PLA表位肽免疫微球诱导CTL对肝癌细胞的杀伤作用

Polylatic acid microspheres-induced CTL cytotoxicity against hepatocellular carcinoma cell lines

目的：考察两种载肽聚乳酸（（polylatic acid，PLA）免疫微球M1（hAFP158～166）和M2（hAFP218～226）在体外诱导特异性CTL的能力及其对肝癌细胞的杀伤作用。方法：制备分别荷载表位肽hAFP158～166、hAFP218～226的PLA免疫微球M1和M2，体外刺激HLA—A2^＋健康志愿者的外周血单个核细胞（PBMC）作为效应细胞，实验分为3组：对照组、hAFP表达组和hAFP阴性组。采用标准^（51）Cr释放法检测CTL杀伤活性。结果：两种免疫微球在体外均能刺激人PBMC增殖，形成大量可见克隆；两者诱导的效应细胞对hAFP^＋的荷肽他细胞、HepG-2和Alexander的杀伤率均达75％以上，均显著高于不表达hAFP的膀胱癌细胞BTT和未荷肽的他细胞，差异非常显著（P＜0，01），而两者杀伤活性之间没有明显差异（P＞0．05）。结论：两种载肽聚乳酸免疫微球均能在体外诱导产生特异性CTL，并对表达靶抗原的肝癌细胞有较强杀伤作用。

Objective： To investigate the in vitro efficiency of two kinds of polylatic acid （PLA） immunomicrospheres ：M1 （ hAFP158 ～ 166 ） and M2 （ hAFP218 ～ 226） in specific inducement of CTL and the cytotoxicity of CTL against hepatocellular carcinoma ceils. Methods： Pripheral blood monocytes （PBMC） of HLA-A2 healthy volunteers stimulated in vitro by peptide-loading microspheres were taken as effectors. The experiments were divided into three groups： control group, hAFP^＋ tumor ceils group, and hAFP- tumor ceils group. The specific cytolysis of target ceils was assessed by ^（51）Cr-release assay. Results： Both M1 and M2 induced proliferation of HLA-A2^＋ PBMC, forming visible clones. The effector ceils induced by M1 and M2 both had an cytolysis rate over 75% for hAFP^＋ tumor ceils, which was significantly higher than that for hAFP-tumor cells （P〈0. 01 ）. But there was no significant difference in cytolysis rate concerning the two kinds of microspheres （P〉0. 05 ）. Conclusion： The two kinds of microspheres can both induce specific CTL in vitro, which can effectively kill hAFP^＋ tumor ceils.