B cells can contribute to immunity through production of antibodies, presentation of antigen to T cells, and secretion of cytokines. Our findings suggest that the innate and the antibody-independent regulatory functions of B cells are connected. Remarkably, we found that activated B cells can, also as a result of intrinsic Toll-like receptor (TLR) signaling, suppress protective immunity towards the intracellular pathogen Salmonella typhimurium. Altogether, we demonstrated that activated B cells can regulate pathways of cellular immunity through provision of IL-10, and thereby impact on the course of autoimmune disease, and on the host’s interactions with pathogens. A model will be proposed to explain how these suppressive effects resulting from MyD88-signaling in B cells can confer advantageous properties to the immune system in its combat with pathogens, by granting improved robustness of microbial sensing, and by allowing accelerated kinetic of induction of immunity, while preventing excessive tissue inflammation.
Dr. Simon Fillatreau is group leader at the Deutsches Rheuma-Forschungszentrum Berlin.
Moderation: Professor Dr. Barbara Bröker