Antigen-induced B cell apoptosis is independent of complement C4

Clin Exp Immunol. 2007 Oct;150(1):132-9. doi: 10.1111/j.1365-2249.2007.03456.x. Epub 2007 Jul 23.

Abstract

Deficiencies in early complement components are associated with the development of systemic lupus erythematosus (SLE) and therefore early complement components have been proposed to influence B lymphocyte activation and tolerance induction. A defect in apoptosis is a potential mechanism for breaking of peripheral B cell tolerance, and we hypothesized that the lack of the early complement component C4 could initiate autoimmunity through a defect in peripheral B lymphocyte apoptosis. Previous studies have shown that injection of a high dose of soluble antigen, during an established primary immune response, induces massive apoptotic death in germinal centre B cells. Here, we tested if the antigen-induced apoptosis within germinal centres is influenced by early complement components by comparing complement C4-deficient mice with C57BL/6 wild-type mice. We demonstrate that after the application of a high dose of soluble antigen in wild-type mice, antibody levels declined temporarily but were restored almost completely after a week. However, after antigen-induced apoptosis, B cell memory was severely limited. Interestingly, no difference was observed between wild-type and complement C4-deficient animals in the number of apoptotic cells, restoration of antibody levels and memory response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens / immunology
  • Apoptosis / immunology*
  • B-Lymphocytes / immunology*
  • Complement C4 / deficiency*
  • Complement C4 / immunology*
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Germinal Center / immunology
  • Immune Tolerance
  • Immunologic Memory
  • Lupus Erythematosus, Systemic / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Nitrophenols / immunology
  • Phenylacetates

Substances

  • Antigens
  • Complement C4
  • Nitrophenols
  • Phenylacetates
  • 4-hydroxy-5-nitrophenyl acetic acid