CD4 and infection: The antiviral activity of GS-9620 in isolated macrophages, CD4+ T cells, and total PBMCs was assessed following infection with replication-competent strain HIV-1BaL or a single-cycle VSV G glycoprotein (VSV-G)-pseudotyped HIV-1 reporter virus encoding the luciferase protein (HIV-1VSV-G-LUC).