囊素与杂交瘤细胞的结合及结合肽的鉴定

【目的】囊素(BS)是禽类和哺乳动物中具有重要免疫调节功能的多肽,能有效促进杂交瘤细胞抗体的分泌,为探讨杂交瘤细胞是否有BS受体分子的表达。【方法和结果】本研究采用荧光显微镜、激光扫描共聚焦显微镜和流式细胞仪分析的方法,检测BS与杂交瘤细胞的结合特性。实验结果证实BS与杂交瘤细胞的结合具有特异性、趋饱和性和可逆性。为进一步分析BS与杂交瘤细胞的结合位点,实验中以BS分子作为靶标,对噬菌体随机12肽库进行了4轮亲和筛选,ELISA和竞争抑制试验显示2个噬菌体克隆能特异性与BS结合。对阳性噬菌体克隆进行序列测定分析表明,其插入的12肽分别为:ACTKHLCLLQPL、MSCNDTLCLLPN,保守序列为LCLL。体外实验表明,2个人工合成的12均都能在一定程度上抑制BS与杂交瘤细胞的特异性结合。【结论】本研究表明杂交瘤细胞具有BS结合的受体,这为进一步研究BS促杂交瘤细胞抗体分泌的信号传导通路奠定了基础。

Expression of bursin receptor on membranes of hybridoma cell and Identification of binding peptide of bursin from 12-merrandom phage display peptide library

Abstract: Objective] Bursin (BS) could greatly promote the production of monoclonal antibody in hybridoma cell. We studied the interaction between BS and hybridoma cell. Methods] Fluorescence microscopy, Laser Scanning Confocal Microscope (LSCM) and fluorescence activated cell sorter (FACS) were used. Results] Fluorescence microscopy revealed specific binding of FITC-BS to hybridoma cell. FACS analysis demonstrated that the binding was specific, saturable and reversibility. BS was used as target protein to screen its binding peptides from 12-mer random phage display peptide library. After four rounds of biopanning, 20 phage clones were randomly selected and identified. ELISA and competitive inhibition test results indicated that 2 phage clones were identified as positive clones. The amino acid sequences analysis shown that the sequences were ACTKHLCLLQPL or MSCNDTLCLLPN, which sharing a conservative sequence LCLL. In vitro experiments suggested that the two binding peptides can inhibit BS specific binding to hybridoma cell. Conclusion] These results confirmed that existence of BS receptor in the membrane of hybridoma cell, which involved in hybridoma cell secreting monoclonal antibody signal pathway.