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Journal of Biomedicine and Biotechnology
Volume 2010, Article ID 121094, 8 pages
http://dx.doi.org/10.1155/2010/121094
Research Article

Construction and Characterization of a Novel Fusion Protein MG7-scFv/SEB against Gastric Cancer

Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, China

Received 20 September 2009; Revised 4 January 2010; Accepted 13 January 2010

Academic Editor: Xin-yuan Guan

Copyright © 2010 Qiang Tong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Antibody-targeted superantigen has been developed into a new strategy to treat many malignant tumors. In this study, for specific targeting to gastric cancer cell, superantigen SEB (Staphylococcal Enterotoxin B) was genetically fused to the single-chain variable fragment of gastric carcinoma-associated antibody MG7(MG7-scFv) that recognizes the MG7 antigen frequently expressed in gastric cancer cell. The recombinant MG7-scFv/SEB fusion proteins are expressed in E. coli as inclusion bodies, and the purified MG7-scFv/SEB retains high binding affinity with gastric cancer cell SGC-7901 (positive MG7 antigen expression). When incubated with effector cell—peripheral blood mononuclear cells (PBMCs), MG7-scFv/SEB could effectively inhibit the proliferation and induce apoptosis of SGC-7901. After being treated with MG7-scFv/SEB, PBMCs remarkably increased the production of Th1 cytokines (IFN-gamma, IL-2), and slightly increased the production of Th2 cytokines (IL-4, IL-10) in vitro. It was observed that gastric-tumor-bearing rats administrated with MG7-scFv/SEB showed more inflammatory cell infiltration, more significant tumor inhibition, and longer survival time than those of rats treated with SEB or NS (Normal Saline). The data indicated that MG7-scFv/SEB fusion protein could specifically target gastric cancer cell, enhance the activity of T cells and induce tumor cell apoptosis to exert the antitumor effect on gastric cancer.