Title Expression of Escherichia coli Heat-labile Enterotoxin B Subunit (LTB) in Saccharomyces cerevisiae
Author Mohammad Ahangarzadeh Rezaee1, Abbas Rezaee1,*, Seyed Mohammad Moazzeni1, Ali Hatef Salmanian2, Yoko Yasuda3, Kunio Tochikubo3, Shahin Najar Pirayeh1, and Mohsen Arzanlou1
Address 1Faculty of Medical Sciences, Tarbiat Modarres University, P.O.Box 14115-111, Tehran, Iran, 2National Institute for Genetic Engineering and Biotechnology (NIGEB), P.O.Box 14155-6343, Tehran, Iran, 3Department of Microbiology, Nagoya City University Medical School, Mizuho-ku, Nagoya 467-8601, Japan
Bibliography Journal of Microbiology, 43(4),354-360, 2005,
Key Words enterotoxigenic Escherichia coli, LTB, Saccharomyces cerevisiae, gene expression, immunoblotting
Abstract Heat-labile enterotoxin B subunit (LTB) of enterotoxigenic Escherichia coli (ETEC) is both a strong mucosal adjuvant and immunogen. It is a subunit vaccine candidate to be used against ETEC-induced diarrhea. It has already been expressed in several bacterial and plant systems. In order to construct yeast expressing vector for the LTB protein, the eltB gene encoding LTB was amplified from a human origin enterotoxigenic E. coli DNA by PCR. The expression plasmid pLTB83 was constructed by inserting the eltB gene into the pYES2 shuttle vector immediately downstream of the GAL1 promoter. The recombinant vector was transformed into S. cerevisiae and was then induced by galactose. The LTB protein was detected in the total soluble protein of the yeast by SDS-PAGE analysis. Quantitative ELISA showed that the maximum amount of LTB protein expressed in the yeast was approximately 1.9% of the total soluble protein. Immunoblotting analysis showed the yeast-derived LTB protein was antigenically indistinguishable from bacterial LTB protein. Since the whole-recombinant yeast has been introduced as a new vaccine formulation the expression of LTB in S. cerevisiae can offer an inexpensive yet effective strategy to protect against ETEC, especially in developing countries where it is needed most.
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