Lack of pseudotype formation between human immunodeficiency virus type 1 and Epstein-Barr virus in productively coinfected B lymphoblastoid cell lines.

Human immunodeficiency virus (HIV) can form pseudotypes with other enveloped viruses, including herpes simplex virus, when the two viruses coinfect the same cell. Pseudotypes between HIV and Epstein-Barr virus (EBV) have not been described. We observed unusually high levels of HIV-1 replication in SCID mice transplanted with human peripheral blood mononuclear cells (hu-PBL-SCID mice) when the mice developed EBV-associated 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 pose a novel biohazard to laboratory workers. To assess whether HIV-1 and EBV can form such pseudotypes, we established and characterized CD4-positive B lymphoblastoid cell lines (LCL) that contained cells infected with both EBV and HIV-1. A high-titered virus pool from these LCL could induce HIV infection in the Burkitt's lymphoma (BL) line BJA-B, but not in the BL line Ramos. Infection of BJA-B was blocked by neutralizing antibody to HIV gp120 but not by neutralizing anti-EBV gp350. These experiments provide no evidence for pseudotype formation, suggesting a low risk for EBV:HIV pseudotypes in natural infection of humans or in human cells transplanted to SCID mice.