NF-κB-Binding Proteins Induced by HSV-1 Infection of U937 Cells Are Not Involved in Activation of Human Immunodeficiency Virus

Abstract

Molecular interactions between the herpes simplex virus type 1 (HSV-1) and human immunodeficiency virus (HIV) were investigated in U937 cells. Nonpermissive HSV-1 infection of U937 cells activated HIV as determined in transient expression assays with hybrid constructions containing the HIV-LTR-directed chloramphenicol acetyltransferase gene. Activation was independent of κB-enhancer elements whereas these elements were required for HSV-1-mediated activation in another cell line (C6). κB-binding proteins were induced in U937 cells by HSV-1 infection. Four species (45, 55, 75, and 75/80 kDa) were identified by DNA-protein cross-linking. Methylation interference analysis defined close contact only with the third residue of the previously established critical contact triplet GGG. Transient expression assays using mutants in HIV-LTR revealed the presence a cis-response element (GGTCA palindrome) in the negative regulatory region.