人乳头瘤病毒18型E6、E7蛋白T细胞表位筛选

目的 筛选人乳头瘤病毒18型E6、E7蛋白在小鼠中的T细胞表位.方法 以重组痘苗病毒rVVJ18 E7、E6分别免疫C57BL/6和BALB/c小鼠,利用覆盖E6和E7蛋白全长序列的肽库或截短的多肽,用酶联免疫斑点方法 （ELISPOT）和细胞内因子染色检测其所诱发的细胞免疫反应.结果 重组痘苗病毒rVVJ18 E7、E6免疫的两种品系小鼠均可检测到E6肽库刺激产生的特异性细胞免疫反应,经筛选确定E667-75（KCIDFYSRI）为C57BL/6小鼠、E660-68（IPHAAGHKC）为BALB/c小鼠识别的CD8＋的T细胞表位.两种小鼠中均未检测到E7蛋白诱发的细胞免疫反应.结论 筛选到分别被BALB/c和C57BL/6小鼠识别的两条针对E6蛋白的不同T细胞表位,为今后评价HPV18疫苗中E6蛋白的细胞免疫效果提供了实验依据.

Identification specific T lymphocyte epitopes on E6 protein of human papillomavirus type 18 in mice

Objective To identify specific T lymphocyte epitope on E6 protein of human papillomavirus type 18 in mice. Methods Infection with one recombinant vaccinia virus rVVJ18 E7, E6 respectively in C57 BL/6 and BALB/c mice, specific cellular immune responses were detected by ELISPOT or intracellular cytokine stainings by using a series of overlapping synthetic peptides covering full length of the amino acid sequence of E6 and E7 proteins or various truncated peptides. Results The rVVJ18 E7, E6 generated significant E6 specific T-cell immune responses in vaccinated mice. Mapping of the epitope of E6 revealed that the peptides E667-75 (KCIDFYSRI) and E660-68 ( IPHAAGHKC ) presented respectively by C57BL/6 and BALB/c mice were the optimal peptides to activate E6-specific CD8 + T lymphocytes. However no positive cellular immune responses stimulated with various E7 peptides were detected by ELISPOT in immunized mice. Conclusions Two specific T lymphocyte epitopes were identified on E6 protein in C57BL/6 and BALB/c mice, which will provide the basis to evaluate cellular immune response elicited by HPV18 E6 protein based vaccine.