Green J M, Thompson C B
Department of Medicine, University of Chicago, Ill., USA.
Immunol Res. 1994;13(4):234-43. doi: 10.1007/BF02935615.
Antigen-specific activation of the T cell is accomplished by engagement of the T cell receptor (TCR) by an antigen (Ag)/MHC complex presented on the surface of an antigen- presenting cell (APC). However, it has been demonstrated that engagement of the TCR by Ag/HC complexes alone is normally insufficient to lead to a proliferative response and the development of effector function. Thus it has been proposed that the APC also provides additional signals which serve to modulate the T cell's response. These second or costimulatory signals are thought to be critical in the generation of a T cell-driven immune response. Several receptors have been proposed to be capable of serving as costimulatory receptors. Candidate molecules include CD28 and LFA-1 as well as other receptors. In this review the studies that we have performed to clarify the role of both LFA-1 and CD28 in providing costimulatory activity for T cell activation are discussed. In addition, we present evidence that under certain conditions, TCR signalling alone can be sufficient to lead to T cell proliferation.
T细胞的抗原特异性激活是通过抗原呈递细胞（APC）表面呈现的抗原（Ag）/MHC复合物与T细胞受体（TCR）结合来实现的。然而，已经证明仅Ag/HC复合物与TCR结合通常不足以导致增殖反应和效应功能的发展。因此，有人提出APC还提供额外的信号来调节T细胞的反应。这些第二信号或共刺激信号被认为在T细胞驱动的免疫反应的产生中至关重要。已经提出几种受体能够作为共刺激受体。候选分子包括CD28和LFA-1以及其他受体。在这篇综述中，我们讨论了为阐明LFA-1和CD28在为T细胞激活提供共刺激活性方面的作用而进行的研究。此外，我们提供证据表明在某些条件下，仅TCR信号就足以导致T细胞增殖。
