大肠癌CA-Hb3抗原体外可诱导特异性CTL反应

在5例大肠癌患者的瘤细胞诱导自身外周血淋巴细胞的CTL反应中,有2例诱导成功,其肿瘤细胞CA-Hb_3抗原的表达呈强阳性;另3例无诱导作用,其肿瘤细胞CA-Hb_3的表达呈弱阳性.借助脂质体将CA-Hb_3导入3例弱阳性的肿瘤细胞内,免疫组化证实有2例瘤细胞的CA-Hb_3的表达转呈强阳性,该瘤细胞能诱导出CTL反应.阻断细胞内HLA-Ⅰ类分子与CA-Hb_3结合及在细胞膜上的表达皆能抑制CTL的杀伤反应.结果表明用大肠癌CA-Hb-3抗原可以增强肿瘤细胞的免疫原性,所诱导的CTL具有抗原特异性及MHC-Ⅰ类分子限制.

Specific Cytotoxic T Lymphocytes Responses Induced by Colorectal Cancer Antigen CA-Hb3 in vitro

CTL responses by autologous colorectal cancer cells were observed in five cases. The specific CTL was induced from two cases, in which tumor associated antigen, CA-Hb_3, was strongly positive. The CTL could not induced from other three cases in which CA-Hb_3 antigen was weakly positive. Weakly positive tumor cells in the three cases were loaded CA-Hb_3 antigen into cytoplasmas by the cationic liposomes and tested by immunohistochemical assay. The results showed that CA-Hb_3 antigen of tumor cells in two cases changed to strongly positive, and could induce CTL responses successfully. With blocking agents BFA and anti-MHC-I monoclonal antibody, CTL responses could be blocked. Our results suggested that soluble CA-Hb_3 antigen could enhance the immunogenity of colorectal cancer cells and induce effective anti-tumor cellular immune responses.