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 Ascón, M. A.
Right arrow Articles by Pascual, D. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ascón, M. A.
Right arrow Articles by Pascual, D. W.

 Previous Article  |  Next Article 

Infection and Immunity, November 1998, p. 5470-5476, Vol. 66, No. 11
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Oral Immunization with a Salmonella typhimurium Vaccine Vector Expressing Recombinant Enterotoxigenic Escherichia coli K99 Fimbriae Elicits Elevated Antibody Titers for Protective Immunity

Miguel A. Ascón,1 David M. Hone,2 Nancy Walters,1 and David W. Pascual1,*

Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717,1 and Institute of Human Virology, Medical Biotechnology Center, University of Maryland Biotechnology Institute, Baltimore, Maryland 212012

Received 7 April 1998/Returned for modification 11 June 1998/Accepted 20 August 1998

Bovine enterotoxigenic Escherichia coli (ETEC) continues to cause mortality in piglets and newborn calves. In an effort to develop a safe and effective vaccine for the prevention of F5+ ETEC infections, a balanced lethal asd+ plasmid carrying the complete K99 operon was constructed and designated pMAK99-asd+. Introduction of this plasmid into an attenuated Salmonella typhimurium Delta aro Delta asd strain, H683, resulted in strain AP112, which stably expresses E. coli K99 fimbriae. A single oral immunization of BALB/c and CD-1 mice with strain AP112 elicited significant mucosal immunoglobulin A (IgA) titers that remained elevated for >11 weeks. IgA and IgG responses in serum specific for K99 fimbriae were also induced, with a prominent IgG1, as well as IgG2a and IgG2b, titer. To assess the derivation of these antibodies, a K99 isotype-specific B-cell ELISPOT analysis was conducted by using mononuclear cells from the lamina propria of the small intestines (LP), Peyer's patches (PP), and spleens of vaccinated and control BALB/c mice. This analysis revealed elevated numbers of K99 fimbria-specific IgA-producing cells in the LP, PP, and spleen, whereas elevated K99 fimbria-specific IgG-producing cells were detected only in the PP and spleen. These antibodies were important for protective immunity. One-day-old neonates from dams orally immunized with AP112 were provided passive protection against oral challenge with wild-type ETEC, in contrast to challenged neonates from unvaccinated dams or from dams vaccinated with a control Salmonella vector. These results confirm that oral Salmonella vaccine vectors effectively deliver K99 fimbriae to mucosal inductive sites for sustained elevation of IgA and IgG antibodies and for eliciting protective immunity.

* Corresponding author. Mailing address: Veterinary Molecular Biology, Montana State University, Bozeman, MT 59717-3610. Phone: (406) 994-6244. Fax: (406) 994-4303. E-mail: dpascual{at}montana.edu.

Infection and Immunity, November 1998, p. 5470-5476, Vol. 66, No. 11
0019-9567/98/$04.00+0
Copyright © 1998, 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 © 1998 by the American Society for Microbiology. All rights reserved.