Rozendaal L, Pals S T, Schilham M, Melief C J, Gleichmann E
Central Laboratory, the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Eur J Immunol. 1989 Sep;19(9):1669-75. doi: 10.1002/eji.1830190922.
An acute graft-vs.-host reaction (GVHR) was induced by i.v. injection of 10(8) lymphoid cells from C57BL/10 (B10) donors (H-2b/b) into adult non-irradiated (B10 X DBA/2)F1 mice (H-2b/d). Previous experiments have established that spleen cells obtained from such GVHF1 mice suppress the primary antibody response of normal F1 spleen cells to sheep red blood cells. This type of suppression was termed "allosuppression", and it was shown to be mediated by Ly-2+ T cells of donor origin that react against H-2 antigens of the host. It was unclear, however, whether the actual mechanism of allosuppression was due to suppressive factors generated by donor T cells or whether the latter killed the F1 B cells. Here, we show that for their suppressive effect GVHF1 spleen cells need direct cell contact with F1 spleen cells; no suppressive effect was measured in a double-chamber culture system in which the GVHF1 spleen cells were separated from the responding normal F1 spleen cells by a cell-tight membrane filter. The suppressive effect only affected cells expressing the appropriate H-2 class I alloantigen; in mixed cultures of irradiated F1 spleen cells and GVHF1 spleen cells with third-party B cells the antibody response of the third-party B cells was not suppressed. GVHF1 spleen cells showed cytotoxic T lymphocyte (CTL) activity specific for the allogeneic F1 H-2 antigen. The suppressive effect of the GVHF1 spleen cells did not differ from that exerted by cloned CTL specific for MHC class I alloantigens; cloned CTL suppressed the primary antibody response of murine spleen cells without affecting the response of third-party B cells added to the cultures. The combined findings show that "allosuppression" in vitro is not due to suppression of F1B cells, but to a direct killing of these cells by alloreactive CTL.
通过静脉注射来自C57BL/10（B10）供体（H-2b/b）的10⁸个淋巴细胞，诱导成年未受照射的（B10×DBA/2）F1小鼠（H-2b/d）发生急性移植物抗宿主反应（GVHR）。先前的实验已证实，从此类发生GVH的F1小鼠获得的脾细胞可抑制正常F1脾细胞对绵羊红细胞的初次抗体反应。这种抑制类型被称为“同种异体抑制”，并且已表明它是由供体来源的Ly-2⁺T细胞介导的，这些T细胞针对宿主的H-2抗原发生反应。然而，尚不清楚同种异体抑制的实际机制是由于供体T细胞产生的抑制因子，还是由于后者杀死了F1 B细胞。在此，我们表明，为发挥其抑制作用，发生GVH的F1脾细胞需要与F1脾细胞直接接触；在双室培养系统中未检测到抑制作用，在该系统中，发生GVH的F1脾细胞通过细胞紧密的膜滤器与反应性正常F1脾细胞分离。抑制作用仅影响表达适当H-2 I类同种异体抗原的细胞；在受照射的F1脾细胞与发生GVH的F1脾细胞和第三方B细胞的混合培养物中，第三方B细胞的抗体反应未受到抑制。发生GVH的F1脾细胞表现出对同种异体F1 H-2抗原具有特异性的细胞毒性T淋巴细胞（CTL）活性。发生GVH的F1脾细胞的抑制作用与针对MHC I类同种异体抗原的克隆CTL所发挥的抑制作用没有差异；克隆CTL抑制小鼠脾细胞的初次抗体反应，而不影响添加到培养物中的第三方B细胞的反应。综合研究结果表明，体外的“同种异体抑制”不是由于对F1 B细胞的抑制，而是由于同种反应性CTL对这些细胞的直接杀伤。
