Epstein-Barr病毒特异性T细胞对重组痘苗病毒表达LMP和EBNA2的靶细胞的识别

本文用EB病毒转化自体淋巴细胞所建立的类淋巴母细胞系(LCL),以及用EB病毒潜伏感染膜蛋白(LMP)基因和核蛋白-2(EBNA2)基因与痘苗病毒重组的重组病毒(Vac-LMP和Vac-EBNA2)感染的自身纤维母细胞,同时作为刺激细胞和靶细胞,以~(51)Cr释放法检测5例血清中EB病毒VCA—IgA抗体阳性者及1例阴性健康者外周血单个核细胞(PBMC)的特异性T细胞杀伤效应。结果表明,用自身LCL激活的EB病毒特异性T细胞杀伤效应高峰出现在第14～28天;参与杀伤性细胞免疫反应的T细胞亚群主要是T3、T8阳性的细胞毒性T细胞,其对靶细胞的识别及杀伤受HLA-I的限制。用重组牛痘病毒感染的纤维母细胞作靶细胞或刺激细胞,有1例供者可接受LMP,另1例可接受EBNA2的刺激,并对相应的靶细胞产生特异性T细胞杀伤反应,表明EB病毒-LMP和EBNA2可能既是EB病毒特异性T细胞的刺激抗原,又是其识别的靶抗原。

EPSTEIN-BARR VIRUS SPECIFIC CYTOTOXIC RESPONSE TO AUTOLOGOUS FIBROBLASTS EXPRESSING ANTIGENS LMP AND EBNA2 IN RECOMBINANT VACCINIA VIRUSES

Epstein-Barr virus specific T-cell responses from 5 EBV seropositive and J seronegative donors are investigated by using autologous fibroblasts infected with EB virus gene recombinant vaccinia viruses-LMP or EBNA2 as the stimulators or target cells. The results demonstrate that in vitro when peripheral blood mononuclear cells of EBV-immune donors are cocul-tured with inactivated autologous LCLs, the peak of EBV specific cytoto-xic T cell response appears from day 14 to day 28, decreases after day 30, reappears after LCLs re-stimulation. The T cell subsets involved in this cellular responses is mainly T3, T8 positive cytotoxic T cells. The recognition of T cells are restricted by HLA-I. The fibroblasts infected with EB virus gene recombinant vaccinia virus-LMP or EBNA2 express EBV-LMP or EBNA2 protein on the cell surface using APAAP staining. The EBV specific cytotoxic T cells stimulated with inactivated autologous LCLs from donors MM or CS can recognize autologous LCLs and also autologous fibroblasts expressing EBV-LMP ( MM ) or EBNA2 ( CS ) respectively. The EBV specific cytotoxic responses from MM and CS can be induced by autologous fibroblasts infected with vaccinia -LMP or Vaccinia-EB NA2.Previous studies on cell-mediated immunity have suggested that when using the LMP and EBNA2 recombinant viruses as a source of the antigens to stimulate peripheral blood lymphocytes and as targets on autologous fibroblasts, both these proteins are antigens involved in the normal cell-mediated anti-EBV immune responses. The present findings suggest that different individuals and HLA- typing may have different responses to EB virus antigens.