Apoptotic cell fragments locally activate tingible body macrophages in the germinal center

Germinal centers(GCs)that form within lymphoid follicles during antibody responses are sites of massive cell death.Tingible body macrophages(TBMs)are tasked with apoptotic cell clearance to prevent secondary necrosis and autoimmune activation by intracellular self antigens.We show by multiple redundant and complementary methods that TBMs derive from a lymph node resident,CD169-lineage,CSF1R-blockade-resistant precursor that is prepositioned in the follicle.