The roles of CD4 and CD8 in T cell activation.
The roles of CD4 and CD8 in T cell activation.
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DOI：
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发表时间：
1991-05
影响因子：
7.8
通讯作者：
M. Miceli;J. Parnes
中科院分区：
文献类型：
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作者：
M. Miceli;J. Parnes
CD 4和CD 8 T细胞表面分子通过与抗原呈递细胞（APC）上的它们各自的II类和I类主要组织相容性复合体（MHC）配体结合而在T细胞识别和活化中起作用。虽然CD 4和CD 8能够在T细胞受体（TCR）不存在的情况下与MHC分子结合，但越来越多的证据表明，它们可能主要通过与TCR复合以形成用于识别抗原结合的MHC的“辅助受体”来发挥作用。使用基因转移研究，我们已经证明，CD 4和CD 8可以增加抗原诱导的IL-2的生产，通过不同的机制取决于他们是否可以结合MHC独立的TCR或与TCR复合。在CD 4和CD 8可以结合与TCR相同的MHC配体的情况下，它们通过在很大程度上依赖于它们的胞质尾的机制最大程度地增强抗原诱导的IL-2产生。抗原诱导的IL-2产生的增强也可以在CD 4和CD 8结合在不同于TCR识别的MHC配体上的情况下发生。在这种情况下，这种增强的幅度不是那么大，似乎（至少对于CD 8）是独立的胞质尾区和相关的p56 lck。共受体功能对CD 4或CD 8胞质尾区的依赖性可能反映了相关细胞内酪氨酸激酶p56 lck的活性。（250字处删节）
CD4 and CD8 T cell surface molecules play a role in T cell recognition and activation by binding to their respective class II and class I major histocompatibility complex (MHC) ligands on an antigen presenting cell (APC). Though CD4 and CD8 are capable of binding to MHC molecules in the absence of the T cell receptor (TCR), increasing evidence suggests that they may primarily function by complexing with the TCR to form a 'co-receptor' for recognition of antigen-bound MHC. Using gene transfer studies we have demonstrated that CD4 and CD8 can augment antigen-induced IL-2 production through different mechanisms dependent on whether or not they can bind MHC independently of the TCR or complexed with the TCR. Under circumstances where CD4 and CD8 can bind to the same MHC ligand as the TCR, they potentiate antigen-induced IL-2 production maximally by a mechanism in large part dependent on their cytoplasmic tails. Enhancement of antigen-induced IL-2 production can also occur under circumstances where CD4 and CD8 bind on MHC ligand distinct from that recognized by the TCR. In this instance, the magnitude of this enhancement is not as great and appears (at least for CD8) to be independent of the cytoplasmic tail and the associated p56lck. The dependence of co-receptor function on the cytoplasmic tail of CD4 or CD8 may reflect the activity of the associated intracellular tyrosine kinase p56lck.(ABSTRACT TRUNCATED AT 250 WORDS)