BACKGROUND OF THE INVENTION 
     The invention relates to novel chemokine-like proteins and their use to suppress the proliferation of actively dividing myeloid cells, e.g., myeloid progenitor cells, myeloid stem cells, and leukemic cells. 
     Each year approximately 173,000 of the people who undergo chemotherapy become neutropenic, which causes them to become susceptible to infection and anemia (Hecht, Drug and Market Development, 4:49, 1993). One method of treatment for neutropenia, e.g., chemotherapy-induced neutropenia, includes stimulation of progenitor cells with differentiation factors including granulocyte macrophage-colony stimulating factor (GM-CSF), granulocyte-colony stimulating factor (G-CSF), and erythropoietin (EPO) as a method of salvaging cells surviving chemotherapy. Approximately 100,000 patients annually are suitable for receiving G-CSF for this purpose. G-CSF is used to stimulate growth of white blood cell progenitors, and EPO has been used to stimulate production of red blood cells, however, there are no megakaryocyte progenitor stimulating factors currently available. 
     An alternative approach for preventing neutropenia is to inhibit cell proliferation with low doses of various chemokines, which inhibits cell cycling, thereby protecting the progenitor cells from the effects of chemotherapy and/or radiation therapy. After chemotherapy has ended, the chemokine treatment is also stopped, which allows the progenitor cells to resume normal proliferation. 
     Chemokines are small inducible proteins that are related by amino acid homology, chromosome location, and structural similarities, including the presence of four position-invariant cysteine residues in their primary amino acid sequence that form two disulfide bonds. The amino acid sequences of various naturally occurring, wild-type chemokine proteins are shown in FIG. 1. 
     Certain chemokines, known as beta chemokines, have a Cys--Cys pair as the first two cysteines, and include macrophage inflammatory protein-1 alpha (MIP-1α), MIP-1β, macrophage chemotactic and activating factor (MCAF, also known as monocyte chemo-attractant protein-1 (MCP-1)), MCP-3, and Regulated on Activation, Normal T-cell Expressed and Secreted protein (RANTES). The beta chemokines are potent chemoattractants for a variety of blood cell components, including monocytes, eosinophils, and T-lymphocytes, but not neutrophils. 
     Other chemokines, known as alpha chemokines, have a Cys-X-Cys triplet as the first two cysteines (X can be any amino acid other than cysteine), and include the human-derived proteins interleukin-8 (IL-8), GRO-α (also called melanoma-growth stimulating activity (MGSA/GRO), MIP-2α (also known as GRO-β), MIP-2β (also known as GRO-γ), neutrophil activating peptide-2 (NAP-2), platelet factor 4 (PF4), gamma interferon inducible protein 10 (γIP-10), Epithelial derived Neutrophil Activating protein (78 amino acids in length)(ENA-78), β-thromboglobulin (βTG), connective tissue-activating peptide-III (CTAP-III), and platelet basic protein (PBP). The alpha chemokines are potent chemoattractants and all except PF4 and γIP-10 activate neutrophils. 
     Chemokines have been shown to regulate proliferation and/or differentiation of hematopoietic stem and progenitor cells in vitro and in vivo. For example, MIP-1α, γIP-10, IL-8, Gro-β, PF4, and MCP-1 have been shown to inhibit the proliferation of colony forming unit-granulocyte macrophage (CFU-GM), burst forming unit-erythroid cells (BRU-E), and colony forming unit-multipotential progenitor cells (CFU-GEMM), at concentrations greater than 25 ng/ml when administered to mice. See, e.g., Broxmeyer et al., J. Immunol., 150:3448-3458 (1993). 
     On the other hand, several members of the chemokine family, including NAP-2, Gro-α, Gro-γ, RANTES, and MIP-1β have been shown not to possess such inhibitory activities, but Gro-α and Gro-γ have been shown to interfere with the inhibitory activity of IL-8 and PF4. Furthermore, Broxmeyer et al., WO 94/13321, states that combinations of any two of MCAF, MIP-1α, MIP-2α, IL-8, γIP-10 and PF4 provide a decrease in the concentrations required for suppressing progenitor cell proliferation. 
     Several groups have also examined the ability of chemokines to inhibit the proliferation of progenitor cells in vivo. For example, Maze et al., J. Immunol., 149:1004 (1992), observed that murine MIP-1α suppressed proliferation and absolute numbers of granulocyte-macrophage, erythroid, and multipotential progenitor cells from mice femurs and spleens at doses between 2 and 10 μg per mouse, injected intravenously. Murine MIP-1β, which was unable to inhibit cell proliferation in vitro, displayed no biological activity in vivo either. 
     Recombinant human chemokines have also been demonstrated to inhibit proliferation of CFU-GM, CFU-GEMM, and BFU-E following intravenous injection into mice. Furthermore, active chemokines cause a significant decrease in the number of progenitor cells in S-phase. For example, Dunlop et al., Blood, 79:2221 (1992), observed that recombinant human MIP-1α was able to suppress CFU-S in a dose dependent manner in vitro, and to reduce the high proliferative state of the CFU-S compartment to a quiescent state in vivo. 
     Human MIP-1α has been shown to protect progenitor cells in vivo from the cytotoxic effects of the chemotherapeutic drug cytosine arabinoside (ARA-C), and Caen et al., Blood, 82:162a (1993), has reported that PF4, at doses between 1 and 5 μg/mouse, protected hematopoietic precursor cells from the adverse effects of the chemotherapeutic, 5-fluorouracil. Lord et al., Blood, 79:2605-2609 (1992), also observed that MIP-1α protected myeloid progenitors in a murine system from the cytotoxic effects of hydroxyurea. 
     In addition, Gewirtz et al., J. Clin. Invest., 68:56 (1989), observed that a peptide from PF4 containing the C-terminal 24 amino acids inhibited proliferation of megakaryocyte progenitors in vitro at a concentration of 25 μ/ml. A shorter peptide containing only the last 13 amino acids from PF4 was found to be inactive in the assay. Similarly, a peptide containing the C-terminal 18 amino acids from β-thromboglobulin did not inhibit proliferation. 
     Recently, Caen et al., Blood, 82:162a (1993), reported that a dodecapeptide, Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Glu-Ala-Pro, which is able to inhibit human and murine megakaryocyte and platelet production, can also protect hematopoietic precursor cells in vivo (1-5 μg/mouse) during 5-fluorouracil chemotherapy. 
     Although G-CSFs are the drugs most commonly used to treat chemically-induced neutropenia, they have certain drawbacks. For example, G-CSFs do not prevent a drop in white blood cell count, i.e., they do not avoid neutropenia, but merely shorten the low point or nadir in the blood count. G-CSFs also fail to stimulate platelet development, and thus do not protect platelets. Moreover, G-CSFs are expensive, and are therefore often administered only after the white cell count drops below about 1000. 
     SUMMARY OF THE INVENTION 
     The present invention is based on the discovery that chemokines contain specific &#34;active domains&#34; that are defined herein as regions of several contiguous amino acids in chemokines that, in combinations of two or more active domains, are necessary for the chemokine&#39;s ability to suppress the proliferation of actively dividing myeloid cells, e.g., myeloid progenitor cells, myeloid stem cells, and leukemic cells. Based on this discovery, the invention includes novel chemokine-like proteins that contain two or more of these &#34;active domains&#34; and thus suppress the proliferation of actively dividing myeloid cells, i.e., that have a myelosuppressive activity. Certain of these new chemokine-like proteins have a much higher myelosuppressive activity than naturally occurring, wild-type chemokines. 
     Based on these discoveries, the invention features the new proteins and methods to treat chemotherapy-induced, as well as radiation-induced, neutropenia. The invention also features new methods of screening and treating patients with certain myelogenous leukemias as well as other hyperproliferative blood diseases. In addition, the new proteins can be used to identify, purify, and expand progenitor-specific cell populations in an ex vivo setting for re-introduction into a patient following radiation or chemotherapy. 
     In general, the invention features a protein having the amino acid sequence of a wild-type chemokine, e.g., IL-8, having four cysteine residues, with the following modifications: a) amino acids DLQ as the 3 contiguous amino acids on the N-terminus side of and proximal to the first cysteine residue of the wild-type chemokine; and b) amino acids ELXVX 1  X 2  X 3  X 4  X 5  X 6  as the 10 amino acids on the N-terminus side of and proximal to the third cysteine of the wild-type chemokine, wherein X is any amino acid, e.g., R, N, E, or Q, and X 1  X 2  X 3  X 4  X 5  X 6  can be any six consecutive amino acids on the N-terminus side of and proximal to the third cysteine of the wild-type chemokine. In particular, the protein can have the amino acid sequence SAKDLQCQCIKTYSKPFHPKFIKELRVIESGPHCANTEIIVKLSDGRELCLDPKENWVQRVVEKFLKRAENS (SEQ ID NO:16). 
     The invention further features a protein having the amino acid sequence of a wild-type chemokine, e.g., PF-4, having four cysteine residues, with the following modifications: a) amino acids ELR as the 3 contiguous amino acids on the N-terminus side of and proximal to the first cysteine residue of the wild-type chemokine; and b) amino acids XDLQ as the 4 amino acids on the C-terminus side of and proximal to the fourth cysteine of the wild-type chemokine; wherein X can be any amino acid, e.g., L. In particular, the protein can have the amino acid sequence SAKELRCQCVKTTSQVRPRHITSLEVIKAGPHCPTAQLIATLKNGRKICLDLQAPLYKKIIKKLLES (SEQ ID NO:22). 
     In addition, the invention features a protein having the amino acid sequence of a wild-type chemokine, e.g., PF4, having four cysteine residues, with the following modifications: a) amino acids DLQ as the 3 contiguous amino acids on the N-terminus side of and proximal to the first cysteine residue of the wild-type chemokine; and b) amino acids ACLNPASPIVK (SEQ ID NO:44) replacing 11 amino acids including the fourth cysteine of the wild-type chemokine, wherein the C in ACLNPASPIVK corresponds to the fourth cysteine residue. In particular, the protein can have the amino acid sequence EAEEDGDLQCLCVKTTSQVRPRHITSLEVIKAGPHCPTAQLIATLKNGRKACLNPASPIVKKIIKKLLES (SEQ ID NO:26). 
     The invention further features a protein having the amino acid sequence of a wild-type chemokine, e.g. PF4, having four cysteine residues, with the following modifications: a) amino acids DLQ as the 3 contiguous amino acids on the N-terminus side of and proximal to the first cysteine residue of the wild-type chemokine; and b) amino acids IATLKNGQK (SEQ ID NO:43) and Z as the 10 amino acids on the N-terminus side of and proximal to the fourth cysteine of the wild-type chemokine, wherein Z is any amino acid, e.g., I, A, L, or R. In particular, the protein can have the amino acid sequence EAEEDGDLQCLCVKTTSQVQPQHITSLEVIKAGPHCPTAQLIATLKNGQKICLDLQAPLYKKIIKKLLES (SEQ ID NO:28). 
     In any of these new proteins, the wild-type chemokine can be, e.g., IL-8, GRO-α, MIP-2α, MIP-1α, PF4, NAP-2, ENA-78, PBP, CTAP-III, βTG, γIP-10, MCAF, or RANTES. 
     The invention also features a method of suppressing proliferation of an actively dividing myeloid cell by contacting the cell with an effective amount of any of the new chemokine-like proteins of the invention. The cell can be cultured in vitro, or ex vivo, or the cell can be in vivo. 
     Furthermore, the invention features an adjunctive method for use with chemotherapy or radiation therapy in a patient by administering an effective amount of a chemokine-like protein of the invention to the patient, and administering chemotherapy or radiation therapy to the patient in conjunction with the administration of the protein. As used herein, &#34;in conjunction with&#34; means before, during, or after, or any combination thereof. 
     The invention also features a method of treating a hyperproliferative myeloid disease, e.g., chronic myelogenous leukemia, polycythemia vera, or a hypermegakaryocytopoietic disorder, in a patient by administering to the patient an effective amount of a chemokine-like protein of the invention. 
     In addition, the invention features methods of detecting and/or isolating CD34 +   myeloid cells in a sample of cells by obtaining a sample of cells, contacting the sample with a chemokine-like protein under conditions that allow the protein to bind to any CD34 +   myeloid cells in the sample to form bound complexes, and detecting any bound complexes in the sample as an indication of the presence of CD34 +  myeloid cells in the sample, or removing any bound complexes from the sample, and separating CD34 +  myeloid cells from the bound complexes to isolate the CD34 +  myeloid cells from the sample. 
     The invention further features nucleic acids encoding the chemokine-like proteins of the invention, such as nucleic acids having the sequence of SEQ ID NO:34 or SEQ ID NO:41. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
     Other features and advantages of the invention will be apparent from the detailed description including the drawings, and from the claims. 
    
    
     DRAWINGS 
     FIG. 1 is a representation of the wild-type amino acid sequences of representative members of the human chemokine family of proteins (SEQ ID NOS:1-15). 
     FIG. 2 is a representation of the amino acid sequences of novel chemokine-like proteins of the invention (SEQ ID NOS:16-28) compared to the wild-type amino acid sequences of IL-8 (SEQ ID NO:1) and PF4 (SEQ ID NO:6). 
     FIG. 3A is a representation of the nucleotide sequence of human PF4 cDNA (SEQ ID NO:29) and the translated amino acid sequence, as well as the sequences of the four amplimers used for its synthesis (SEQ ID NOS:30-33). 
     FIG. 3B is a representation of the nucleotide sequence of the cDNA of new chemokine-like protein PF4M2 (SEQ ID NO:34) and the translated amino acid sequence, as well as the sequences of the two amplimers used for its synthesis (SEQ ID NOS:33 and 35). 
     FIG. 4A is a representation of the nucleotide sequence of human IL-8 cDNA (SEQ ID NO:36) and the translated amino acid sequence, as well as the sequences of the four amplimers used for its synthesis (SEQ ID NOS:37-40). 
     FIG. 4B is a representation of the nucleotide sequence of the cDNA of new chemokine-like protein IL-8M1 (SEQ ID NO:41) and the translated amino acid sequence, as well as the sequences of the two amplimers used for its synthesis (SEQ ID NOS:40 and 42). 
     FIG. 5 is a schematic summary of the chemokine active domains necessary for myelosuppression and their locations in wild-type IL-8 and PF4, and in new chemokine-like proteins. 
     FIGS. 6A to 6F are graphs representing the inhibition of myeloid progenitor colony formation in in vitro assays of new chemokine-like proteins compared to wild-type PF4 and IL-8. 
     FIG. 7A is a bar graph comparing the influence of wild-type IL-8 and PF4 and new chemokine-like protein IL-8M1 on the cycling status of granulocyte-macrophage progenitor cells in vivo. 
     FIG. 7B is a bar graph comparing the influence of wild-type IL-8 and PF4 and new chemokine-like protein IL-8M1 on the absolute numbers of granulocyte-macrophage progenitor cells in vivo. 
    
    
     DETAILED DESCRIPTION 
     A series of new chemokine-like proteins were made using wild-type amino acid sequences of known chemokines as templates, and including at least two active domains, with at least one of the new active domains originating from a chemokine other than the template chemokine. Other new proteins that included only one active domain were used as controls. These new chemokine-like proteins were then tested for myelosuppressive activity in in vitro assays and in in vivo animal models described below. In addition, several of these new proteins were found not to activate neutrophils, and thus are not inflammatory. 
     The amino acid sequences of the new chemokine-like proteins are shown in FIG. 2, in which the bold amino acids represent active domains that have been discovered to be required for the myelosuppressive activity of the wild-type chemokines and new chemokine-like proteins. Underlined amino acids are different from those normally found at that location in the wild-type chemokine template. Variations of these new chemokine-like proteins can be made and tested as described below. 
     Chemokines 
     Chemokines having normal, wild-type amino acid sequences are available in natural or recombinant form. For example, natural PF4 can be isolated from human platelet extracts. Natural IL-8 has been isolated from either stimulated human endothelial cells or human monocytes. Other chemokines such as PBP or βTG can be isolated from various human cell sources. The wild-type amino acid sequences of several representative members of the human chemokine family are shown in FIG. 1. As used herein, the term &#34;chemokine&#34; or &#34;wild-type chemokine&#34; includes both the natural and recombinant forms of the proteins that have a wild-type amino acid sequence. 
     Recombinant MIP-1α (rMIP-1α), rMIP-1β, rMIP-2α, and rMIP-2β are produced using yeast expression vectors as described in Tekamp-Olson et al., J. Exp. Med., 172:911 (1990), or can be obtained from Chiron Corp. (Emeryville, Calif.). Recombinant IL-8 (rIL-8), PF4 (rPF4), NAP-2 (rNAP-2), CTAP-III (rCTAP-III), GROα (rGRO-α), and GROβ (rGROβ) were cloned and expressed in E. coli at Repligen (Cambridge, Mass.). Both the 77- and 72-amino acid forms of IL-8 were cloned and expressed at Repligen, and can be purchased from Pepro Tech, Rocky Hills, N.J. The 77-amino acid form of rIL-8 and the natural form of PF4 can also be purchased from Sigma Chemical Co. (St. Louis, Mo.). Recombinant preparations of IL-8, MCAF and RANTES are available from Pepro Tech (Rocky. Hills, N.J). Recombinant NAP-2 (rNAP-2) can be purchased from Bachem Bioscience, Philadelphia, Pa. Other cytokines, including recombinant EPO (rEPO) can be purchased from Amgen Corporation (Thousand Oaks, Calif.). Human rGM-CSF, rGROα, IL-3, and SLF (also called mast cell growth factor, stem cell factor, and c-kit ligand) can be obtained from Immunex Corporation (Seattle, Wash.). 
     Human chemokines were purified prior to use and no endotoxin was detected in these samples using a standard limulus lysate assay. 
     Human Bone Marrow Progenitor Cells 
     Human bone marrow cells were obtained by aspiration from the posterior iliac crest of healthy volunteers. Low density (LD) cells (&lt;1.077 g/cm 3 ) were retrieved after density cut separation on FICOLL-HYPAQUE™ (Pharmacia Fine Chemicals, Piscataway, N.J). 
     Methods of Making Chemokine-Like Proteins 
     New chemokine-like proteins can be made using standard synthetic techniques, or can be generated using recombinant DNA technology and expressed in bacterial, yeast, or mammalian cells using standard techniques. 
     Chemical Synthesis 
     Chemokine-like proteins can be synthesized based on the amino acid sequences described herein and variations thereof by standard solid-phase methods using the tert-butyloxy-carbonyl and benzyl protection strategy described in Clark-Lewis et al., P.N.A.S., USA, 90:3574-3577 (1993) and Clark-Lewis et al., Biochemistry, 30:3128-3135 (1991). After deprotection with hydrogen fluoride, the proteins are folded by air oxidation and purified by reverse-phase HPLC. Purity is determined by reverse-phase HPLC and isoelectric focusing. Amino acid incorporation is monitored during synthesis, and the final composition is determined by amino acid analysis. The correct covalent structure of the protein can be confirmed using ion-spray mass spectrometry (SCIEX APIII). 
     Recombinant Expression of Chemokine-Like Proteins 
     New chemokine-like proteins can also be generated using recombinant DNA techniques. For example, mutant chemokine genes were generated using standard polymerase chain reaction (PCR) amplification of synthetic oligonucleotide primers, e.g., as described in Mullis et al., U.S. Pat. No. 4,800,159. The primers were designed to be less than 100 bases in length with a minimal overlap of at least 25 bases, and were synthesized using an Applied Biosystems 394 DNA/RNA synthesizer. A large (10 to 40 base) region upstream of a restriction site was included to facilitate restriction endonuclease digestion and to enhance visualization of endonuclease digested DNA versus undigested DNA on an agarose gel. Oligonucleotide primers were amplified by 25 to 30 cycles of PCR using standard reaction conditions. Outside primer concentration was 0.4 pmoles/μl and all inside primer concentrations were 0.004 pmoles/μl in the reaction. Following amplification, the selected gene was digested with restriction endonucleases Bam HI and Nde I and electrophoresed on a 1% LMP agarose/3% NuSieve gel containing 40 mM Tris, acetate, 2 mM Na 2  EDTA.2H 2  O (TAE) buffer. Bands corresponding to the doubly cut gene were excised from the gel and used in ligation reactions. 
     The digested DNA was ligated into the pMEK vector (derivatized pET 9a vector, Novagen, Madison, Wis.) and was selected for by kanamycin resistance. This vector permits protein expression only following induction of the cells with isopropyl-β-D-thiogalactoside (IPTG). Following the ligation reaction, the vector including the gene segment was electroporated into XL1 Blue E. coli cells and screened on agar-kanamycin plates. Colonies were chosen and the correct inserts were screened by restriction digests of DNA mini-preps (5 colonies per plate). The DNA sequences of positive clones were confirmed using an Applied Biosystems Prism Taq Dye Deoxy Terminator sequencing kit and an Applied Biosystems 373A DNA sequencer. 
     Following sequence confirmation, the resulting plasmids were electroporated into BL21 (DE3) E. coli cells. Colonies were screened on kanamycin plates and grown in 50 ml cultures for examination of expression levels following induction with IPTG. 
     Platelet Factor 4 (PF4) 
     The following general methods were used to synthesize, clone, and express a PF4 gene. First, the gene for PF4 was obtained by directing the bacterial expression of the protein. As shown in FIG. 3A (SEQ ID NO:29,/=signal peptide cleavage site), four partially complementary oligonucleotides (amplimers) were synthesized (PF4-1 to PF4-4). Amplimer PF4-1 (SEQ ID NO:30) was a 57 mer and included an Nde I restriction site, the ATG translation start codon, and sense strand nucleotides 101 to 157 of the published human PF4 cDNA (Poncz et al., Blood, 69:219-223 (1987)) [codons Glu 32  to Val 50  of the precursor (Glu 1  to Val 19  of the mature secreted form)]. PF4-2 (SEQ ID NO:31), a 100 mer, contained the antisense nucleotides 232 to 133, extending to the first two positions of codon Thr 75  of the precursor (Thr 44  of the secreted form), with the 3&#39; 25 nucleotides being complementary to the 3&#39; 25 nucleotides of PF4-1. PF4-3 (SEQ ID NO:32), a 99 mer, contained sense nucleotides 205 to 303, extending to the coding strand sequence of Leu 99  of the precursor (Leu 68  of the mature secreted form), with positions 1 through 27 being complementary to positions 1 though 27 of PF4-2. PF4-4 (SEQ ID NO:33), a 90 mer, contained antisense nucleotides 313 to 274, extending to the TAG 102  translation stop of the precursor (TAG 71  of the mature secreted form), and contained additional nucleotides for restriction sites for cloning. The sequence of these amplimers were such that the final double-stranded DNA fragment would encode the amino acid sequence of human PF4 as shown in FIG. 3A (SEQ ID NO:29). 
     The four amplimers were annealed to create a gapped PF4 gene, and PCR amplification was then used to fill in the gaps and amplify the full-length gene so that it could be cloned into an expression vector for production of the protein. The four amplimers were mixed at final concentrations of 5 μM of PF4-1, 0.05 μM of PF4-2, 0.05 μM of PF4-3, and 5 μM of PF4-4. This mixture was diluted 6.25-fold and amplified using Pfu polymerase (Stratagene, La Jolla, Calif.) per the manufacturer&#39;s conditions without adding any template in addition to the amplimer mixture. The reaction was subjected to 35 cycles of amplification at 98° C. for 1 minute, 50° C. for 1 minute, and 72° C. for 3 minutes. The success of the amplification was verified by agarose gel electrophoresis of a portion of the PCR reaction mixture. 
     The amplified PF4 DNA fragment was purified and concentrated from the remainder of the reaction using a Quiagen PCR Purification kit (Quiagen, Inc., Chatsworth, Calif.). One half of the purified PF4 DNA fragment was digested with 60 units each of the restriction enzymes NdeI and BamHI in a 50 μl reaction volume. The digested fragment was purified by low melting point agarose gel electrophoresis and ligated with gel purified NdeI/BamHI-digested pET3a (Novagen, Madison, Wis.) to create the E. coli expression plasmid pETPF4-1. The pET3a backbone was derived from the plasmid pARVH which consisted of the pET3a vector with an MGSA/Gro-related sequence cloned in the NdeI to BamHI restriction site. This plasmid was digested with NdeI and BamHI to remove the MGSA/Gro fragment so that the PF4 fragment could be inserted. The PF4 DNA fragment insert of the resulting pETPF4-1 plasmid was sequenced in its entirety, which confirmed that the correct sequence was present. 
     For initial expression, the plasmid pETPF4-1 was used to transform E. coli strain BL21. The transformants were grown to an OD of 1.2, and then induced to express the PF4 gene by the addition of 0.4 mM IPTG to the culture medium. After 2 hours, the cells were pelleted, and a small portion was examined by SDS-PAGE and Western blotting to confirm expression of PF4. 
     Interleukin-8 
     The gene for IL-8 was synthesized in a similar fashion except that the oligonucleotide amplimers were made such that the final sequence would encode the IL-8 amino acids as in FIG. 4A (SEQ ID NO:36). Amplimer IL-8-1 (SEQ ID NO:37) was a 59 mer and included an NdeI restriction site, the ATG translation start codon, and sense strand nucleotides 1-59 of the human IL-8 cDNA. IL-8-2 (SEQ ID NO:38) was a 99 mer and included antisense nucleotides 42 to 140 of the human IL-8 cDNA. IL-8-3 (SEQ ID NO:39), also a 99 mer, included sense strand nucleotides 109 to 207. IL-8-4 (SEQ ID NO:40), was a 37 mer, and included anti-sense strand nucleotides 183 to 219 of the IL-8 cDNA extending to the TAG translation stop of the gene and an additional stretch of nucleotides for restriction sites for cloning. 
     Purification 
     The synthetic genes for human PF4, IL-8, and new chemokine-like proteins were expressed in E. coli (BL21) cells and grown in 10 liter containers. Cells were grown for 4 hours at 37° C. followed by induction with IPTG (0.4 mM) overnight. Approximately 550 g of cell paste containing inclusion bodies was obtained, of which 100 g was suspended in lysis buffer (0.05M Tris-HCl, pH 8.0, 5 mM EDTA, 5 mM DTT, 0.1% Triton-X100) and lysed by DYNOMIL™ disruption in the presence of 0.1% α-toluenesulfonylfluoride (PMSF). The lysed preparation was treated with two aliquots of DNase I, concomitantly added with MgCl 2  and incubated for 0.5 hours at 4° C. 
     Following DNase I treatment, the suspension was centrifuged overnight at 4° C. at 13,000 rpm. The precipitate from the centrifugation step was extracted in 150 mls of 0.05M Tris-HCl, pH 8.0, 6M Guanidine-HCl, and 50 mM DTT overnight at 25° C. The extracted material was dialyzed against buffer containing 25 mM sodium acetate, pH 4.0, 8M urea, and 50 mM DTT and loaded onto a S-Sepharose column equilibrated with 25 mM sodium acetate, pH 4.0, 8M urea. The column, containing bound protein, was washed with 25 mM sodium acetate, pH 4.0, to remove the urea followed by a second buffer wash containing 25 mM sodium acetate, pH 4.0, 0.5M NaCl. The protein was then eluted with buffer containing 50 mMTris-HCl, pH 8.0, 1M NaCl. 
     Fractions containing the appropriate chemokine or chemokine-like protein were refolded by overnight incubation in the presence of 1 mM oxidized/2 mM reduced glutathione at 25° C. The extent of refolding of the proteins was monitored using POROS™ analytical chromatography. The reduced protein species were observed to elute from the POROS™ column at different acetonitrile concentrations relative to the refolded species. Refolded fractions were pooled and rechromatographed by C4 semi-preparative reverse phase HPLC using a 0 to 100% acetonitrile gradient in 0.1% TFA:H 2  O. Peak fractions were pooled and lyophilized for concentration determination. 
     Purity of the final proteins was assessed by Coomassie staining of SDS PAGE, analytical C4 reverse phase HPLC, and amino acid analysis. Protein concentrations were determined by amino acid analysis and an bicinchoninic acid (BCA) assay described by Smith et al., Anal. Biochem., 150:76-85 (1985). Typically, several hundred milligrams of &gt;95% pure material was isolated from 100 g of starting material. 
     For small scale purifications, cells were grown in a 500 ml shaker flask containing 300 μg/ml kanamycin until an absorbance of 0.6 at 600 nm was reached. Cells were then induced with IPTG for 3 hours at 37° C. followed by centrifugation at 14,000×g for 30 minutes. The cell paste was resuspended in 20 ml of 1× phosphate buffered saline (PBS, Gibco) and sonicated for 3 minutes at 4° C. using a Braun-Sonic model 1510 sonicator at 200 W. The lysed material was centrifuged for 30 minutes at 13,000×g, and the precipitated material was resuspended in buffer containing 6M Guanidine-HCl as described above. Small scale purification of chemokine proteins was identical to the purification described above for the large scale isolation of chemokines. 
     Determination of Protein Concentration 
     Protein concentrations were determined using the BCA protein assay described above and results were calculated based on concentrations obtained from a standard dilution series of bovine serum albumin. Amino acid analysis of chemokines was obtained following hydrolysis of the proteins for 24 hours at 90° C. in 12M HCl. Following hydrolysis, samples were derivatized and analyzed according to the method of Bidlingmeyer et al., J. Chromatography, 336:93-104 (1984). 
     Specific Chemokine-Like Proteins 
     The genes that express the new chemokine-like proteins can be made by either of two methods. In the first method, a wild-type chemokine gene, e.g., one of the IL-8 or PF4 genes described above, is used as a template, and the desired amino acid substitutions are made in this amino acid template by PCR amplification using, e.g., a sense 5&#39; amplimer that contains the sequence for the desired modified codon(s). This results in the amplification of a new gene that encodes a new protein with the desired amino acid sequence. 
     Alternatively, genes encoding the new chemokine-like proteins can be synthesized without a template using the four overlapping amplimer strategy described above with amplimers containing appropriate sequence changes such that the final amplified DNA fragment will encode the desired amino acid sequence in the expressed new chemokine-like protein. 
     A variety of new chemokine-like proteins were made using the wild-type amino acid sequences of human PF4 and IL-8 (FIGS. 3A and 4A, respectively) as the template. As shown in FIG. 2, these new proteins are similar in amino acid sequence to certain wild-type chemokines, in this case IL-8 or PF4, but include specific amino acid substitutions and/or insertions that make these new proteins distinct and unique compared to the wild-type chemokines. In addition, these substitutions provide the new chemokine-like proteins with an unexpected enhanced myelosuppressive activity. 
     In particular, as shown in FIG. 4B, the cDNA encoding new protein IL-8M1 (SEQ ID NO:41) was synthesized using a 5&#39; sense amplimer IL-8M1-1 (SEQ ID NO:42), which contains a nucleotide mutation designed to result in the substitution of the amino acid sequence DLQ for the sequence ELR in wild-type IL-8 in the amino terminus of the protein. Because the remainder of the IL-8M1 sequence was to be the same as the wild-type IL-8 sequence, the 3&#39; antisense amplimer used was the same one used in the synthesis of the cDNA encoding wild-type IL-8 described above, amplimer IL-8-4 (SEQ ID NO:40). This amplimer was chosen because no other mutation was desired, and this amplimer will produce no further mutation in the wild-type IL-8 sequence. 
     As shown in FIG. 3B, the cDNA encoding new protein PF4M2 (SEQ ID NO:34) was synthesized using a 5&#39; sense amplimer PF4M2-1 (SEQ ID NO:35), which contains a nucleotide mutation designed to result in the substitution of the amino acid sequence MSAKELRCQC (SEQ ID NO:45) for the sequence EAEEDGDLQCLQ (SEQ ID N0:46) in wild-type PF4 in the amino terminus of the protein. The second amplimer used was the same one used in the synthesis of the cDNA encoding wild-type PF4 described above, the 3&#39; antisense amplimer PF4-4 (SEQ ID NO:33). 
     Based on the methods, techniques, and assay results described herein, additional new proteins can be created using other wild-type chemokines as the template or structural basis. As described below and shown schematically in FIG. 5, the amino acid changes in a template based on a first wild-type chemokine must introduce at least one new myelosuppressive active domain from one region of a second wild-type chemokine into the template, while maintaining a myelosuppressive active domain of the first chemokine in another region of the template or introducing another active domain from the second or a third wild-type chemokine. 
     FIG. 5 shows that wild-type IL-8, having active domains 1 (ELR of IL-8) and 2 (ELRV of IL-8), provides a normal level of myelosuppressive activity. Wild-type PF4, having active domains 3 (the first DLQ of PF4) and 4 (the second DLQ of PF4), also provides a normal level of myelosuppressive activity. If either of these active domains are removed, the resulting protein loses its myelosuppressive activity. For example, PF4M1, which is missing domain 3; PF4-412, which is missing domain 4; and IL-8M4, M3, and M6, which are all missing domain 2; all lack myelosuppressive activity. On the other hand, new chemokine-like protein PF4M2 includes active domains 1 and 4, and has unexpectedly high myelosuppressive activity. Similarly, IL-8M1 includes domains 3 and 2, and has unexpectedly high myelosuppressive activity. 
     Examples of new chemokine-like proteins based on PF4 include PF4M1 and PF4M2. Testing of PF4M1 showed that destroying an active domain found in PF4 also destroys PF4&#39;s myelosuppressive activity. PF4M1 was generated by creating a point mutation in the N-terminal end of wild-type PF4 that changed the amino acids D 7  L 8  Q 9  (PF4&#39;s first active domain) proximal to and on the N-terminus side of the first cysteine to the amino acids DLR. As shown by the assay results described below, this change destroyed PF4&#39;s first active domain and resulted in a protein without myelosuppressive activity. 
     Testing of PF4M2 showed that replacing an active domain in PF4 with an active domain from a second chemokine creates a new highly myelosuppressive protein. PF4M2 was generated by replacing the entire N-terminus up to the first cysteine of wild-type PF4 with the corresponding N-terminus of wild-type IL-8. This change replaced PF4&#39;s first active domain with IL-8&#39;s first active domain (E 4  L 5  R 6 ) while maintaining PF4&#39;s second active domain (D 54  L 55  Q 56 ), and resulted in a highly active new protein. 
     New proteins PF4-412, PF4-413, and PF4-414 were generated by replacing amino acids 51 to 61 of wild-type PF4 with the corresponding amino acids from wild-type IL-8, NAP-2, or GROα, respectively. Of these new proteins, PF4-412 and PF4-413 were essentially inactive, because the substitution of the new domains from IL-8 and NAP-2 destroyed PF4&#39;s second active domain without introducing a new active domain. PF4-414 retained the first active domain of PF4 and included an active domain from GROα, and had a higher activity than wild-type PF4. 
     PF4-421 was generated from an exchange of amino acids 25 to 31 of wild-type PF4 with the corresponding amino acids from wild-type IL-8. This resulted in a new protein that maintained PF4&#39;s two active domains and introduced IL-8&#39;s second active domain (E 24  L 25  R 26  V 27 ). This protein had about the same activity as wild-type PF4. 
     PF4-426 was created by replacing all three Arg (R) residues of wild-type PF4 with Glu residues (Q) to achieve a novel region at amino acids 42 to 50. These changes created a region in the new protein equivalent to a corresponding region in GROβ that includes an active domain, while maintaining the first active domain of PF4. As a result, PF4-426 was highly active. 
     Examples of new chemokine-like proteins based on IL-8 include IL-8M1, IL-8M3, IL-8M4, IL-8M6, IL-8M7, and IL-8M64. IL-8M1 was generated by replacing the amino acids ELR proximal and on the N-terminus side of the first cysteine of normal IL-8 (IL-8&#39;s first active domain) with the amino acids DLQ from the corresponding location in wild-type PF4. Thus, this new protein included PF4&#39;s first active domain and IL-8&#39;s second active domain and was highly active. 
     IL-8M3, IL-8M4, and IL-8M6 were generated by creating one or two point mutations within the IL-8 dimer interface (IL-8&#39;s second active domain including the amino acids ELRV between the second and third cysteines in normal IL-8). These mutations destroyed IL-8&#39;s second active domain and, as expected, resulted in inactive proteins. 
     IL-8M7 was generated by replacing the entire C-terminus after the fourth cysteine of normal IL-8 with the corresponding C-terminus of normal PF4. This substitution resulted in a new protein having IL-8&#39;s first and second active domains and PF4&#39;s second active domain, and had about the same activity as wild-type IL-8. 
     IL-8M64 was generated by truncating the last eight amino acids from the C-terminus of normal IL-8, which resulted in a new protein with about the same activity as wild-type IL-8. 
     Testing of specific New Chemokine-Like Proteins 
     The different chemokine-like proteins shown in FIG. 2 were tested in both in vitro and in vivo assays to demonstrate their ability to inhibit proliferation of progenitor cells. Wild-type PF4 and IL-8 by themselves were shown to inhibit stem cell proliferation at concentrations as low as 25 ng/ml, whereas the new chemokine-like proteins were shown to have equivalent myelosuppressive activity at much lower concentrations. 
     New Chemokine-Like Proteins Inhibit Progenitor Cell Proliferation In Vitro 
     Chemokine-like proteins made as described herein can be tested by standard in vitro assays to determine whether they inhibit the formation of GM colony (CFU-GM) and cluster formation. Such assays are well known and representative assays are described in Gentile et al., U.S. Pat. Nos. 5,149,544 and 5,294,544. In these assays, bone marrow or spleen cells are stimulated with, e.g., CSF, in an in vitro culture system. The inhibitory activity of the new chemokine-like protein is measured as the amount it decreases the CSF-stimulated colony and cluster formation. 
     In particular, the new proteins described above were tested as follows. LD cells were plated at a density of 5×10 5  cells in 0.3% agar culture medium with 10% FBS (Hyclone, Logan, Utah) for assessment of CFU-GM. CFU-GM colonies (&gt;40 cells/group) were stimulated by human rGM-CSF (100 U/ml) in combination with human rSLF (50 ng/ml). All colonies were tested in the absence or presence of different concentrations of new chemokine-like proteins to examine potency of inhibition of proliferation. 
     Colonies were scored after 14 days incubation at lowered (5%) O 2  tension, and 5% CO 2  in a humidified environment in an ESPEC N 2  --O 2  --CO 2  incubator BNP-210 (Taoi ESPEC Corp., South Plainfield, N.J.). Three plates were scored per determination. The results are expressed in Table I below as a mean percent change from control ±1 S.E.M. for the number of experiments shown in experiments in which the control number of colonies. per 1×10 5  cells/ml ranged from 115±5 (mean ±1 S.E.M.) to 382±10. The inhibition shown, while partial inhibition of the total colony formation, is 90 to 100% inhibition of the steel factor enhanced colony formation. 
     In the table, those data marked with a &#34; b  &#34; represent a significant change from control, p&lt;0.01 (Students t test), while those data marked with a &#34; c  &#34; represent a significant change from control, p&lt;0.05. The in vitro results are also shown in the graphs of FIGS. 6A to 6F. 
     
                                           TABLE I__________________________________________________________________________Chemokine concentration (ng/ml)Chemokine 100  50   25   10   1    0.1  0.01 0.001__________________________________________________________________________PF4 WT -41 ± 3.sup.b      -40 ± 2.sup.b           -25 ± 7.sup.b                -10 ± 6                     -3 ± 2PF4M1 -9 ± 10      -5 ± 6           -2 ± 2                -6 ± 1PF4M2 -43 ± 2.sup.b      -44 ± 2.sup.b           -42 ± 3.sup.b                -46 ± 2.sup.b                     -47 ± 2.sup.b                          -42 ± 5.sup.b                               -19 ± 8.sup.c                                    -3 ± 2PF4-412 -6 ± 4      -3 ± 3           -1 ± 1PF4-413 -19 ± 10.sup.c      -14 ± 16           -8 ± 8                -2 ± 1                     +1 ± 1PF4-414 -45 ± 1.sup.b      -44 ± 1.sup.b           -44 ± 2.sup.b                -43 ± 2.sup.b                     -42 ± 5.sup.b                          -43 ± 1.sup.b                               -34 ± 8.sup.b                                    -3 ± 3PF4-421 -42 ± 6.sup.b      -40 ± 4.sup.b           -29 ± 3.sup.b                -25 ± 9.sup.c                     -8 ± 4                          +1 ± 1PF4-426 -45 ± 3.sup.b      -44 ± 4.sup.b           -45 ± 1.sup.b                -46 ± 1.sup.b                     -45 ± 3.sup.b                          -44 ± 4.sup.b                               -40 ± 3.sup.b                                    -20 ± 1.sup.cIL-8WT -42 ± 2.sup.b      -43 ± 2.sup.b           -21 ± 5.sup.b                -4 ± 2                     -3 ± 6IL-8M1 -43 ± 4.sup.b      -43 ± 4.sup.b           -44 ± 1.sup.b                -46 ± 2.sup.b                     -46 ± 2.sup.b                          -46 ± 2.sup.b                               -40 ± 1.sup.b                                    -25 ± 4.sup.bIL-8M3 -8 ± 3      -4 ± 3           -1 ± 2                -7 ± 2IL-8M4 -1 ± 2      -1 ± 2IL-8M6 -2 ± 2      -1 ± 2           +1 ± 1IL-8M7 -43 ± 4.sup.b      -45 ± 2.sup.b           -25 ± 2.sup.b                -2 ± 3                     0 ± 2IL-8M64 -43 ± 1.sup.b      -43 ± 2.sup.b           -27 ± 5.sup.b                -10 ± 7                     -8 ± 5                          -5 ± 1__________________________________________________________________________ 
    
     As shown in Table I, wild-type PF4 and IL-8 were effective to inhibit colony formation by human bone marrow GM progenitor cells at concentrations of at least 25 ng/ml. At 10 ng/ml, neither one provided more than insignificant inhibition. 
     New chemokine-like protein PF4M1, in which the first active domain of PF4 was destroyed, was essentially inactive. PF4M2, however, which included the first active domain of wild-type IL-8 and the second active domain of wild-type PF4, had a much higher activity than wild-type PF4. Although PF4-412 and PF4-413 both retained PF4&#39;s first active domain, they were essentially inactive because they both lacked a second active domain. PF4-414, which retained PF4&#39;s two active domains and included a new active domain from GROα, had a higher activity than wild-type PF4. PF4-421, which retained PF4&#39;s two active domains and included the second active domain from wild-type IL-8, had a somewhat higher activity than wild-type PF4. PF4-426, which retained PF4&#39;s first active domain and included an active domain from wild-type GROβ, was highly active. 
     New chemokine-like protein IL-8M1, which included PF4&#39;s first active domain and IL-8&#39;s second active domain, was active down to 0.001 ng/ml, which was quite surprising, since IL-8M1 was also found to be significantly inhibited in its ability to activate neutrophils. The D 7  L 8  Q 9  amino acids (first active domain) from wild-type PF4 appear to make this new chemokine-like protein act as if PF4 and IL-8 were both present and acting synergistically, but with a much higher activity per total amount of protein than can be achieved by merely combining the two wild-type proteins. 
     On the other hand, new proteins IL-8M3, IL-8M4, and IL-8M6 were essentially inactive, because each lacked an intact second active domain. IL-8M7, which included wild-type IL-8&#39;s first and second active domains and PF4&#39;s second active domain, had about the same activity as the wild-type IL-8. IL-8M64, which retained wild-type IL-8&#39;s first and second active sites, but which lacked the last 8 amino acids of wild-type IL-8, also had about the same activity as wild-type IL-8. 
     The data in Table I are also represented in graphical form in FIGS. 6A to 6F. FIG. 6A shows the percent inhibition of myeloid progenitor colony formation by PF4M2 and PF4-413 compared to wild-type PF4 (PF4 WT). FIG. 6B shows the percent inhibition by PF4-426 and PF4-412 compared to PF4 WT. FIG. 6C shows the percent inhibition by PF4-414, PF4-421, and PF4M1. FIG. 6D shows the percent inhibition by IL-8M1 and IL-8M3 compared to IL-8 WT. FIG. 6E shows the percent inhibition by IL-8M1, IL-8M64, and IL-8M6. FIG. 6F shows the percent inhibition by IL-8M1, IL-8M7, and IL-8M4. These graphs are all on the same scale, therefore, the activity of different new proteins can be directly compared. 
     As noted above, all of the results, taken together, show that there are two active domains within IL-8 involved in myelosuppressive activity.(E 4  L 5  R 6  and E 24  L 25  R 26  V 27 ). Likewise, PF4 also has two active domains (D 7  L 8  Q 9  and D 54  L 55  Q 56 ) . In addition, since IL-8M1 is highly active at inhibiting proliferation of progenitor cells, yet does not activate neutrophils, this new chemokine-like protein will not elicit the adverse neutrophil chemoattractant and inflammatory effects observed with wild-type IL-8. With the exception of PF4M2, which possesses the ELR domain of IL-8, none of the new chemokine-like proteins based on PF4, including the highly active PF4-414 and PF4-426, elicited any response on human neutrophils. 
     Furthermore, the data obtained from PF4-426 shows that the amino acid sequence IATLKNGQK (SEQ ID NO:43) from wild-type Gro-β is responsible, in conjunction with PF4&#39;s first active domain, for the high myelosuppressive activity observed. This sequence, which is present in Gro-β, but not in Gro-α or Gro-γ, is therefore believed to contain an active domain of this protein. 
     In addition, the data obtained from PF4-414 shows that the amino acid sequence ACLNPASPIVK (SEQ ID NO:44) from wild-type Gro-α is responsible, in conjunction with PF4&#39;s first active domain, for a high myelosuppressive activity. Although Gro-α is itself inactive in suppressing myeloid cell proliferation, it competes with IL-8 and PF4 for progenitor cell suppression, which suggests that it is able to interact on the cell surface and block activity. Thus, it is possible that Gro-α lacks some activation sequence required for myelosuppression, but includes a sequence responsible for binding. Without the activation sequence, wild-type Gro-α has no myelosuppressive activity, but remains a competitive binding protein. However, when combined with an active domain from PF4 as described herein, the resulting new protein has very potent myelosuppressive activity. This sequence ACLNPASPIVK (SEQ ID NO:44) is therefore believed to contain an active domain of Gro-α. 
     New Chemokine-Like Proteins Inhibit Progenitor Cell Proliferation In Vivo 
     Wild-type PF4 and IL-8, and new chemokine-like protein IL-8M1 were also tested in an in vivo model as follows. Murine models for assessing progenitor cell proliferation were carried out substantially as described in Cooper et al., Exp. Hematol., 22:186-193 (1994). The results of this in vivo model, together with the in vitro assay results described above, are predictive of the efficacy of the new proteins in treating patients, e.g., humans. 
     Control medium, control diluent, wild-type IL-8 and PF4, and the new chemokine-like protein IL-8M1 were evaluated for effects on myelopoiesis in vivo in mice, with endpoints being nucleated cellularity and differentials in the bone marrow, spleen, and peripheral blood, and absolute numbers and cycling status of myeloid progenitor cells in the marrow and spleen. In each test, groups of three C3H/HeJ mice were exposed to a particular test sample. C3H/HeJ mice were used because they are relatively insensitive to the effects of endotoxin. Thus, any potential endotoxin contamination in the chemokine samples did not influence the in vivo results. 
     C3H/HeJ mice were purchased from the Jackson Laboratory (Bar Harbor, Me.), were housed in a conventional animal facility, and were injected intravenously with 0.2 ml/mouse sterile pyrogen-free saline, or the stated amount of a specific chemokine or chemokine-like protein, as described in Mantel et al., P.N.A.S., USA, 90:2232 (1993). The mice were sacrificed 24 hours later. 
     The cycling status of hematopoietic progenitor cells, i.e., the proportion of progenitor cells in DNA synthesis (S phase of the cell cycle), was estimated as described in Maze et al., J. Immunol., 149:1004 (1992) and Cooper et al., Exp. Hematol., 22:186 (1994). The high specific activity (20 Ci/mM)-tritiated thymidine (50 μCi/mL) (New England Nuclear, Boston, Mass.) kill technique was used, and is based on a calculation in vitro of the reduction in the number of colonies formed after pulse exposure of cells for 20 minutes to &#34;hot&#34; tritiated thymidine as compared with a control such as McCoy&#39;s medium or a comparable amount of non-radioactive &#34;cold&#34; thymidine. 
     In brief, femoral bone marrow was removed from the sacrificed mice, treated with high-specific-activity tritiated thymidine, and plated in 0.3% agar culture medium with 10% FBS in the presence of 10% volume/volume pokeweed mitogen mouse spleen cell cultured medium. Colonies (&gt;40 cells/aggregate) and clusters (3-40 cells) were scored after 7 days of incubation. 
     Three plates were scored for each sample for a statistical analysis. Each mouse was evaluated separately in groups of three mice each. Results are shown in Table II below, and are expressed as the mean ±1 standard deviation (SD). The results are derived from the averages of each of the individual mice within a group. The probability of significant differences between groups was determined by Student&#39;s t-test (two-tailed). Parentheses indicate the percent change from control. In the table, those data marked with a &#34; c  &#34; represent a significant percent change from control, p&lt;0.005 (Students t test), while those data marked with a &#34; d  &#34; represent a significant percent change from control, p&lt;0.025, and those data marked with an &#34; e  &#34; represent a significant percent change from control, p&lt;0.01. All other differences are not significantly different from control, p&gt;0.1. 
     
                                           TABLE II__________________________________________________________________________  Nucleated cells/           Absolute No.                     CFU-GM/femur × 10.sup.-3  femur × 10.sup.-6           CFU-GM colonies                     CFU-GM colonies/clusters__________________________________________________________________________control saline  25.7 ± 2.5           28.1 ± 3.7                     34.2 ± 3.1IL-8 10 ug  23.2 ± 4.7           14.6 ± 1.6 (-48.1).sup.c                     18.8 ± 1.6 (-45).sup.cIL-8 1.0 ug  21.3 ± 1.4           26.3 ± 3.9 (-6.3)                     29.5 ± 3.3 (-13.7)IL-8 0.01 ug  23.2 ± 0.4           29.5 ± 2.2 (+4.8)                     33.4 ± 2.4 (-2.5)IL-8M1 10 ug  23.0 ± 3.9           16.2 ± 2.4 (-42.4).sup.c                     19.7 ± 2.6 (-42.5).sup.cIL-8M1 1.0 ug  22.1 ± 2.4           15.6 ± 0.6 (-44.7).sup.c                     18.2 ± 1.1 (-46.8).sup.cIL-8M1 .01 ug  23.1 ± 5.4           16.9 ± 4.2 (-39.7).sup.d                     20.3 ± 4.7 (-40.7).sup.ePF4 10 ug  25.0 ± 6.7           17.1 ± 4.2 (-39.3).sup.d                     20.8 ± 5.8 (-39.3).sup.dPF4 1.0 ug  21.6 ± 1.0           29.7 ± 2.4 (+5.5)                     34.0 ± 3.0 (-0.7)PF4 0.01 ug  21.8 ± 2.1           26.8 ± 3.4 (-4.8)                     30.5 ± 4.4 (-10.8)  Nucleated cells/           Percent CFU-GM in Cycle  femur × 10.sup.-6           CFU-GM colonies                     CFU-GMcolonies/clusters__________________________________________________________________________Control saline  25.7 ± 2.5           55.0 ± 5.1                     49.1 ± 4.2IL-8 10 ug  23.2 ± 4.7           0.5 ± 2.9 (-99.1).sup.c                     2.2 ± 7.3 (-95.6).sup.cIL-8 1.0 ug  21.3 ± 1.4           48.5 ± 8.7 (-11.8)                     44.9 ± 7.3 (-8.6)IL-8 0.01 ug  23.2 ± 0.4           51.6 ± 5.9 (-6.3)                     48.1 ± 7.3 (-2.1)IL-8M1 10 ug  23.0 ± 3.9           2.2 ± 4.3 (-96.0).sup.c                     4.3 ± 4.7 (-91.3).sup.cIL-8M1 1.0 ug  22.1 ± 2.4           2.9 ± 3.0 (-94.7).sup.c                     -0.4 ± 7.0 (-100).sup.cIL-8M1 .01 ug  23.1 ± 5.4           14.7 ± 11.7 (-73.3).sup.c                     10.7 ± 9.2 (-78.3).sup.cPF4 10 ug  25.0 ± 6.7           1.5 ± 6.1 (-97.2).sup.c                     -0.3 ± 6.8 (-100).sup.cPF4 1.0 ug  21.6 ± 1.0           50.9 ± 7.6 (-7.5)                     47.9 ± 7.6 (-2.5)PF4 0.01 ug  21.8 ± 2.1           50.8 ± 5.8 (-7.6)                     46.8 ± 5.6 (-4.8)__________________________________________________________________________ 
    
     The in vivo results are shown in Table II above (and are represented in graphical form in FIGS. 7A and 7B). As shown, wild-type IL-8 and PF4 were effective at a dosage of 10 μg/mouse, but were not significantly effective at lower dosages of 1.0 or 0.01 μg/mouse. Similarly, cell cycling was completely inhibited at a dosage of 10 μg/mouse. As expected, these in vivo data confirmed the results of the in vitro assay described above. 
     The new chemokine-like protein IL-8M1, however, was effective at a dosage as low as 0.01 μg/mouse. At this dosage, progenitor cell cycling was suppressed from approximately 55% down to 14.7%+/-11.7%, for a total reduction of 73.3% compared to control. The results were similar for the two studies of absolute number of colony forming units per mouse femur (top of Table II), and the percentage of cells in the replicating cycle (bottom of Table II). 
     The results of the in vivo tests are also depicted in graphical form in FIGS. 7A and 7B. As shown in FIG. 7A, dosages of 1.0 and 0.01 μg of wild-type IL-8 and PF4 had little effect on the percentage of CFU-GM in cycle, which is normally about 50 to 55 percent. However, even at a dosage of 0.01 μg, new chemokine-like protein IL-8M1 reduced the percentage of cells in cycle to less than 15 percent, and to less than 5.0 percent at a dosage of 1.0 μg. IL-8M1 also reduced the percentage of cells in cycle to less than 5.0 percent at a dosage of 10.0 μg, as did wild-type IL-8 and PF4. 
     As shown in FIG. 7B, absolute numbers of G-M progenitor cells were also affected by the presence of chemokines. Wild-type PF4 and IL-8 decreased total cell numbers only at the 10 μg doses, while IL-8M1, being the more potent agent, inhibited the proliferation of progenitor cells at doses as low as 0.01 μg/mouse. The decrease in absolute numbers of progenitor cell in vivo indicates that cell proliferation has been inhibited, and is a good correlate of the cell cycling assay described above. 
     Uses of New Chemokine-Like Proteins 
     The new chemokine-like proteins can be used both as diagnostic and therapeutic agents. 
     Diagnostic uses 
     The subclass of progenitor cells that respond to the presence of chemokines has been shown to include a cell population which contains the cell surface marker CD34. Therefore, the new chemokine-like proteins can be used as diagnostic agents to identify CD34 +  progenitor cells in a sample population. For example, a solid substrate or matrix coated with a new chemokine-like protein can be used to separate out cells that are responsive to the protein from a sample of cells removed from a patient. After culturing or expansion of these CD34 +  cells ex vivo, these cells can be re-introduced into the patient following transplant, chemotherapy, or radiation therapy. 
     Furthermore, the new chemokine-like proteins can be used as diagnostic screening agents to identify patients with hyperproliferative diseases who would be responsive to therapy with the new chemokine-like proteins. For example, an in vitro assay, e.g., as described above, is used to test whether a particular new chemokine-like protein suppresses the proliferation of myeloid cells, e.g., leukemic cells, in a sample taken from a patient. A positive result, e.g., an inhibition of proliferation of 50 percent compared to a control, indicates that the patient can be treated using the new protein as a therapeutic agent to suppress the proliferation of myeloid leukemias. 
     Therapeutic Uses 
     The new chemokine-like proteins of the invention can be administered to a patient as adjunctive agents before and/or during chemotherapy or radiation therapy to protect myeloid progenitor cells from the cytotoxic effects of the chemotherapeutic agents or radiation. The new proteins place myeloid cells into a myeloprotected, slow-cycling state, thereby inhibiting or decreasing cell damage that could otherwise be caused by cell-cycle active chemotherapy drugs such as cytosine arabinoside, 5-fluorouracil, or hydroxyurea. The use of the new proteins also permits the administration of higher doses of chemotherapeutics without compromising the ability of the patient to generate mature functional blood cells. 
     The new chemokine-like proteins are administered to a patient in the same way as normal, wild-type chemokines are administered, e.g., injected intravenously or subcutaneously, in a pharmaceutically acceptable carrier. For example, 30% acetonitrile/0.1% trifluoroacetic acid (ACN), as suggested for MIP-1α in Cooper et al. supra, can be used as a carrier. 
     As described above, in vivo murine studies with IL-8M1 have shown that effective suppression of progenitor cell proliferation occurs at dosages of approximately 10.0 to 0.01 μg per animal, although 1.0 to 0.01 μg per animal is preferred. This translates into a dosage of approximately 0.5 to 500 μg/kg. Assuming the average human patient weighs 70 kgs, the effective amount for a human would be approximately 0.035 to 35.0 mg. Thus, a suitable dosage for therapy in a human patient would be in the range of about 0.035 to 35.0 mg, with a preferred range of about 0.5 to 5 mg. 
     Note that in chemotherapy, specific protocols may vary, and factors such as tumor size, growth rate, and location of the tumor all affect the course of adjunctive therapy with the new proteins. Administration of chemotherapeutic agents as well as the new chemokine-like proteins requires knowledge of the extent of disease, the toxicity of previous treatment courses, and the timing of the expected drug toxicity. 
     The new chemokine-like proteins also can be used to inhibit hyperproliferative myeloid based diseases such as chronic myelogenous leukemia, polycythemia vera, and hypermegakaryocytopoietic disorders. Hyperproliferative states in such disorders occur because the progenitor cells are unable to negatively regulate cell growth and replication. Administration of the new chemokine-like proteins is expected to inhibit cell replication resulting in the inhibition of the abnormal cell growth. This expected effect is based on indications that certain populations of myeloid leukemia cells are responsive to the inhibitory effects of wild-type chemokines. Dosages of chemokine-like proteins for treating hyperproliferative myeloid based diseases would be similar to those dosages described above for use of the proteins as adjuncts to chemotherapy. 
     In addition, the new chemokine-like proteins also can be used to prevent myeloid progenitor cells from becoming leukemic as the result of the administration of chemotherapeutic agents. The chemokine-like proteins are administered in the same way described above. 
     OTHER EMBODIMENTS 
     It is to be understood that while the invention has been described in conjunction with the detailed description thereof, that the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications within the scope of the invention will be apparent to those skilled in the art to which the invention pertains. 
     
         __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 46(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 72 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:SerAlaLysGluLeuArgCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysGluLeuArgValIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspProLysGluAsnTrpValGlnArgValValGluLys505560PheLeuLysArgAlaGluAsnSer6570(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 73 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:AlaSerValAlaThrGluLeuArgCysGlnCysLeuGlnThrLeuGln151015GlyIleHisProLysAsnIleGlnSerValAsnValLysSerProGly202530ProHisCysAlaGlnThrGluValIleAlaThrLeuLysAsnGlyArg354045LysAlaCysLeuAsnProAlaSerProIleValLysLysIleIleGlu505560LysMetLeuAsnSerAspLysSerAsn6570(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 73 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:AlaProLeuAlaThrGluLeuArgCysGlnCysLeuGlnThrLeuGln151015GlyIleHisLeuLysAsnIleGlnSerValAsnValLysSerProGly202530ProHisCysAlaGlnThrGluValIleAlaThrLeuLysAsnGlyGln354045LysAlaCysLeuAsnProAlaSerProMetValLysLysIleIleGlu505560LysMetGluLysAsnGlyLysSerAsn6570(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 73 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:AlaSerValValThrGluLeuArgCysGlnCysLeuGlnThrLeuGln151015GlyIleHisLeuLysAsnIleGlnSerValAsnValArgSerProGly202530ProHisCysAlaGlnThrGluValIleAlaThrLeuLysAsnGlyLys354045LysAlaCysLeuAsnProAlaSerProMetValGlnLysIleIleGlu505560LysIleLeuAsnLysGlySerThrAsn6570(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:AlaGluLeuArgCysHisCysIleLysThrThrSerGlyIleHisPro151015LysAsnIleGlnSerLeuGluValIleGlyLysGlyThrHisCysAsn202530GlnValGluValIleAlaThrLeuLysAspGlyArgLysIleCysLeu354045AspProAspAlaProArgIleLysLysIleValGlnLysLysLeuAla505560GlyAspGluSerAlaAsp6570(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:GluAlaGluGluAspGlyAspLeuGlnCysLeuCysValLysThrThr151015SerGlnValArgProArgHisIleThrSerLeuGluValIleLysAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045ArgLysIleCysLeuAspLeuGlnAlaProLeuTyrLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 77 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:ValProLeuSerArgThrValArgCysThrCysIleSerIleSerAsn151015GlnProValAsnProArgSerLeuGluLysLeuGluIleIleProAla202530SerGlnPheCysProArgValGluIleIleAlaThrMetLysLysLys354045GlyGluLysArgCysLeuAsnProGluSerLysAlaIleLysAsnLeu505560LeuLysAlaValSerLysGluMetSerLysArgSerPro657075(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 78 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:AlaGlyProAlaAlaAlaValLeuArgGluLeuArgCysValCysLeu151015GlnThrThrGlnGlyValHisProLysMetIleSerAsnLeuGlnVal202530PheAlaIleGlyProGlnCysSerLysValGluValValAlaSerLeu354045LysAsnGlyLysGluIleCysLeuAspProGluAlaProPheLeuLys505560LysValIleGlnLysIleLeuAspGlyGlyAsnLysGluAsn657075(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 81 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:GlyLysGluGluSerLeuAspSerAspLeuTyrAlaGluLeuArgCys151015MetCysIleLysThrThrSerGlyIleHisProLysAsnIleGlnSer202530LeuGluValIleGlyLysGlyThrHisCysAsnGlnValGluValIle354045AlaThrLeuLysAspGlyArgLysIleCysLeuAspProAspAlaPro505560ArgIleLysLysIleValGlnLysLysLeuAlaGlyAspGluSerAla65707580Asp(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 84 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:AsnLeuAlaLysGlyLysGluGluSerLeuAspSerAspLeuTyrAla151015GluLeuArgCysMetCysIleLysThrThrSerGlyIleHisProLys202530AsnIleGlnSerLeuGluValIleGlyLysGlyThrHisCysAsnGln354045ValGluValIleAlaThrLeuLysAspGlyArgLysIleCysLeuAsp505560ProAspAlaProArgIleLysLysIleValGlnLysLysLeuAlaGly65707580AspGluSerAla(2) INFORMATION FOR SEQ ID NO:11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 94 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:SerSerThrLysGlyGlnThrLysArgAsnLeuAlaLysGlyLysGlu151015GluSerLeuAspSerAspLeuTyrAlaGluLeuArgCysMetCysIle202530LysThrThrSerGlyIleHisProLysAsnIleGlnSerLeuGluVal354045IleGlyLysGlyThrHisCysAsnGlnValGluValIleAlaThrLeu505560LysAspGlyArgLysIleCysLeuAspProAspAlaProArgIleLys65707580LysIleValGlnLysLysLeuAlaGlyAspGluSerAlaAsp8590(2) INFORMATION FOR SEQ ID NO:12:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 78 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:HisMetGlnProAspAlaIleAsnAlaProValThrCysCysTyrAsn151015PheThrAsnArgLysIleSerValGlnArgLeuAlaSerTyrArgArg202530IleThrSerSerLysCysProLysGluAlaValIlePheLysThrIle354045ValAlaLysGluIleCysAlaAspProLysGlnLysTrpValGlnAsp505560SerMetAspHisLeuAspLysGlnThrGlnThrProLysThr657075(2) INFORMATION FOR SEQ ID NO:13:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 72 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:PheSerAlaSerLeuAlaAlaAspThrProThrAlaCysCysPheSer151015TyrThrSerArgGlnIleProGlnAsnPheIleAlaAspTyrPheGlu202530ThrSerSerGlnCysSerLysProGlyValIlePheLeuThrLysArg354045SerArgGlnValCysAlaAspProSerGluGluTrpValGlnLysTyr505560ValSerAspLeuGluLeuSerAla6570(2) INFORMATION FOR SEQ ID NO:14:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 66 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:ProTyrSerSerAspThrThrProCysCysPheAlaTyrIleAlaArg151015ProLeuAspArgAlaHisIleLysGluTyrPheTyrThrSerGlyLys202530CysSerAsnProAlaValValPheValThrArgLysAsnArgGlnVal354045CysAlaAsnProGluLysLysTrpTyrArgGluTyrIleAsnSerLeu505560GluMet65(2) INFORMATION FOR SEQ ID NO:15:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 65 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:GlySerAspProProThrAlaCysCysPheSerTyrThrAlaArgLys151015LeuProArgAsnPheValValAspTyrTyrGluThrSerSerLeuCys202530SerGlnProAlaValValPheGlnThrLysArgSerLysGlnValCys354045AlaAspProSerGluSerTrpValGlnGluTyrValTyrAspLeuGlu505560Leu65(2) INFORMATION FOR SEQ ID NO:16:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 72 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:16:SerAlaLysAspLeuGlnCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysGluLeuArgValIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspProLysGluAsnTrpValGlnArgValValGluLys505560PheLeuLysArgAlaGluAsnSer6570(2) INFORMATION FOR SEQ ID NO:17:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 72 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:17:SerAlaLysGluLeuArgCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysGluTyrArgArgIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspProLysGluAsnTrpValGlnArgValValGluLys505560PheLeuLysArgAlaGluAsnSer6570(2) INFORMATION FOR SEQ ID NO:18:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 72 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:18:SerAlaLysGluLeuArgCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysLeuGluArgValIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspProLysGluAsnTrpValGlnArgValValGluLys505560PheLeuLysArgAlaGluAsnSer6570(2) INFORMATION FOR SEQ ID NO:19:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 72 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:19:SerAlaLysGluLeuArgCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysGluLeuArgAlaIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspProLysGluAsnTrpValGlnArgValValGluLys505560PheLeuLysArgAlaGluAsnSer6570(2) INFORMATION FOR SEQ ID NO:20:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 68 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:20:SerAlaLysGluLeuArgCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysGluLeuArgValIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspLeuGlnAlaProLeuTyrLysLysIleIleLysLys505560LeuLeuGluSer65(2) INFORMATION FOR SEQ ID NO:21:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 64 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:21:SerAlaLysGluLeuArgCysGlnCysIleLysThrTyrSerLysPro151015PheHisProLysPheIleLysGluLeuArgValIleGluSerGlyPro202530HisCysAlaAsnThrGluIleIleValLysLeuSerAspGlyArgGlu354045LeuCysLeuAspProLysGluAsnTrpValGlnArgValValGluLys505560(2) INFORMATION FOR SEQ ID NO:22:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 67 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:22:SerAlaLysGluLeuArgCysGlnCysValLysThrThrSerGlnVal151015ArgProArgHisIleThrSerLeuGluValIleLysAlaGlyProHis202530CysProThrAlaGlnLeuIleAlaThrLeuLysAsnGlyArgLysIle354045CysLeuAspLeuGlnAlaProLeuTyrLysLysIleIleLysLysLeu505560LeuGluSer65(2) INFORMATION FOR SEQ ID NO:23:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:23:GluAlaGluGluAspGlyAspLeuArgCysLeuCysValLysThrThr151015SerGlnValArgProArgHisIleThrSerLeuGluValIleLysAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045ArgLysIleCysLeuAspLeuGlnAlaProLeuTyrLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:24:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:24:GluAlaGluGluAspGlyAspLeuGlnCysLeuCysValLysThrThr151015SerGlnValArgProArgHisIleThrSerLeuGluValIleLysAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045ArgLysLeuCysLeuAspProLysGluAsnTrpValLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:25:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:25:GluAlaGluGluAspGlyAspLeuGlnCysLeuCysValLysThrThr151015SerGlnValArgProArgHisIleThrSerLeuGluValIleLysAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045ArgLysIleCysLeuAspProAspAlaProArgIleLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:26:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:26:GluAlaGluGluAspGlyAspLeuGlnCysLeuCysValLysThrThr151015SerGlnValArgProArgHisIleThrSerLeuGluValIleLysAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045ArgLysAlaCysLeuAsnProAlaSerProIleValLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:27:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:27:GluAlaGluGluAspGlyAspLeuGlnCysLeuCysValLysThrThr151015SerGlnValArgProArgHisIleLysGluLeuArgValIleGluAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045ArgLysIleCysLeuAspLeuGlnAlaProLeuTyrLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:28:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:28:GluAlaGluGluAspGlyAspLeuGlnCysLeuCysValLysThrThr151015SerGlnValGlnProGlnHisIleThrSerLeuGluValIleLysAla202530GlyProHisCysProThrAlaGlnLeuIleAlaThrLeuLysAsnGly354045GlnLysIleCysLeuAspLeuGlnAlaProLeuTyrLysLysIleIle505560LysLysLeuLeuGluSer6570(2) INFORMATION FOR SEQ ID NO:29:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 439 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:29:CCGCAGCATGAGCTCCGCAGCCGGGTTCTGCGCCTCACGCCCCGGGCTGCTGTTCCTGGG60GTTGCTGCTCCTGCCACTTGTGGTCGCCTTCGCCAGCGCTGAAGCTGAAGAAGATGGGGA120CCTGCAGTGCCTGTGTGTGAAGACCACCTCCCAGGTCCGTCCCAGGCACATCACCAGCCT180GGAGGTGATCAAGGCCGGACCCCACTGCCCCACTGCCCAACTGATAGCCACGCTGAAGAA240TGGAAGGAAAATTTGCTTGGACCTGCAAGCCCCGCTGTACAAGAAAATAATTAAGAAACT300TTTGGAGAGTTAGCTACTAGCTGCCTACGTGTGTGCATTTGCTATATAGCATACTTCTTT360TTTCCAGTTTCAATCTAACTGTGAAAGAAACTTCTGATATTTGTGTTATCCTTATGATTT420TAAATAAACAAAATAAATC439(2) INFORMATION FOR SEQ ID NO:30:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 57 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:30:GAAGCTGAAGAAGATGGGGACCTGCAGTGCCTGTGTGTGAAGACCACCTCCCAGGTC57(2) INFORMATION FOR SEQ ID NO:31:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 100 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:31:CGTGGCTATCAGTTGGGCAGTGGGGCAGTGGGGTCCGGCCTTGATCACCTCCAGGCTGGT60GATGTGCCTGGGACGGACCTGGGAGGTGGTCTTCACACAC100(2) INFORMATION FOR SEQ ID NO:32:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 99 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:32:CTGCCCCACTGCCCAACTGATAGCCACGCTGAAGAATGGAAGGAAAATTTGCTTGGACCT60GCAAGCCCCGCTGTACAAGAAAATAATTAAGAAACTTTT99(2) INFORMATION FOR SEQ ID NO:33:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 40 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:33:CTAACTCTCCAAAAGTTTCTTAATTATTTTCTTGTACAGC40(2) INFORMATION FOR SEQ ID NO:34:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 204 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:34:ATGAGTGCTAAAGAACTTAGATGTCAGTGCGTGAAGACCACCTCCCAGGTCCGTCCCAGG60CACATCACCAGCCTGGAGGTGATCAAGGCCGGACCCCACTGCCCCACTGCTCAGCTGATA120GCCACGCTGAAGAATGGAAGGAAAATTTGCTTGGACCTGCAAGCCCCGCTGTACAAGAAA180ATAATTAAGAAACTTTTGGAGAGT204(2) INFORMATION FOR SEQ ID NO:35:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 57 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:35:ATGAGTGCTAAAGAACTTAGATGTCAGTGCGTGAAGACCACCTCCCAGGTCCGTCCC57(2) INFORMATION FOR SEQ ID NO:36:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 219 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:36:ATGAGTGCTAAAGAACTTAGATGTCAGTGCATAAAGACATACTCCAAACCTTTCCACCCC60AAATTTATCAAAGAACTGAGAGTGATTGAGAGTGGACCACACTGCGCCAACACAGAAATT120ATTGTAAAGCTTTCTGATGGAAGAGAGCTCTGTCTGGACCCCAAGGAAAACTGGGTGCAG180AGGGTTGTGGAGAAGTTTTTGAAGAGGGCTGAGAATTCA219(2) INFORMATION FOR SEQ ID NO:37:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 59 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:37:ATGAGTGCTAAAGAACTTAGATGTCAGTGCATAAAGACATACTCCAAACCTTTCCACCC59(2) INFORMATION FOR SEQ ID NO:38:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 99 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:38:CCATCAGAAAGCTTTACAATAATTTCTGTGTTGGCGCAGTGTGGTCCACTCTCAATCACT60CTCAGTTCTTTGATAAATTTGGGGTGGAAAGGTTTGGAG99(2) INFORMATION FOR SEQ ID NO:39:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 99 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:39:AACACAGAAATTATTGTAAAGCTTTCTGATGGAAGAGAGCTCTGTCTGGACCCCAAGGAA60AACTGGGTGCAGAGGGTTGTGGAGAAGTTTTTGAAGAGG99(2) INFORMATION FOR SEQ ID NO:40:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 37 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:40:TGAATTCTCAGCCCTCTTCAAAAACTTCTCCACAACC37(2) INFORMATION FOR SEQ ID NO:41:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 219 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:41:ATGAGTGCTAAAGACCTGCAGTGTCAGTGCATAAAGACATACTCCAAACCTTTCCACCCC60AAATTTATCAAAGAACTGAGAGTGATTGAGAGTGGACCACACTGCGCCAACACAGAAATT120ATTGTAAAGCTAAGCGATGGAAGAGAGCTGTGTCTGGACCCCAAGGAAAACTGGGTGCAG180AGGGTTGTGGAGAAGTTTTTGAAGAGGGCTGAGAATTCA219(2) INFORMATION FOR SEQ ID NO:42:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 47 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:42:ATGAGTGCTAAAGACCTGCAGTGTCAGTGCATAAAGACATACTCCAA47(2) INFORMATION FOR SEQ ID NO:43:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 9 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:43:IleAlaThrLeuLysAsnGlyGlnLys15(2) INFORMATION FOR SEQ ID NO:44:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:44:AlaCysLeuAsnProAlaSerProIleValLys1510(2) INFORMATION FOR SEQ ID NO:45:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 10 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:45:MetSerAlaLysGluLeuArgCysGlnCys1510(2) INFORMATION FOR SEQ ID NO:46:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 12 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(xi) SEQUENCE DESCRIPTION: SEQ ID NO:46:GluAlaGluGluAspGlyAspLeuGlnCysLeuGln1510__________________________________________________________________________
The invention relates to novel chemokine-like proteins that include two or more newly discovered active domains from different chemokines. Active domains are regions of several contiguous amino acids that are necessary for chemokines' ability to suppress the proliferation of actively dividing myeloid cells, e.g., myeloid progenitor cells, myeloid stem cells, and leukemic cells. The new chemokine-like proteins provide higher myelosuppressive activity than naturally occurring, wild-type chemokines.