Extended Postexposure Protection Against Vaginal Simian/Human Immunodeficiency Virus Infection With Tenofovir Alafenamide Fumarate/Elvitegravir Inserts in Macaques.

Vaginal inserts that can be used on demand before or after sex may be a desirable human immunodeficiency virus (HIV) prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF, 20 mg) and elvitegravir (EVG, 16 mg) were highly protective against repeated simian/human immunodeficiency virus (SHIV) vaginal exposures when administered to macaques 4 hours before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8 hours or 24 hours after exposure maintains high efficacy (94.4% and 77.2%, respectively). These data extend the protective window by TAF/EVG inserts and inform their clinical development for on-demand prophylaxis in women.

Pharmacokinetics and efficacy of topical inserts containing tenofovir alafenamide fumarate and elvitegravir administered rectally in macaques.

BACKGROUND: Topical on-demand forms for HIV pre-exposure prophylaxis (PrEP) may be a desirable alternative for people that prefer not to use daily PrEP. CONRAD has developed inserts containing tenofovir alafenamide (TAF) and elvitegravir (EVG) for on-demand vaginal or rectal pericoital use. We assessed the pharmacokinetics (PK) and pre-exposure efficacy of rectally applied TAF/EVG inserts in macaques. METHODS: PK was assessed in 12 pigtailed macaques. Tenofovir (TFV) and EVG levels were assayed in rectal biopsies and secretions, and tenofovir-diphosphate (TFV-DP) levels in biopsies and peripheral blood mononuclear cells (PBMC). Drug biodistribution was evaluated in 10 animals at necropsy 4 h post-dosing. For efficacy assessments, one or two TAF/EVG inserts were administered to macaques (n = 6) 4 h before repeated rectal SHIV162p3 challenges. FINDINGS: One TAF/EVG insert resulted in rapid and high EVG and TFV-DP in rectal tissue 4 h after application. Adding a second insert led to a 10-fold increase in EVG and TFV-DP in rectal tissue. Efficacy of one and two TAF/EVG inserts were 72.6% (CI 24.5%-92.6%) and 93.1% (CI 73.3%-99.2%), respectively. INTERPRETATION: Although high TFV-DP and EVG levels were observed with one rectal TAF/EVG insert, it only conferred partial protection from rectal SHIV challenges. Adding a second insert led to an increase in TFV and EVG in rectal tissues resulting in higher (>90%) efficacy. These results highlight the high efficacy of TAF/EVG inserts as topical on-demand rectal PrEP, as well as the need for appropriate drug coverage in the deep rectum and colon to achieve high protection. FUNDING: The work related to animal studies was funded by CDC intramural funds and an interagency agreement between CDC and USAID (USAID/CDC IAA AID-GH-T-15-00002). The work related to the insert formulation was funded by U.S. PEPFAR through USAID under a Cooperative Agreement (AID-OAA-A-14-00010) with CONRAD/Eastern Virginia Medical School. The findings and conclusions of this manuscript are those of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention (CDC), USAID, President's Emergency Plan for AIDS Relief (PEPFAR), Eastern Virginia Medical School (EVMS), or the US government.

Chronic Opioid Administration is Associated with Prevotella-dominated Dysbiosis in SIVmac251 Infected, cART-treated Macaques.

People living with the human immunodeficiency virus (HIV) have an elevated risk of opioid misuse due to both prescriptions for HIV-associated chronic pain and because injection drug use remains a primary mode of HIV transmission. HIV pathogenesis is characterized by chronic immune activation and microbial dysbiosis, and translocation across the gut barrier exacerbating inflammation. Despite the high rate of co-occurrence, little is known about the microbiome during chronic opioid use in the context of HIV and combination antiretroviral therapy (cART). We recently demonstrated the reduction of the CD4 + T-cell reservoir in lymphoid tissues but increased in microglia/macrophage reservoirs in CNS by using morphine-treated, simian immunodeficiency virus (SIV)-infected rhesus macaques with viremia suppressed by cART. To understand whether morphine may perturb the gut-brain axis, fecal samples were collected at necropsy, DNA isolated, and 16S rRNA sequenced and changes of the microbiome analyzed. We found that morphine treatment led to dysbiosis, primarily characterized by expansion of Bacteroidetes, particularly Prevotellaceae, at the expense of Firmicutes and other members of healthy microbial communities resulting in a lower α-diversity. Of the many genera in Prevotellaceae, the differences between the saline and morphine group were primarily due to a higher relative abundance of Prevotella_9, the taxa most similar to Prevotella copri, an inflammatory pathobiont in the human microbiome. These findings reinforce previous research showing that opioid abuse is associated with dysbiosis, therefore, warranting additional future research to elucidate the complex interaction between the host and opioid abuse during HIV and SIV infection.

Proinflammatory oscillations over the menstrual cycle drives bystander CD4 T cell recruitment and SHIV susceptibility from vaginal challenge.

BACKGROUND: The menstrual cycle influences HIV infection-risk in women, although the timing and underlying mechanism are unclear. Here we investigated the contribution of the menstrual cycle to HIV susceptibility through evaluating immune behavior with infection-risk over time. METHODS: Blood and vaginal lavage samples were collected from 18 pig-tailed macaques to evaluate immune changes over reproductive cycles, and from 5 additional animals undergoing repeated vaginal exposures to simian HIV (SHIV). Peripheral blood mononuclear cell (PBMC) samples from healthy women (n = 10) were prospectively collected over the course of a menstrual cycle to profile T cell populations. Immune properties from PBMC and vaginal lavage samples were measured by flow cytometry. Plasma progesterone was measured by enzyme immunoassay. The oscillation frequency of progesterone concentration and CCR5 expression on CD4 T cells was calculated using the Lomb-Scargle periodogram. SHIV infection was monitored in plasma by RT-PCR. Immune measures were compared using generalized estimating equations (GEE). FINDINGS: Macaques cycle-phases were associated with fluctuations in systemic immune properties and a type-1 inflammatory T cell response with corresponding CCR5+ memory CD4 T cell (HIV target cell) infiltration into the vaginal lumen at the late luteal phase. Power spectral analysis identified CCR5 oscillation frequencies synchronized with reproductive cycles. In a repetitive low-dose vaginal challenge model, productive SHIV163P3 infection only occurred during intervals of mounting type-1 T cell responses (n = 5/5). Finally, we identify similar type-1 inflammatory T cell responses over the menstrual cycle are occurring in healthy women. INTERPRETATION: These data demonstrate that periodic shifts in the immune landscape under menstrual cycle regulation drives bystander CCR5+ CD4 T cell recruitment and HIV susceptibility in the female reproductive tract. FUNDING: This study was supported by the U.S. Centers for Disease Control and Prevention, Atlanta, GA 30329 and NIH grants to Emory University (K23AI114407 to A.N.S., the Emory University Center for AIDS research [P30AI050409], and Atlanta Clinical and Translational Sciences Institute [KLR2TR000455, UL1TR000454]). DISCLAIMER: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the U.S. Centers for Disease Control and Prevention or the Department of Health and Human Services.

Single oral dose for HIV pre or post-exposure prophylaxis: user desirability and biological efficacy in macaques.

BACKGROUND: Daily oral pre- or post-exposure prophylaxis (PrEP or PEP) is highly effective in preventing HIV infection. However, many people find it challenging to adhere to a daily oral regimen. Chemoprophylaxis with single oral doses of antiretroviral drugs taken before or after sex may better adapt to changing or unanticipated sexual practices and be a desirable alternative to daily PrEP or PEP. We investigated willingness to use a single oral pill before or after sex among men who have sex with men (MSM) and assessed the biological efficacy of a potent antiretroviral combination containing elvitegravir (EVG), emtricitabine (FTC), and tenofovir alafenamide (TAF). METHODS: Data on willingness to use single-dose PrEP or PEP were obtained from the 2017 cycle of the American Men's Internet Survey (AMIS), an annual online behavioral surveillance survey of MSM in the United States. Antiretroviral drug levels were measured in humans and macaques to define drug distribution in rectal tissue and identify clinically relevant doses for macaque modeling studies. The biological efficacy of a single dose of FTC/TAF/EVG as PrEP or PEP was investigated using a repeat-challenge macaque model of rectal HIV infection. FINDINGS: Through pharmacokinetic assessment in humans and macaques we found that EVG penetrates and concentrates in rectal tissues supporting its addition to FTC/TAF to boost and extend chemoprophylactic activity. Efficacy estimates for a single oral dose given to macaques 4h before or 2h after SHIV exposure was 91•7%[35•7%-98•9%] and 100%, respectively, compared to 80•1%[13•9%-95•4%] and 64•6%[-19•4%-89•5%] when single doses were given 6 and 24h post challenge, respectively. A two-dose regimen at 24h and 48h after exposure was also protective [77•1%[1•7%-94•7%]. INTERPRETATION: Informed by user willingness, human and macaque pharmacokinetic data, and preclinical efficacy we show that single-dose prophylaxis before or after sex is a promising HIV prevention strategy. Carefully designed clinical trials are needed to determine if any of these strategies will be effective in humans. FUNDING: Funded by CDC intramural funds, CDC contract HCVJCG2-2016-03948 (to CFK), and a grant from the MAC AIDS Fund and by the National Institutes of Health [P30AI050409] - the Emory Center for AIDS Research (to MZ and TS).

Macaques as model hosts for studies of HIV-1 infection.

Increasing evidence indicates that the host range of primate lentiviruses is in part determined by their ability to counteract innate restriction factors that are effectors of the type 1 interferon (IFN-1) response. For human immunodeficiency virus type 1 (HIV-1), in vitro experiments have shown that its tropism may be narrow and limited to humans and chimpanzees because its replication in other non-human primate species is hindered by factors such as TRIM5α (tripartite motif 5 alpha), APOBEC3G (apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3), and tetherin. Based on these data, it has been hypothesized that primate lentiviruses will infect and replicate in a new species if they are able to counteract and evade suppression by the IFN-1 response. Several studies have tested whether engineering HIV-1 recombinants with minimal amounts of simian immunodeficiency virus sequences would enable replication in CD4(+) T cells of non-natural hosts such as Asian macaques and proposed that infection of these macaque species could be used to study transmission and pathogenesis. Indeed, infection of macaques with these viruses revealed that Vif-mediated counteraction of APOBEC3G function is central to cross-species tropism but that other IFN-induced factors may also play important roles in controlling replication. Further studies of these macaque models of infection with HIV-1 derivatives could provide valuable insights into the interaction of lentiviruses and the innate immune response and how lentiviruses adapt and cause disease.