IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by John, M.
Right arrow Articles by Ryan, E. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by John, M.
Right arrow Articles by Ryan, E. T.

 Previous Article  |  Next Article 

Infection and Immunity, March 2000, p. 1171-1175, Vol. 68, No. 3
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

In Vitro and In Vivo Analyses of Constitutive and In Vivo-Induced Promoters in Attenuated Vaccine and Vector Strains of Vibrio cholerae

Manohar John,1 Thomas I. Crean,1 Stephen B. Calderwood,1,2 and Edward T. Ryan1,*

Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts 02114,1 and Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 021152

Received 8 September 1999/Returned for modification 4 November 1999/Accepted 26 November 1999

The optimal promoter for in vivo expression of heterologous antigens by live, attenuated vaccine vector strains of Vibrio cholerae is unclear; in vitro analyses of promoter activity may not accurately predict expression of antigens in vivo. We therefore introduced plasmids expressing the B subunit of cholera toxin (CtxB) under the control of a number of promoters into V. cholerae vaccine strain Peru2. We evaluated the tac promoter, which is constitutively expressed in V. cholerae, as well as the in vivo-induced V. cholerae heat shock htpG promoter and the in vivo-induced V. cholerae iron-regulated irgA promoter. The functionality of all promoters was confirmed in vitro. In vitro antigenic expression was highest in vaccine strains expressing CtxB under the control of the tac promoter (2 to 5 µg/ml/unit of optical density at 600 nm [OD600]) and, under low-iron conditions, in strains containing the irgA promoter (5 µg/ml/OD600). We orally inoculated mice with the various vaccine strains and used anti-CtxB immune responses as a marker for in vivo expression of CtxB. The vaccine strain expressing CtxB under the control of the tac promoter elicited the most prominent specific anti-CtxB responses in vivo (serum immunoglobulin G [IgG], P <=  0.05; serum IgA, P <=  0.05; stool IgA, P <=  0.05; bile IgA, P <=  0.05), despite the finding that the tac and irgA promoters expressed equivalent amounts of CtxB in vitro. Vibriocidal antibody titers were equivalent in all groups of animals. Our results indicate that in vitro assessment of antigen expression by vaccine and vector strains of V. cholerae may correlate poorly with immune responses in vivo and that of the promoters examined, the tac promoter may be best suited for expression from plasmids of at least certain heterologous antigens in such strains.

* Corresponding author. Mailing address: Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114. Phone: (617) 726-3815. Fax: (617) 726-7416. E-mail: etryan{at}partners.org.

Infection and Immunity, March 2000, p. 1171-1175, Vol. 68, No. 3
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2000 by the American Society for Microbiology. All rights reserved.