9.1C3对CD2和CD3诱导的杀伤作用的影响及其机制探讨

目的 探讨9．1C3分子对CD2和CD3诱导的PBMC杀伤作用的影响及其作用机制。方法 以活化PBMC为效应细胞，采用重导向杀伤实验（redirected cytotoxicity assay,RCA),观察9.1C3对CD2、CD3介导效应细胞杀伤P815细胞作用的影响。以Jurka细胞为模型，用相应的抗体刺激细胞，通过荧光分光光度计，测定9.1C3对CD2、CD3诱导[Ca^2 ]i升高的影响。结果 9.1C3 mAb能显著抑制CD2 mAb介导活化PBMC对P815细胞的杀伤作用，但对CD3 mAb介导杀伤的抑制作用较弱。以Jurkat细胞为模型，发现CD2 mAb经羊抗鼠Ig(goat anti mouse Ig,GAM Ig)交联后能诱导[Ca^2 ]i的升高，当同时加入9.1C3 mAb时,[Ca^2 ]i的升高受到抑制；CD3 mAb在没有GAM Ig交联时即能引起[Ca^2 ]i的升高，而9.1C3 mAb对CD3 mAb诱导[Ca^2 ]i的升高有赖于GAM Ig的交联。结论 9.1C3分子对CD2和CD3介导的杀伤的抑制程度不同。抑制杀伤细胞脱颗粒依赖的[Ca^2 ]i升高可能是9.1C3分子抑制活化型受体CD2介导细胞毒作用的作用机制之一。

Study on the effects and its mechanism of 9.1C3 on CD2 or CD3 mediated cytotoxicities

Aim To explore the effects and its mechanism of 9.1C3 on CD2 or CD3 mediated cytotoxicities of activated PBMC. Methods The effects of 9.1C3 on CD2 or CD3 induced cytotoxicities were investigated by using redirected cytotoxicity assay, in which activated PBMC were used as effectors, and Fc receptor expressing P815 were used as target cells. The effects of 9.1C3 on CD2 or CD3 mediated [Ca2+]i increase in Jurkat cells were detected by spectrofluorometer. Results CD2 mediated cytotoxicity was inhibited significantly by 9.1C3 mAb, whereas CD3 mediated cytotoxicity was inhibited by 9.1C3 mAb to less extent. CD2 mediates [Ca2+]i increase in crosslinking dependent manner, and [Ca2+]i increase was inhibited in the presence of 9.1C3 mAb. However, CD3 mediates [Ca2+]i increase in crosslinking independent manner, and the increase was only inhibited in the presence of 9.1C3 mAb and crosslinker. Conclusion 9.1C3 can inhibit CD2 or CD3 molecule mediated cytotoxicities to different extent. The inhibition of CD2 mediated [Ca2+]i increase may be one mechanism of inhibitory effect of 9.1C3 on CD2 molecule mediated cytotoxicity. The lower inhibitory effect of 9.1C3 on CD3 molecule mediated cytotoxicity may be due to the absence of crosslinker in the experiment of incubating effect cells with antibodies in RCA.