Interactions between HIV-1 and cytomegalovirus in human osteosarcoma cells carrying both viruses

Cytomegalovirus (CMV) and the human immunodeficiency virus type 1 (HIV-1) may interact in the pathogenesis of AIDS. We compared CMV replication in human osteosarcoma (HOS) cells to that in HOS cells genetically engineered to contain an envelope-deficient HIV-1 proviral construct (designated HOS-HXG). Following acute CMV infection of each cell line, HOS-HXG cells contained higher numbers of intranuclear CMV nucleocapsids than did HOS cells. Infectious CMV could be persistently detected in culture supernatant fluids of the CMV-infected HOS-HXG cells, whereas CMV was lost over several weeks from HOS cells infected with CMV in parallel. HIV-1 CMV pseudotypes were not detected in supernatant fluids from CMV-infected HOS-HXG cells. On day 119 after CMV infection, these cultures were superinfected with HIV-1. These dually infected HOS-HXG cells produced infectious HIV-1 and exhibited markedly enhanced CMV replication compared to parental CMV-infected HOS-HXG cells. Two different HIV-1 tat gene function antagonists, Ro24-7429 and chemically modified antibodies to the Tat protein, did not inhibit the replication of CMV in either acute or persistent infections of HOS-HXG cells at concentrations that inhibited HIV-1 replication.