Apasov S, Redegeld F, Sitkovsky M
Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Curr Opin Immunol. 1993 Jun;5(3):404-10. doi: 10.1016/0952-7915(93)90060-6.
The list of cells with cytotoxic potential now may include small resting T cells, but the exact nature of 'lethal hit delivery' by cytotoxic T lymphocytes remains elusive. Cell-mediated cytotoxicity by cytotoxic T lymphocytes is a complex, multistep process which seems likely to be mediated by several different pathways. Recent experimental evidence for the functioning of a novel cytotoxic mechanism through a target cell's surface receptor illustrates and emphasizes the necessity to study the interactions of cytotoxic T lymphocytes and target cells as a whole. Progress is evident in the description of molecular requirements for triggering cytotoxicity, cell-cell contacts and the regulation of the effector responses of cytotoxic T lymphocytes by extracellular, intracellular and granular proteins. Extracellular Ca(2+)-dependent secretion of perforin and protease(s) may explain several aspects of cellular cytotoxicity, whereas the apoptosis-mediating cell surface Fas protein is now implicated in Ca(2+)-independent cytotoxicity.
现在，具有细胞毒性潜能的细胞列表可能包括静止的小T细胞，但细胞毒性T淋巴细胞“致命一击传递”的确切性质仍然难以捉摸。细胞毒性T淋巴细胞介导的细胞毒性是一个复杂的多步骤过程，似乎可能由几种不同的途径介导。最近关于通过靶细胞表面受体发挥作用的新型细胞毒性机制的实验证据表明并强调了将细胞毒性T淋巴细胞与靶细胞的相互作用作为一个整体进行研究的必要性。在描述触发细胞毒性的分子要求、细胞间接触以及细胞外、细胞内和颗粒蛋白对细胞毒性T淋巴细胞效应反应的调节方面取得了明显进展。穿孔素和蛋白酶的细胞外Ca(2+)依赖性分泌可能解释细胞毒性的几个方面，而介导凋亡的细胞表面Fas蛋白现在与Ca(2+)非依赖性细胞毒性有关。
