<prompt> Cytotoxic T lymphocytes CTLs:Recognize the same antigens as CD4 T cellsSecrete cytokines that stimulate the differentiation and proliferation of B cellsAre impoant in the control of viral infectionsMost often recognize antigens that have been phagocytosed, degraded, and presented on the surface of an APC  <response>: Cytotoxic CD8 T cells recognize peptides derived from antigens synthesized within the cell when presented by MHC class I molecules. This mechanism allows presentation of peptides derived from viruses. Also Know: Cytotoxic cytolytic T lymphocytes are also specific effectors of the cellular immune response, paicularly against virus-infected cells. In this example, a virus e.g., influenza virus is inhaled and infects a cell of the respiratory tract. Viral envelope glycoproteins appear on the surface of the infected cell in association with class I MHC proteins. A cytotoxic T cell binds its antigen-specific receptor to the viral antigen-class I MHC protein complex and is stimulated to grow into a clone of cells by interleukin-2 produced by helper T cells. These cytotoxic T cells specifically kill influenza virus-infected cells and not cells infected by other viruses by recognizing viral antigen-class I MHC protein complexes on the cell surface and releasing perforins that destroy the membrane of the infected cell. Ref: Levinson W. 2012. Chapter 57. Immunity. In W. Levinson Ed, Review of Medical Microbiology Immunology, 12e. 