HIV interactions with monocytes and dendritic cells: viral latency and reservoirs

Abstract

HIV is a devastating human pathogen that causes serious immunological diseases in humans around the world. The virus is able to remain latent in an infected host for many years, allowing for the long-term survival of the virus and inevitably prolonging the infection process. The location and mechanisms of HIV latency are under investigation and remain important topics in the study of viral pathogenesis. Given that HIV is a blood-borne pathogen, a number of cell types have been proposed to be the sites of latency, including resting memory CD4+ T cells, peripheral blood monocytes, dendritic cells and macrophages in the lymph nodes, and haematopoietic stem cells in the bone marrow. This review updates the latest advances in the study of HIV interactions with monocytes and dendritic cells, and highlights the potential role of these cells as viral reservoirs and the effects of the HIV-host-cell interactions on viral pathogenesis.

Figure 1

Locations of HIV-1 replication and latency and routes of transmission between haematopoietic cell populations. All cell types shown are susceptible to HIV-1 entry and integration of the proviral DNA. Some anatomical locations are shown; those outside of marked areas are in the bloodstream, lymphatic system and/or tissues. Black arrows represent differentiation and/or maturation and may represent more than one step and could involve multiple intermediate cell types. Purple arrows represent routes of trans infection, and relative rates are shown as high or low. "Rep" indicates productive HIV-1 replication with relative rates shown as high or low. HIV-1 cis infection routes are not shown, as any susceptible cell may be infected by productive replication from another cell. Those cells in which HIV-1 latency is thought to occur should be considered as putative viral reservoirs and therapeutic targets.