Effect of pyrimidinone treatment on lethal and immunosuppressive murine cytomegalovirus infection

The 2-amino-5-halo-pyrimidinones, which are potent interferon inducers and antiviral agents, were found to be protective against lethal cytomegalovirus (CMV) challenge in weanling or neonatal mice when administered before virus challenge. This protection was dependent upon the dosage of pyrimidinone administered. Weanling mice infected with a sublethal challenge of CMV exhibited moderate to severe immunosuppression as measured by reduced splenic cell blastogenic responses in vitro to the mitogen concanavalin A. Treatment of mice with pyrimidinones during the course of CMV immunosuppression resulted in substantial augmentation of splenic cell blastogenic responses. The degree of augmentation appeared to be dependent on the severity of CMV-induced immunosuppression.