RETRIEVAL OF HUMAN CYTOMEGALOVIRUS GLYCOPROTEIN-B FROM THE INFECTED CELL-SURFACE FOR VIRUS ENVELOPMENT

Surface biotinylation of human cytomegalovirus (HCMV)-infected fibrobl asts under pulse-chase conditions was used to define the cellular rout e of the dominant viral envelope glycoprotein gB into the cytoplasmic compartment of viral maturational envelopment. The results showed that a major fraction of gB was re-internalized from the infected cell sur face prior to incorporation into the viral envelope. Viral particles c arrying biotinylated gB were subsequently released into the culture me dium. Viral release appeared to be inhibited in the presence of gB-spe cific antibody or when infected cultures were incubated at room temper ature, but was not reduced by inhibitors of cellular glycoprotein tran sport. To our knowledge this is the first report describing that HCMV gB is retrieved from the infected cell surface prior to viral envelopm ent.