The role of mitogenic lectins in T-cell triggering
The role of mitogenic lectins in T-cell triggering
复制标题
有丝分裂凝集素在 T 细胞触发中的作用
作者：
E. Larsson;A. Coutinho
T淋巴细胞的激活过程需要代谢活跃的非θ辅助细胞的参与。正如Habu和Raff2首次确凿地证明的那样，这一要求也适用于凝集素依赖的触发。因此，有丝分裂凝集素对T细胞的激活依赖于是否存在la阳性的非T细胞3，4。仅是刀豆蛋白A(ConA)等凝集素与T细胞表膜的结合并不能触发细胞经历有丝分裂周期。这只能通过ConA刺激的细胞培养的条件培养液(CM)中存在的生长因子的活性来实现。然而，这种生长因子不能激活正常的、静止的T细胞，尽管它们有能力在无限期的时间内保持激活的T细胞的指数增长。因此，要想有丝分裂，凝集素不仅必须诱导T细胞生长因子的原位产生，还必须使静止的T细胞对这些生长因子的有丝分裂活性敏感。在这篇报道中，我们证明了ConA与纯化的T细胞的结合可以在相对较短的时间内改变它们对生长因子的功能敏感性，即使这种结合不足以刺激它们增殖。
THE process of T-lymphocyte activation requires the participation of metabolically active non-θ-bearing accessory cells1. As first conclusively shown by Habu and Raff2, this requirement is also true of lectin-dependent triggering. Thus, T-cell activation by mitogenic lectins depends on the presence of la-positive non-T cells3,4. The mere binding of lectins such as concanavalin A (Con A) to the surface membrane of T cells does not trigger the cells to go through the mitotic cycle. This can only be achieved by the activity of growth factors present in conditioned media (CM) from Con A-stimulated cell cultures5. Such growth factors, however, cannot activate normal, resting T cells, although they are competent to maintain activated T cells in exponential growth for indefinite periods of time6. Hence, to be mitogenic a lectin must not only induce the in situ production of T-cell growth factors, but must also render resting T cells sensitive to the mitogenic activity of these growth factors. In this report we demonstrate that the binding of Con A to purified T cells can in a relatively short time, modify their functional sensitivity to growth factors, even though this binding is not sufficient to stimulate them to proliferate.