (1999). Readily available sequence comparison and multiple sequence alignment algorithms are, respectively, the Basic Local Alignment Search Tool (BLAST) (Altschul et al., 1997)and ClustalW programs. BLAST is available on the Internet at ncbi.nlm.nih.gov and a version of ClustalW is available at 2.ebi.ac.uk.
Industrial strains of microorganisms (e.g., Aspergillus niger, Aspergillus ficuum, Aspergillus awamori, Aspergillus oryzae, Trichoderma reesei, Mucor miehei, Kluyveromyces lactis, Pichia pastoris, Saccharomyces cerevisiae, Escherichia coli, Bacillus subtilis or Bacillus licheniformis) or plant species (e.g., canola, soybean, corn, potato, barley, rye, wheat) may be used as host cells for the recombinant production of the TCR peptides. As the first step in the heterologous expression of a high affinity TCR protein or soluble protein, an expression construct is assembled to include the TCR or soluble TCR coding sequence and control sequences such as promoters, enhancers and terminators. Other sequences such as signal sequences and selectable markers may also be included. To achieve extracellular expression of the scTCR, the expression construct may include a secretory signal sequence. The signal sequence is not included on the expression construct if cytoplasmic expression is desired. The promoter and signal sequence are functional in the host cell and provide for expression and secretion of the TCR or soluble TCR protein. Transcriptional terminators are included to ensure efficient transcription. Ancillary sequences enhancing expression or protein purification may also be included in the expression construct.
Various promoters (transcriptional initiation regulatory region) may be used according to the invention. The selection of the appropriate promoter is dependent upon the proposed expression host. Promoters from heterologous sources may be used as long as they are functional in the chosen host.
Promoter selection is also dependent upon the desired efficiency and level of peptide or protein production. Inducible promoters such as tac are often employed in order to dramatically increase the level of protein expression in E. coli. Overexpression of proteins may be harmful to the host cells. Consequently, host cell growth may be limited. The use of inducible promoter systems allows the host cells to be cultivated to acceptable densities prior to induction of gene expression, thereby facilitating higher product yields.
Various signal sequences may be used according to the invention. A signal sequence which is homologous to the TCR coding sequence may be used. Alternatively, a signal sequence which has been selected or designed for efficient secretion and processing in the expression host may also be used. For example, suitable signal sequence/host cell pairs include the B. subtilis sacB signal sequence for secretion in B. subtilis, and the Saccharomyces cerevisiae α-mating factor or P. pastoris acid phosphatase phoI signal sequences for P. pastoris secretion. The signal sequence may be joined directly through the sequence encoding the signal peptidase cleavage site to the protein coding sequence, or through a short nucleotide bridge consisting of usually fewer than ten codons, where the bridge ensures correct reading frame of the downstream TCR sequence.
Elements for enhancing transcription and translation have been identified for eukaryotic protein expression systems. For example, positioning the cauliflower mosaic virus (CaMV) promoter 1000 bp on either side of a heterologous promoter may elevate transcriptional levels by 10- to 400-fold in plant cells. The expression construct should also include the appropriate translational initiation sequences. Modification of the expression construct to include a Kozak consensus sequence for proper translational initiation may increase the level of translation by 10 fold.
A selective marker is often employed, which may be part of the expression construct or separate from it (e.g., carried by the expression vector), so that the marker may integrate at a site different from the gene of interest. Examples include markers that confer resistance to antibiotics (e.g., bla confers resistance to ampicillin for E. coli host cells, nptII confers kanamycin resistance to a wide variety of prokaryotic and eukaryotic cells) or that permit the host to grow on minimal medium (e.g., HIS4 enables P. pastoris or His− S. cerevisiae to grow in the absence of histidine). The selectable marker has its own transcriptional and translational initiation and termination regulatory regions to allow for independent expression of the marker. If antibiotic resistance is employed as a marker, the concentration of the antibiotic for selection will vary depending upon the antibiotic, generally ranging from 10 to 600 μg of the antibiotic/mL of medium.
The expression construct is assembled by employing known recombinant DNA techniques (Sambrook et al., 1989; Ausubel et al., 1999). Restriction enzyme digestion and ligation are the basic steps employed to join two fragments of DNA. The ends of the DNA fragment may require modification prior to ligation, and this may be accomplished by filling in overhangs, deleting terminal portions of the fragment(s) with nucleases (e.g., ExoIII), site directed mutagenesis, or by adding new base pairs by PCR. Polylinkers and adaptors may be employed to facilitate joining of selected fragments. The expression construct is typically assembled in stages employing rounds of restriction, ligation, and transformation of E. coli. Numerous cloning vectors suitable for construction of the expression construct are known in the art (λZAP and pBLUESCRIPT SK-1, Stratagene, LaJolla, Calif.; pET, Novagen Inc., Madison, Wis.—cited in Ausubel et al., 1999) and the particular choice is not critical to the invention. The selection of cloning vector will be influenced by the gene transfer system selected for introduction of the expression construct into the host cell. At the end of each stage, the resulting construct may be analyzed by restriction, DNA sequence, hybridization and PCR analyses.
The expression construct may be transformed into the host as the cloning vector construct, either linear or circular, or may be removed from the cloning vector and used as is or introduced onto a delivery vector. The delivery vector facilitates the introduction and maintenance of the expression construct in the selected host cell type. The expression construct is introduced into the host cells by any of a number of known gene transfer systems (e.g., natural competence, chemically mediated transformation, protoplast transformation, electroporation, biolistic transformation, transfection, or conjugation) (Ausubel et al., 1999; Sambrook et al., 1989). The gene transfer system selected depends upon the host cells and vector systems used.
For instance, the expression construct can be introduced into S. cerevisiae cells by protoplast transformation or electroporation. Electroporation of S. cerevisiae is readily accomplished, and yields transformation efficiencies comparable to spheroplast transformation.
Monoclonal or polyclonal antibodies, preferably monoclonal, specifically reacting with a TCR protein at a site other than the ligand binding site may be made by methods known in the art. See, e.g., Harlow and Lane (1988) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratories; Goding (1986) Monoclonal Antibodies: Principles and Practice, 2d ed., Academic Press, New York; and Ausubel et al. (1999) Current Protocols in Molecular Biology, John Wiley & Sons, Inc., New York.
High affinity TCR proteins in cell-bound or soluble form which are specific for a particular pMHC are useful, for example, as diagnostic probes for screening biological samples (such as cells, tissue samples, biopsy material, bodily fluids and the like) or for detecting the presence of the cognate pMHC in a test sample. Frequently, the high affinity TCR proteins are labeled by joining, either covalently or noncovalently, a substance which provides a detectable signal. Suitable labels include but are not limited to radionuclides, enzymes, substrates, cofactors, inhibitors, fluorescent agents, chemiluminescent agents, magnetic particles and the like. Additionally the TCR protein can be coupled to a ligand for a second binding molecules: for example, the TCR protein can be biotinylated. Detection of the TCR bound to a target cell or molecule can then be effected by binding of a detectable streptavidin (a streptavidin to which a fluorescent, radioactive, chemiluminescent, or other detectable molecule is attached or to which an enzyme for which there is a chromophoric substrate available). United States Patents describing the use of such labels and/or toxic compounds to be covalently bound to the scTCR protein include but are not limited to U.S. Pat. Nos. 3,817,837; 3,850,752; 3,927,193; 3,939,350; 3,996,345; 4,277,437; 4,275,149; 4,331,647; 4,348,376; 4,361,544; 4,468,457; 4,444,744; 4,640,561; 4,366,241; RE 35,500; 5,299,253; 5,101,827; 5,059,413. Labeled TCR proteins can be detected using a monitoring device or method appropriate to the label used. Fluorescence microscopy or fluorescence activated cell sorting can be used where the label is a fluorescent moiety, and where the label is a radionuclide, gamma counting, autoradiography or liquid scintillation counting, for example, can be used with the proviso that the method is appropriate to the sample being analyzed and the radionuclide used. In addition, there can be secondary detection molecules or particle employed where there is a detectable molecule or particle which recognized the portion of the TCR protein which is not part of the binding site for the cognate pMHC ligand or other ligand in the absence of a MHC component as noted herein. The art knows useful compounds for diagnostic imaging in situ; see, e.g., U.S. Pat. Nos. 5,101,827; 5,059,413. Radionuclides useful for therapy and/or imaging in vivo include 111Indium, 97Rubidium, 125Iodine, 131Iodine, 123Iodine, 67Gallium, 99Technetium. Toxins include diphtheria toxin, ricin and castor bean toxin, among others, with the proviso that once the TCR-toxin complex is bound to the cell, the toxic moiety is internalized so that it can exert its cytotoxic effect. Immunotoxin technology is well known to the art, and suitable toxic molecules include, without limitation, chemotherapeutic drugs such as vindesine, antifolates, e.g. methotrexate, cisplatin, mitomycin, anthrocyclines such as daunomycin, daunorubicin or adriamycin, and cytotoxic proteins such as ribosome inactivating proteins (e.g., diphtheria toxin, pokeweed antiviral protein, abrin, ricin, pseudomonas exotoxin A or their recombinant derivatives. See, generally, e.g., Olsnes and Pihl (1982) Pharmac. Ther. 25:355-381 and Monoclonal Antibodies for Cancer Detection and Therapy, Eds. Baldwin and Byers, pp. 159-179, Academic Press, 1985.
High affinity TCR proteins specific for a particular pMHC ligand are useful in diagnosing animals, including humans believed to be suffering from a disease associated with the particular pMHC. The sc TCR molecules of the present invention are useful for detecting essentially any antigen, including but not limited to, those associated with a neoplastic condition, an abnormal protein, or an infection or infestation with a bacterium, a fungus, a virus, a protozoan, a yeast, a nematode or other parasite. The high affinity sc TCR proteins can also be used in the diagnosis of certain genetic disorders in which there is an abnormal protein produced. Exemplary applications for these high affinity proteins is in the treatment of autoimmune diseases in which there is a known pMHC. Type I diabetes is relatively well characterized with respect to the autoantigens which attract immune destruction. Multiple sclerosis, celiac disease, inflammatory bowel disease, Crohn's disease and rheumatoid arthritis are additional candidate diseases for such application. High affinity TCR (soluble) proteins with binding specificity for the p/MHC complex on the surface of cells or tissues which are improperly targeted for autoimmune destruction can serve as antagonists of the autoimmune destruction by competing for binding to the target cells by cytotoxic lymphocytes. By contrast, high affinity TCR proteins, desirably soluble single chain TCR proteins, which specifically bind to an antigen or to a p/MHC on the surface of a cell for which destruction is beneficial, can be coupled to toxic compounds (e.g., toxins or radionuclides) so that binding to the target cell results in subsequent binding and destruction by cytotoxic lymphocytes. The cell targeted for destruction can be a neoplastic cell (such as a tumor cell), a cell infected with a virus, bacterium or protozoan or other disease-causing agent or parasite, or it can be a bacterium, yeast, fungus, protozoan or other undesirable cell. Such high affinity sc TCR proteins can be obtained by the methods described herein and subsequently used for screening for a particular ligand of interest.
The high affinity TCR compositions can be formulated by any of the means known in the art. They can be typically prepared as injectables, especially for intravenous, intraperitoneal or synovial administration (with the route determined by the particular disease) or as formulations for intranasal or oral administration, either as liquid solutions or suspensions. Solid forms suitable for solution in, or suspension in, liquid prior to injection or other administration may also be prepared. The preparation may also, for example, be emulsified, or the protein(s)/peptide(s) encapsulated in liposomes.
The active ingredients are often mixed with excipients or carriers which are pharmaceutically acceptable and compatible with the active ingredient. Suitable excipients include but are not limited to water, saline, dextrose, glycerol, ethanol, or the like and combinations thereof. The concentration of the high affinity TCR protein in injectable, aerosol or nasal formulations is usually in the range of 0.05 to 5 mg/ml. The selection of the particular effective dosages is known and performed without undue experimentation by one of ordinary skill in the art. Similar dosages can be administered to other mucosal surfaces.
In addition, if desired, vaccines may contain minor amounts of auxiliary substances such as wetting or emulsifying agents, pH buffering agents, and/or adjuvants which enhance the effectiveness of the vaccine. Examples of adjuvants which may be effective include but are not limited to: aluminum hydroxide; N-acetyl-muramyl-L-threonyl-D-isoglutamine (thr-MDP); N-acetyl-nor-muramyl-L-alanyl-D-isoglutamine (CGP 11637, referred to as nor-MDP); N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine-2-(1′-2′-dipalmitoyl-sn-glycero-3hydroxyphosphoryloxy)-ethylamine (CGP 19835A, referred to as MTP-PE); and RIBI, which contains three components extracted from bacteria: monophosphoryl lipid A, trehalose dimycolate and cell wall skeleton (MPL+TDM+CWS) in a 2% squalene/Tween 80 emulsion. Such additional formulations and modes of administration as are known in the art may also be used.
The high affinity TCR proteins of the present invention and/or pMHC-binding fragments having primary structure similar (more than 90% identity) to the high affinity TCR proteins and which maintain the high affinity for the cognate ligand may be formulated into vaccines as neutral or salt forms. Pharmaceutically acceptable salts include but are not limited to the acid addition salts (formed with free amino groups of the peptide) which are formed with inorganic acids, e.g., hydrochloric acid or phosphoric acids; and organic acids, e.g., acetic, oxalic, tartaric, or maleic acid. Salts formed with the free carboxyl groups may also be derived from inorganic bases, e.g., sodium, potassium, ammonium, calcium, or ferric hydroxides, and organic bases, e.g., isopropylamine, trimethylamine, 2-ethylamino-ethanol, histidine, and procaine.
High affinity TCR proteins for therapeutic use, e.g., those conjugated to cytotoxic compounds are administered in a manner compatible with the dosage formulation, and in such amount and manner as are prophylactically and/or therapeutically effective, according to what is known to the art. The quantity to be administered, which is generally in the range of about 100 to 20,000 μg of protein per dose, more generally in the range of about 1000 to 10,000 μg of protein per dose. Similar compositions can be administered in similar ways using labeled high affinity TCR proteins for use in imaging, for example, to detect tissue under autoimmune attack and containing the cognate pMHCs or to detect cancer cells bearing a cognate pMHC on their surfaces. Precise amounts of the active ingredient required to be administered may depend on the judgment of the physician or veterinarian and may be peculiar to each individual, but such a determination is within the skill of such a practitioner.
The vaccine or other immunogenic composition may be given in a single dose; two dose schedule, for example two to eight weeks apart; or a multiple dose schedule. A multiple dose schedule is one in which a primary course of vaccination may include 1 to 10 or more separate doses, followed by other doses administered at subsequent time intervals as required to maintain and/or reinforce the immune response, e.g., at 1 to 4 months for a second dose, and if needed, a subsequent dose(s) after several months. Humans (or other animals) immunized with the retrovirus-like particles of the present invention are protected from infection by the cognate retrovirus.
Standard techniques for cloning, DNA isolation, amplification and purification, for enzymatic reactions involving DNA ligase, DNA polymerase, restriction endonucleases and the like, and various separation techniques are those known and commonly employed by those skilled in the art. A number of standard techniques are described in Sambrook et al. (1989) Molecular Cloning, Second Edition, Cold Spring Harbor Laboratory, Plainview, N.Y.; Maniatis et al. (1982) Molecular Cloning, Cold Spring Harbor Laboratory, Plainview, N.Y.; Wu (ed.) (1993) Meth. Enzymol. 218, Part I; Wu (ed.) (1979) Meth Enzymol. 68; Wu et al. (eds.) (1983) Meth. Enzymol. 100 and 101; Grossman and Moldave (eds.) Meth. Enzymol. 65; Miller (ed.) (1972) Experiments in Molecular Genetics, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.; Old and Primrose (1981) Principles of Gene Manipulation, University of California Press, Berkeley; Schleif and Wensink (1982) Practical Methods in Molecular Biology; Glover (ed.) (1985) DNA Cloning Vol. I and II, IRL Press, Oxford, UK; Hames and Higgins (eds.) (1985) Nucleic Acid Hybridization, IRL Press, Oxford, UK; and Setlow and Hollaender (1979) Genetic Engineering: Principles and Methods, Vols. 1-4, Plenum Press, New York. Abbreviations and nomenclature, where employed, are deemed standard in the field and commonly used in professional journals such as those cited herein.
All references cited in the present application are incorporated by reference herein to supplement the disclosure and experimental procedures provided in the present Specification to the extent that there is no inconsistency with the present disclosure.
The following examples are provided for illustrative purposes, and are not intended to limit the scope of the invention as claimed herein. Any variations in the exemplified articles and/or methods which occur to the skilled artisan are intended to fall within the scope of the present invention.
General methods for making high affinity TCRs are given in U.S. patent application Ser. No. 09/009,388, filed Jan. 20, 1998, and WO99/36569, filed Jan. 20, 1999, which are hereby incorporated by reference to the extent not inconsistent with the disclosure herewith.
The 2C scTCR used as the scaffold for directed evolution (T7) contained six mutations (βG17E, βG42E βL81S, αL43P, αW82R, and αI118N) that have been shown to increase the stability of the TCR but still allow pMHC binding [see, e.g., Shusta, E. V. et al. (1999) J. Mol. Biol. 292, 949-956].
Mutagenic PCR of the T7 scTCR VαCDR3 was performed using an AGA2-specific upstream primer (GGCAGCCCCATAAACACACAGTAT (SEQ ID NO:3)) and a degenerate downstream primer CTTTTGTGCCGGATCCAAATGTCAG(SNN)5GCTCACAGCACAGAAGTACACGGCCGA GTCGCTC (SEQ ID NO:4). Underlined bases indicate the positions of silent mutations introducing unique BamHI and EagI restriction sites. The purified PCR product was digested with NdeI and BamHI and ligated to NdeI-BamHI digested T7/pCT302 [Boder and Wittrup (1997) supra; Kieke et al. (1999) supra; Shusta et al. (1999) supra]. The ligation mixture was transformed into DH10B electro-competent E. coli (Gibco BR1, Gaithersburg, Md.), and transformants were pooled into 250 ml LB supplemented with ampicillin at 100 μg/ml and grown overnight at 37� C. Plasmid DNA was transformed into the yeast, (Saccharomyces cerevisiae) strain EBY100 by the method of Gietz and Schiestl [Geitz et al. (1995) Yeast 11:355-360].
The yeast library [Shusta et al. (1999) Curr. Opin. Biotechnol. 10:117-122] was grown in SD-CAA (2% dextrose, 0.67% yeast nitrogen base, 1% casamino acids (Difco, Livonia, Mich.)) at 30� C. to an OD600=4.0. To induce surface scTCR expression, yeast were pelleted by centrifugation, resuspended to an OD600=1.0 in SG-CAA (2% galactose, 0.67% yeast nitrogen base, 1% casamino acids), and incubated at 20� C. for about 24 hr. In general, about 107 cells/tube were incubated on ice for 1 hr with 50 μl of QL9/Ld/IgG dimers [Dal Porto et al. (1993) supra] diluted in phosphate buffered saline, pH 7.4 supplemented with 0.5 mg/ml BSA (PBS-BSA). After incubation, cells were washed and labeled for 30 min with FITC-conjugated goat anti-mouse IgG F(ab7)2 (Kirkegaard & Perry, Gaithersburg, Md.) in PBS-BSA. Yeast were then washed and resuspended in PBS-BSA immediately prior to sorting. Cells exhibiting the highest fluorescence were isolated by FACS sorting with a Coulter 753 bench. After isolation, sorted cells were expanded in SD-CAA and induced in SG-CAA for subsequent rounds of selection. A total of four sequential sorts were performed. The concentrations of QL9/Ld/IgG dimers used for staining were 50 μg/ml for sorts 1-3 and 0.5 μg/ml for the final sort. The percentages of total cells isolated from each sort were 5.55, 2.68, 2.56, and 0.58%, respectively. Aliquots of sorts 3 and 4 were plated on SD-CAA to isolate individual clones which were analyzed by flow cytometry using a Coulter Epics XL instrument.
The T7 and qL2 open reading frames were excised from pCT302 NheI-XhoI and ligated into NheI-XhoI digested pRSGALT, a yeast expression plasmid [Shusta et al. (1999) supra]. Ligated plasmids were transformed into DH10B electro-competent E. coli (Gibco BRL). Plasmid DNA was isolated from bacterial cultures and transformed into Saccharomyces cerevisiae BJ5464 (α ura3-52 trp1 leu2 1 his3 200 pep4: HIS3 prb1 1.6R can1 GAL) [Shusta et al. (1999) supra]. Yeast clones were grown in one liter SD-CAA/Trp (20 mg/L tryptophan) for 48 hr at 30� C. To induce scTCR secretion, cells were pelleted by centrifugation at 4000�g, resuspended in one liter SG-CAA/Trp supplemented with 1 mg/ml BSA, and incubated for 72 hr at 20� C. Culture supernatants were harvested by centrifugation at 4000�g, concentrated to about 50 ml, and dialyzed against PBS, pH 8.0. The 6His-tagged scTCRs were purified by native nickel affinity chromatography (Ni-NTA Superflow, Qiagen, Valencia, Calif.; 5 mM and 20 mM imidazole, pH 8.0 wash; 250 mM imidazole elution) [Shusta et al. (1999) supra].
The binding of soluble scTCRs to QL9/Ld was monitored in a competition format as described previously [Manning et al. (1998) supra; Sykulev et al. (1994) supra]. Peptide-upregulated T2-Ld cells (3�105/well) were incubated for one hour on ice in the presence of 125I-labeled anti-Ld Fabs (30-5-7) and various concentrations of scTCRs. Bound and unbound 125I 30-5-7 Fabs were separated by centrifugation through olive oil/dibutyl phthalate. Inhibition curves were constructed to determine inhibitor concentrations yielding 50% of maximal inhibition. Dissociation constants were calculated using the formula of Cheng and Pursoff [Cheng (1973) Biochem. Pharm. 22:3099-3108]. To monitor direct binding of scTCRs to cell-bound pMHC, peptide-upregulated T2-Ld cells (5�105/tube) were incubated for 40 min on ice with biotinylated soluble scTCRs followed by staining for 30 min with streptavidin-phycoerythrin (PharMingen, San Diego, Calif.). Cellular fluorescence was detected by flow cytometry.
Using the same library of yeast-displayed mutants of the CDR3α region of the TCR, it was possible to select for higher affinity TCRs that are specific for yet a different peptide bound to a different MHC molecule. In this case the peptide called SIYR (SIYRYYGL (SEQ ID NO:5)) was bound to the MHC molecule called Kb, and this ligand complex was used in fluorescent form to select by flow cytometry. Sixteen clones expressing high affinity TCR were sequenced, each showing a different sequence in the CDR3α region (
As an example of the specificity of these TCRs, the mutant 3SQ2 was stained with various agents, including the secondary reagent alone (SA:PE), the anti-Vβ antibody F23.2, and three peptide/Kb complexes (OVA/Kb, dEV8/Kb, and SIYR/Kb). As shown in
The mutant TCR 3SQ2 was also expressed as a soluble protein in the yeast secretion system and tested after biotinylation for its ability to bind directly to pMHC on the surface of tumor cells. As shown in
To determine if the same TCR scaffold could be used to isolate higher affinity forms against yet a different peptide bound to the same MHC, we screened the TCR CDR3α library with the peptide called dEV8 (EQYKFYSV (SEQ ID NO:6)), bound to Kb. After several sorts by flow cytometry with the biotinylated dEV8/Kb ligand (followed by phycoerythrin-streptavidin, PE-SA), there was a significant enrichment of yeast cells that bound to the dEV8/Kb (as indicated by PE levels in
Six of the clones that were isolated by selection with dEV8/Kb were sequenced and the CDR3 sequences all differed (
To prove the antigen specificity of the isolated clones, one of the dEV8/Kb selected clones (4d1) was examined with a panel of different antibodies and ligands (
The examples described above used a library of TCR that were mutated within a region of the α chain called CDR3. In order to show that other regions of the TCR could also be mutated to yield higher affinity TCR, a library of random mutants within five contiguous amino acid residues of the CDR3 region of the β chain was produced, using the qL2 TCR mutant as the starting material. This library was then selected with the QL9/Ld ligand at concentrations below that detected with the qL2 mutant. Five yeast clones, selected by flow cytometry, were sequenced and each showed a different nucleotide and amino acid sequence (
Although the description above contains many specificities, these should not be construed to limit the scope of the invention but as merely providing illustrations of some of the presently-preferred embodiments of this invention. For example, ligands other than those specifically illustrated may be used. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. All references cited herein are incorporated to the extent not inconsistent with the disclosure herewith.
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Trailing Edge Boomers (born 1955- 1964)
Trailing Edge Boomers grew up during Watergate and the fall of Saigon. Unlike the leading edge boomers, they came of age during a poor economy and rising inflation. They're said to be both less optimistic and more distrustful of government. They have been characterized as "realistic idealists with concerns for practicality" [Meridith, 2002].
Though the numbers are high when it comes to divorce and re-marriage, many are strongly committed to family and want the best for their kids. Job hopping and career changes are common. As they try to balance parenting, careers, and time for their own fulfillment, many are seeking greater control of their lives.
Like the Leading Edgers, it looks as if this group also will continue working beyond traditional retirement. According to some marketers, trailing edge boomers will continue to exhibit their individualism and focus on self-indulgence [Meridith, 2002].
Today's Trailing Edge Boomers are 42-52 years of age.

subset: commoncrawl


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Curiosity Rover on Mars Predicted to Encounter Moving Sand Dunes
Mountain View, CA -- The dunes in Gale Crater on Mars, near the landing site of the Curiosity rover, are moving. Until a few years ago, it was thought that the surface of Mars was largely inactive, with its landscapes no longer undergoing any significant modification. The identification of widespread active sand dune migration is one of several recent discoveries that has disproved this claim.
A recent paper by Simone Silvestro of the SETI Institute and colleagues demonstrates that sand dunes in Gale crater, located between the Curiosity rover and its final destination, Aeolis Mons ("Mount Sharp"), are among the actively migrating dunes on Mars. These dunes are moving towards the southwest at a rate of 0.4 meters per Earth year (an average of just over 1 mm per day). This indicates that the work of the wind is probably the most important process currently shaping the landscape in Gale crater. The images used in this study are from the High Resolution Imaging Science Experiment (HiRISE), the camera onboard the Mars Reconnaissance Orbiter.
Two main wind patterns have formed the dunes: winds from the northwest, and winds from the northeast. The northeasterly wind has most significantly changed the dunes and ripples in the last few years near a potential path of Curiosity. An atmospheric model, the Mars Regional Atmospheric Modeling System (MRAMS), produces wind predictions that support both of these findings.
The Curiosity rover must pass through this dune field on its traverse up the mountain, and it is likely that the rover will be able to see these dunes in action as it drives by them. These observations will be the first in situ study of dune migration on another world in the Solar System.
Silvestro, S., Vaz, D.A., Ewing, R.C., Rossi, A.P., Fenton, L.K., Michaels, T.I., Flahaut, J., Geissler, P.E. (2013) Pervasive aeolian activity along rover Curiosity's traverse in Gale Crater, Mars. Geology, doi:10.1130/G34162.1.
Lori Fenton is a researcher at the SETI Institute and contributor to the Cosmic Diary Blog (A piece of Mars) http://cosmicdiary.org/lfenton/
Tim Michaels is a researcher at the SETI Institute.
About SETI Institute
The Institute's mission is to explore, understand, and explain the origin and nature of life in the universe, and to apply the knowledge gained to inspire and guide present and future generations. We have a passion for discovery, and for sharing knowledge as scientific ambassadors to the public, the press, and the government.


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You are currently browsing the category archive for the 'Analytics' category.
At the end of November I was at a different sort of conference to the ones I normally get to attend. This one, Design4learning was held at the OU in Milton Keynes, but was a more general education conference. Described as "The Conference aims to advance the understanding and application of blended learning, design4learning and learning analytics " Design4learning covered topics such as MOOCs, elearning, learning design and learning analytics.
There were a useful series of presentations at the conference and several of them are available from the conference website. We'd put together a poster for the conference talking about the work we've started to do in the library on 'library analytics' – entitled 'Learning Analytics – exploring the value of library data and it was good to talk to a few non-library people about the wealth of data that libraries capture and how that can contribute to the institutional picture of learning analytics.
Our poster covered some of the exploration that we've been doing, mainly with online resource usage from our EZProxy logfiles. In some cases we've been able to join that data with demographic and other data from surveys to start to look in a very small way at patterns of online library use.
Design4learning conference poster v3
The poster also highlighted the range of data that libraries capture and the sorts of questions that could be asked and potentially answered. It also flagged up the leading-edge work by projects such as Huddersfield's Library Impact Data Project and the work of the Jisc Lamp project.
An interesting conference and an opportunity to talk with a different group of people about the potential of library data.
For me two big themes came to mind after this year's Future of Technology in Education Conference (FOTE). Firstly, around creativity, innovation and co-creation; and secondly about how fundamental data and analytics is becoming.
Creativity, innovation and co-creation
Several of the speakers talked about innovation and creativity. Dave Coplin talked of the value of Minecraft and Project Spark and the need to create space for creativity, while Bethany Koby showed us examples of some of the maker kits 'Technology Will Save Us' are creating.
Others talked of 'flipping the classroom' and learning from students as well as co-creation and it was interesting in the Tech start-up pitchfest that a lot of the ideas were student-created tools, some working in the area of collaborative learning.
Data and analytics
The second big trend for me was about analytics and data. I was particularly interested to see how many of the tools and apps being pitched at the conference had an underlying layer of analytics. Evaloop which was working in the area of student feedback, Knodium – a space for student collaboration, Reframed.tv – offering interaction and sharing tools for video content, Unitu – an issues tracking tool and MyCQs – a learning tool, all seemed to make extensive use of data and analytics, while Fluency included teaching analytics skills. It is interesting to see how many app developers have learnt the lessons of Amazon and Google of the value of the underlying data.
Final thoughts and what didn't come up at the conference
I didn't hear the acronymn MOOC at all – slightly surprising as it was certainly a big theme of last year's conference. Has the MOOC bubble passed? or is it just embedded into the mainstream of education? Similarly Learning Analytics (as a specific theme). Certainly analytics and data was mentioned (as I've noted above) but of Learning Analytics – not a mention, maybe it's embedded into HE practice now?
Final thoughts on FOTE. A different focus to previous years but still with some really good sessions and the usual parallel social media back-channels full of interesting conversations. Given that most people arrived with at least one mobile device, power sockets to recharge them were in rather short supply.
To Birmingham at the start of last week for the latest Jisc Library Analytics and Metrics Project (http://jisclamp.mimas.ac.uk/) Community Advisory and Planning group meeting. This was a chance to catchup with both the latest progress and also the latest thinking about how this library analytics and metrics work will develop.
At a time when learning analytics is a hot topic it's highly relevant to libraries to consider how they might respond to the challenges of learning analytics. [The 2014 Horizon report has learning analytics in the category of one year or less to adoption and describes it as 'data analysis to inform decisions made on every tier of the education system, leveraging student data to deliver personalized learning, enable adaptive pedagogies and practices, and identify learning issues in time for them to be solved.'
LAMP is looking at library usage data of the sort that libraries collect routinely (loans, gate counts, eresource usage) but combines it with course, demographic and achievement data to allow libraries to start to be able to analyse and identify trends and themes from the data.
LAMP will build a tool to store and analyse data and is already working with some pilot institutions to design and fine-tune the tool. We got to see some of the work so far and input into some of the wireframes and concepts, as well as hear about some of the plans for the next few months.
The day was also the chance to hear from the developers of a reference management tool called RefMe (www.refme.com). This referencing tool is aimed at students who often struggle with the typically complex requirements of referencing styles and tools. To hear about one-click referencing, with thousands of styles and with features to intergrate with MS Word, or to scan in a barcode and reference a book, was really good. RefMe is available as an iOS or Android app and as a desktop version. As someone who's spent a fair amount of time wrestling with the complexities of referencing in projects that have tried to get simple referencing tools in front of students it is really good to see a start-up tackling this area.
I picked up over the weekend via the No Shelf Required blog that EBSCO Discovery usage data is now being added into Plum Analytics. EBSCO's press release talks about providing "researchers with a much more comprehensive view of the overall impact of a particular article". Plum Analytics have fairly recently been taken over by EBSCO (and here) so it's not so surprising that they'd be looking at how EBSCO's data could enhance the metrics available through Plum Analytics.
It's interesting to see the different uses that activity data in this sphere can be put to. There are examples of it being used to drive recommendations, such as hot articles, or Automated Contextual Research Assistance. LAMP is talking of using activity data for benchmarking purposes. So you're starting to see a clutch of services-being driven by activity data just as the like's of Amazon drive so much of what appears on their sales site by data driven by customer activity.
Infographics and data visualisations seem to be very popular at the moment and for a while I've been keeping an eye on visual.ly as they have some great infographics and data visualisations. One of the good things about the visual.ly infographics is that there is some scope to customise them. So for example there is one about the 'Life of a hashtag' that you can customise and several others around facebook and twitter that you can use.
I picked up on twitter the other week that they had just brought out a Google Analytics infographic. That immediately got my interest as we make a lot of use of GA. You just point it to your site through your Google Analytics account and then get a weekly email 'Your weekly insights' created dynamically from your Google Analytics data.
It's a very neat idea and quite a useful promotional tool to give people a quick snapshot of what is going on. So you get Pageviews over the past three weeks, what the trends are for New and Returning Visitors and reports on Pages per visit and Time on site and how that has changed in the past week.
It's quite useful for social media traffic showing how facebook and twitter traffic has changed over the past week and as these types of media are things that you often want quite quick feedback on it is a nice visual way of being able to show what difference a particular activity might have had.
Obviously as a free tool, there's a limit to the customisation you can do. So it might be nice to have visits or unique visitors to measure change in use of the site, or your top referrals, or particular pages that have been used most frequently. The time period is something that possibly makes it less useful for me in that I'm more likely to be want to compare against the previous month (or even this month last year). But no doubt visual.ly would build a custom version for you if you wanted something particular.
But as a freely available tool it's a useful thing to have. The infographic is nicely presented and gives a visually appealing presentation of analytics data that can often be difficult to present to audiences who don't necessarily understand the intricacies of web analytics.
The Google Analytics Visual.ly infographic is at https://create.visual.ly/graphic/google-analytics/
Encouraged by some thinking about what sort of prototype resource usage tools we want to build to test with users in a forthcoming 'New tools' section I've been starting to think about what sort of features you could offer to library users to let them take advantage of library data.
Early steps
For a few months we've been offering users of our mobile search interface (which just does a search of our EBSCO discovery system) a list of their recently viewed items and their recent searches. The idea behind testing it on a mobile device was that giving people a link to their recent searches or items viewed would make it easier for people to get back to things that they had accessed on their mobile device by just clicking single links rather than having to bookmark them or type in fiddly links. At the moment the tool just lists the resources and searches you've done through the mobile interface.
But our next step is to make a similar tool available through our main library website as a prototype of the 'articles I've viewed'. And that's where we start to wonder about whether the mobile version of the searches/results should be kept separate from the rest of your activities, or whether user expectations would be that, like a Kindle ebook that you can sync across multiple devices, your searches and activity should be consistent across all platforms?
At the moment our desktop version has all your viewed articles, regardless of the platform you used. But users might want to know in future which device they used to access the material maybe? Perhaps because some material isn't easily accessible through a mobile device. But that opens up another question, in that the mobile version and the desktop version may be different URLs so you might want them to be pulled together as one resource with automatic detection of your device when you go to access the resource.
Next steps
With the data about what resources are being accessed and what library web pages are being accessed it starts to open up the possibility of some more user-centred use of library activity and analytics data.
So you could conceive of being able to match that there is a spike of users accessing the Athens problems FAQ page and be able to tie that to users trying to access Athens-authenticated resources. Being able to match activity with students being on a particular module could allow you to push automatically some more targeted help material, maybe into the VLE website for relevant modules, as well as flag up an indication of a potential issue to the technical and helpdesk teams.
You could also contemplate mining reading lists and course schedules to predict when there are particular activities that are scheduled and automatically schedule pushing relevant help and support or online tutorials to students. Some of the most interesting areas seem to me to be around building skills and using activity (or lack of activity) to trigger promotion of targeted skills building activities. So knowing that students on module X should be doing an activity that involves looking at this set of resources, and being able to detect the students that haven't accessed those resources, offering them some specific help material, or even contact from a librarian. Realistically those sorts of interventions simply couldn't be managed manually and would have to rely on some form of learning analytics-type trigger system.
One of the areas that would be useful to look at would be some form of student dashboard for library engagement. So this could give students some data about what engagement they have had with the library, e.g. resources accessed, library skills completed, library badges gained, library visits, books/ebooks borrowed etc. Maybe set against averages for their course, and perhaps with some metrics about what high-achieving students on their course last time did. Add to that a bookmarking feature, lists of recent searches and resources used, with lists of loans/holds. Finished off with useful library contacts and some suggested activities that might help them with their course based on what is know about the level of library skills needed in the course.
Before you can do some of the more sophisticated learning analytics-type activities I suspect it would be necessary is to have a better understanding of the impact that library activities/skills/resources have on student retention and achievement. And that seems to me to argue for some really detailed work to understand library impact at a 'pedagogic' level.
A quick trip to Manchester yesterday to take part in a Symposium at ALT-C on 'Big Data and Learning Analytics' with colleagues from the OU (Simon Buckingham Shum, Rebecca Ferguson, Naomi Jeffrey and Kevin Mayles) and Sheila MacNeill from JISC CETIS (who has blogged about the session here).
It was the first time I'd been to ALT-C and it was just a flying visit on the last morning of the conference so I didn't get the full ALT-C experience. But I got the impression of a really big conference, well-organised and with lots of different types of sessions going on. There were 10 sessions taking place at the time we were on, including talks from invited speakers. So lots of choice of what to see.
But we had a good attendance at the session and there seemed a good mix of people and a good debate and questions during the symposium. Trying to both summarise an area like Learning Analytics and also give people an idea of the range of activities that are going on is tricky in a one-hour symposium but hopefully gave enough of an idea of some of the work taking place and some of the issues and concerns that there are.
Cross-over with other areas
Sheila had a slide pointing out the overlaps between the Customer Relationship Management systems world, Business Intelligence and Learning Analytics, and it struck me that there's also another group in the Activity Data world that crosses over. Much of the work I mentioned (RISE and Huddersfield's fanstastic work on Library impact) came out of JISC's Activity Data funding stream and some of the synthesis project work has been 'synthesised' into a website 'Exploiting activity data in the academic environment' http://www.activitydata.org/ Many of the lessons learnt that are listed here, particularly around what you can do with the data, are equally relevant to Learning Analytics. JISC are also producing an Activity Data report in the near future.
Interesting questions
A lot of the questions in the session were as much around the ethics as the practicality. Particularly interesting was the idea that there were risks of Learning Analytics in encouraging a view that so much could be boiled down to a set of statistics, which sounded a bit like norms to me. The sense-making element seems to be really key, as with so much data and statistics work.
I'd talked a bit about also being able to use the data to make recommendations, something we had experimented with in the RISE project. It was interesting to hear views about the dangers of them reducing rather than expanding choice by narrowing the choices as people are encouraged to select from a list of recommendations which reinforces the recommendations leading to a loop. If you are making recommendations based on what people on a course looked at then I'd agree that it is a risk, especially as I think there's a huge probability that people are often going to be looking at resources that they have to look at for their course anyway.
When it comes to other types of recommendations (such as people looking at this article also viewed this other article, and people searching for this search term look at these items) then there is still some chance of recommendations reinforcing a narrow range of content, but I'd suggest that there is still some chance of serendipitous discovery of material that you might not ordinarily have seen. I'm aware that we've very much scratched the surface with recommendations and used simple algorithms that were designed around the idea that the more people who viewed that pattern the better the recommendation. But it may be that more complex algorithms that throw in some 'randomness' might be useful.
One of the elements I think that is useful about the concept of recommendations is that people largely accept them (and perhaps expect them) as they are ubiquitous in sites like Amazon. And I wonder if you could almost consider them as a personalisation feature that indicates that your service is modern and up-to-date and is engaging with users. For many library systems that still look to be old-fashioned and 'librarian'-orientated then perhaps it is equally important to be seen to have these types of features as standard.
Update: Slides from the introductory presentation are here
Having read Matthiew Reidsma's blog post recently on how the fold metaphor in web design doesn't really exist I was intrigued to see that the latest version of Google's In-page Analytics has introduced a 'fold' feature to show how much web page activity takes place below a certain point on the page. The 'fold' idea is connected to a design concept that essentially says that people only look at what they see immediately in front of them on a web page and that they don't scroll up and down the screen.
In the latest version of Google Analytics In-Page Analytics you get an orange line that slides up and down the page to show how much activity takes place below that line. Because of the way that analytics handles traffic to external links by adding the traffic figures together it isn't all that accurate a tool, but I find it is interesting that Google saw the need to introduce this sort of feature. Making the feature slide up and down looks like the thought was that you could use it as a tool to plan where you might put the most important content. But I'm not convinced that it is all that useful as the tool only moves up and down vertically, it doesn't move from left to right. And critically for me it doesn't really represent how your users viewed your content. To make the tool work I think I'd want to segment the users by people using a particular resolution and then look at the In-Page Analytics for that segment only. I need to do some investigation to see if segmenting people by screen resolution is feasible.
Thinking about screen resolutions made me check back to the Google Analytics data to see what screen resolutions people use to access one of our sites. While nearly 60% are using just four different screen resolutions from 1024 upwards there have been a total of 1,326 different screen resolutions in just three months. That seems to me to be an astonishing number but it's probably a reflection of two things. Firstly that we are getting more people using mobile devices, both phones and tablets. Secondly I think it reflects the fact that our latest site has been designed to cope with a wide variety of screen resolutions (largely as a design feature to allow it to work on phones and tablets) and as a consequence if users want to resize their screen to pretty much any resolution they want, the content should reflow reasonably well.
The second aspect of data that caught my interest today was Harvard's Library Innovation Laboratory. I must admit that when I saw the link to it I did wonder whether it was going to be a list of library tools aimed directly at users (I'm sure I've seen the name used elsewhere recently for just such a list). I know we are looking at redoing our library toolbox to update it and library lab or labspace sounded like a good name for something like that. But the Library Innovation Laboratory is much more interesting proof of concept for anyone with any interest in what you can do with library activity data.
Using library circulation data that has been contributed to the LibraryCloud there are some really imaginative prototype visualisations in the Stack View and Shelf Rank tools. Two values are shown instantly. The book width is determined by the numbers of pages in the book and the book colour corresponds to the volume of loans so the darker the blue the greater the traffic. Titles are then shown as a stack one on top of each other. It's a really neat visualisation of the data and I'm already wondering if that approach would work equally well with visualising library data that is entirely electronic resources. [It's actually one of the big problems about anything to do with electronic resources – that there isn't really a universal icon or symbol that you can use that everyone recognises that it relates to stuff that is online and in electronic form].
There's quite a lot of interesting stuff in the site and also in the LibraryCloud site at www.librarycloud.org. One of the things that particularly interested me (from experiences with the RISE Activity Data project) was the section about data privacy and anonymisation, as a key requirement always has to be that with any dataset where the aspiration is for open release, it must be prepared in a way that ensures that users are unable to be identified individually.
LibraryCloud currently has data from Harvard and Northeastern Universities and Darien, San Francisco and San Jose public libraries. A couple of sites to keep an eye on over the next few months.
Courtesy of a couple of tweets from @psychemedia and @simonjbains two items about data and data visualisation caught my attention today on twitter. Firstly a great post by Pete Warden 'What the Sumerians can teach us about data' on his PeteSearch blog and secondly Harvard's Library Innovation Laboratory. Both items covering particular aspects of data, one talking about the history of data, the other a great set of examples of how to use and visualise data, in Harvard's case library circulation data using the LibraryCloud library metadata repository.
A history of data
I found the blog post on the Sumerians to be particularly interesting. The starting point is the contention that their greatest achievement was the invention of data and there are some good examples of how the written language was used to record who owned what (or who owed what to whom). I like the comparison made between the 'threats of supernatural retribribution' being used to protect the integrity of the data with modern warnings over video copying, both being 'ways of forcefully expressing society's norms, rather than a credible threat of punishment'
It find it interesting how often we seem to find that early examples of writing often turn out to be lists, in other words data rather than stories. Another example that comes to mind are the Vindolanda tablets. These are from the Roman period and found during excavations at a roman fort in Northern England.
"… for dining pair(s) of blankets … paenulae, white (?) … from an outfit: paenulae … and a laena and a (?) … for dining loose robe(s) … under-paenula(e) … vests … from Tranquillus
under-paenula(e) … [[from Tranquillus]]
from Brocchus tunics … half-belted (?) … tunics for dining (?) … (Back, 2nd hand?) … branches (?), number … a vase …
with a handle rings with stones (?) …"http://vindolanda.csad.oxon.ac/TV-II-196 (Tab. Vindol. II 196)
I also thought the comments making a comparion between instructions for interpreting omens and predicting the future from data to be really interesting. A great deal is often made of the importance of 'facts and data' and it has long seemed to me that the critical factor isn't the data that you have, but how you interpret it and what decisions you make. And it often seems to me that the interpretation of data and decision making is a much less scientific exercise.
Part two covering the Harvard Library Innovation Laboratory to follow in the next blog post.


text:
Giving Thanks To You24 Nov 2011, by Made By Survivors Programs in
Giving Thanks To You
Today we are giving thanks to you. Made By Survivors has seen significant growth over the years. We have served over 1,000 survivors of human trafficking through school sponsorship, education, employment, and helping to construct shelter homes. Without you none of this would be possible.
Today we are giving our thanks to you. If you have
* Bought from Made By Survivors
* Donated to Made By Survivors
* Listened to any of our staff and volunteers
* Interviewed us
* Shared our story
* Went on a trip with Made By Survivors
Then you have helped Made by Survivors serve human trafficking survivors and at risk groups.
We also give thanks to you because Made By Survivors continues to expand because of you. Last year Made By Survivors opened to jewelry centers in India teaching girls how to become goldsmiths, which is a high respectable and profitable career in India. Now Made By Survivors has the opportunity to open a 3rd employment center in a border town of West Bengal – Jalpaiguri. Through MBS partnership with Women's Interlink Foundation a shelter and employment center will be established to serve survivors and high risk women and men in the community, especially those from the tribes.
So thank you. Made By Survivors has come a long way since 2005 and it is to you we give thanks.