title: The interaction of gamma delta T cells with activated macrophages is a property of the V gamma 1 subset.
abstract: Immunoregulation is an emerging paradigm of gammadelta T cell function. The mechanisms by which gammadelta T cells mediate this function, however, are not clear. Studies have identified a direct role for gammadelta T cells in resolving the host immune response to infection, by eliminating populations of activated macrophages. The aim of this study was to identify macrophage-reactive gammadelta T cells and establish the requirements/outcomes of macrophage-gammadelta T cell interactions during the immune response to the intracellular bacterium, Listeria monocytogenes (Lm). Using a macrophage-T cell coculture system in which peritoneal macrophages from naive or Lm-infected TCRdelta(-/-) mice were incubated with splenocytes from naive and Lm-infected alphabeta/gammadelta T cell-deficient and wild-type mice, the ability to bind macrophages was shown to be restricted to gammadelta T cells and the GV5S1 (Vgamma1) subset of gammadelta T cells. Macrophage adherence resulted in a 4- to 10-fold enrichment of Vgamma1(+) T cells. Enrichment of Vgamma1 T cells was dependent upon the activation status of macrophages, but independent of the activation status of gammadelta T cells. Vgamma1 T cells were cytotoxic for activated macrophages with both the binding to and killing of macrophages being TCR dependent because anti-TCRgammadelta Abs inhibited both Vgamma1 binding and killing activities. These studies establish the identity of macrophage cytotoxic gammadelta T cells, the conditions under which this interaction occurs, and the outcome of this interaction. These findings are concordant with the involvement of Vgamma1 T cells in macrophage homeostasis during the resolution of pathogen-mediated immune responses.
authors.affiliation: School of Biochemistry and Molecular Biology, University of Leeds, Leeds, United Kingdom.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Dalton
authors.forename: Jayne
authors.initials: J
authors.lastname: Pearson
authors.forename: Phillip
authors.initials: P
authors.lastname: Scott
authors.forename: Simon R
authors.initials: SR
authors.lastname: Carding
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000276:immunology; D002450:Cell Communication / Q000276:immunology*; D016923:Cell Death / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D008089:Listeria monocytogenes / Q000254:growth & development / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008262:Macrophage Activation / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta