Herpesvirus saimiri-encoded proteins Tip and StpC modulate human immunodeficiency virus type 1 replication in T-cell lines and lymphocytes independently of viral tropism

Herpesvirus saimiri (HVS)-transformed T-lymphocytes are permissive for both X4 and R5 strains of human immunodeficiency virus type 1 (HIV-1). HVS-encoded proteins tyrosine-kinase interacting protein (Tip) and saimiri transformation-associated protein subgroup C (StpC) were previously implicated in altering HIV permissiveness. MOLT4 cells expressing StpC or StpC and Tip are permissive for X4 strains of HIV-1. In contrast, HIV-1 was restricted in MOLT4 cells expressing Tip alone. Here we show that MOLT4 cells and primary lymphocytes expressing StpC are permissive for R5 strains of HIV-1 while Tip expression restricted R5 strains. These results suggest that intracellular immunization with Tip and StpC could be developed as models for therapeutic strategies targeting both X4 and R5 strains of HIV-1. (C) 2004 Elsevier Inc. All rights reserved.