Sunday, May 5, 2024
5/5/2024
PROJECT SUMMARY The induction of autoantibody and autoimmunity in patients treated with TNF inhibitors (TNFi) is well-known; however, the mechanism by which TNFi induce breach of B cell tolerance is yet to be determined. In humans, TNFi affect B and T cell homeostasis via disruption of germinal center (GC) formation which is pivotal for high affinity antigen-specific antibody production and negative selection of autoreactive B cells. Similarly, in mice, TNF signaling deficiency prevents GC formation, induces TFH and CD4+IL-17 producing cell expansion, and alters autoantibody profiles. This small focused study proposes that TNF deficiency, together with a second inducing stimulus, compromises B cell selection via reduction of negative B cell signaling and enhancement of T effector cell activities. To test this hypothesis, the first aim utilizes: 1) TNF deficient mice of 2 different backgrounds, autoreactive Sle1.TNF-/- mice induced with a TLR9 agonist and NZM2328.TNFR1/2 double deficient mice, and 2) Sle1.TNF-/-.Yaa, in which male mice over express TLR7, to determine the mechanism for the signaling defect of activated B cells that alters B cell selection via either GC and/or extrafollicular pathway. The second aim will address similar questions in TNFi treated patients by identifying changes in CD22 binding dynamics which thereby affect BCR signaling in autoreactive B cells. This aim is made possible due to the development of the novel ANA reagent that identify enriched autoreactive B cells in both humans and mice. The results from this study will elucidate the effects of TNFi on regulating B cell tolerance and improve our understanding of how the immune system regulates B cell tolerance in GC and extrafollicular pathways.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).
