LACK OF PSEUDOTYPE FORMATION BETWEEN HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 AND EPSTEIN-BARR-VIRUS IN PRODUCTIVELY COINFECTED B-LYMPHOBLASTOIDCELL-LINES

Human immunodeficiency virus (HIV) can form pseudotypes with other env eloped viruses, including herpes simplex virus, when the two viruses c oinfect the same cell. Pseudotypes between HIV and Epstein-Barr virus (EBV) have not been described. We observed unusually high levels of HI V-1 replication in SCID mice transplanted with human peripheral blood mononuclear cells (hu-PBL-SCID mice) when the mice developed EBV-assoc iated human B cell lymphoproliferative disease. If this enhancement of HIV-1 replication were due to pseudotype formation rather than direct infection of B lymphoblastic cells by HIV-1, the pseudotypes could po se a novel biohazard to laboratory workers. To assess whether HIV-1 an d EBV can form such pseudotypes, we established and characterized CD4- positive B lymphoblastoid cell lines (LCL) that contained cells infect ed with both EBV and HIV-1. A high-titered virus pool from these LCL c ould induce HIV infection in the Burkitt's lymphoma (BL) line BJA-B, b ut not in the BL line Ramos. Infection of BJA-B was blocked by neutral izing antibody to HIV gp120 but not by neutralizing anti-EBV gp350. Th ese experiments provide no evidence for pseudotype formation, suggesti ng a low risk for EBV:HIV pseudotypes in natural infection of humans o r in human cells transplanted to SCID mice. (C) 1995 Academic Press, I nc.