Journal article
The CD4+ T cell immunodominant Anaplasma marginale major surface protein 2 stimulates γδ T cell clones that express unique T cell receptors
Journal of leukocyte biology, Vol.77(2), pp.199-208
02/2005
Handle:
https://hdl.handle.net/2376/109237
PMID: 15522917
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)+ γδ T cells and CD4+ αβ T cells proliferated, leading to a predominance of γδ T cells. As γδ T cells proliferate in A. marginale‐stimulated lymphocyte cultures, this study hypothesized that γδ T cells respond to the abundant, immunodominant MSP2. To test this hypothesis, γδ T cell clones were isolated from MSP2 vaccinates and assessed for antigen‐specific proliferation and interferon‐γ secretion. Seven WC1+ γδ T cell clones responded to A. marginale and MSP2, and three of these proliferated to overlapping peptides from the conserved carboxy region. The γδ 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‐γ and ‐δ chains of peripheral blood lymphocytes identified two novel TCR‐γ chain constant (Cγ) regions. It is important that all seven MSP2‐specific γδ T cell clones used the same one of these novel Cγ regions. The TCR complementarity‐determining region 3 was less conserved than those of MSP2‐specific CD4+ αβ T cell clones. Together, these data indicate that WC1+ γδ T cells recognize A. marginale MSP2 through the TCR and contribute to the immunodominant response to this protein.
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Details
- Title
- The CD4+ T cell immunodominant Anaplasma marginale major surface protein 2 stimulates γδ T cell clones that express unique T cell receptors
- Creators
- Kevin K LahmersJunzo NorimineMitchell S AbrahamsenGuy H PalmerWendy C Brown
- Publication Details
- Journal of leukocyte biology, Vol.77(2), pp.199-208
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Number of pages
- 10
- Grant note
- USDA National Research Initiative Competitive Grants Program (00‐52100‐9612) NIH National Institute of Allergy and Infectious Diseases (R01‐AI44005; K08‐AI53594)
- Identifiers
- 99900547269101842
- Language
- English
- Resource Type
- Journal article