The Compartmental Biology of HIV in the Male Genital Tract

Inclusion Criteria:

• Born male between the ages of 18 and 60
• HIV positive taking TDF/FTC (and a third drug) as treatment; or HIV negative men receiving TDF/FTC as pre-exposure prophylaxis; HIV positive men taking tenofovir alafenamide
• if on routine treatment must have been taking medication for at least 3 months and adherence to medication as assessed by blood plasma HIV RNA less than 50 copies per mL.
• documentation of at least 80% adherence to antiretroviral (ART) regimen, through clinician or self-report, with no missed doses in the 3 days prior to the inpatient visit.
• willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other trial procedures.

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, or neurologic disease that would pose unnecessary risk or interfere with study results.
• unwilling or unable to abstain from sexual activity 72 hours prior to overnight sampling visit
• unlikely to remain on current drug regimen during study period
• anemia that precludes blood donation
• unable to provide semen specimen
• current receipt of other medications that may affect endogenous nucleotide concentrations, such as additional HIV nucleoside reverse transcriptase inhibitors, ribavirin, or adefovir