Cytotoxic antibody in cattle and sheep exposed to bovine leukemia virus.

Sera from bovine leukemia virus-infected cattle and sheep lysed fetal lamb kidney cells in the presence of rabbit complement. This cytolytic activity was removed completely from the sera by absorption with bovine leukemia virus (BLV). Antiserum against surface glycoprotein antigens of BLV contained cytolytic antibody but antiserum against the internal protein p24 did not. The complement-dependent antibody cytotoxicity test employing the trypan-blue dye exclusion method appeared to be suitable for routine diagnosis of BLV infection.