INFECTION OF BLOOD AND BONE-MARROW CELLS WITH THE HUMAN CYTOMEGALOVIRUS IN-VIVO

The human cytomegalovirus (HCMV) is a major pathogen in immunocompromi sed patients. Both, primary infection and reactivation of latent virus can cause disease. Peripheral blood leukocytes (PBL) most likely play an important role in viral persistence and dissemination of infection . However, an open question has been whether HCMV actively replicates in PBL in vivo and whether the progenitor cells in the bone marrow are also infected. Previous studies on this issue are controversial. Here we summarize data on the tropism of HCMV for mature leukocyte populat ions as well as bone marrow progenitor cells during HCMV viremia. All cell populations were highly purified by a fluorescence activated cell sorter (FAGS) and analyzed by PCR for the presence of viral genomic D NA. Moreover, mature leukocyte populations were investigated for mRNA expression of regulatory and Viral structural proteins. We could show, that HCMV DNA was detected most frequently in granulocytes and monocy tes as well as in CD34(+) progenitor cells of immunosuppressed patient s. Viral mRNA expression was found in granulocytes, monocytes, and lym phocyte fractions. In contrast, no HCMV DNA was found in healthy, sero positive individuals.