The main goal of the Nagarajan lab research program focuses on how the innate branch of the immune system regulates adaptive immunity, as it relates to the pathogenesis of autoimmune disease such as lupus or rheumatoid arthritis (RA)-induced cardiovascular disease. IgG-Fcgamma receptor (FcgR)-mediated signaling is critical for mediating host defense against infectious disease, but they also mediate disease pathology in autoimmunity and atherosclerosis. Specifically, we are studying the role of IgG-Fcgamma receptor (FcgR) signaling network in innate immune cells activation that contributes to autoantibody production and T cell subset activation associated with autoimmune, and cardiovascular diseases. We are using a repertoire of relevant knockout mouse and humanized FcgR mouse models to address the questions of how FcgR-mediated signaling promotes autoimmune disease-induced atherosclerosis. As a translational component, we are collaborating with rheumatologists and cardiologists to analyze changes in innate and T cell subsets in patients with lupus or RA, who has premature atherosclerosis.