An ex vivo gut mucosal explant assay to compare HIV tissue susceptibility shows increased HIV susceptibility with methamphetamine exposure

Background Existing ex vivo mucosal explant models for HIV assess viral replication but do not fully capture the ability of tissue to support productive infection and transfer to target cells, an important indicator of tissue susceptibility. Additional tools to investigate relative mucosal susceptibility to HIV are necessary to better understand risk factors, such as substance use, or to evaluate therapeutics. Results We developed an ex vivo gut mucosal explant assay incorporating a CCR5/CXCR4-expressing GFP-reporter cell co-culture to quantify both viral replication and transfer. Susceptibility was quantified using a composite metric based on time to infection endpoint across viral doses. Modulators of susceptibility, including anti-CD3 stimulation, tenofovir, and methamphetamine, were evaluated. The assay reliably detected differences in tissue susceptibility under various experimental conditions. We detected enhanced susceptibility following anti-CD3 stimulation, while tenofovir pretreatment reduced susceptibility in a dose-dependent manner. Methamphetamine exposure resulted in a modest but significant increase in gut tissue susceptibility to HIV. Conclusions This novel ex vivo explant susceptibility assay advances HIV mucosal transmission research by measuring both viral production and transfer. It can detect subtle changes in susceptibility, providing a versatile platform for evaluating prevention therapeutics, host and microbial factors, and substance use effects.