Follicular dendritic cells are cells that facilitate antigen recognition by B cells in follicles. This kind of dendritic cell is not bone marrow derived and is not a kind of blood cell. It is purely a resident of the follicles of secondary lymphoid organs. B cells form germinal centers around follicular dendritic cells in lymphoid organs. Dendritic cells form from monocytes, white blood cells which circulate in the body and, depending on the right signal, can turn into dendritic cells or macrophages. The monocytes in turn are formed from stem cells in the bone marrow.
In normal tissue this antibody identifies dendritic cells and a proportion of B lymphocytes. Evidence in pathological tissue and functional studies suggests it binds to an epitope expressed by antigen presenting cells. Within the macrophage/dendritic cell populations the epitope seen by RFD1 is coexpressed with RFD7 by a subset of cells that exhibit suppressive activity on T cell stimulation.