T-independent activation-induced cytidine deaminase expression, class-switch recombination, and antibody production by immature/transitional 1 B cells

J Immunol. 2007 Mar 15;178(6):3593-601. doi: 10.4049/jimmunol.178.6.3593.

Abstract

Inflammation elicits a splenic lymphopoiesis of unknown physiologic significance but one that juxtaposes developing B cells and exogenous Ag. We show that immature and transitional 1 (immature/T1) B cells constitutively express activation-induced cytidine deaminase and B lymphocyte-induced maturation protein 1 in amounts that support accelerated plasmacytic differentiation and limited class-switch recombination. In vivo, activation of immature/T1 B cells by TLR ligands or bacterial vaccine rapidly induces T1 cells to divide, proliferate, and secrete IgM, IgG, or IgA Ab; in vitro, proliferation and differentiation are substantially enhanced by B cell-activating factor. We propose that inflammation-induced extramedullary lymphopoiesis represents a specialized mechanism for innate Ab responses to microbial pathogens.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibody Formation*
  • B-Cell Activating Factor / biosynthesis
  • B-Cell Activating Factor / immunology
  • Bacterial Vaccines / immunology*
  • Cell Division / immunology
  • Cytidine Deaminase / biosynthesis*
  • Cytidine Deaminase / immunology
  • Gene Expression Regulation, Enzymologic / immunology*
  • Immunity, Innate
  • Immunoglobulin Class Switching / immunology*
  • Immunoglobulins / biosynthesis
  • Immunoglobulins / immunology
  • Lymphopoiesis / immunology
  • Mice
  • Mice, Knockout
  • Mice, Nude
  • Plasma Cells / immunology*
  • Plasma Cells / metabolism
  • Spleen / immunology
  • Spleen / metabolism
  • Toll-Like Receptors / agonists
  • Toll-Like Receptors / immunology

Substances

  • B-Cell Activating Factor
  • Bacterial Vaccines
  • Immunoglobulins
  • Toll-Like Receptors
  • AICDA (activation-induced cytidine deaminase)
  • Cytidine Deaminase