CD4~+CD25~+T细胞在CD8~+T细胞抗肿瘤免疫中的调节作用

实验旨在研究CD4+CD25+T细胞在CD8+T细胞抗肿瘤免疫中的调节作用。将小鼠脾脏中分离的单个核细胞分为两组,即去除CD4+CD25+T细胞组和未去除CD4+CD25+T细胞组,测定树突状细胞提呈的肿瘤抗原多肽刺激不同T细胞增殖活性、细胞因子IFN-γ分泌,以及多肽特异性CD8+T细胞对同源性胃癌细胞株MFC的杀伤活性。结果显示预先去除未致敏T细胞中的CD4+CD25+T细胞,所诱导的特异性CD8+CTL对肿瘤细胞免疫应答增强,表现为反应性T细胞对树突状细胞提呈的肿瘤抗原多肽增殖反应增强,IFN-γ分泌量提高及CD8+T细胞对MFC杀伤活性增强。这些结果表明,预先去除未致敏T细胞中的CD4+CD25+T细胞,肿瘤抗原多肽修饰的树突状细胞肿瘤疫苗效能可明显增加。CD4+CD25+T细胞在CD8+T细胞抗肿瘤免疫中起下调作用。

The regulatory role of CD4~+CD25~+ T cells in the CD8~+ T cells mediated anti-tumor immunity

The regulatory role of CD4+CD25+ T cells in the CD8+ T cell mediated anti-tumor immunity was investigated in the present study, in which the mononucleated cells (MNC) isolated from mouse spleen were divided into the CD4 +CD25 + T cells eliminated group of mice and that without elimination of cells, and the proliferative activity of T lymphocytes induced by peptides of tumor antigens presented through dendritic cells, release of IFN-γ and the killing activity of peptide-specific CD8+ T cells to the homologous gastric carcinoma cell line MFC were assayed in vitro, respectively. The experimental results demonstrated that the CD8+ T cells in group of mice with elimination of CD4+CD25+ T cells could induce enhanced anti-tumor immunity in terms of stronger proliferative activity of T lymphocytes against peptide pulsed dendritic cells, elevation of IFN-γ secretion as well as enhanced cell lysis against homologous cancer cells. It is concluded that the elimination of the CD4+CD25+ T cells in the na?觙ve T cells population can significantly improve the potency of peptide augmented dendritic cells based tumor vaccine, and the CD4+CD25+ T cells can down-regulate the CD8+ T cell mediated anti-tumor immunity.