Regulation of autoreactive B cell responses to endogenous TLR ligands

Autoimmunity. 2010 Feb;43(1):76-83. doi: 10.3109/08916930903374618.


Immune complexes containing DNA and RNA are responsible for disease manifestations found in patients with systemic lupus erythematosus (SLE). B cells contribute to SLE pathology through BCR recognition of endogenous DNA- and RNA- associated autoantigens and delivery of these self-constituents to endosomal TLR9 and TLR7, respectively. B cell activation by these pathways leads to production of class-switched DNA- and RNA-reactive autoantibodies, contributing to an inflammatory amplification loop characteristic of disease. Intriguingly, self-DNA and RNA are typically non-stimulatory for TLR9/7 due to the absence of stimulatory sequences or the presence of molecular modifications. Recent evidence from our laboratory and others suggests that B cell activation by BCR/TLR pathways is tightly regulated by surface-expressed receptors on B cells, and the outcome of activation depends on the balance of stimulatory and inhibitory signals. Either IFNalpha engagement of the type I IFN receptor or loss of IgG ligation of the inhibitory FcgammaRIIB receptor promotes B cell activation by weakly stimulatory DNA and RNA TLR ligands. In this context, autoreactive B cells can respond robustly to common autoantigens. These findings have important implications for the role of B cells in vivo in the pathology of SLE.

Publication types

  • Review

MeSH terms

  • Animals
  • Autoantigens / immunology
  • B-Lymphocytes / immunology*
  • Disease Models, Animal
  • Humans
  • Immunity, Innate / immunology
  • Lupus Erythematosus, Systemic / immunology*
  • Lymphocyte Activation
  • Toll-Like Receptor 7 / immunology*
  • Toll-Like Receptor 9 / immunology*


  • Autoantigens
  • Toll-Like Receptor 7
  • Toll-Like Receptor 9