Evidence for the opposing roles of different gamma delta T cell subsets in macrophage homeostasis

Eur J Immunol. 2006 Jul;36(7):1729-38. doi: 10.1002/eji.200635959.

Abstract

To ensure invading pathogens are eliminated with minimal damage to host tissues it is essential that macrophage activation be tightly regulated. Previously we demonstrated that a subset of gammadelta T cells (Vgamma1(+)) contributes to resolving pathogen-induced immune responses by killing activated macrophages. However, the exaggerated macrophage response seen in infected Vgamma1(+) T cell-deficient mice suggests that gammadelta T cells play a broader role in macrophage homeostasis and other subsets might promote macrophage activation. Using a macrophage:gammadelta T cell co-culture system we have shown that gammadelta T cells increase the activity of macrophages activated in vivo by Listeria monocytogenes infection. In a dose-dependent manner, gammadelta T cells up-regulated production of cytokines (TNF-alpha, IL-6, IL-10) and chemokines (MIP-1alpha, MIP-1beta) by Listeria-elicited macrophages. The ability to increase macrophage cytokine production was prominent among Vgamma4(+) gammadelta T cells. Reciprocally, Vgamma4(+) gammadelta T cells were activated by Listeria-elicited macrophages, resulting in production of the anti-inflammatory cytokine, IL-10. gammadelta T cell adoptive transfer experiments showed that Vgamma4(+) T cells protected TCRdelta(-/-) mice against Listeria-induced liver injury and necrosis. These findings identify distinct and non-overlapping roles for gammadelta T cell subsets in regulating macrophage function during pathogen-induced immune responses.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chemokines / metabolism
  • Coculture Techniques
  • Dose-Response Relationship, Immunologic
  • Homeostasis / immunology*
  • Listeria monocytogenes / immunology
  • Macrophages / immunology*
  • Macrophages / metabolism
  • Macrophages / microbiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism*
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism*
  • T-Lymphocyte Subsets / microbiology

Substances

  • Chemokines
  • Receptors, Antigen, T-Cell, gamma-delta