Evolution and Latency of T-Tropic and M-Tropic HIV in People Infected with Subtype C

Univ Of North Carolina Chapel Hill, Chapel Hill NC

Investigators

Abstract

PROJECT ABSTRACT Studies of people infected with HIV-1 from the subtype B lineage of virus have led to important insights on the nature of the transmitted virus, early dispersal of the virus throughout the body, evolution of macrophage-tropic virus late in the course of infection (especially in the CNS), and the phenomenon of latency (especially within CD4+ T cells in the lymphoid system). However, these questions have been studied to only a limited extent in people who have HIV-1 infections from the most common subtype, i.e. subtype C. In addition, the nature of viral evolution within the CNS to form macrophage-tropic HIV-1, and the cell types that may contribute to a latent reservoir within the CNS are poorly understood. The proposed work is built on the availability of a unique autopsy tissue repository and a novel model cell culture system to explore these questions in the context of infection with HIV-1 from subtype C lineage. The tissue repository for autopsy tissue from recently deceased individuals infected with subtype C lineage has been established at the University of the Witwatersrand by Drs. Papathanasopoulos and Wagner, and additional autopsy tissue samples are being collected for this repository. In addition, Drs. Symons and Nijhuis have access to viable human brain tissue (from non-HIV donors) collected during rapid autopsy which they have used to develop in vitro infection models for primary microglia and single nuclei analysis. These tools, coupled with Drs. Swanstrom and Joseph expertise in viral evolution and genetics are the basis of an international collaboration that will bring new insights into the nature of HIV-1 latency in the brain and do so in the setting of the most common lineage of HIV-1 infection. With these aims we will: i) determine the frequency that macrophage-tropic virus evolves within the immune-privileged confines of the CNS; ii) identify which cell types within the CNS are expressing virus; iii) determine how early macrophage-tropic virus evolve in the disease course; iv) compare long-lived viral DNA populations in the CNS to those in lymphoid tissue to determine if there are compartmentalized reservoirs; v) sort nuclei based on cell origin to determine which CNS cell types contain long-lived viral DNA; vi) use sorted nuclei to search for virus-expressing cells; vii) use M-tropic subtype C viral clones to establish a validated model of viral latency in primary microglia cells. Finally, we will explore these questions in samples collected from both men and women to examine if sex is a significant biological determinant of the nature of the CNS reservoir.