Binding of Divalent H-2K^(d)/IgG2aFc Fusion Protein to Murine Macrophage via Fc-FcR Interaction

作     者：Wei Xiao Xueling Chen Lin Zhou Shengjun Lu Zhihui Liang Xiongwen Wu 

作者机构：Department of Immunology Tongji Medical College Huazhong University of Science ＆ Technology Wuhan 430030 China Department of Immunology School of Medicine Shihezi University Shihezi 832002 China 

出 版 物：《Cellular & Molecular Immunology》 (中国免疫学杂志（英文版）)

年 卷 期：2007年第4卷第2期

页      面：147-151页

核心收录：

学科分类：1002[医学-临床医学] 1001[医学-基础医学(可授医学、理学学位)] 100102[医学-免疫学] 100214[医学-肿瘤学] 10[医学] 

基　　金：supported by a grant from the National Natural Science Foundation of China(NO.30271201) 

主　　题：H-2K^d/IgG2aFc divalent MHC fusion protein Fc receptor 

摘      要：Peptide-MHC class I complex （pMHC） is a specific ligand for TCR recognition, and important for CD8^＋T cell activation. Here we described a genetically engineered divalent class I major histocompatibility complex （MHC） molecule, H-2K^d/IgG2aFc, a fusion protein consisting of the extracellular domains of H-2K^d, a murine MHC class I molecule, and the Fc region of IgG2a. This fusion protein is expected to attach the H-2K^d molecule to the surface of murine macrophage （MФ） through its Fc portion binding to Fc receptor （FcR） of MФ. cDNAs coding for the extracellular domains of H-2K^d and the Fc region of IgG2a were cloned respectively, and then recombined into plasmid pcDNA3.1（＋）. The H-2K^d/IgG2aFc protein was expressed by the plasmid-transfected cell line J558L, and purified from its supernatant with a Staphylococcal Protein A （SPA） column. The fusion protein showed a 58.4 kDa band as revealed by SDS-PAGE and Western blotting with murine IgG-specific antibody, which consists with that expected for extracellular domains of H-2K^d heavy chain plus the Fc region of IgG2a. The sandwich ELISA assay with antibodies specific for Fc portion and for H-2K^d indicated the fusion protein consists of both Fc portion and H-2K^d. Peritoneal MФ of C57BL/6 （H-2K^b） can be stained with H-2K^d specific monoclonal antibody （mAb） after incubated with the H-2K^d/IgG2aFc fusion protein. These results demonstrate the fusion protein can be used to attach the H-2K^d molecule to the surface of murine MФ, and provides a novel means to manipulate the T cell recognized epitope on the surface of murine MФ, which can be applied to activate antigen-specific cytotoxic T lymphocyte （CTL）.