Decidual macrophages as an ex‐vivo model to study active HIV‐1 viral reservoir

Abstract

An important step towards the eradication of HIV‐1 infection is deal with latent viral reservoirs. These reservoirs are long‐lived infected cells that replicate and produce virus and/or are infected cells located in sanctuary sites. Current models to investigate ex‐vivo tissue macrophages involve risky and invasive procedures. Decidual macrophages (DM) obtained from placental tissue represent a non‐invasive approach to study HIV‐1 pathogenesis. Macrophages are considering long‐lived cells that can harbor proviral DNA and establish an active viral reservoir. We hypothesize that DM represents an ex‐vivo model to study HIV‐1 active viral reservoir on patients with viral load under limit of detection. Six term placentas were collected from healthy women. After enzymatic digestion, DM were selected using CD14+ microbeads. Purified DM were infected with both CCR5 and CXCR4 tropic HIV‐1 virus for 72 hours after activation. Supernatant were collected every 24 hours and viral RNA was detected by sensitive RT‐PCR and active infection by p24 ELISA. Infected DM were harvested and DNA, RNA and protein were obtained. Copies of proviral DNA was determined by RT‐PCR using HIV‐1 gag gene primers. Host restriction factor SAMHD1 was quantified by western blot. CD4+ T‐cell line was used as a positive control. Results demonstrated that decidual macrophages can be infected and harbor the proviral DNA. These findings will be employed in HIV‐1 infected pregnant women under suppressive cART to demonstrate whether tissue macrophages are a true viral reservoir in HIV‐1 infection and transmission.