Effects of retrovirus protein on the feline one-way mixed leukocyte reaction

The objective of this study was to evaluate the effects of feline retrovirus protein on cat lymphocyte recognition of allogeneic cells in the mixed leukocyte reaction (MLR), using u.v.-inactivated feline leukaemia virus (FeLV) and a non-disease-producing endogenous cat virus (RD-114). Twenty micrograms of u.v.-inactivated virus protein from each virus were added to mixed leukocyte cultures. FeLV induced significant suppression of the MLR (P less than 0.005) whereas no significant suppression was found using RD-114. Since feline leukaemia infection is associated with immunosuppression, the retrovirus proteins may be interfering with the response of immunocompetent cells when they are confronted with an altered host cell.