The role of B cells, IgG and Fcγ receptor signalling in health and disease (BIgG) 

Summary

IgG antibodies are the soluble effector molecules of the adaptive immune system. They are critical for defence against a variety of microbes but may also be pathogenic in some autoimmune diseases and in organ transplant rejection. Many effector functions of antibody are mediated via the binding of the Fc portion of IgG to cell surface Fcgamma receptors (FcgRs). FcgRs are expressed by most cells of the immune system. 

Previously, we have investigated the role of the inhibitory receptor FcyRIIB in susceptibility to autoimmunity. Mice deficient in FcgRIIB are susceptible to autoimmune diseases. We showed that in humans, a single nucleotide polymorphism (SNP) in the FCGR2B gene (rs1050501) results in profound receptor dysfunction, and contributes to susceptibility to systemic lupus erythematosus (SLE). 

More recently, we have shown that IgG immune complexes can stimulate an expansion of lymphatic conduits within lymph nodes and how immune complexes affect DC chemotaxis and trafficking. The migration of DCs from tissues to draining lymph nodes is critical for their function, as it is here that they present peripherally acquired antigen to CD4 T cells, enforcing tolerance or initiating an immune response. 

Participation: For this study we recruited 12 participants from the Cambridge BioResource. Visits took place at the Cambridge BioResource's clinical facility on the Cambridge Biomedical campus. 

Organisation: This study is organised by Dr. Menna R. Clatworthy from the Department of Medicine, the University of Cambridge.