Defining the impact of cannabinoids on the HIV reservoir in humanized mice - Abstract Cannabis (CB) use is prevalent amongst people with HIV (PWH) but its impact on HIV infection and the latent viral reservoir has not been fully examined. In particular, the impact of CB on the HIV reservoir in solid tissues such as the brain is completely unknown. As such, animal models in which dosing can be carefully controlled and tissue samples can be analyzed will be important to fully understand how CB impacts HIV reservoir characteristics in tissues. Our central hypothesis is that CB induces an immunosuppressive cellular state that impacts viral transcription and maintenance of the HIV reservoir in tissues. The overall goal of this proposal is to develop a humanized mouse model of CB exposure during HIV infection and to use this model to learn how CB use affects characteristics of the tissue resident HIV reservoir. In the R61 phase, HIV infected humanized mice expressing hIL-34 to promote microglial CNS reconstitution will be exposed to a range of THC doses during infection, both before and after viral suppression with antiretroviral therapy (ART). The impact of THC exposure on viremia, viral suppression, immune markers and cytokines in peripheral blood will be examined. In the R33 phase, we will use this model to address three major questions. First, viral DNA (vDNA) and viral RNA (vRNA) levels in the brains and spleens of infected mice that have been dosed with THC will be quantified to determine the impact of THC on the size and transcriptional activity of the viral reservoir in these tissues. Second, we will examine whether THC exposure affects HIV latency reversal in vivo. We hypothesize that cross-talk between inflammatory signaling pathways activated by potent latency reversing agents (LRAs) such as the non-canonical NF-kB agonist AZD5582 and anti-inflammatory pathways activated by CB use could significantly alter the outcome of LRA dosing in vivo. To test this hypothesis, THC or control exposed HIV infected mice will be dosed with AZD5582, and the impact of THC on viremia and viral reactivation in tissues will be examined. Finally, we will use this model to perform a deep single cell characterization of infected cells in the brains and spleens of ART-suppressed humanized mice in the presence and absence of THC exposure. Spleen and brain tissues will be profiled using a combined single cell ATACseq/RNAseq method to identify and characterize HIV vDNA+ or vRNA+ cells and to compare the abundance and phenotype of these cells between CB dosed mice and controls. If successful, this proposal will reveal new insights into how CB affects HIV infection and the characteristics of the tissue-resident HIV reservoir. This in turn will guide novel HIV cure strategies that are optimized for CB-using PWH.
