Infection of the human T-cell-derived leukemia line Molt-4 by Epstein-Barr virus (EBV): induction of EBV-determined antigens and virus reproduction

We have reported previously that human T-cell-derived Molt-4 cells become susceptible to Epstein-Barr virus (EBV) infection after implantation of functional EBV receptors into the plasma membranes of Molt-4 cells (Volsky et al., 1980). In the present work, we expand this finding by analyzing the following: (i) Virus adsorption vs viral penetration—using [³H]thymidine-labeled EBV, we demonstrate that the virus could adsorb to both the untreated and the receptor-implanted Molt-4 cells. However, only the altered cells became susceptible to EBV penetration followed by the viral antigen synthesis; (ii) EBV substrain specificity of infection—EBV P3HR-1 virus induced the nuclear (EBNA), early (EA), and virus capsid (VCA) antigens, whereas EBV B-95-8 virus induced only EBNA; (iii) virus reproduction—in situ hybridization was used to demonstrate the EBV-DNA synthesis in the P3HR-1 virus-infected cells. In addition, immature herpes-like particles were observed in electron micrographs of infected cells. It is concluded that EBV infection of human T-cell-derived Molt-4 cells may lead to a full viral-lytic cycle in a portion of infected cells. The results suggest, however, that the primary EBV productive infection may not necessarily involve any immunofluorescence-detectable EBNA synthesis.