T细胞疫苗免疫前后外周血CD4~ 和CD8~ T细胞变化的分析

目的 观察T细胞疫苗免疫前后外周血CD4~+和CD8~+T细胞的变化情况,探讨T细胞疫苗诱导特异性免疫耐受的作用及其机理。方法 制备针对Wistar大鼠的SD大鼠T细胞疫苗,用制备好的T细胞疫苗去免疫正常的SD大鼠,同时设特异性抗原对照组和空白对照组。于免疫前和免疫后规定时点分别进行单向混合淋巴细胞反应(MTT法),于相同时点通过流式细胞分析对外周血CD4~+和CD8~+T细胞进行检测。结果 在T细胞疫苗组,平均OD值免疫后比免疫前显著降低(P<0.01)CD4/CD8比值免疫后比免疫前显著降低(P<0.05);在特异性抗原对照组,免疫后的OD值显著高于免疫前(P<0.01),同时CD4/CD8比值于免疫后显著增高(P<0.05);空白对照组各时点各指标比较无显著差异(P>0.05)。结论T细胞疫苗可以诱导同种抗原特异性免疫耐受,CD4~+反应性T细胞克隆与CD8~+抗独特型T细胞克隆相对比例优势的转换可能在T细胞疫苗诱导的免疫耐受形成中发挥关键作用。

An analysis of peripheral CD4~+ T cells and CD8~+ T cells between pre- and post-immunization of T cell vaccination

Objective To observe the changes of peripheral CD4+ T cells and CD8+ T cells between pre- and post-immunization of T cell vaccination, further to investigate the mechanism of T cell vaccination in inducing specific immune tolerance. Methods T cell vaccination was made from the spleen cells of SD rats, which were induced by Con A and were challenged with the spleen cells of Wistar rats. Normal SD rats were vaccinated intraperitoneally with T cell vaccination or the spleen cells of Wistar rats (specific allogenic-antigen control) or 1 640 culture buffer (blank control) respectively; One-way mixed lymphocyte reaction (MLR) were performed and peripheral CD4+ T cells and CD8+ T cells were measured by flow cytometric analysis before and after vaccination. Results In T cell vaccination group, the inhibition rate of MLR was significantly increased after vaccination( P < 0.01), the ratio of CD4/CD8 decreased significantly during the period of post-immunization (P<0.01); In specific-Ag control group, the OD value was increased significantly after immunization and the radio of CD4/CD8 was higher after immunization compared with pre-immunization level( P < 0.01);There was no difference statistically between different time points in blank control group.Conclusion T cell vaccination can induce specific immune tolerance , clone transforming from CD4+ T cells to CD8+ T cells may be critical in inducing specific immune tolerance.