Modulating drug efflux transporter expression on the macrophage reservoir of HIV

Our overall objective is to identify the impact of macrophage phenotype dependent drug transporter expression on the intracellular disposition of antiretrovirals and replication of HIV-1 in the macrophage reservoir. While the CD4+ T cell reservoir is the primary reservoir of HIV-1, the macrophage reservoir has increased acceptance. Macrophages are a heterogeneous cell population, and across their activity differentially express drug transporters, resulting in differences in intracellular concentrations of antiretrovirals. Our previous work shows higher expression of the efflux transporter MRP1 in pro-inflammatory M1 macrophages, and higher expression of P-gp and BCRP in the anti-inflammatory M2 phenotype. The vast majority of antiretrovirals are substrates of at least one of these transporters. Developing strategies to increase intracellular concentrations of antiretrovirals across their spectrum of activation is necessary to combat replication in the macrophage reservoir of HIV-1. Our overall hypothesis is that the macrophage reservoir of HIV-1 requires phenotype-specific interventions to control viral replication. Our specific hypothesis is that macrophages across their spectrum of activation differentially efflux antiretrovirals, resulting in altered HIV replication between polarized macrophage subsets. This is based on our preliminary data showing altered drug efflux transporter expression across the spectrum of macrophage activation, and data showing that inhibitors of drug efflux influence intracellular antiretroviral concentrations and viral replication in a phenotype-specific manner. We propose two aims. Aim 1: Characterize the impact of macrophage phenotype specific drug efflux transporter expression on intracellular antiretroviral concentrations and HIV-1 viral replication. We hypothesize that phenotype-specific differences in drug efflux transporters will result in altered intracellular antiretroviral concentrations and differences in HIV-1 replication between macrophage subsets. We will utilize monocyte derived macrophages (MDM) differentiated from healthy donors. Polarized macrophages will be treated with antiretrovirals and infected with HIV-1. Intracellular antiretroviral concentrations and viral replication will be assessed between macrophages populations across multiple timepoints. Antiretroviral and viral replication kinetics will be assessed. Aim 2: Identify strategies to increase intracellular antiretroviral concentrations in macrophages across their spectrum of activation. We hypothesize that increasing intracellular antiretroviral concentrations in the macrophage reservoir of HIV will require phenotype specific strategies. We will utilize MDM and both directly block the activity of drug transporters and modulate the activity of cell signaling pathways known to control transporter expression, including NF-κB and JNK. The successful completion of this project will result in new insights into the causes of heterogeneity of the macrophage reservoir of HIV-1 and identify targets to increase antiretroviral concentrations in macrophages across their spectrum of activation. Future work will utilize these identified targets as a means to develop novel strategies to combat HIV-1 replication in the macrophage reservoir of HIV-1. Project Number: 1R03AI192029-01A1 | Fiscal Year: 2025 | NIH Institute/Center: National Institute of Allergy and Infectious Diseases (NIAID) | Principal Investigator: Theodore Cory | Institution: UNIVERSITY OF TENNESSEE HEALTH SCI CTR, MEMPHIS, TN | Award Amount: $77,000 | Activity Code: R03 | Study Section: HIV Molecular Virology, Cell Biology, and Drug Development Study Section[HVCD] View on NIH RePORTER: https://reporter.nih.gov/project-details/1R03AI19202901A1