Human immunodeficiency virus types 1 and 2 have different replication kinetics in human primary macrophage culture

This study compares the replication of primary isolates of human immunodeficiency virus type 2 (HIV-2) and type 1 (HIV-1) in monocyte-derived macrophages (MDMs). Eleven HIV-2 and five HIV-1 primary isolates that use CCR5, CXCR4 or both coreceptors to enter cells were included. Regardless of coreceptor preference, 10 of 11 HIV-2 viruses could enter, reverse transcribe and produce fully infectious virus in MDMs with efficiency equal to that in peripheral blood mononuclear cells. However, the kinetics of replication of HIV-2 compared with HIV-1 over time were distinct. HIV-2 had a burst of virus replication 2 days after infection that resolved into an apparent 'latent state' at day 3. HIV-1, however, continued to produce infectious virions at a lower, but steady, rate throughout the course of infection. These results may have implications for the lower pathogenesis and viral-load characteristics of HIV-2 infection.