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, 11G2, 3E8, B-4D-4, A-13). In the Harderian glands of Cy treated chickens, 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 lymphocytes severely decreased or disappeared in Cy treated chickens, though no significant alteration in T cell distribution was observed.