CTLA-4纳米抗体增强肿瘤特异性T淋巴细胞抗肝癌作用研究

目前原发性肝癌的过继T细胞疗效亟待提高。纳米抗体是目前可得到的稳定可结合抗原的最小单位，具有高水溶性、稳定性和靶向性。本项目拟用前期工作中筛选出的CTLA-4特异性纳米抗体CTLA-4/Nb16，结合本课题组高效的肿瘤/DC融合细胞诱导特异性T淋巴细胞技术，探索CTLA-4纳米抗体增强DC/HepG2融合细胞诱导的肿瘤特异性T淋巴细胞抗肝癌作用及其机制。首先在体外对CTLA-4纳米抗体生物学活性进行鉴定，其次通过建立荷人T细胞淋巴瘤裸鼠动物模型，对其体内抗肿瘤生物活性加以验证；进一步研究CTLA-4纳米抗体在体外对融合细胞诱导的肿瘤特异性CTL的增殖、分泌及对靶细胞的杀伤效应，最后从体内研究CTLA-4纳米抗体增强肿瘤特异性CTL过继治疗荷人肝癌裸鼠的效果及相关机制。本研究的完成将为肝癌的过继治疗提供一条有潜在临床应用价值的新策略。

Adoptive T-cell therapy should be improved on the primary hepatocellular carcinoma. Cytotoxic tlymphocyte-associated antigen 4 (CTLA-4) is an important negative T cell costimulatory molecule and highly expressed in activated T cells. Nanobody is a minimal antigen-binding functional fragment with higher water solubility, stability and targeted ability. A CTLA-4 specific nanobody (CTLA4-Nb16) was screened in our previous study. In our project, the efficient anti-hepatoma effect and mechanism of the specific T lymphocytes enhanced by CTLA-4 nanobody is explored combined with the high efficiency technology of tumor/DC fusion cell. First, the biologic activity of CTLA-4 nanobody is evaluated in vitro and the anti-hepatoma activity is studied in vivo with the nude mice model of bearing human T cell lymphoma Jurkat cells. Then, the proliferation, secretion and killing effect on target cells of specific T lymphocytes induced by DC/HepG2 with CTLA-4 nanobody are evaluated. Last, the therapeutic effect and mechanism of the specific T lymphocytes are investigated. The aim of the project is to provide a potential clinical value of adoptive T-cell therapy on the primary hepatocellular carcinoma.