Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China.
J Immunol Res. 2019 Dec 30;2019:7914326. doi: 10.1155/2019/7914326. eCollection 2019.
Single B cell antibody technology is a method for isolating antigen-specific B cells from human peripheral blood and obtaining antibody genes in developing antibody drugs. However, owing to immune tolerance to autoantigen, human autoantigen-specific B cells are difficult to acquire by conventional single B cell technology. In this study, we constructed a nitrated T-cell epitope named NitraTh by incorporating -nitrophenylalanine into a universal T helper epitope. NitraTh had enhanced ability to activate CD4 T cells and can be recognized by CD4 T cells with different HLA class II haplotypes. This NitraTh can also break immune tolerance to autoantigens, such as human epidermal growth factor receptor 2 (HER2) and cannabinoid receptor 1, and induce strong specific IgM B cell responses . HER2-NitraTh vaccine can also stimulate the generation of HER2-specific IgG B cells in human immune system mice, which was established by cotransplanting lymphocytes and autologous dendritic cells in immunodeficient mice. We obtained 30 fully human IgG antibody genes by sorting single B cells from the human immune system mice immunized with HER2-NitraTh vaccine. The analysis of antibody genes showed that sorted B cells underwent the extensive somatic mutation of the antibody genes. We randomly selected eight genes for cloning, six of which expressed antibodies that can bind to HER2. Hence, we provided a convenient and effective method in acquiring fully human antibody genes against self-proteins, which can be used in developing therapeutic antibody drugs.
单细胞抗体技术是一种从人外周血中分离抗原特异性 B 细胞并获得抗体基因以开发抗体药物的方法。然而，由于对自身抗原的免疫耐受，传统的单细胞技术难以获得人自身抗原特异性 B 细胞。在本研究中，我们通过将 -硝基苯丙氨酸掺入通用 T 辅助表位构建了一个硝化 T 细胞表位，命名为 NitraTh。NitraTh 具有增强激活 CD4 T 细胞的能力，并且可以被具有不同 HLA Ⅱ类单倍型的 CD4 T 细胞识别。这种 NitraTh 还可以打破对自身抗原（如人表皮生长因子受体 2（HER2）和大麻素受体 1）的免疫耐受，并诱导强烈的特异性 IgM B 细胞反应。HER2-NitraTh 疫苗还可以刺激免疫缺陷小鼠中人类免疫系统小鼠中 HER2 特异性 IgG B 细胞的产生，该小鼠通过共移植淋巴细胞和自体树突状细胞建立。我们从用 HER2-NitraTh 疫苗免疫的人类免疫系统小鼠中分离的单个 B 细胞中获得了 30 个完全人 IgG 抗体基因。抗体基因的分析表明，分选的 B 细胞经历了抗体基因的广泛体细胞突变。我们随机选择了 8 个基因进行克隆，其中 6 个表达能够结合 HER2 的抗体。因此，我们提供了一种获取针对自身蛋白的完全人抗体基因的便捷有效方法，可用于开发治疗性抗体药物。
