Brief Reports
Copyright ©The Author(s) 2005. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 21, 2005; 11(31): 4899-4903
Published online Aug 21, 2005. doi: 10.3748/wjg.v11.i31.4899
Disulfide-stabilized single-chain antibody-targeted superantigen: Construction of a prokaryotic expression system and its functional analysis
Jian-Li Wang, Yu-Ling Zheng, Ru Ma, Bao-Li Wang, Ai-Guang Guo, Yong-Qiang Jiang
Jian-Li Wang, Bao-Li Wang, Ai-Guang Guo, Department of Life Science, Northwest Sci-Tech University of Agriculture and Forestry, No. 22 Xi nong Road, Yangling 712100, Shaanxi Province, China
Yong-Qiang Jiang, Yu-Ling Zheng, Ru Ma, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, No. 20 Dongda Street, Fengtai District, Beijing 100071, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 30271478
Correspondence to: Yong-Qiang Jiang, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, No. 20 Dongda Street, Fengtai District, Beijing 100071, China. jiangyq@nic.bmi.ac.cn
Telephone: +86-10-6694-8487
Received: December 15, 2004
Revised: February 13, 2005
Accepted: February 18, 2005
Published online: August 21, 2005
Abstract

AIM: To construct the expression vector of B3 (scdsFv)-SEA (D227A) and to identify its binding and cytotoxic ability to B3 antigen positive carcinoma cell lines.

METHODS: This fusion protein was produced by a bacterial expression system in this study. It was expressed mainly in the inclusion body. The gene product was solubilized by guanidine hydrochloride, refolded by conventional dilution method, and purified using SP-sepharose cation chromatography.

RESULTS: The expression vector B3 (scdsFv)-SEA-PET was constructed, the expression product existed mainly in the inclusion body, the refolding product retained the binding ability of the single-chain antibody and had cytotoxic effect on HT-29 colon carcinoma cells. The stability assay showed that the resulting protein was stable at 37 °C.

CONCLUSION: This genetically engineered B3 (scdsFv)-SEA fusion protein has bifunction of tumor targeting and tumor cell killing and shows its promises as an effective reagent for tumor-targeted immunotherapy.

Keywords: B3 monoclonal antibody, Single-chain disulfide-stabilized Fv, Superantigen