title: Identification of novel gammadelta T-cell subsets following bacterial infection in the absence of Vgamma1+ T cells: homeostatic control of gammadelta T-cell responses to pathogen infection by Vgamma1+ T cells.
abstract: Although gammadelta T cells are a common feature of many pathogen-induced immune responses, the factors that influence, promote, or regulate the response of individual gammadelta T-cell subsets to infection is unknown. Here we show that in the absence of Vgamma1+ T cells, novel subsets of gammadelta T cells, expressing T-cell receptor (TCR)-Vgamma chains that normally define TCRgammadelta+ dendritic epidermal T cells (DETCs) (Vgamma5+), intestinal intraepithelial lymphocytes (iIELs) (Vgamma7+), and lymphocytes associated with the vaginal epithelia (Vgamma6+), are recruited to the spleen in response to bacterial infection in TCR-Vgamma1-/- mice. By comparison of phenotype and structure of TCR-Vgamma chains and/or -Vdelta chains expressed by these novel subsets with those of their epithelium-associated counterparts, the Vgamma6+ T cells elicited in infected Vgamma1-/- mice were shown to be identical to those found in the reproductive tract, from where they are presumably recruited in the absence of Vgamma1+ T cells. By contrast, Vgamma5+ and Vgamma7+ T cells found in infected Vgamma1-/- mice were distinct from Vgamma5+ DETCs and Vgamma7+ iIELs. Functional analyses of the novel gammadelta T-cell subsets identified for infected Vgamma1-/- mice showed that whereas the Vgamma5+ and Vgamma7+ subsets may compensate for the absence of Vgamma1+ T cells by producing similar cytokines, they do not possess cytocidal activity and they cannot replace the macrophage homeostasis function of Vgamma1+ T cells. Collectively, these findings identify novel subsets of gammadelta T cells, the recruitment and activity of which is under the control of Vgamma1+ T cells.
authors.affiliation: Research Institute of Cellular and Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom.
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Newton
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Andrew
authors.forename: Jane E
authors.initials: JE
authors.lastname: Dalton
authors.forename: Rainy
authors.initials: R
authors.lastname: Mears
authors.forename: Simon R
authors.initials: SR
authors.lastname: Carding
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005260:Female; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D019675:Genes, T-Cell Receptor gamma; D006706:Homeostasis; D006801:Humans; D008089:Listeria monocytogenes / Q000276:immunology / Q000472:pathogenicity*; D008088:Listeriosis / Q000276:immunology* / Q000382:microbiology; D008213:Lymphocyte Activation; D017737:Macrophages, Peritoneal / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013154:Spleen / Q000166:cytology / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta