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 Brown, W. C.
Right arrow Articles by Palmer, G. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Brown, W. C.
Right arrow Articles by Palmer, G. H.

 Previous Article  |  Next Article 

Infection and Immunity, November 1998, p. 5406-5413, Vol. 66, No. 11
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

CD4+ T-Lymphocyte and Immunoglobulin G2 Responses in Calves Immunized with Anaplasma marginale Outer Membranes and Protected against Homologous Challenge

Wendy C. Brown,1,* Varda Shkap,2 Daming Zhu,1 Travis C. McGuire,1 Wenbin Tuo,1 Terry F. McElwain,1 and Guy H. Palmer1

Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164,1 and Department of Parasitology, Kimron Veterinary Institute, Bet-Dagan, Israel2

Received 26 May 1998/Returned for modification 28 July 1998/Accepted 4 September 1998

Protective immunity against the ehrlichial pathogen Anaplasma marginale has been hypothesized to require induction of immunoglobulin G2 (IgG2) antibody against outer membrane protein epitopes and coordinated activation of macrophages for phagocytosis and killing. In the present study, cell-mediated immune responses, including induction of IgG isotype switching, were characterized in calves immunized with purified outer membranes of the Florida strain of A. marginale. Importantly, these calves were subsequently shown to be protected upon experimental challenge with the Florida strain, and calves which developed the highest IgG2 titers were completely protected against infection. Peripheral blood mononuclear cells (PBMC) obtained after immunization proliferated strongly in response to both whole A. marginale homogenates and purified outer membranes, and this responsiveness persisted until the time of challenge. Responding cells were shown to be CD4+ T cells, and CD4+ T-cell lines cultured for 2 to 4 weeks also proliferated specifically in response to A. marginale and produced high titers of gamma interferon. The helper T-cell response included recognition of conserved epitopes, as PBMC proliferation was stimulated by the homologous Florida strain, four genetically distinct A. marginale strains, and Anaplasma ovis. The outer membrane proteins stimulating the PBMC responses in protected calves included major surface proteins (MSPs) MSP-1, MSP-2, and MSP-3, which were previously shown to induce partial protection against infection. These studies demonstrate, for the first time, potent helper T-cell responses in cattle protectively immunized with outer membranes against A. marginale challenge and identify three MSPs that are recognized by immune T cells. These experiments provide the basis for subsequent identification of the helper T-cell epitopes on MSP-1, MSP-2, and MSP-3 that are needed to evoke anamnestic antibody and effector T-cell responses elicited by protein or nucleic acid immunization.

* Corresponding author. Mailing address: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040. Phone: (509) 335-6067. Fax: (509) 335-8529. E-mail: wbrown{at}vetmed.wsu.edu.

Infection and Immunity, November 1998, p. 5406-5413, 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.