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During the activation of lymphocytes, co-stimulation is often crucial to the development of an effective immune response. Co-stimulation is required in addition to the antigen-specific signal from their antigen receptors.〔Janeway CA, Travers P, Walport M, Shlomchik M (2001). ''Immunobiology 5 : The Immune System in Health and Disease, 5th ed.'' New York: Garland Pub., ISBN 0-8153-3642-X〕 == T Cell Co-stimulation == T cells require two signals to become fully activated. A first signal, which is antigen-specific, is provided through the T cell receptor which interacts with peptide-MHC molecules on the membrane of antigen presenting cells (APC). A second signal, the co-stimulatory signal, is antigen nonspecific and is provided by the interaction between co-stimulatory molecules expressed on the membrane of APC and the T cell. One of the best characterized costimulatory molecules expressed by T cells is CD28, which interacts with CD80 (B7.1) and CD86 (B7.2) on the membrane of APC. Another costimulatory receptor expressed by T cells is ICOS ( Inducible Costimulator), which interacts with ICOS-L. T cell co-stimulation is necessary for T cell proliferation, differentiation and survival. Activation of T cells without co-stimulation may lead to T cell anergy, T cell deletion or the development of immune tolerance. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「costimulation」の詳細全文を読む スポンサード リンク
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