Antiphospholipid antibodies mediate autoimmunity against dying cells

Autoimmunity. 2013 Aug;46(5):302-6. doi: 10.3109/08916934.2013.783025. Epub 2013 May 29.

Abstract

The Antiphospholipid Syndrome (APS) is characterized by thrombosis and pregnancy loss, clinical events mediated by pathogenic anti-phospholipid autoantibodies (aPL). β2-glycoprotein I (β2GPI) is the major autoantigens recognized by aPL. β2GPI is a cationic protein that binds to negatively charged surfaces such as those of apoptotic cells. This feature may lead to two major events: i) immunization with β2GPI fosters the Fc-receptor-mediated uptake by antigen presenting cells of apoptotic material decorated with β2GPI and the activation of β2GPI-specific T cells which in turn provide help to β2GPI-specific B cells for the production of anti-β2GPI; ii) apoptotic bodies decorated with β2GPI can be opsonized by anti-β2GPI and shifted towards a pro-inflammatory clearance by macrophages; epitope spread can occur with the generation of autoimmunity against nuclear autoantigens. In the presence of a predisposing genetic background and of a particular cytokine environment (type I interferons), the sequential emergence of autoantibodies can evolve into overt clinical disease. The spectrum of clinical phenotypes of the patients can be modulated by several factors affecting the pathogenicity of anti-β2GPI (e.g. domain specificity). We conclude that dying cells may play a dual role in APS: (I) as immunogen for the induction of aPL (etiology) and (II) as targets of aPL for the chronification of inflammation and the development of autoimmune diseases (pathology).

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Antibodies, Antiphospholipid / biosynthesis
  • Antibodies, Antiphospholipid / physiology*
  • Apoptosis / genetics
  • Apoptosis / immunology
  • Autoantibodies / biosynthesis
  • Autoimmunity / genetics
  • Autoimmunity / immunology*
  • Cell Death / genetics
  • Cell Death / immunology*
  • Disease Models, Animal
  • Humans
  • beta 2-Glycoprotein I / biosynthesis
  • beta 2-Glycoprotein I / immunology

Substances

  • Antibodies, Antiphospholipid
  • Autoantibodies
  • beta 2-Glycoprotein I