Serum from patients with SLE instructs monocytes to promote IgG and IgA plasmablast differentiation

J Exp Med. 2012 Jul 2;209(7):1335-48. doi: 10.1084/jem.20111644. Epub 2012 Jun 11.

Abstract

The development of autoantibodies is a hallmark of systemic lupus erythematosus (SLE). SLE serum can induce monocyte differentiation into dendritic cells (DCs) in a type I IFN-dependent manner. Such SLE-DCs activate T cells, but whether they promote B cell responses is not known. In this study, we demonstrate that SLE-DCs can efficiently stimulate naive and memory B cells to differentiate into IgG- and IgA-plasmablasts (PBs) resembling those found in the blood of SLE patients. SLE-DC-mediated IgG-PB differentiation is dependent on B cell-activating factor (BAFF) and IL-10, whereas IgA-PB differentiation is dependent on a proliferation-inducing ligand (APRIL). Importantly, SLE-DCs express CD138 and trans-present CD138-bound APRIL to B cells, leading to the induction of IgA switching and PB differentiation in an IFN-α-independent manner. We further found that this mechanism of providing B cell help is relevant in vivo, as CD138-bound APRIL is expressed on blood monocytes from active SLE patients. Collectively, our study suggests that a direct myeloid DC-B cell interplay might contribute to the pathogenesis of SLE.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Autoantibodies / immunology
  • Autoantibodies / pharmacology
  • B-Cell Activating Factor / immunology
  • B-Cell Activating Factor / metabolism
  • B-Lymphocytes / drug effects
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism
  • Cell Differentiation / drug effects
  • Cell Differentiation / immunology*
  • Cells, Cultured
  • Child
  • Child, Preschool
  • Coculture Techniques
  • Dendritic Cells / drug effects
  • Dendritic Cells / immunology
  • Dendritic Cells / metabolism
  • Female
  • Flow Cytometry
  • Humans
  • Immunoglobulin A / immunology
  • Immunoglobulin G / immunology
  • Infant
  • Interleukin-10 / immunology
  • Interleukin-10 / metabolism
  • Lupus Erythematosus, Systemic / blood
  • Lupus Erythematosus, Systemic / immunology*
  • Male
  • Monocytes / drug effects
  • Monocytes / immunology*
  • Monocytes / metabolism
  • Plasma Cells / drug effects
  • Plasma Cells / immunology*
  • Plasma Cells / metabolism
  • Serum / immunology
  • Syndecan-1 / immunology
  • Syndecan-1 / metabolism
  • Tumor Necrosis Factor Ligand Superfamily Member 13 / immunology
  • Tumor Necrosis Factor Ligand Superfamily Member 13 / metabolism
  • Young Adult

Substances

  • Autoantibodies
  • B-Cell Activating Factor
  • Immunoglobulin A
  • Immunoglobulin G
  • Syndecan-1
  • Tumor Necrosis Factor Ligand Superfamily Member 13
  • Interleukin-10