MURINE CYTOMEGALOVIRUS DNA IN PERIPHERAL-BLOOD OF LATENTLY INFECTED MICE IS DETECTABLE ONLY IN MONOCYTES AND POLYMORPHONUCLEAR LEUKOCYTES

Cytomegalovirus (CMV), as do other herpesviruses, establishes a lifelo ng latent infection in its natural host. While in immunologically inta ct hosts most CMV infections are subclinical, clinical disease follows severe immunosuppression and immunodeficiency. In these situations CM V may produce serious life-threatening disease, and virus reactivated from the latent state is often responsible. Essential to understanding this virus and its pathogenesis is the need to define particular tiss ue and cell types harboring viral DNA. We searched for viral DNA and R NA in subpopulations of blood cells from mice latently infected with m urine CMV by using differential centrifugation and fluorescent antibod y cell sorting followed by polymerase chain reaction analysis. Followi ng intravenous inoculation, the viral DNA was found to be present in t he buffy coal al and after 21 days postinfection, and both granulocyte s and peripheral blood mononuclear leukocytes (PBML) were reservoirs. Further analysis of the PBML fraction by separation into Mac-1(+) and Mac-1(-) cells revealed that monocytes harbored the DNA while lymphocy tes were not sites of persistence. We conclude that in buffy coat of l atently infected mice the viral DNA is present only in cells of the my eloid lineage. The relationship of this DNA to the latent infection is discussed. (C) 1996 Academic Press, Inc.