Raulet D H, Bevan M J
J Exp Med. 1982 Jun 1;155(6):1766-84. doi: 10.1084/jem.155.6.1766.
We investigated the antigenic requirements for restimulation of H-2- restricted cytolytic T lymphocytes (CTL) in vitro to determine whether H-2 I region-restricted helper T cells are required in these responses. In one set of experiments, we studied the in vitro response of (responder x nonresponder)F(1) female T cells to the male antigen H-Y. We chose to examine this response because it has been suggested that the defect in nonresponder strains is a failure of helper T cells to recognize H-Y in association with nonresponder I region determinants. However, we find that nonresponder male stimulator cells are as effective as F(1) male stimulator cells at inducing H-Y-specific CTL responses. This finding calls into question reports that secondary CTL responses to H-Y are dependent upon the activation of H-Y- specific helper T cells restricted to responder type I region determinants. In a second set of experiments, we examined the requirements for restimulation of H-2-restricted T cells specific for minor-histocompatibility antigens from long-term mixed lymphocyte cultures. These cultures were established by repeatedly restimulating cultures of specific T cells with H- 2-matched stimulator cells expressing foreign minor histocompatibility antigens. We found that H-2D-restricted T ceils, including CTL, could be restimulated with cells that were matched with the responding cells at only the D region genes. This response did not appear to result from positive allogeneic effects or from antigen processing and "representation" by responder type APC that might contaminate the cultures. Thus, we find no evidence for a requirement for I region-restricted helper T cells in these CTL responses. However, helper T cells are required because we find that CTL lines derived by limit-dilution cloning from these long-term MLC are absolutely dependent upon exogenous helper factors for growth. The most simple interpretation of these results is that the helper cells are restricted to H-2 antigens other than I region antigens or to antigens that code outside of the H-2 complex. Finally, we show that factor-dependent CTL lines must recognize their specific antigen to proliferate, even in the presence of exogenous factors. The requirement of activated CTL for antigen to proliferate provides an explanation for how specific CTL can be selectively enriched in MLC by specific antigen stimulation. Furthermore, it is at variance with reports that memory CTL or activated CTL require only interleukin 2 for restimulation.
我们研究了体外再次刺激H-2限制性细胞溶解T淋巴细胞（CTL）的抗原需求，以确定这些反应中是否需要H-2 I区限制性辅助性T细胞。在一组实验中，我们研究了（应答者×非应答者）F1雌性T细胞对雄性抗原H-Y的体外反应。我们选择研究这种反应是因为有人提出非应答者品系的缺陷在于辅助性T细胞无法识别与非应答者I区决定簇相关联的H-Y。然而，我们发现非应答者雄性刺激细胞在诱导H-Y特异性CTL反应方面与F1雄性刺激细胞一样有效。这一发现对关于H-Y的二次CTL反应依赖于受应答者I区决定簇限制的H-Y特异性辅助性T细胞激活的报道提出了质疑。在第二组实验中，我们研究了长期混合淋巴细胞培养物中针对次要组织相容性抗原的H-2限制性T细胞再次刺激的需求。这些培养物是通过用表达外来次要组织相容性抗原的H-2匹配刺激细胞反复刺激特异性T细胞培养物而建立的。我们发现，包括CTL在内的H-2D限制性T细胞可以用仅在D区基因与应答细胞匹配的细胞进行再次刺激。这种反应似乎不是由阳性同种异体效应或可能污染培养物的应答者型抗原呈递细胞的抗原加工和“呈递”导致的。因此，我们没有发现这些CTL反应需要I区限制性辅助性T细胞的证据。然而，辅助性T细胞是必需的，因为我们发现从这些长期混合淋巴细胞培养物中通过有限稀释克隆获得的CTL系的生长绝对依赖于外源性辅助因子。对这些结果最简单的解释是，辅助性细胞受限于I区抗原以外的H-2抗原或H-2复合体外编码的抗原。最后，我们表明，即使存在外源性因子，依赖因子的CTL系增殖也必须识别其特异性抗原。活化的CTL增殖需要抗原，这就解释了特异性CTL如何通过特异性抗原刺激在混合淋巴细胞培养物中被选择性富集。此外，这与记忆性CTL或活化的CTL再次刺激仅需要白细胞介素2的报道不一致。
