Microparticles That Form Immune Complexes as Modulatory Structures in Autoimmune Responses

Figure 4

Role of MPs in RA. The high concentrations of MPs from different leukocyte populations reported in the synovial fluid from RA patients must be citrullinated and form ICs with anti-CCP antibodies and RF autoantibodies. These complex structures could be recognized by Mo/MΦ through isotype-specific Fc receptors (FcγR and FcμR) and induce the production of proinflammatory cytokines such as TNF-alpha, IL-6, and the chemokines CCL2, CCL3, and RANTES. These soluble factors participate in the systemic inflammation in the synovium and the destructive changes observed in the joints of RA patients. IL-6 is also involved in the induction of plasma cells (PCs) producing autoantibodies.