Humans and Squirrel Monkeys With Epstein-Barr Virus 1.2.3

ABSTRACT-With the use of Epstein-Barr virus (EBV), attempts were made to Infect epithelial nasopharyngeal explant cell cul-tures prepared from nonmalignant human and squirrel monkey tissue. Explants were exposed to EBV from both HR-1 and B95-8 cells and examined for EBV-speclflc antigens by Immunofluores-cence and electron microscopy. Among the human specimens, no epithelial nasopharyngeal cells were found that could be In-fected with EBV. However, similar explants derived from squirrel monkey tissue were Infected. The results were consistent with the hypothesis that EBV can Infect at least certain explanted epithelial cells of the nasopharynx.-JNCI 64: 1085-1090. 1980. The association of EBV with NPC is supported by the fact that patients with NPC generally have high titers of antibody directed against EBV-specific anti-gens, such as EA and VCA (1, 2). Furthermore, fluctuations in EBV-specific IgG and IgA levels related to the clinical course of the disease have also been described (2-4). EBV DNA can be detected in NPC biopsy tissues (5, 6), and the EBV genome is associated primarily, if not solely, with the epithelial elements of tumors rather than with infiltrating lymphocytes (7). Because most laboratory data thus far suggest that EBV is a B-Iymphocyte-tropic virus, it is unclear how the virus becomes associated with the epithelial ele-ments of the nasopharynx. One possible explanation is that epithelial cells in the nasopharynx of all individ-uals or only in certain individuals have receptors for EBV. To support that hypothesis, we showed that explants prepared from NPC biopsy specimens could be directly infected with HR-l-derived EBV (8). How-ever, normal epithelial cells from the human or animal nasopharynx have not been directly infected with EBV in the laboratory. We have continued our studies in an attempt to find human or squirrel monkey nasophar-yngeal epithelial cells that might have the receptor for EBV. The basis for making this determination was the ability of EBV to attach and penetrate the membranes of cells exposed to EBV concentrates and the expres-sion of virus-specific function ( s)