BIOL 1010U Lecture Notes - Leprosy, Natural Killer Cell, Humoral Immunity
Document Summary
T cell effector i: cd4 + t cells and cytokines. Antigen recognition of mhc/ag on apc does not occur at site of entry, but usually in lymph nodes/spleen. Activated t cells then migrate to target tissues. T cells then engage cells expressing appropriate ag/mhc to exert functions (release interleukins) T cell subsets distinguished by mhc recognized and cytokines produce dictate effector functions. Il2r complex of that associate non-covalently to cell surface essential for immune function, as chains are involved in many ilr"s. Note: activation upregulates to make high affinity complex. Already exists but is slow on slow off. Il2 is not absolutely necessary b/c other cytokines can replace function. But chain is b/c it is shared by the other cytokines. Il7 growth factor for immature t cells (cd4-, cd8-) in thymus produced by thymus stromal cells. Ilr"s are coupled to tyrosine kinases to initiate signaling cascade. Ligand binding initiates receptor clustering to activate intracellular cytoplasmic tyrosine kinase.
