Staphylococcus aureus infection of mice expands a population of memory γδ T cells that are protective against subsequent infection

J Immunol. 2014 Apr 15;192(8):3697-708. doi: 10.4049/jimmunol.1303420. Epub 2014 Mar 12.

Abstract

The development of vaccines against Staphylococcus aureus has consistently failed in clinical trials, likely due to inefficient induction of cellular immunity. T cell-derived IL-17 is one of the few known correlates of antistaphylococcoal immunity, conferring protection against S. aureus infections through its ability to promote phagocytic cell effector functions. A comprehensive understanding of the discrete T cell subsets critical for site-specific IL-17-mediated bacterial clearance will therefore be necessary to inform the development of vaccines that efficiently target cellular immunity. In this study, we have identified a population of CD44+ CD27- memory γδ T cells, expanded upon infection of C57BL/6 mice with S. aureus, which produce high levels of IL-17 and mediate enhanced bacterial clearance upon reinfection with the bacterium. These cells are comprised largely of the Vγ4+ subset and accumulate at the site of infection subsequent to an initial Vγ1.1+ and Vγ2+ T cell response. Moreover, these Vγ4+ T cells are retained in the peritoneum and draining mediastinal lymph nodes for a prolonged period following bacterial clearance. In contrast to its critical requirement for γδ T cell activation during the primary infection, IL-1 signaling was dispensable for activation and expansion of memory γδ T cells upon re-exposure to S. aureus. Our findings demonstrate that a γδ T cell memory response can be induced upon exposure to S. aureus, in a fashion analogous to that associated with classical αβ T cells, and suggest that induction of IL-17-expressing γδ T cells may be an important property of a protective vaccine against S. aureus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adoptive Transfer
  • Animals
  • Cytokines / genetics
  • Cytokines / metabolism
  • Disease Models, Animal
  • Female
  • Gene Expression Regulation
  • Immunity, Innate
  • Immunologic Memory*
  • Interleukin-17 / biosynthesis
  • Interleukin-17 / genetics
  • Male
  • Mice
  • Mice, Knockout
  • Peritonitis / immunology
  • Peritonitis / microbiology
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism*
  • Signal Transduction
  • Staphylococcal Infections / genetics
  • Staphylococcal Infections / immunology*
  • Staphylococcal Infections / metabolism
  • Staphylococcal Infections / therapy
  • Staphylococcus aureus / immunology*
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism*

Substances

  • Cytokines
  • Interleukin-17
  • Receptors, Antigen, T-Cell, gamma-delta