Guerder S, Carding S R, Flavell R A
Section of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
J Immunol. 1995 Dec 1;155(11):5167-74.
B7-CD28 costimulation is essential for the activation of CD4+ T helper cells, mainly by regulating IL-2 and other cytokine production. The requirement for this costimulatory pathway in the activation of CD8+ T cells, however, is still poorly understood. Here we analyzed the role of B7-CD28 costimulation in the differentiation of Ag-specific CTL precursor. We found that the activation of not only IL-2 production but also cytotoxic function in CD8 T cells requires B7 costimulation. The costimulatory signal, which cannot be replaced by exogenous IL-2, is directly implicated in the activation of the lytic machinery in CD8 T cells. Moreover, B7-CD28 costimulation appears to play a critical role in the accumulation of mRNA encoding at least one of the granzymes required for cytolytic function, granzyme B or CTLA-1. The production of IFN-gamma by CD8 T cells, however, does not appear to require costimulation.
B7 - CD28共刺激对于CD4 + T辅助细胞的激活至关重要，主要是通过调节白细胞介素-2（IL-2）和其他细胞因子的产生来实现。然而，对于这条共刺激途径在CD8 + T细胞激活中的需求仍了解甚少。在此，我们分析了B7 - CD28共刺激在抗原特异性CTL前体分化中的作用。我们发现，CD8 + T细胞中不仅IL-2的产生需要激活，其细胞毒性功能的激活也需要B7共刺激。这种共刺激信号不能被外源性IL-2替代，它直接参与CD8 + T细胞溶细胞机制的激活。此外，B7 - CD28共刺激似乎在编码细胞溶解功能所需的至少一种颗粒酶（颗粒酶B或CTLA-1）的mRNA积累中起关键作用。然而，CD8 + T细胞产生γ干扰素（IFN-γ）似乎不需要共刺激。
