Age-associated B cells as a connection between anti-viral response and autoimmunity. (P4355)

Abstract

Abstract Recently our group has discovered a subset of B cells, called age-associated B cells (ABCs), which appear in elderly female mice and autoimmune prone mice of either gender. Our experiments suggest that these B cells can produce autoantibodies and contribute to autoimmune diseases. It has been shown that ABCs develop from follicular B cells and their appearance depends on TLR7 signaling. Here we demonstrate that ABCs also appear at the peak of the response to viral infection. These cells secrete antiviral class-switched (IgG) antibodies and are the major contributors in anti-viral humoral response. Appearance of ABCs during viral infection depends on TLR7 and IFN gamma signaling since mice deficient in these genes fail to accumulate ABCs during infection. Overall, our data suggest a new role of ABCs as a major contributor to anti-viral response. Moreover, ABCs can serve as a new connection between anti-viral response and autoimmunity as they are capable to secrete antibodies with broad reactivity against both self and viral antigens.