Immunohistochemical investigations of lymphocytes in the lymphoid organs of cyclophosphamide treated chickens.

The localization of lymphocytes in the lymphoid organs of cyclophosphamide (Cy) treated chickens and untreated control chickens was compared immunohistochemically using a variety of monoclonal antibodies (CT3, 2-6, 11-39, TCR1, TCR2, TCR3, L22, 11G, 3E8, B-4D-4, A-13). In the Harderian glands of Cy treated chickens, an an increase of T cells was observed, though T cells were a few in untreated controls. These increased T cells consisted of CD4 positive or CD8 positive cells. Further, these T cells were stained with TCR2 or TCR3 antibody, and a small number of cells were stained with TCR1 antibody. In other lymphoid organs such as the bursa of Fabricius, thymus, spleen and cecal tonsils, B lymphocyctes severely decreased or disappeared in Cy treated chickens, though no significant alteration in T cell distribution was observed.