超抗原SEB和SEC诱导的树突状细胞对T细胞的影响

目的：阐明超抗原葡萄球菌肠毒素B（SEB）和葡萄球菌肠毒素C（SEC）诱导树突状细胞(dendritic cells，DC)促进T细胞活化、增殖、分泌及其对肝癌HcaF细胞的杀伤作用。 方法： 以SEB或SEC诱导DC刺激T细胞，免疫组化染色检测DC表达S-100蛋白；流式细胞术检测DC表达I-Eκ和CD80分子水平，检测T细胞受刺激后CD69的表达、IL-2和TNF-α的生成；用MTT法检测T细胞增殖及其对HcaF细胞的杀伤效应。 结果： 体外试验表明，DC高表达S-100蛋白，SEB或SEC诱导的DC高表达I-Eκ和CD80分子；SEB或SEC能诱导DC促进T细胞活化，其浓度以100 μg/L时作用最强；SEB或SEC能诱导DC促进T细胞增殖、大量分泌IL-2和TNF-α, 被激活的T细胞对HcaF细胞的杀伤率高达83.2%±12.8%，明显优于肿瘤抗原诱导的DC所激活的T细胞对HcaF细胞的杀伤作用；SEB与SEC的诱导作用无明显差异。 结论： 超抗原SEB或SEC能诱导DC显著增强T细胞活化、增殖、分泌和杀伤肿瘤细胞，并优于肿瘤抗原的诱导作用，SEB和SEC的作用相似，为超抗原SEB或SEC与DC联合应用于临床肿瘤的治疗提供了证据。

Effects of dendritic cells induced by superantigen staphylococcal enterotoxin B or staphylococcal enterotoxin C on T lymphocytes

AIM: To evaluate the effect of staphylococcal enterotoxin B (SEB) or staphylococcal enterotoxin C (SEC) combining with dendritic cells (DC) on T cell functions and in vitro anti-HcaF tumor cytotoxicity of activated T cells. METHODS: S-100 protein expression in DC was detected by immune histochemistry staining. The expressions of I-Eκ and CD80 molecules on DC, the expression of CD69 molecule on T cells and the production of IL-2 and TNF-α by T cells were determined with flow cytometry. The proliferation of T cells and its cytotoxicity to HcaF tumor cells were detected by MTT assay. RESULTS: In vitro experiments showed that isolated DC expressed high level of S-100 protein. SEB or SEC-induced DC highly expressed I-Eκ and CD80 molecules and that SEB or SEC-induced DC promoted the activation and proliferation of T cells. 100 μg/L of SEB or SEC was the most effective concentrations to induce T cells to secret IL-2 and TNF-α. The T cells activated by SEB or SEC combined with DC showed significant cytotoxicity to HcaF cells, appearing a stronger role than tumor antigen combined with DC. There was no difference in the role for T lymphocytes between both SEB and SEC. CONCLUSIONS: The results indicate that SEB or SEC combined with DC is an effective way to enhance T cell functions, producing stronger cytotoxicity to HcaF tumor cells than tumor antigen-loaded DC used at present, which offers a forceful evidence for the possibility of superantigen SEB or SEC combining with DC to be applied to clinical tumor immunotherapy.