IN-VITRO GENERATION OF HUMAN CYTOMEGALOVIRUS PP65 ANTIGENEMIA, VIREMIA, AND LEUKODNAEMIA

Immunocompromised patients with disseminated human cytomegalovirus (HC MV) infection have circulating PMN carrying MCMV pp65 (antigenemia), i nfectious virus (viremia), and viral DNA (leukoDNAemia). Because HCMV does not fully replicate in PMN, it is generally hypothesized that vir ions and viral materials are taken up by phagocytosis from fully permi ssive HCMV-infected endothelial cells. However, no experimental eviden ce has ever been provided for these PMN-endothelium interactions. PMN from 11 donors were cocultured with endothelial cells infected with an endothelium-adapted HCMV strain and with human fibroblasts infected w ith low-passaged clinical and laboratory-adapted HCMV strains. pp65-po sitive PMN were detected after coculture with both HCMV-infected endot helial and fibroblast cells, provided that wild and not laboratory-ada pted strains were used. In addition, cocultured PMN carried infectious virus as demonstrated by virus isolation and presence of complete vir us particles by electron microscopy, Moreover, high levels of viral DN A were consistently detected by quantitative PCR in cocultured PMN. Th us, we have generated in vitro the three most important viral paramete rs detected in patients with disseminated HCMV infection (antigenemia, viremia, and leukoDNAemia). The failure of laboratory-adapted HCMV st rain to induce this phenomenon demonstrates that important modificatio ns have occurred in attenuated viral strains affecting basic biologica l functions.