Article

Positive selection is not required for thymic maturation of transgenic gamma delta T cells.

Laboratory of Cellular and Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0420, USA.
Journal of Experimental Medicine (Impact Factor: 13.91). 06/1996; 183(5):2033-41. DOI: 10.1084/jem.183.5.2033
Source: PubMed

ABSTRACT Previously published reports describing thymic differentiation in two TCR gamma delta transgenic mouse models have suggested that gamma delta T cells require MHC-mediated positive selection to reach full maturity. Recent studies indicate that recognition of antigen by mature gamma delta T cells is not MHC restricted, raising the issue of why developing gamma delta T cells would even require MHC-driven positive selection. Therefore, we have reinvestigated the requirements for development and selection in G8 gamma delta T cell receptor (TCR) transgenic mice. Analyses of absolute cell numbers, phenotypic subsets, and functional competence of thymic and peripheral G8 gamma delta T cells indicate that these cells can fully mature in class I MHC-deficient mice. Moreover, mixed bone marrow chimeras demonstrate that gamma delta T cells of mutant B2-microglobulin (beta 2m zero) origin are partially deleted in the presence of H-2d-bearing thymocytes (previously believed to be the haplotype mediating positive selection). We conclude that there is no requirement for class I-like molecules for the maturation/development of these transgenic gamma delta T cells and that the differences in thymocyte phenotype and number observed are, instead, attributable to effects of clonal deletion.

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Available from: Edina Schweighoffer, Apr 02, 2015
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