Article

Positive selection of MHC class Ib-restricted CD8(+) T cells on hematopoietic cells.

Department of Immunology and Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
Nature Immunology (Impact Factor: 24.97). 09/2002; 3(8):772-9. DOI: 10.1038/ni814
Source: PubMed

ABSTRACT Unlike conventional CD8(+) T cells, major histocompatibility complex (MHC) class Ib-restricted CD8(+) T cells show an activated phenotype in uninfected mice and respond rapidly to foreign invaders. The underlying factors that contribute to these differences are not well understood. We show here that the activated phenotype of MHC class Ib-restricted CD8(+) T cells was partially acquired as a result of interactions in the thymus and reflected an increased capacity to be selected via interactions with MHC molecules on hematopoietic cells. Using bone marrow-chimeric mice, we have shown that MHC class Ib-restricted, but not MHC class Ia-restricted, CD8(+) T cells specific for Listeria monocytogenes were efficiently selected when MHC class I was expressed only on hematopoietic cells. Thus, the distinct functional properties of MHC class Ib-restricted versus MHC class Ia-restricted CD8(+) T cells may result, at least in part, from the different ways in which they are positively selected in the thymus.

Full-text

Available from: Kevin B Urdahl, May 07, 2015
0 Followers
 · 
80 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The intracellular pathogen Mycobacterium tuberculosis (Mtb) and its human host have long co-evolved. Although the host cellular immune response is critical to the control of the bacterium information on the specific contribution of different immune cell subsets in humans is incomplete. Mucosal associated invariant T (MAIT) cells are a prevalent and unique T-cell population in humans with the capacity to detect intracellular infection with bacteria including Mtb. MAIT cells detect bacterially derived metabolites presented by the evolutionarily conserved major histocompatibility complex-like molecule MR1. Here, we review recent advances in our understanding of this T-cell subset and address the potential roles for MR1-restricted T cells in the control, diagnosis, and therapy of tuberculosis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
    Immunological Reviews 03/2015; 264(1). DOI:10.1111/imr.12271 · 12.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Prepublished online 8 J Immunol Material Supplementary 5.DC1.html http://www.jimmunol.org/content/suppl/2011/04/08/jimmunol.100282 expressing promyelocytic leukemia zinc finger protein (PLZF) show an innate property both in mice and humans. In this article, we report that the thymic T–T interaction is essential for the conversion of CD8 + T cells into innate phenotype in the physiological condition. CD8 + T cells developed in the presence of PLZF + CD4 + T cells showed marked upregulation of eomesodermin (Eomes), activation/memory phenotype, and rapid production of IFN-g on ex vivo stimulation. Their development was highly dependent on the PLZF expression in T–T CD4 + T cells and the IL-4 secreted by PLZF + T–T CD4 + T cells. The same events may take place in humans, as a substantial number of Eomes expressing innate CD8 + T cells were found in human fetal thymi and spleens. It suggests that PLZF + T–T CD4 + T cells in combination with Eomes + CD8 + T cells might actively participate in the innate immune response against various pathogens, particularly in human perinatal period. The Journal of Immunology, 2011, 186: 5749–5757. I nnate or nonconventional T cells represent a distinct lineage of T cells restricted by nonclassical MHC class Ib molecules expressed mainly on hematopoietic cells (1–5). During thy-mic ontogeny, these cells acquire memory markers (CD44 hi CD122 hi NK1.1 int) as a result of a maturation process in the ab-sence of antigenic encounters. In general, innate T cells have several features in common, such as a rapid response on antigenic encounter and dependence on IL-15, the B7–CD28 interaction, and the signaling lymphocytic activation molecule-associated protein (SLAM–SAP) signaling pathway (3, 4). To date, in-variant NKT (iNKT) cells, gd T cells, mucosa-associated invariant T (MAIT) cells, H2-M3–restricted CD8 + T cells, and CD8aa +
    The Journal of Immunology 01/2011; 186(10):5749. · 5.36 Impact Factor
  • Source