HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Published online before print November 2, 2004

This Article Full Text (Reprint (PDF)) All Versions of this Article: jlb.0804482v1 77/2/199    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lahmers, K. K. Articles by Brown, W. C. Search for Related Content PubMed PubMed Citation Articles by Lahmers, K. K. Articles by Brown, W. C.

© by The Society for Leukocyte Biology
Journal of Leukocyte Biology, doi:10.1189/jlb.0804482

Received for publication August 31, 2004.
Revised October 6, 2004.
Accepted for publication October 9, 2004.

Article

The CD4⁺ T cell immunodominant Anaplasma marginale major surface protein 2 stimulates T cell clones that express unique T cell receptors

Kevin K. Lahmers ^*, Junzo Norimine ^*, Mitchell S. Abrahamsen , Guy H. Palmer ^*, and Wendy C. Brown ^*@

*Department of Veterinary Microbiology and Pathology, Washington State University, Pullman; and Department of Veterinary Pathobiology, University of Minnesota, St. Paul

^@ To whom correspondence should be addressed. E-mail: wbrown{at}vetmed.wsu.edu.

	Abstract

Major surface protein 2 (MSP2) of the bovine rickettsial pathogen Anaplasma marginale is an abundant, serologically immunodominant outer membrane protein. Immunodominance partially results from numerous CD4⁺ T cell epitopes in highly conserved amino and carboxy regions and the central hypervariable region of MSP2. However, in long-term cultures of lymphocytes stimulated with A. marginale, workshop cluster 1 (WC1)⁺ T cells and CD4⁺ T cells proliferated, leading to a predominance of T cells. As T cells proliferate in A. marginale-stimulated lymphocyte cultures, this study hypothesized that T cells respond to the abundant, immunodominant MSP2. To test this hypothesis, T cell clones were isolated from MSP2 vaccinates and assessed for antigen-specific proliferation and interferon- secretion. Seven WC1⁺ T cell clones responded to A. marginale and MSP2, and three of these proliferated to overlapping peptides from the conserved carboxy region. The T cell response was not major histocompatibility complex-restricted, although it required antigen-presenting cells and was blocked by addition of antibody specific for the T cell receptor (TCR). Sequence analysis of TCR- and - chains of peripheral blood lymphocytes identified two novel TCR- chain constant (C) regions. It is important that all seven MSP2-specific T cell clones used the same one of these novel C regions. The TCR complementarity-determining region 3 was less conserved than those of MSP2-specific CD4⁺ T cell clones. Together, these data indicate that WC1⁺ T cells recognize A. marginale MSP2 through the TCR and contribute to the immunodominant response to this protein.

Key Words: MSP2 • TCR • bovine

This article has been cited by other articles:

				K. K. Lahmers, J. F. Hedges, M. A. Jutila, M. Deng, M. S. Abrahamsen, and W. C. Brown Comparative gene expression by WC1+ {gamma}{delta} and CD4+ {alpha}{beta} T lymphocytes, which respond to Anaplasma marginale, demonstrates higher expression of chemokines and other myeloid cell-associated genes by WC1+ {gamma}{delta} T cells. J. Leukoc. Biol., October 1, 2006; 80(4): 939 - 952. [Abstract] [Full Text] [PDF]

				J. R. Abbott, G. H. Palmer, K. A. Kegerreis, P. F. Hetrick, C. J. Howard, J. C. Hope, and W. C. Brown Rapid and Long-Term Disappearance of CD4+ T Lymphocyte Responses Specific for Anaplasma Marginale Major Surface Protein-2 (MSP2) in MSP2 Vaccinates following Challenge with Live A. marginale J. Immunol., June 1, 2005; 174(11): 6702 - 6715. [Abstract] [Full Text] [PDF]