This pilot study will assess the impact of four antimicrobial products (3 topical, one systemic) on the foreskin microbiome and HIV susceptibility of foreskin-derived CD4+ T cells. Participants will include HIV-uninfected Ugandan men presenting for elective male circumcision to reduce their HIV risk.
RATIONALE: The foreskin is the site of most HIV acquisition in uncircumcised heterosexual men, and male circumcision (MC) reduces HIV risk by almost 60%. However, cultural and practical barriers have led to suboptimal uptake. Foreskin inflammation, defined by elevated levels of pro-inflammatory cytokines in the prepuce, is a key determinant of HIV acquisition risk in uncircumcised men, and anaerobic bacteria within the foreskin microbiome may be an important cause of this inflammation. OBJECTIVES: A pilot in vivo - in vitro clinical study of four potential interventions to reduce HIV susceptibility in the foreskin by altering the microbiome. The study is a collaboration between the University of Toronto, IAVI-UVRI, and the Entebbe General Hospital. We will recruit 125 men presenting for elective MC, along with regular female sexual partners (if applicable). Participants will be randomized (n=25 per group) to immediate MC, or to one of four intervention arms: twice-daily application of topical metronidazole 0.75%; twice-daily application of topical clindamycin 2%; twice daily application of hydrogen peroxide 1%; or oral tinidazole 2g once a day for two days. Swabs for immune and microbiome studies will be collected before and after product. After 4 weeks the MC procedure will be performed; foreskin CD4+ T cell susceptibility to HIV will be quantified using a flow cytometry-based pseudovirus assay, and tissue immunohistochemistry performed. The primary and secondary endpoints are outlined below. A secondary study will assess the impact of penile topical antibiotic application on immunology and the microbiome in the genital tract of female sexual partners. OUTCOMES: This in vivo - in vitro clinical trial will define the causal role of the penile microbiome in HIV susceptibility, and will assess potential strategies to take forward into HIV efficacy trials in uncircumcised heterosexual men.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
125
Please see description under arms
Please see description under arms
Please see description under arms
UVRI-IAVI HIV Vaccine Program
Entebbe, Wakiso, Uganda
RECRUITING% HIV entry into foreskin derived CD4+ T cells
This measure will utilize a validated pseudovirus entry assay.
Time frame: 4 weeks
Tissue density of HIV-susceptible CD4+ T cells
The density of CD4+ T cells in foreskin tissues will be assayed using immunohistochemistry, and the % pseudovirus entry (see primary endpoint, above) will be used to calculate the tissue density of HIV-susceptible CD4+ T cells.
Time frame: 4 weeks
CD4+ T cell subsets in foreskin tissue
Immunofluorescence microscopy (IF) will be used to quantify CD4+ T cell subsets foreskin tissue after circumcision.
Time frame: 4 weeks
Density of Langerhans cells in foreskin tissue
Immunofluorescence microscopy (IF) will be used to quantify Langerhans cells in foreskin tissue after circumcision.
Time frame: 4 weeks
Presence of foreskin inflammation
Cytokine/chemokines will be assayed by ELISA, and foreskin inflammation defined as the presence of ≥3/7 inflammatory cytokines within the top quartile for that cytokine.
Time frame: 4 weeks
Foreskin microbiome composition
The foreskin (prepuce) microbiome will be characterized based on 16S rRNA sequencing.
Time frame: 4 weeks
Foreskin tissue explant HIV susceptibility
Foreskin tissue susecptibility to HIV infection will be quantified, based on p24 ELISA after ex vivo incubation with a primary HIV isolate.
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Please see description under arms
Time frame: 4 weeks