Acceptability of a Dapivirine/Placebo Gel Administered Rectally to HIV-1 Seronegative Adults (MTN-026).

This study describes the acceptability of a rectal microbicide gel formulation using dapivirine (DPV) among men and women from two countries (United States and Thailand) participating in the Microbicide Trials Network-026 trial. We evaluated participants' acceptability of a rectal DPV/placebo gel as part of a Phase I trial (N = 26; 18 male, 8 female). Participants reported favorable acceptability of the study gel, with most participants reporting that they liked the gel the same (n = 14; 53.8%) or more (n = 11; 42.4%) than when they started the trial. Over half of participants noted that they would prefer the gel over condoms (n = 13; 50%) or that they liked condoms and the gel equally (n = 8; 30.8%). Side effects across products included leakage (n = 8; 30.8%), diarrhea (n = 4; 15.4%), or soiling (n = 1; 3.8%). The high acceptability of a rectal gel underscores its promise as a short-acting biomedical prevention, warranting future research for HIV prevention.Trial Registration: NCT03239483.

RESUMEN: Este estudio describe la aceptabilidad de un microbicida rectal (RM) con dapivirina (DPV) formulado como un gel por hombres y mujeres de dos países (Estados Unidos y Tailandia) que participaron como parte del Microbicide Trials Network (MTN)-026. Evaluamos la aceptabilidad de un gel rectal de DPV y un placebo como parte de un estudio de Fase I (N = 26; 18 hombres, 8 mujeres). Los participants informaron una aceptabilidad favorable sobre el gel del estudio; la mayoría de los participantes informaron que les gustó el gel igual (n = 14; 53.8%) o más (n = 11; 42.4%) que cuando comenzaron el estudio. Más de la mitad de los participantes señalaron que preferirían el gel sobre los condones (n = 13; 50%) o que les gustaban los condones y el gel por igual (n = 8; 30,8%). Los efectos de los productos incluyeron fugas (n = 8; 30,8%), diarrea (n = 4; 15,4%) o ensuciamiento (n = 1; 3,8%). La alta aceptabilidad de un gel rectal enfatiza su promesa para la prevención biomédica de acción corta y justifica futuras investigaciones para la prevención del VIH.

A Mixed-Methods Study Examining Adherence to and Acceptability of Intravaginal Rings for HIV Prevention: Behavioral Results of MTN-027.

Intravaginal rings (IVR) containing antiretroviral drugs are a promising method for HIV prevention. We triangulated quantitative and qualitative assessments to evaluate the acceptability of four IVRs used continuously for 28 days as part of a Phase I trial (N = 48 HIV-negative women; ages 18-45). Adherence was high throughout the trial, yet 30% of participants reported involuntary IVR expulsions followed by re-insertion. Most participants (93.6%) felt comfortable with the IVR being inside their body. Participants reported liking the IVR more (36.2%) or the same amount (55.3%) since starting the study. When given the option of choosing between the IVR and/or a male condom for HIV-prevention, most reported preferring the IVR (n = 29, 63.0%), and over a quarter of the sample reported liking them equally (n = 12, 26.1%). We observed no differences in IVR acceptability across the study arms. High adherence and acceptability underscores the promise of an IVR as a female-controlled, sustained mechanism for HIV prevention.

Phase 1 Pharmacokinetic Trial of 2 Intravaginal Rings Containing Different Dose Strengths of Vicriviroc (MK-4176) and MK-2048.

BACKGROUND: Vaginal rings (VRs) are a promising approach for sustained delivery of antiretroviral (ARV) medication to prevent human immunodeficiency virus (HIV) infection in women. Combination ARV VRs could increase efficacy. METHODS: MTN-028, a phase 1 trial in 19 HIV-uninfected women, evaluated 2 VRs containing vicriviroc (VCV) and MK-2048. Participants were randomized 2:1 to a low-dose (VCV, 91 mg; MK-2048, 10 mg) or original-dose (VCV, 182 mg; MK-2048, 30 mg) ring used for 28 days. Safety was assessed by documenting adverse events (AEs). Drug concentrations were evaluated in plasma, cervicovaginal fluid (CVF), and cervical tissue samples. RESULTS: All AEs reported were grade 1 or 2, with no statistically significant differences in related genitourinary AEs or grade ≥2 AEs observed between arms (P = >.99). VCV/MK-2048 concentrations rose rapidly, with higher plasma area under the concentration-time curve (AUC) in the original-dose arm (geometric mean ratio, 3.29 for VCV and 1.49 for MK-2048) and similar AUCs across arms for CVF samples. Cervical tissue concentrations were higher in the original-dose arm (geometric mean ratio, 7.94 for VCV and 6.45 for MK-2048), with greater drug released based on residual drug levels. Plasma and CVF concentrations for both drugs fell rapidly after ring removal. CONCLUSIONS: In this first study evaluating 2 doses of a combination VCV/MK-2048 VR, both rings were found to be safe and well tolerated. VCV and MK-2048 were detectable in plasma, CVF, and cervical tissue samples, and drug release and plasma drug exposure were higher for the original-dose than for the low-dose ring.

Phase 1 Safety and Pharmacokinetics Study of MK-2048/Vicriviroc (MK-4176)/MK-2048A Intravaginal Rings.

BACKGROUND: Vaginal rings (VR) containing antiretroviral (ARV) drugs can be utilized for prevention of human immunodeficiency virus (HIV) with potential for improved adherence compared to daily pills. Combination ARV VRs could improve efficacy. METHODS: MTN-027, a single-blind, randomized, placebo-controlled trial in 48 women, evaluated VRs containing MK-2048 (30 mg) and vicriviroc (VCV, 182 mg), alone or in combination, and placebo used continuously for 28 days. Safety was assessed by recording adverse events. Drug concentrations were quantified in plasma, vaginal fluid, cervical tissue, and rectal fluid. Cervical tissue was utilized for ex vivo HIV inhibition analysis. RESULTS: There was no difference in related genitourinary adverse events between treatment arms compared to placebo. VCV and MK-2048 released from single or combination VRs both achieved peak concentrations in vaginal fluids, which were substantially higher compared to plasma (200× for VCV, 30× for MK-2048) and rectal fluid. In an ex vivo challenge assay, the antiviral activity of VCV and/or MK-2048 was not correlated with tissue-associated drug concentrations. Most women (77%) were fully adherent to 28 days of continuous VR use and found the VR acceptable. CONCLUSIONS: VCV and/or MK-2048 containing VRs were safe and acceptable. Both VCV and MK-2048 were quantifiable in all matrixes tested with peak compartmental drug concentrations similar for single and combination drug VRs. Tissue-associated VCV and/or MK-2048 did not correlate with inhibition of HIV infection. These data highlight the need to assess adequacy of drug dosing in the VR and measuring genital tissue drug concentrations to develop more precise concentration-response relationships.

Phase 2a Safety, Pharmacokinetics, and Acceptability of Dapivirine Vaginal Rings in US Postmenopausal Women.

BACKGROUND: Postmenopausal women have unique sociobiological human immunodeficiency virus (HIV) risks. We evaluated the safety, pharmacokinetics, and acceptability of a microbicide dapivirine (DPV) vaginal ring (VR) versus placebo in postmenopausal women. METHODS: We enrolled 96 HIV-negative postmenopausal US women in a phase 2a double-blind, randomized (3:1) trial of monthly VRs containing 25 mg DPV or placebo used continuously for 12 weeks. We assessed safety by adverse events (AEs). DPV concentrations were quantified in plasma and vaginal fluid. Steady-state concentrations were analyzed at 4, 8, and 12 weeks using repeated measures ANOVA. We assessed acceptability by self-report. RESULTS: We found no differences in the proportion of women with related grade 2 or higher reproductive system AEs (DPV: 6/72 (8%), placebo: 3/24 (13%), P = .68) or grade 3 or higher AEs (DPV: 4/72 (6%), placebo: 0/24 (0%), P = .57). In the DPV arm, 2/72 (3%) declined to resume product use due to AEs. Median DPV concentrations in plasma (262.0 pg/mL at week 12) and vaginal fluid (40.6 ng/mg at week 12) were constant over 12 weeks and exceeded the in vitro 50% effective concentration by 5000-fold in vaginal fluid by week 4. VR acceptability was high; 84/93 (90%) "very much liked or liked" the VR. CONCLUSIONS: DPV VRs were safe, well tolerated, and acceptable in postmenopausal women. Plasma concentrations were comparable to published data on DPV use in reproductive-age women (median plasma concentration: 264 pg/mL). Given the reassuring safety and pharmacokinetic data, the DPV VR is promising for preexposure prophylaxis in postmenopausal women. CLINICAL TRIALS REGISTRATION: NCT02010593.

Pharmacokinetics of Dapivirine Transfer into Blood Plasma, Breast Milk, and Cervicovaginal Fluid of Lactating Women Using the Dapivirine Vaginal Ring.

Breastfeeding (BF) women are an important population for biomedical HIV prevention strategies, but they are rarely included in trials. The 25-mg dapivirine vaginal ring (VR) reduced women's risk of sexually transmitted HIV infection in two phase 3 trials conducted in Africa. We conducted a phase 1, open-label study (MTN-029/IPM 039) of dapivirine VR use among lactating women in Pittsburgh, PA, and Birmingham, AL, USA. MTN-029/IPM 039 enrolled 16 healthy adult women who had already weaned their infants but were still able to express breast milk. Women were instructed to use the VR continuously for 14 days and provided milk, plasma, and cervicovaginal fluid (CVF) samples for pharmacological analysis. No infants were exposed to the drug, but infant dosage was estimated according to FDA guidance. Adverse events (AEs) were collected at all contacts. The study was completed with 100% participant retention. Median dapivirine concentrations were 676 pg/ml in breast milk, 327 pg/ml in plasma (milk/plasma ratio ∼2.0), and 36.25 ng/mg in CVF. Six participants experienced 10 total AEs, none of which required VR discontinuation. The estimated mean daily infant dosage was 74.3 ng/kg/day. In this first study of dapivirine exposure during lactation, dapivirine VR use was associated with lower concentrations of detectable dapivirine in milk and plasma than in CVF samples and a favorable safety profile. Estimated daily levels of infant dapivirine exposure were also low. Additional studies are needed to evaluate longer periods of dapivirine VR use among BF mother-infant pairs living in regions with higher incidence of sexually transmitted HIV infection. (This study has been registered at ClinicalTrials.gov under registration no. NCT02808949.).

Impact of Sex on the Pharmacokinetics and Pharmacodynamics of 1% Tenofovir Gel.

BACKGROUND: Tenofovir (TFV) gel partially protected against human immunodeficiency virus (HIV) in one but not subsequent trials. The disappointing results were attributed largely to poor adherence. However, timing of gel application relative to sex may impact pharmacokinetics and contribute to outcomes. Thus, we conducted a single-dose pharmacokinetic study of TFV gel applied 1 or 24 hours before or 1 hour before and 1 hour after (BAT) sex and compared results with dosing without sex. METHODS: Twenty-four couples were enrolled; cervicovaginal lavage (CVL) and tissue were collected 2 hours after sex with matching timed collections at no sex visits and assayed for drug concentrations and CVL anti-HIV activity. RESULTS: Compared with dosing without sex, median TFV concentrations after sex decreased 72% and 78% (P < .001) in CVL, 75% and 71% (P < .001) in vaginal tissue, and 75% (P = .06) and 55% (P < .001) in cervical tissue with -1 hour and -24 hour dosing, respectively. Median concentration of TFV-diphosphate also decreased significantly in cervical tissue with -1 hour, dosing. BAT dosing resulted in drug levels at least as great as those in the absence of sex. Percent inhibition of HIV infection by post-coital CVL increased significantly from median (interquartile range) of 55% (54%) in the absence of gel to 99% (7%), 77% (57%), and 100% (0.4%) with -1 hour, -24 hour, or BAT dosing, respectively, and correlated significantly with drug concentration. CONCLUSIONS: Timing of TFV gel application relative to sex significantly impacts drug levels. BAT dosing or sustained delivery may be optimal for preexposure prophylaxis.

Broadly Neutralizing Anti-HIV Antibodies Prevent HIV Infection of Mucosal Tissue Ex Vivo.

Broadly neutralizing monoclonal antibodies (nAbs) specific for HIV are being investigated for use in HIV prevention. Due to their ability to inhibit HIV attachment to and entry into target cells, nAbs may be suitable for use as topical HIV microbicides. As such, they would present an alternative intervention for individuals who may not benefit from using antiretroviral-based products for HIV prevention. We theorize that nAbs can inhibit viral transmission through mucosal tissue, thus reducing the incidence of HIV infection. The efficacy of the PG9, PG16, VRC01, and 4E10 antibodies was evaluated in an ex vivo human model of mucosal HIV transmission. nAbs reduced HIV transmission, causing 1.5- to 2-log10 reductions in HIV replication in ectocervical tissues and ≈3-log10 reductions in HIV replication in colonic tissues over 21 days. These antibodies demonstrated greater potency in colonic tissues, with a 50-fold higher dose being required to reduce transmission in ectocervical tissues. Importantly, nAbs retained their potency and reduced viral transmission in the presence of whole semen. No changes in tissue viability or immune activation were observed in colonic or ectocervical tissue after nAb exposure. Our data suggest that topically applied nAbs are safe and effective against HIV infection of mucosal tissue and support further development of nAbs as a topical microbicide that could be used for anal as well as vaginal protection.

Distinct Pharmacodynamic Activity of Rilpivirine in Ectocervical and Colonic Explant Tissue.

A long-acting injectable form of rilpivirine (RPV) is being evaluated in clinical trials for the prevention of HIV infection. Preclinical testing was undertaken to define RPV pharmacokinetic (PK) and pharmacodynamic (PD) activities in ectocervical and colonic tissue treated in vitro Tenfold dilutions of RPV were added to the basolateral medium of polarized ectocervical and colonic explant tissues. To half the explants, HIV-1BaL was applied to the apical tissue surface. After culture overnight, all the explants were washed and the RPV in the explants not exposed to HIV was quantified using a validated liquid chromatography-mass spectrometry assay. For efficacy, explants exposed to HIV remained in culture, and supernatants were collected to assess viral replication using a p24 enzyme-linked immunosorbent assay. The data were log10 transformed, and PK/PD correlations were determined using GraphPad Prism and SigmaPlot software. The application of RPV to the basolateral medium at 10 µM and 1 µM was effective in protecting ectocervical and colonic tissues, respectively, from HIV infection. When the RPV in paired ectocervical and colonic explant tissues was quantified, significant inverse linear correlations (P < 0.001) between p24 and RPV concentrations were obtained; more viral replication was noted at lower drug levels. Using a maximum effect model, RPV concentrations of 271 nM in ectocervical tissue and 45 nM in colonic tissue were needed to achieve a 90% effective concentration (EC90). These data demonstrate that RPV can suppress HIV infection in mucosal tissue but that higher levels of RPV are needed in female genital tract tissue than in gastrointestinal tract tissue for protection.

Detectable Tenofovir Levels in Breast-Feeding Infants of Mothers Exposed to Topical Tenofovir.

Lactation studies are necessary evaluations of medications for reproductive-age women. We evaluated pharmacokinetics (PK), pharmacodynamics, safety, and adherence profiles associated with 7 days of 1% tenofovir (TFV) vaginal gel use during lactation. Tenofovir levels (maternal/infant serum, milk) and anti-HIV activity (milk), adverse events (AEs), and adherence were measured for 17 HIV-1-seronegative breast-feeding mother-infant pairs. Tenofovir use was well-tolerated and detected at low levels in maternal serum, milk, and infant serum but demonstrated no anti-HIV activity in milk.

The effect of menopause on the innate antiviral activity of cervicovaginal lavage.

OBJECTIVE: Reproductive hormones are known to impact innate mucosal immune function of the lower genital tract. Our objectives were to determine the effect of hormonal status on intrinsic antiviral (herpes simplex virus [HSV]-1, HSV-2, and human immunodeficiency virus [HIV]-1) activity of cervicovaginal lavage (CVL). STUDY DESIGN: CVL was collected from 165 asymptomatic women including postmenopausal women (n = 29); women not on contraception in days 1-14 (n = 26) or days 15-28 (n = 27) of the menstrual cycle; and women using the levonorgestrel intrauterine device (n = 28), depot medroxyprogesterone acetate (n = 28), or combined oral contraceptives (n = 27). The anti-HSV-1/-2 and the anti-HIV-1 activity of the CVL were measured using plaque assays and the Jurkat-Tat-CCR5 assay, respectively. RESULTS: CVL from all of the groups had modest antiviral activity. Anti-HIV-1 activity was decreased in CVL from postmenopausal women when compared to premenopausal women (11% vs 34%, P = .002). However, there was no difference in anti-HIV-1 activity among premenopausal women regardless of phase of menstrual cycle or contraceptive use. Anti-HIV-1 activity was associated with the protein content of the CVL (r = 0.44, P < .001). There was no difference in anti-HSV-1 or -2 activity by hormonal group. CONCLUSION: Menopause is associated with decreased innate HIV-1 activity in the lower genital tract, suggesting that factors in the vaginal fluid could play a role in increased susceptibility of HIV-1 infection in postmenopausal women. Hormonal contraceptive use, menopause, and phase of menstrual cycle did not have a measurable impact on the intrinsic anti-HSV-1 or -2 activity.

Formulation and characterization of polymeric films containing combinations of antiretrovirals (ARVs) for HIV prevention.

PURPOSE: To develop polymeric films containing dual combinations of anti-HIV drug candidate tenofovir, maraviroc and dapivirine for vaginal application as topical microbicides. METHODS: A solvent casting method was used to manufacture the films. Solid phase solubility was used to identify potential polymers for use in the film formulation. Physical and chemical properties (such as water content, puncture strength and in vitro release) and product stability were determined. The bioactivity of the film products against HIV was assessed using the TZM-bl assay and a cervical explant model. RESULTS: Polymers identified from the solid phase solubility study maintained tenofovir and maraviroc in an amorphous state and prevented drug crystallization. Three combination film products were developed using cellulose polymers and polyvinyl alcohol. The residual water content in all films was <10% (w/w). All films delivered the active agents with release of >50% of film drug content within 30 min. Stability testing confirmed that the combination film products were stable for 12 months at ambient temperature and 6 months under stressed conditions. Antiviral activity was confirmed in TZM-bl and cervical explant models. CONCLUSIONS: Polymeric films can be used as a stable dosage form for the delivery of antiretroviral combinations as microbicides.

Pharmacodynamic Activity of Dapivirine and Maraviroc Single Entity and Combination Topical Gels for HIV-1 Prevention.

PURPOSE: Dapivirine (DPV), a non-nucleoside reverse transcriptase inhibitor, and maraviroc (MVC), a CCR5 antagonist, were formulated into aqueous gels designed to prevent mucosal HIV transmission. METHODS: 0.05% DPV, 0.1% MVC, 0.05% DPV/0.1% MVC and placebo gels were evaluated for pH, viscosity, osmolality, and in vitro release. In vitro assays and mucosal tissues were used to evaluate anti-HIV activity. Viability (Lactobacilli only) and epithelial integrity in cell lines and mucosal tissues defined safety. RESULTS: The gels were acidic and viscous. DPV gel had an osmolality of 893 mOsm/kg while the other gels had an osmolality of <100 mOsm/kg. MVC release was similar from the single and combination gels (~5 µg/cm(2)/min(1/2)), while DPV release was 10-fold less from the single as compared to the combination gel (0.4331 µg/cm(2)/min(1/2)). Titrations of the gels showed 10-fold more drug was needed to protect ectocervical than colonic tissue. The combination gel showed ~10- and 100-fold improved activity as compared to DPV and MVC gel, respectively. All gels were safe. CONCLUSIONS: The DPV/MVC gel showed a benefit blocking HIV infection of mucosal tissue compared to the single entity gels. Combination products with drugs affecting unique steps in the viral replication cycle would be advantageous for HIV prevention.

Vaginal Microbicide Film Combinations of Two Reverse Transcriptase Inhibitors, EFdA and CSIC, for the Prevention of HIV-1 Sexual Transmission.

PURPOSE: EFdA is a potent nucleoside reverse transcriptase inhibitor (NRTI) with activity against a wide spectrum of wild-type and drug resistant HIV-1 variants. CSIC is a tight-binding non-nucleoside reverse transcriptase inhibitor (NNRTI) with demonstrated anti-HIV properties important for use in topical prevention of HIV transmission. The objective of this study was to develop and characterize film-formulated EFdA and CSIC for use as a female-controlled vaginal microbicide to prevent sexual transmission of HIV. METHODS: Assessments of EFdA- and CSIC-loaded films included physicochemical characteristics, in vitro cytotoxicity, epithelia integrity studies, compatibility with the normal vaginal Lactobacillus flora and anti-HIV bioactivity evaluations. RESULTS: No significant change in physicochemical properties or biological activity of the combination films were noted during 3 months storage. In vitro cytotoxicity and bioactivity testing showed that 50% cytotoxic concentration (CC50) of either EFdA or CSIC was several orders of magnitude higher than the 50% effective concentration (EC50) values. Film-formulated EFdA and CSIC combination showed additive inhibitory activity against wild type and drug-resistant variants of HIV. Epithelial integrity studies demonstrated that the combination vaginal film had a much lower toxicity to HEC-1A monolayers compared to that of VCF®, a commercial vaginal film product containing nonoxynol-9. Polarized ectocervical explants showed films with drug alone or in combination were effective at preventing HIV infection. CONCLUSIONS: Our data suggest that vaginal microbicide films containing a combination of the NRTI EFdA and the NNRTI CSIC have potential to prevent HIV-1 sexual transmission.

Y chromosome and HIV DNA detection in vaginal swabs as biomarkers of semen and HIV exposure in women.

BACKGROUND: The inability to quantify sexual exposure to HIV limits the power of HIV prevention trials of vaccines, microbicides, and preexposure prophylaxis in women. We investigated the detection of HIV-1 and Y chromosomal (Yc) DNA in vaginal swabs from 83 participants in the HPTN 035 microbicide trial as biomarkers of HIV exposure and unprotected sexual activity. METHODS: One hundred forty-three vaginal swabs from 85 women were evaluated for the presence of Yc DNA (Quantifiler Duo DNA quantification kit; Applied Biosystems) and total HIV-1 DNA (single-copy in-house quantitative polymerase chain reaction assay). Y DNA detection was paired with self-reported behavioral data with regard to recent coitus (≤1 week before collection) and condom usage (100% vs. <100% compliance). RESULTS: Yc DNA was detected in 62 (43%) of 143 swabs. For the 126 visits at which both behavioral data and swabs were collected, Yc DNA was significantly more frequent in women reporting less than 100% condom usage (odds ratio, 10.69; 95% confidence interval, 2.27-50.32; P = 0.003). Notably, 27 (33%) of 83 swabs from women reporting 100% condom usage were positive for Yc DNA. HIV DNA was only detected in swabs collected postseroconversion. CONCLUSIONS: The use of Yc DNA in HIV prevention trials could reliably identify subgroups of women who have unprotected sexual activity and could provide valuable exposure-based estimates of efficacy.

Extracts from Acacia catechu suppress HIV-1 replication by inhibiting the activities of the viral protease and Tat.

BACKGROUND: Acacia catechu (Mimosa family) stem bark extracts have been used traditionally as a dietary supplement as well as a folk medicine given its reported anti-inflammatory, immunomodulatory, hepatoprotective, antioxidant, anti-microbial and anti-tumor activities. The present study was undertaken to evaluate the anti-HIV-1 activity of the extracts from stem bark of A. catechu. METHODS: The aqueous and 50% ethanolic extracts of A. catechu stem bark were prepared and 50% ethanolic extract was further fractioned by successively partitioning with petroleum ether, chloroform and n-butanol. All the extracts and fractions were evaluated for cytotoxicity and anti-HIV-1 activity using different in vitro assays. The active n-butanol fraction was evaluated for its inhibition against HIV-1 reverse transcriptase, integrase, protease, pro-viral genome integration and viral Tat protein mediated transactivation. The effect of n-butanol fraction on the induction of pro-inflammatory cytokines secretion in Vk2/E6E7 cells and transepithelial resistance in Caco-2 and HEC-1A cells was investigated. RESULTS: The aqueous and 50% ethanolic extracts of A. catechu showed IC50 values of 1.8 ± 0.18 µg/ml and 3.6 ± 0.31 µg/ml, respectively in cell-free virus based assay using TZM-bl cells and HIV-1NL4.3 (X-4 tropic). In the above assay, n-butanol fraction exhibited anti-HIV-1 activity with an IC50 of 1.7 ± 0.12 µg/ml. The n-butanol fraction showed a dose-dependent inhibition against HIV-1NL4.3 infection of the peripheral blood lymphocytes and against HIV-1BaL(R-5-tropic) as well as two different primary viral isolates of HIV-1 infection of TZM-bl cells. The n-butanol fraction demonstrates a potent inhibitory activity against the viral protease (IC50 = 12.9 µg/ml), but not reverse transcriptase or integrase. Further, in Alu-PCR no effect on viral integration was observed. The n-butanol fraction interfered with the Tat-mediated Long Terminal Repeat transactivation in TZM-bl cells, mRNA quantitation (qRT-PCR) and electrophoretic mobility shift assay (EMSA). The n-butanol fraction did not cause an enhanced secretion of pro-inflammatory cytokines in Vk2/E6E7 cells. Additionally, no adverse effects were observed to the monolayer formed by the Caco-2 and HEC-1A epithelial cells. CONCLUSIONS: The results presented here show a potential anti-HIV-1 activity of A. catechu mediated by the inhibition of the functions of the viral protein and Tat.

Use of human mucosal tissue to study HIV-1 pathogenesis and evaluate HIV-1 prevention modalities.

The use of human mucosal tissue models is an important tool advancing our understanding of the specific mechanisms of sexual HIV transmission. Despite 30 years of study, major gaps remain, including how HIV-1 transverses the epithelium and the identity of the early immune targets (gate keepers). Because defining HIV-1 transmission in vivo is difficult, mucosal tissue is being used ex vivo to identify key steps in HIV-1 entry and early dissemination. Elucidating early events of HIV-1 infection will help us develop more potent and specific HIV-1 preventatives such as microbicides and vaccines. Mucosal tissue has been incorporated into testing regimens for antiretroviral drugs and monoclonal antibodies. The use of mucosal tissue recapitulates the epithelium and immune cells that would be exposed in vivo to virus and drug. This review will discuss the use of mucosal tissue to better understand HIV-1 pathogenesis and prevention modalities.

Mucosal Escherichia coli bactericidal activity and immune mediators are associated with HIV-1 seroconversion in women participating in the HPTN 035 trial.

The mucosal environment may impact the risk for human immunodeficiency virus type 1 (HIV-1) acquisition. Immune mediators were measured in vaginal fluid collected from HPTN 035 participants who acquired HIV-1 and from those who remained HIV-1 negative (controls). Mediator concentrations were similar in samples obtained before as compared to after HIV-1 acquisition in the 8 seroconverters. Compared with controls, seroconverters were more likely to have detectable levels of HßD-2 (odds ratio [OR], 2.39; P = .005) and greater Escherichia coli bactericidal activity (OR, 1.22; P = .01) prior to seroconversion. E. coli bactericidal activity remained significant in a multivariable analysis (P = .02) and may be a biomarker for HIV-1 acquisition.

Characterization of UC781-tenofovir combination gel products for HIV-1 infection prevention in an ex vivo ectocervical model.

HIV continues to be a problem worldwide. Topical vaginal microbicides represent one option being evaluated to stop the spread of HIV. With drug candidates that have a specific action against HIV now being studied, it is important that, when appropriate and based on the mechanism of action, the drug permeates the tissue so that it can be delivered to specific targets which reside there. Novel formulations of the nucleotide reverse transcriptase inhibitor tenofovir (TFV) and the nonnucleoside reverse transcriptase inhibitor UC781 have been developed and evaluated here. Gels with three distinct rheological properties were prepared. The three gels released both UC781 and TFV under in vitro conditions at concentrations equal to or above the reported 50% effective concentrations (EC(50)s). The drug concentrations in ectocervical tissues were well in excess of the reported EC(50)s. The gels maintain ectocervical viability and prevent infection of ectocervical explants after a HIV-1 challenge. This study successfully demonstrates the feasibility of using this novel combination of antiretroviral agents in an aqueous gel as an HIV infection preventative.

Sublimable C5A delivery provides sustained and prolonged anti-HIV microbicidal activities.

We have identified a short amphipathic helical peptide, called C5A, which exhibits potent microbicidal activities in vitro and which offers protection from vaginal HIV transmission in vivo in a humanized mouse model. However, there are many obstacles to overcome before C5A can be considered a true microbicidal candidate. First, it must be stabilized against enzymatic degradation in a continuously warm and moist environment. Second, it must be delivered in a controlled manner to achieve long-term and coitally independent efficacy. We demonstrate in this in vitro study that the combination of two matrices with different subliming properties ((hexamethylcyclotrisiloxane [HMCS] and cyclododecane [CDD]) containing 10% labile C5A yielded the best results in terms of controlled release and preserved anti-HIV activity of the peptide when pre-exposed to cell-free medium or cell culture at body temperature for up to 2 months.