胃癌肝高转移细胞结合肽的特异性鉴定

Identification of phage displayed peptides specifically binding to high liver-metastatic gastric cancer cells

目的 鉴定选择性噬菌体阳性克隆是否可与胃癌肝高转移细胞—XGC9811 -L特异性结合。方法 利用竞争结合试验检测噬菌体阳性克隆与XGC9811-L细胞的结合效率。竞争抑制实验确定阳性噬菌体与靶细胞的结合性是否通过外源呈现肽发挥作用。细胞结合ELI-lSA实验和免疫荧光技术鉴定phage20与靶细胞XGC9811-L结合的特异性。结果 在8个阳性克隆中,phage20与XGC9811 -L细胞的结合效率最高,达100%,是原噬菌体肽库的50倍,随着外源呈现肽浓度的增加,phage20与靶细胞的结合力随之减弱。phage20可与XGC9811 -L特异结合,并可内化入细胞。结论 在8个噬菌体阳性克隆中,phage20与XGC9811-L细胞具有高度结合力,并呈现出明显的细胞特异性。

Objective To identify whether eight candidate phages c ould specifically bind to the high liver-metastatic gastric cancer cells (XGC-9 811-L). Methods Competitive binding assays were performe d to test the binding efficiency of the selected candidate phages to XGC9811-L. The competitive inhibition test was carried out to determine if phage binding wa s mediated through the displayed peptides. Immunofluorescent technique and ELISA were used to test the cell-specificity of selected peptides. Results Among 8 candidate phages, phage20 had the highest binding efficienc y to XGC9811-L, which showed 50-fold stronger than the original library. With th e concentra-tion of the peptides increased the binding efficiency of phage20 to XGC9811-L decreased accordingly. The specificity binding assays d emonstrated phage20 could bind to XGC9811-L specifically, furthermore, it could be internalized into the target cells. Conclusion Among t he 8 candidate phages, pahge20 had the highest binding efficiency and showed an obviously cell-specificity.