Protection of mice against fatal herpes simplex type 2 infection by liposomes containing muramyl tripeptide.

Intravenous administration of liposomes containing muramyl tripeptide phosphatidylethanolamine, a lipophilic derivative of muramyl dipeptide that activates macrophages to a cytolytic state in situ, significantly protected mice against lethal challenge with herpes simplex virus type 2. These findings suggest that the systemic activation of macrophages by liposomes containing an immunomodulator can lead to prophylaxis of severe infections caused by herpesviruses.