Anti-vimentin monoclonal antibodies differentiate two resident cell populations in chicken spleen

Splenic stromal cells were studied with anti-vimentin monoclonal antibody clones V9 and 3B4. V9 positive cells were widely distributed both in the red and white pulp, specifically the ellipsoid, but were absent from the germinal centers. These observations suggested that this clone recognized splenic reticular cells. The original name given to the splenic ellipsoid region by Schweigger-Seidel, "Kapillarhülse" or capillary sleeve, would be a more appropriate term than ellipsoid, at least in the chicken because the V9 positive ellipsoid covered the entire length of the penicilliform capillary. The capillary sleeve was decorated by large, 3B4 positive cells that were identical to the ellipsoid-associated cells, a dendritic-like cell. The 3B4 monoclonal antibody recognized large stellate-shaped cells in germinal centers. These data emphasized the cellular difference between ellipsoid-associated cells and the cells of the ellipsoid; the cytoskeletal similarities of the ellipsoid-associated cells and dendritic cells of germinal centers advocate their common cell lineage.