树突状细胞负载甲胎蛋白、细胞毒性T细胞表位肽后的免疫应答

Immune responses of dendritic cells after loaded with cytotoxicity Tlymphocyte epitope based peptide of human α-feto-protein(hAFP)

目的 用负载hAFP 218-226位LLNQHACAV九肽的树突状细胞(dendritic cells,DC)诱导自身淋巴细胞,使之话化为肝细胞癌(HCC)特异性细胞毒性T细胞(cytotoxic T lymphocyte,CTL),并特异性杀伤HCC细胞。方法 在体外用GM-CSF和IL-4诱导HLA-A2~＋健康志愿者外周血单核细胞,使其分化为高纯度DC。用负载hAFP 218-226位LLNQHACAV九肽的DC诱导自身淋巴细胞,使之成为HCC特异性CTL。结果 诱导的DC分泌较高水平的IL-12(17.6~21.5pg/ml),其中以第7天为最高(21.5pg/ml),经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中TNF水平均比在IL-2条件下培养的未活化淋巴细胞高,L929细胞死亡百分率分别为80.6%和11.6%;经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中IL-12水平分别为20.5 pg/ml和46.9 pg/ml,经DC活化后淋巴细胞增殖指数大于3。活化后的淋巴细胞不但特异性杀伤HLA-A2^+的HCC细胞HenG2和负载AFP表位肽的T2细胞,而且还不同程度杀伤HLA-A3^+HCC细胞Alexander和其它表型HCC细胞,对NK细胞敏感的靶细胞慢性髓原白血病细胞K562 也有较强的杀伤作用。结论 负载hAFPHLA-A2限制性CTL九肽的DC对表达AFP HCC的研究和治疗有潜在的应用价值。

ve To study the immune responses of lymphocytes after activated by dendritic cells (DCs) loadedwith cytotoxicity T lymphocyte (CTL) epitope based peptide of human α-fetoprotein (hAFP, 2l8-226 LLNQHACAV).Methods Get high purity DCs by cultured plastic-adherent monocytes isolated from healthy donor of HLA-A2^+ peripheralblood with granulocyte-monocyte clony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) for 7 days. Stimulate self-lymphocytes with DCs that loaded with CTL epitope based peptide of hAFP under the culture medium contains interleukin-2 (IL-2) for 7 days. Analyse IL-l2 and TNF in culture medium and also the specific lysis activity of lymphocytes againstfour strains of primary hepatocellular carcinoma cells. Results After stimulated by DC loaded with CTL epitope basedpeptide derived from hAFP, lymphocytes appeared a good characteristics and the culture medium of activated lymphocytescontained a high level Thl type cytokines of IL-l2 and TNF. Activated lymphocytes not only specifically lysed HLA-A2^+HepG2 line but also had the cytotoxicity against other three primary hepatocellular carcinoma cell lines and T2 target cellloaded with peptide of hAFP. Conclusions The results of this research supply the basic materials for the DC based vaccinewith HLA-A2 restricted peptide epitope derived from hAFP against AFP positive primary hepatocellular carcinoma.