一种细胞接触性抗原特异性抑制信号

A novel cell-contact antigen-specific inhibitory signal(CASIS)

目的 在该实验工作中 ,我们将报道一种在混合淋巴细胞反应 (MLR)系统中产生的一种新的细胞接触性抗原特异性抑制信号 (CASIS) ,此信号可阻碍外周血淋巴细胞 (PBL)的DNA合成反应。方法 我们分别建立了单向、双向和三向MLR ,以DNA合成活动作为此系统中淋巴细胞反应的定量指标。结果 研究表明 :在双向和三向MLR系统中 ,反应性PBL能够抗原特异性地抑制异体来源的刺激性淋巴细胞的生长 ,而双向和三向MLR系统中的上清液不能在单向MLR中产生CASIS现象。因此 ,CASIS的产生依赖于细胞间的接触。此外 ,CASIS独立于MLR系统中抗原递呈细胞 (APC)的数量。抗人类白细胞抗原ABC(HLA ABC)单抗及抗 β2微球蛋白 (β2m )的单抗能影响CASIS ,提示相应的抗原参与了CASIS。再者 ,CASIS现象至少部分地归因于双向MLR中发生的细胞凋亡 (Apoptosis)。 结论 异体抗原激活的PBL会产生CASIS ,它与HLA ABC和 β2m相关 。

Objective In this preliminary work,we report a novel cell contact antigen specific inhibitory signal(CASIS)impairing the DNA synthetic response of the peripheral blood lymphocytes(PBL) cultured in mixed lymphocyte reaction(MLR) systems.Methods We set up one way, two way and three way MLR's,respectively, and used the intensity of the new DNA synthetic activity as a quantitative parameter of the lymphocytic reaction in each system.Results Our results show that the responder PBL were able to antigen specifically and significantly inhibit the growth of the allo stimulator lymphocytes in the two or three way MLR'S, whereas the CASIS could not be elicited in one way MLR's by anything present in the conditioned growth media of the ocrresponding cultures.Hence, the CASIS was not mediated by a factor secreted into the medium, and required, to be triggered, a definite intercellular contact.Furthermore, the CASIS was independent of the actual numbers of antigen presenting cells in MLR's.Monoclonal antibodies directed against either human leukocyte antigen ABC(HLA ABC) or β2 microglobulin(β2m) did also affect the CASIS, which indicated that the corresponding antigens were involved in its operation.Moreover, the CASIS was, at least parlty,due to the induction of apoptosis in the two way MLR's.Conclusion We conclude that the alloantigen activated PBL do produce a CASIS that is HLA ABC dependent and exerts in part its inhibitory function via the apoptosis pathway.