Rubens R P, Henney C S
J Immunol. 1977 Jan;118(1):180-6.
Alloimmune spleen cells (C57BL/6 anti P815), but not normal spleen cells, lyse syngeneic (EL4) target cells in the presence of Con A. Con A dependent cytotoxicity was mediated by T cells and required the continued presence of lectin. Cytolysis in the presence of a succinylated derivative was equivalent to that seen with the parent Con A molecule. In contrast to previous reports of Con A dependent cytolysis, however, we conclude that lysis is not primarily caused by directly cytotoxic T cells. The reasons for this conclusion are: 1. Removal of directly cytotoxic cells by adsorption on P815 monolayers did not alter the Con A dependent cytolysis of EL4 cells; 2. Populations in which no direct T killers were demonstrable (e.g., spleen cells harvested 5 days after alloimmunization) lysed both P815 and EL4 cells in the presence of Con A; and 3. Con A dependent cytolysis, but not direct cytotoxicity, could be induced by culturing normal C57BL/6 spleen cells for 4 days with a sonicated extract of P815 cells. We hypothesize that the cell "activated" to lyse targets in the presence of Con A is a T cell which has differentiated lytic potential following alloantigenic stimulation, but has either insufficient density or affinity of antigen receptors to serve as a directly cytotoxic cell. The role of Con A is viewed as 2-fold: i) to "bridge" killer and target cell, and ii) to "activate" the effector.
同种异体免疫脾细胞（C57BL/6抗P815），而非正常脾细胞，在伴刀豆球蛋白A（Con A）存在的情况下可裂解同基因（EL4）靶细胞。Con A依赖性细胞毒性由T细胞介导，且需要凝集素持续存在。在琥珀酰化衍生物存在的情况下的细胞溶解作用与亲本Con A分子所观察到的相当。然而，与先前关于Con A依赖性细胞溶解的报道相反，我们得出结论，细胞溶解并非主要由直接细胞毒性T细胞引起。得出这一结论的原因如下：1. 通过吸附于P815单层细胞上去除直接细胞毒性细胞，并未改变EL4细胞的Con A依赖性细胞溶解作用；2. 无法证明存在直接T杀伤细胞的细胞群体（例如，同种异体免疫后5天收获的脾细胞）在Con A存在的情况下可裂解P815和EL4细胞；3. 通过用P815细胞的超声提取物培养正常C57BL/6脾细胞4天，可诱导Con A依赖性细胞溶解作用，但不能诱导直接细胞毒性。我们推测，在Con A存在的情况下被“激活”以裂解靶细胞的细胞是一种T细胞，其在同种异体抗原刺激后已分化出溶解潜力，但抗原受体的密度或亲和力不足，无法作为直接细胞毒性细胞发挥作用。Con A的作用被认为有两方面：i）“桥接”杀伤细胞和靶细胞，ii）“激活”效应细胞。
