TLR-activated B cells suppress T cell-mediated autoimmunity

J Immunol. 2008 Apr 1;180(7):4763-73. doi: 10.4049/jimmunol.180.7.4763.

Abstract

TLR sense microbial infections, and control activation of immune responses. Dendritic cells, macrophages, and B lymphocytes express TLR and the TLR-signaling adaptor protein MyD88. The impact of TLR-activated B cells on T cell-mediated inflammation is unknown. In this study, we have used mice carrying B cell-restricted deficiencies in MyD88 or in distinct TLR to examine the impact of TLR-activated B cells on a T cell-mediated autoimmune disease, experimental autoimmune encephalomyelitis (EAE). We demonstrate that TLR-signaling in B cells suppresses inflammatory T cell responses (both Th1 and Th17), and stimulates recovery from EAE. Only certain TLR are required on B cells for resolution of EAE, and these are dispensable for disease initiation, indicating that a category of TLR agonists preferentially triggers a suppressive function in B cells and thereby limits autoimmune disease. The TLR agonists controlling the regulatory function of B cells are provided by components of Mycobacterium tuberculosis present in the adjuvant. Thus, MyD88 signaling in B cells antagonizes MyD88 signaling in other cells, which drives differentiation of Th17 cells and is required for induction of EAE. Altogether, our data indicate that B cells link recognition of microbial products via TLR to suppression of a T cell-mediated autoimmune disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoimmunity / immunology*
  • B-Lymphocytes / immunology*
  • Dendritic Cells / immunology
  • Encephalomyelitis, Autoimmune, Experimental / genetics
  • Encephalomyelitis, Autoimmune, Experimental / immunology
  • Encephalomyelitis, Autoimmune, Experimental / metabolism
  • Interleukin-10 / deficiency
  • Interleukin-10 / genetics
  • Interleukin-10 / immunology
  • Interleukin-10 / metabolism
  • Lymphocyte Activation / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mycobacterium tuberculosis / immunology
  • Myeloid Differentiation Factor 88 / deficiency
  • Myeloid Differentiation Factor 88 / genetics
  • Myeloid Differentiation Factor 88 / immunology
  • Myeloid Differentiation Factor 88 / metabolism
  • Signal Transduction / immunology
  • T-Lymphocytes / immunology*
  • Toll-Like Receptors / agonists
  • Toll-Like Receptors / immunology*

Substances

  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • Toll-Like Receptors
  • Interleukin-10