Cheng Hongyan, Ye Xue, Chang Xiaohong, Ma Ruiqiong, Cong Xu, Niu Yidong, Zhang Menglei, Liu Kai, Cui Heng, Sang Jianli
Key Laboratory of Cell Proliferation and Regulation Biology, College of Life Science, Beijing Normal University, No. 19, Xin Jie Kou Wai Street, HaiDian District, Beijing, 100875, People's Republic of China.
Med Oncol. 2015 Apr;32(4):130. doi: 10.1007/s12032-015-0586-y. Epub 2015 Mar 21.
We previously produced an anti-idiotypic monoclonal antibody, 6B11, which mimics ovarian cancer antigen CA166-9 and induces cellular and humoral immunity. Here, to enhance the immunogenicity of 6B11, we constructed the 6B11ScFv-mIL-12 fusion protein (FP), by fusing single-chain fragment of 6B11 variable region (6B11ScFv) with mouse interleukin-12 (mIL-12), which was expressed in eukaryotic 293EBNA cells transfected with pSBI vectors. A binding activity assay showed 6B11ScFv-mIL-12 to have activities of both 6B11 and mIL-12-it specifically bound both ovarian monoclonal antibody COC166-9 and rabbit anti-mouse IL-12 antibody. The immune activity assay showed 6B11ScFv-mIL-12 to promote proliferation of lymphocytes stimulated by phytohemagglutinin, increase the absolute numbers and percentages of CD3(-)/CD56(+) natural killer cells and CD3(+)/CD56(+) natural killer T cells among peripheral lymphocytes, and increase interferon-γ. The FP was specifically cytotoxic to the CA166-9(+) ovarian cancer cell lines HOC1A and SKOV3 and inhibited growth of ID8 subcutaneous tumors in C57BL/6J mice. This study provides an experimental basis for clinical use of 6B11ScFv-mIL-12 in ovarian cancer therapy. To our knowledge, this is the first report of a fusion protein from an anti-idiotypic antibody and IL-12.
我们之前制备了一种抗独特型单克隆抗体6B11，它模拟卵巢癌抗原CA166-9并诱导细胞免疫和体液免疫。在此，为增强6B11的免疫原性，我们构建了6B11ScFv-mIL-12融合蛋白（FP），即将6B11可变区的单链片段（6B11ScFv）与小鼠白细胞介素-12（mIL-12）融合，该融合蛋白在转染了pSBI载体的真核293EBNA细胞中表达。结合活性分析表明，6B11ScFv-mIL-12具有6B11和mIL-12两者的活性——它能特异性结合卵巢单克隆抗体COC166-9和兔抗小鼠IL-12抗体。免疫活性分析表明，6B11ScFv-mIL-12能促进植物血凝素刺激的淋巴细胞增殖，增加外周淋巴细胞中CD3(-)/CD56(+)自然杀伤细胞和CD3(+)/CD56(+)自然杀伤T细胞的绝对数量和百分比，并增加干扰素-γ。该融合蛋白对CA166-9(+)卵巢癌细胞系HOC1A和SKOV3具有特异性细胞毒性，并能抑制C57BL/6J小鼠ID8皮下肿瘤的生长。本研究为6B11ScFv-mIL-12在卵巢癌治疗中的临床应用提供了实验依据。据我们所知，这是关于抗独特型抗体与IL-12融合蛋白的首次报道。
