Vyakarnam A, Lachmann P J, Sia D Y
Mechanisms in Tumour Immunity Unit, MRC Centre, Cambridge, UK.
Scand J Immunol. 1988 Mar;27(3):337-46. doi: 10.1111/j.1365-3083.1988.tb02355.x.
This paper reports on the characteristics of killing by a human and a murine tuberculin (PPD)-specific T helper clone of targets to which PPD was attached via the lectin concanavalin A (Con A). The killing was specific for PPD from M. tuberculosis; and targets coupled to Con A alone or to PPD from M. paratuberculosis were not killed. Target cells carrying Con A-PPD were more effectively lysed than PPD-pulsed cells. This form of lymphocyte killing, though highly significant, was inefficient. Maximum killing of PPD carrying targets was 30-40% at effector to target ratios of 20:1 and at 16 h. Cells carrying 2 x 10(6) molecules of PPD and less than 1.5 x 10(6) molecules Con A per cell were killed most efficiently. A major distinction between this helper T cell killing and that mediated by cytotoxic T cells was that both TH clones displayed bystander lysis and killed PPD uncoupled targets when these were cultured with syngeneic PPD-bound targets. This suggests that the mechanism of cytotoxicity may involve soluble mediators.
本文报道了人源和鼠源结核菌素（PPD）特异性T辅助细胞克隆对通过凝集素伴刀豆球蛋白A（Con A）连接PPD的靶细胞的杀伤特性。这种杀伤作用对结核分枝杆菌的PPD具有特异性；单独与Con A连接或与副结核分枝杆菌的PPD连接的靶细胞未被杀伤。携带Con A-PPD的靶细胞比PPD脉冲处理的细胞更有效地被裂解。这种淋巴细胞杀伤形式虽然非常显著，但效率不高。在效应细胞与靶细胞比例为20:1且作用16小时时，携带PPD的靶细胞的最大杀伤率为30 - 40%。每个细胞携带2×10⁶个PPD分子且Con A分子少于1.5×10⁶个的细胞被杀伤得最有效。这种辅助性T细胞杀伤与细胞毒性T细胞介导的杀伤之间的一个主要区别在于，两个TH克隆都表现出旁观者裂解作用，并且当与同基因PPD结合的靶细胞一起培养时，会杀伤未偶联PPD的靶细胞。这表明细胞毒性机制可能涉及可溶性介质。
