在抗肿瘤免疫效应中细胞毒T淋巴细胞(CTL)是通过识别肿瘤细胞MHC I类分子结合的肿瘤源性多肽.为分析肿瘤细胞的抗原性及肿瘤抗原的多肽性质,本文选用FBL-3肿瘤细胞,用pH3.3的枸橼酸-磷酸盐缓冲液间隔24～36小时多次酸洗肿瘤细胞,以获得MHC I类分子结合的多肽,并分析酸洗液中多肽混合物的肿瘤抗原性,以及RP-HPLC分离的部分收集液多肽的肿瘤抗原性,为FBL-3肿瘤细胞抗原的确定提供基本数据.结果表明:酸洗法能有效获得肿瘤细胞MHC I类分子相关的多肽抗原,肿瘤细胞多肽抗原的分离、纯化、HPLC分析以及抗原性鉴定是肿瘤抗原性确定的一个重要方法.

T lymphocytes, which play a very important role in tumor immunity, recognize the tumor antigenic peptide presented by MHC molecules on the surface of tumor cells. FBL-3 is a transplantable Friend virus-induced leukemia of B6 (H-2~(b) ) origin, which can induce the CTL against FBL-3 by immunizing B6 mice with attenuated FBL-3. The present paper was to elute immunogenic peptides ( CD8 T cell epitopes) from class I complexes at the cell surface of viable FBL-3 cells by acid treatment. The acid treated cells remained viable but lost sensitivity to be lysed by FBL-3 specific cytotoxic T lymphocytes (CTLs). The sensitivity of the acid-treated cell was restored to the FBL-3 specific CTLs by supplement of the acid-eluted cell-free supematants. Paptides were subsequently fractionated by reverse-phase high performance liquid chromatography (RP-HPLC) . The fractionated peptides in HPLC fractions 5~6 and 23 ~ 60 (tubes) showed the capacity to sensitize RAM-S cells, which could be lysised by FBL-3 specific CTLs. The experiment indicates that this method may be useful in the definition of petide epitopes relevant to tumor cells.

本课题由国家自然科学基金(39370769)，国家青年自然科学基金(39500133)资助