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ISSN 0582-9879 Acta Biochim et Biophysica Sinica 2004, 36(6):430-436 CN 31-1300/Q

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Human Recombinant B7-H3 Expressed in E. coli Enhances T Lymphocyte Proliferation and IL-10 Secretion in Vitro

Guang-Bo ZHANG^#, Yong-Jing CHEN^#, Qin SHI, Hong-Bing MA, Yan GE, Qin WANG, Zhi JIANG, Ying XU, and Xue-Guang ZHANG*

Institute of Biotechnology, Soochow University, Key Laboratory of Clinical Immunology of Jiangsu Province, Suzhou 215007, China

Abstract To explore the biofunctions of human B7-H3 on activated T lymphocyte, the gene of human B7-H3 encoding the extracellular region (IgV-like and IgC-like domains) was obtained by RT-PCR from human lung cells and subcloned into the prokaryotic expression vector pGEX-5X-3 to express glutathione S-transferase (GST) fusion protein. A 49 kD fusion protein (named as GST/hB7-H3 hereafter) was induced by IPTG and purified by standard methods reported in prokaryotic system. In the presence of the first signal imitated by anti-CD₃ monoclonal antibody, T lymphocyte proliferation was observed by incubating purified T cells with soluble GST/hB7-H3 fusion protein by MTT assay. The concentrations of IFN-g and IL-10 in the supernatants of T cells were determined by ELISA. The results showed that the GST/hB7-H3 protein produced in bacteria had modest biological activities to proliferate the T lymphocyte and enhance IFN-g as well as IL-10 secretion.

Key words B7-H3; GST-fusion protein; T lymphocyte proliferation

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Received: February 24, 2004 Accepted: March 26, 2004

This work was supported by the grants from the National Basic Research Program (No. 2001CB51003) and the National Natural Science Foundation of China (300330540)

^#These two authors contributed equally to this work

*Corresponding author: Tel/Fax, 86-512-65104908; E-mail, [email protected]