Monocyte‐derived macrophages as an active HIV‐1 viral reservoir in patients receiving suppressive cART (145.4)

Abstract

Macrophages play a crucial role in HIV‐1 latency and persistent viremia, especially in the establishment of viral reservoir, even when the patients are receiving suppressive cART. Macrophages are long‐lived cells that are resistant to the cytopathic effects of viral replication. Due to their abundant distribution and capacity to migrate into tissues we hypothesized that they can contribute to the maintenance of known viral reservoirs such as that in CD4+ T cells. We differentiated the infected monocytes of four HIV‐ infected patients taking anti‐retroviral therapy to create macrophages. Infected PBMC (peripheral blood mononuclear cells) were cultured for ten days in presence of macrophage colony stimulating factor. After differentiation, the monocyte‐derived macrophages (MDM) were co‐cultured with phytohemagglutinin (PHA)‐activated CD8+‐depleted PBMC’s from healthy patients for four weeks. Supernatants were harvested and analyzed for viral RNA using a sensitive reverse‐transcriptase PCR assay using HIV‐1 gag gene primers. Sequencing of the C2V3 region of the env gene from each patient revealed a 99.6% match with WT HXB2 using HIV Sequence Database (Los Alamos National Laboratory). Results demonstrate that after differentiation into macrophages the infected MDM can still harbor the proviral DNA and were able to release replicate competent virions in the supernatant. Future directions include performing cell to cell infection assay. These findings will be employed in an ex‐vivo model to further analyze HIV‐1 infection and transmission in order to demonstrate whether tissue macrophages are a true viral reservoir in HIV‐1 patients under suppressive cART.Grant Funding Source: NIH Grant R25‐096955