title: Expression of Escherichia coli heat-labile enterotoxin B subunit (LTB) in Saccharomyces cerevisiae.
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.
authors.affiliation: Faculty of Medical Sciences, Tarbiat Modarres University, P.O.Box 14115-111, Tehran, Iran.
authors.forename: Mohammad Ahangarz
authors.initials: MA
authors.lastname: Rezaee
authors.forename: Abbas
authors.initials: A
authors.lastname: Rezaee
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Moazzeni
authors.forename: Ali Hatef
authors.initials: AH
authors.lastname: Salmanian
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Kunio
authors.initials: K
authors.lastname: Tochikubo
authors.forename: Shahin Najar
authors.initials: SN
authors.lastname: Pirayeh
authors.forename: Mohsen
authors.initials: M
authors.lastname: Arzanlou
mesh_terms: D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics; D001428:Bacterial Vaccines / Q000096:biosynthesis* / Q000235:genetics; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000096:biosynthesis* / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000276:immunology / Q000517:prevention & control; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D005822:Genetic Vectors; D006801:Humans; D015151:Immunoblotting; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D014170:Transformation, Genetic; D022223:Vaccines, Subunit / Q000276:immunology
chemical_list: D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; C027538:heat-labile enterotoxin, E coli