Suppression of human lymphocyte mitogen response by disrupted primate retroviruses of type C (baboon endogenous virus) and type D (PMFV).

Disrupted primate retroviruses of type C (baboon endogenous virus, BaEV) and type D (human cell line-derived isolate PMFV) considerably suppressed Concanavalin A - induced blastogenic response of human lymphocytes. Rauscher mouse leukemia virus (RLV) displayed a suppressive activity on murine splenic lymphocytes when tested under analogous conditions. The immunosuppressive activities were shown not to result from cytotoxicity or from virus-mitogen binding.