T and B cells are not required for clearing Staphylococcus aureus in systemic infection despite a strong TLR2-MyD88-dependent T cell activation

J Immunol. 2011 Jan 1;186(1):443-52. doi: 10.4049/jimmunol.1001407. Epub 2010 Dec 3.

Abstract

Staphylococcus aureus infection elicits through its mature lipoproteins an innate immune response by TLR2-MyD88 signaling, which improves bacterial clearing and disease outcome. The role of dendritic cells (DCs) and T cells in this immune activation and the function of T and B cells in defense against S. aureus infection remain unclear. Therefore, we first evaluated DC and T cell activation after infection with S. aureus wild type (WT) and its isogenic mutant, which is deficient in lipoprotein maturation, in vitro. Lipoproteins in viable S. aureus contributed via TLR2-MyD88 to activation of DCs, which promoted the release of IFN-γ and IL-17 in CD4(+) T cells. This strong effect was independent of superantigens and MHC class II. We next evaluated the function of T cells and their cytokines IFN-γ and IL-17 in infection in vivo. Six days after systemic murine infection IFN-γ, IL-17, and IL-10 production in total spleen cells were MyD88-dependent and their levels increased until day 21. The comparison of CD3(-/-), Rag2(-/-), and C57BL/6 mice after infection revealed that IFN-γ and IL-17 originated from T cells and IL-10 originated from innate immune cells. Furthermore, vaccination of mice to activate T and B cells did not improve eradication of S. aureus from organs. In conclusion, S. aureus enhances DC activation via TLR2-MyD88 and thereby promotes T(H)1 and T(H)17 cell differentiation. However, neither T cells and their MyD88-regulated products, IFN-γ and IL-17, nor B cells affected bacterial clearing from organs and disease outcome.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / microbiology
  • Cell Differentiation / immunology
  • Dendritic Cells / immunology
  • Dendritic Cells / metabolism
  • Dendritic Cells / microbiology
  • Immunity, Innate
  • Interferon-gamma / biosynthesis
  • Interleukin-10 / biosynthesis
  • Interleukin-17 / biosynthesis
  • Lipoproteins / physiology
  • Lymphocyte Activation / immunology*
  • Mice
  • Myeloid Differentiation Factor 88 / physiology*
  • Signal Transduction / immunology
  • Staphylococcal Infections / immunology*
  • Staphylococcal Infections / metabolism
  • Staphylococcal Infections / microbiology*
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / growth & development
  • Staphylococcus aureus / immunology*
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism
  • T-Lymphocyte Subsets / microbiology
  • Toll-Like Receptor 2 / physiology*

Substances

  • Interleukin-17
  • Lipoproteins
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • Tlr2 protein, mouse
  • Toll-Like Receptor 2
  • Interleukin-10
  • Interferon-gamma