The direct antiviral cytotoxicity by bovine lymphocytes is not restricted by genetic incompatibility of lymphocytes and target cells.

Experiments were designed to determine if in the ox a requirement for genetic compatibility between antiviral cytotoxic cells and target cells was needed for cytotoxicity to occur. Unrelated bovine animals were immunized with vaccinia or IBR virus (a herpesvirus), and PBL were collected at various times for measurement of their cytotoxicity against autologous or heterologous uninfected or virus-infected fibroblasts. In all instances, cytotoxicity was expressed against heterologous as well as autologous targets and in most cases there was no evidence of enhanced killing of autologous cells. The cytotoxicity was shown to be direct, presumably T cell mediated, and was not attributable to ADCC. The likelihood of the animals under investigation sharing histocompatibility antigens was considered extremely remote but was not formally excluded.