Investigating the development, maintenance, and function of follicular dendritic cells in the spleen 3181

Abstract Description Germinal centers (GCs) are specialized structures within peripheral lymphoid organs that are crucial in generating effective adaptive immune responses. Within the GC, follicular dendritic cells (FDCs) are stromal cells that establish the light zone, where they facilitate the selection of antigen-specific B cells to produce high-affinity antibodies. FDCs are essential for GC reactions, and a deeper understanding of their role in maintaining GC structure could provide insight into vaccine efficacy, autoimmunity, and age-related changes in immune response. However, little is known about their developmental pathways or the mechanisms that maintain their longevity and function. This study investigates these pathways and mechanisms. Using an FDC reporter mouse deficient in TNFα or reconstituted with TNFα-deficient bone marrow, we showed the critical role of TNFα in FDC maintenance in the spleen. Additionally, we identified a prospective FDC precursor population. To explore the lifespan and proliferative potential of FDCs, we employed a genetic timestamp mouse model with inducible GFP labeling of cells. FDCs did not show GFP decay at steady-state or after immunization, suggesting they do not proliferate. These findings highlight some of the requirements for the development, maintenance, and function of FDCs in the spleen. Further application of the reporter mouse may aid in characterizing our potential FDC precursors and uncover additional factors necessary for their maturation. Topic Categories Hematopoiesis and Immune System Development (HEM)