LPS刺激来自人单核细胞的树突状细胞在调节自体CD4+CD25+T细胞活性作用研究

树突状细胞（DC）是现今被认为最具潜能的专职抗原呈递细胞.应用不同方法在体内诱导细胞毒T细胞（CTL）来识别肿瘤相关抗原的肿瘤免疫治疗研究已有报告.然而,在体内免疫治疗的有效性可能仅限制在局部或系统抑制CTL产生和功能.为了检测LPS刺激人单核细胞的DC来抑制自体CD4^＋CD25^＋T细胞能力,使用HLA-A2限制性p53264-272肽作为肿瘤抗原,用LPS（DC-LPS^＋）或不用LPS（DC-LPS^-）产生的DC分别与自体T细胞共同培养.结果显示：在DC-LPS^＋活化的T细胞的CD4^＋CD25^＋T细胞群比DC-LPS^-活化的T细胞要低.这个结果提示,DC-LPS^＋与CD4^＋CD25^＋T细胞群有关联,而且这种特性可能是由于T细胞对肿瘤相关抗原的调节作用.

Role of LPS-Stimulated Human Monocyte-derived Dendritic Cells in the Modulation of Autologous CD4 + CD25 + T Cell Activation

Dendritic cells (DC) are now recognized as the most potent professional antigen presenting cells (APC). Several studies on cancer immunotherapy using different approaches to induce cytotoxic T lymphocytes (CTL) in vivo recognizing tumor-associated antigens have been reported. However, the efficacy of immunotherapy in vivo may be limited by the local or systemic suppression of CTL generation or function. To explore the ability of lipopolysaccharide (LPS) stimulated human monocyte-derived DC involved in activity of autologous CD4 CD25 T cells, HLA-A2 restricted p53_ 264-272 peptide was used as tumor antigen, DC generated with LPS (DC-LPS ) or without LPS (DC-LPS-) were co-cultured with autologous T cells respectively. The results showed that CD4 CD25 T cell population in the DC-LPS activated T cells was lower than that in the DC-LPS- activated T cells. This finding suggest that the relationship between DC-LPS and population of CD4 CD25 T cells exists and this property may contribute to regulation of T cell responses to tumor-associated antigens.