Immunohistological demonstration of virus and tumor associated antigens in tissues in experimental and spontaneous Bovine leukemia virus (BLV) infection

Expression of bovine leukemia virus (BLV) antigens in vivo has not been shown. After BLV infection, however, production of antibodies directed towards BLV proteins (e.g. gp51) can be easily demonstrated. Thus, production of BLV proteins has to take place somewhere in infected cattle. Tissues and organs of experimentally infected cattle were fixed in acetone and embedded in paraffin. Monoclonal antibodies directed to gp51 were used to demonstrate BLV expression immunohistologically by the peroxidase-antiperoxidase (PAP) method. The same samples were also used to demonstrate a tumor associated antigen (TAA) employing a monoclonal antibody. Our results indicate that very few cells, found in the intestinal mucosa, produce gp51 in vivo. The expression of TAA, however, increases significantly shortly after infection with BLV and remains high throughout life.