FcγRIIa, a novel director of cytokine production in infection and autoimmunity

Cytokines are crucial in initiating and effectuating a proper immune response. Here, we identified a novel role for human Fc gamma receptor IIa (FcγRIIa) in directing cytokine responses. We show that FcγRIIa cooperates with Toll-like receptors (TLRs) to enhance the production of specific anti-bacterial cytokines by dendritic cells and macrophages. In addition, we show that the same mechanism of FcγRIIa-TLR cross-talk is erroneously activated in autoimmune diseases such as rheumatoid arthritis, which thereby contributes to the pathogenesis of this disease. The discovery that FcγRIIa is a director of cytokine production in infection and autoimmunity reveals new therapeutic strategies.