Perinatal HIV infection is associated with deficits in muscle function in children and adolescents in Zimbabwe

OBJECTIVES

To determine how muscle strength, power, mass, and density (i.e. quality) differ between children living with HIV (CWH) and those uninfected, and whether antiretroviral therapy (ART) regime is associated with muscle quality.

DESIGN

A cross-sectional study in Harare, Zimbabwe.

METHODS

The study recruited CWH aged 8-16 years, taking ART for at least 2 years, from HIV clinics, and HIV-uninfected children from local schools. Muscle outcomes comprised grip strength measured by hand-held Jamar dynamometer, lower limb power measured by standing long-jump distance, lean mass measured by dual-energy X-ray absorptiometry, and muscle density (reflecting intramuscular fat) by peripheral quantitative computed tomography. Linear regression calculated adjusted mean differences (aMD) by HIV status.

RESULTS

Overall, 303 CWH and 306 without HIV, had mean (SD) age 12.5 (2.5) years, BMI 17.5 (2.8), with 50% girls. Height and fat mass were lower in CWH, mean differences (SE) 7.4 (1.1) cm and 2.7 (0.4)kgs, respectively. Male CWH had lower grip strength [aMD 2.5 (1.1-3.9) kg, P  < 0.001], long-jump distance [7.1 (1.8-12.5) cm, P  = 0.006], muscle density [0.58 (0.12-1.05) mg/cm 3 , P  = 0.018, but not lean mass 0.06 (-1.08 to 1.21) kg, P  = 0.891) versus boys without HIV; differences were consistent but smaller in girls. Mediation analysis suggested the negative effect of HIV on jumping power in boys was partially mediated by muscle density ( P  = 0.032). CWH taking tenofovir disoproxil fumarate (TDF) had lower muscle density [0.56 (0.00-1.13)mg/cm 3 , P  = 0.049] independent of fat mass, than CWH on other ART.

CONCLUSION

Perinatally acquired HIV is associated, particularly in male individuals, with reduced upper and lower limb muscle function, not mass. Intra-muscular fat (poorer muscle quality) partially explained reductions in lower limb function. TDF is a novel risk factor for impaired muscle quality.

Development of tenofovir monobenzyl ester phosphonoamidate prodrugs with improved anti-hepatitis B virus activity and intrahepatic tenofovir enrichment

Various tenofovir (TFV) prodrugs have been developed by introducing masking groups to the hydroxyls of the monophosphonate group to enhance intestinal absorption efficiency and therapeutic effects. However, the reported TFV prodrugs have drawbacks such as low bioavailability, systemic toxicity caused by their breakdown in non-targeted tissues, and potential low intracellular conversion efficiency. In the present study, we developed a class of TFV monobenzyl ester phosphonoamidate prodrugs without substitutions on the benzene ring. Compared with previous TFV prodrugs, compounds 3a and 3b developed in the present study showed higher anti-hepatitis B virus activity, stronger stability and higher levels of intrahepatic enrichment of the metabolic product (TFV), indicating the potential of these compounds as novel prodrugs with high efficiency and low systemic toxicity for the treatment of hepatitis B.

MDSC-targeted liposomal all-trans retinoic acid suppresses mMdscs and improves immunotherapy in HBV infection

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are evolving as a prominent determinant in cancer occurrence and development and are functionally found to suppress T cells in cancer. Not much research is done regarding its involvement in viral infections. This research was designed to investigate the role of MDSCs in hepatitis B virus (HBV) infection and how targeting these cells with our novel all-trans retinoic acid encapsulated liposomal formulation could improve immunotherapy in C57BL/6 mice.

METHODS

Ten micrograms (10 μg) of plasmid adeno-associated virus (pAAV/HBV 1.2, genotype A) was injected hydrodynamically via the tail vein of C57BL/6 mice. An all-trans retinoic acid encapsulated liposomal formulation (L-ATRA) with sustained release properties was used in combination with tenofovir disoproxil fumarate (TDF), a nucleotide analog reverse transcriptase inhibitor (nRTI) to treat the HBV infection. The L-ATRA formulation was given at a dose of 5 mg/kg intravenously (IV) twice a week. The TDF was given orally at 30 mg/kg daily.

RESULTS

Our results revealed that L-ATRA suppresses MDSCs in HBV infected mice and enhanced T-cell proliferation in vitro. In vivo studies showed higher and improved immunotherapeutic effect in mice that received L-ATRA and TDF concurrently in comparison with the groups that received monotherapy. Lower HBV DNA copies, lower concentrations of HBsAg and HBeAg, lower levels of ALT and AST and less liver damage were seen in the mice that received the combination therapy of L-ATRA + TDF.

CONCLUSIONS

In effect, targeting MDSCs with the combination of L-ATRA and TDF effectively reduced mMDSC and improved immunotherapy in the HBV infected mice. Targeting MDSCs could provide a breakthrough in the fight against hepatitis B virus infection.

Membrane-permeable tenofovir-di- and monophosphate analogues

The development of new antiviral agents such as nucleoside analogues or acyclic nucleotide analogues (ANPs) and prodrugs thereof is an ongoing task. We report on the synthesis of three types of lipophilic triphosphate analogues of (R)-PMPA and dialkylated diphosphate analogues of (R)-PMPA. A highly selective release of the different nucleotide analogues ((R)-PMPA-DP, (R)-PMPA-MP, and (R)-PMPA) from these compounds was achieved. All dialkylated (R)-PMPA-prodrugs proved to be very stable in PBS as well as in CEM/0 cell extracts and human plasma. In primer extension assays, both the monoalkylated and the dialkylated (R)-PMPA-DP derivatives acted as (R)-PMPA-DP as a substrate for HIV-RT. In contrast, no incorporation events were observed using human polymerase γ. The dialkylated (R)-PMPA-compounds exhibited significant anti-HIV efficacy in HIV-1/2 infected cells (CEM/0 and CEM/TK-). Remarkably, the dialkylated (R)-PMPA-MP derivative 9a showed a 326-fold improved activity as compared to (R)-PMPA in HIV-2 infected CEM/TK- cells as well as a very high SI of 14,000. We are convinced that this study may significantly contribute to advancing antiviral agents developed based on nucleotide analogues in the future.

Recent data on the role of antiretroviral therapy in weight gain and obesity in persons living with HIV

PURPOSE OF REVIEW

Antiretroviral therapy (ART) has long been implicated in fat alterations and weight variations leading to cardiometabolic consequences. Recent largely prescribed antiretrovirals (ARVs) from the integrase-strand-transfer-inhibitor (INSTI) class have been associated with excessive weight gain/obesity in a minority of persons with HIV (PWH). As well, in the nucleoside reverse transcriptase inhibitors (NRTI) class, tenofovir-alafenamide (TAF), often replacing tenofovir-disoproxil-fumarate (TDF), has been associated with weight gain, a worrying concern in the present worldwide obesogenic environment. The respective role of the different ARV, the risk factors and the mechanisms remain questionable.

RECENT FINDINGS

The INSTIs dolutegravir (DTG) and bictegravir (BIC) and TAF have a proper effect on weight gain, while efavirenz (EFV) and TDF inhibit it. These effects are reported in ART-naïve PWH, in addition to weight gain resulting from the return to health process, and in ART-controlled PWH. Also, INSTIs induce weight gain in adolescents and excessive weight gain during pregnancy. The effects of INSTIs and TAF are additive. Their trajectory differs. Most of the weight gain is observed during the initial 12-month period.The main risk factors are low CD4+ and high viral load (VL) in ART-naïve PWH, Black race or originating from some African countries and female gender. The role of age and BMI differs between studies. The reversibility of the effect of INSTI and TAF appears limited.Regarding the mechanisms, the INSTIs can directly alter adipose tissue in particular through inhibition of fat beiging, resulting in fat fibrosis and hypertrophy. Macrophage infiltration is decreased. The mechanisms explaining the opposite effects of TDF and TAF remain elusive.

SUMMARY

The specific impact of DTG, BIC and TAF on weight gain/obesity in PWH is confirmed in different populations independently of the weight limiting effect of EFV and TDF. ART-linked excessive weight gain is uncommon. African origin and female sex are risk factors that need to be considered. The mechanisms are better understood for INSTIs but unknown for TDF/TAF. The reversibility of weight gain/obesity when stopping INSTI or TAF remains limited.

Nucleos(t)ide analogs for hepatitis B virus infection differentially regulate the growth factor signaling in hepatocytes

BACKGROUND

Recent clinical studies have suggested that the risk of developing HCC might be lower in patients with chronic hepatitis B receiving tenofovir disoproxil fumarate than in patients receiving entecavir, although there is no difference in biochemical and virological remission between the 2 drugs.

METHODS

The effects of nucleoside analogs (NsAs; lamivudine and entecavir) or nucleotide analogs (NtAs; adefovir disoproxil, tenofovir disoproxil fumarate, and tenofovir alafenamide) on cell growth and the expression of growth signaling molecules in hepatoma cell lines and PXB cells were investigated in vitro. The tumor inhibitory effects of NsAs or NtAs were evaluated using a mouse xenograft model, and protein phosphorylation profiles were investigated. The binding of NsAs or NtAs to the insulin receptor (INSR) was investigated by thermal shift assays.

RESULTS

NtAs, but not NsAs, showed direct growth inhibitory effects on hepatoma cell lines in vitro and a mouse model in vivo. A phosphoprotein array revealed that INSR signaling was impaired and the levels of phosphorylated (p)-INSRβ and downstream molecules phosphorylated (p)-IRS1, p-AKT, p-Gab1, and p-SHP2 were substantially reduced by NtAs. In addition, p-epidermal growth factor receptor and p-AKT levels were substantially reduced by NtAs. Similar findings were also found in PXB cells and nontumor lesions of liver tissues from patients with chronic hepatitis B. Prodrug NtAs, but not their metabolites (adefovir, adefovir monophosphate, adefovir diphosphate, tenofovir, tenofovir monophosphate, and tenofovir diphosphate), had such effects. A thermal shift assay showed the binding of NtAs to INSRβ.

CONCLUSIONS

NtAs (adefovir disoproxil, tenofovir disoproxil fumarate, and tenofovir alafenamide), which are adenine derivative acyclic nucleotide analogs, potentially bind to the ATP-binding site of growth factor receptors and inhibit their autophosphorylation, which might reduce the risk of HCC in patients with chronic hepatitis B.

Chidamide Induces Epstein-Barr Virus (EBV) Lytic Infection and Acts Synergistically with Tenofovir to Eliminate EBV-Positive Burkitt Lymphoma

Epstein-Barr virus (EBV) is a type of human γ-herpesvirus, and its reactivation plays an important role in the development of EBV-driven Burkitt lymphoma (BL). Despite intensive chemotherapy, the prognosis of relapsed/refractory BL patients remains unfavorable, and a definitive method to completely eliminate latent EBV infection is lacking. Previous studies have demonstrated that histone deacetylase (HDAC) inhibitors can induce the transition of EBV from latency to the lytic phase. The lytic activation of EBV can be inhibited by tenofovir, a potent inhibitor of DNA replication. Herein, we explored the antitumor effect and EBV clearance potential of a novel HDAC inhibitor called chidamide, combined with tenofovir, in the treatment of EBV-positive BL. In the study, chidamide exhibited inhibitory activity against HDAC. Moreover, chidamide inhibited BL cell proliferation, arrested cell cycle progression, and induced BL cell apoptosis primarily by regulating the MAPK pathways. Additionally, chidamide promoted the transcription of lytic genes, including BZLF1, BMRF1, and BMLF1 Compared with chidamide alone, the addition of tenofovir further induced growth arrest and apoptosis in EBV-positive BL cells and inhibited the transcriptions of EBV lytic genes induced by chidamide alone. Furthermore, our in vivo data demonstrated that the combination of chidamide and tenofovir had superior tumor-suppressive effects in a mouse model of BL cell tumors. The aforementioned findings confirm the synergistic effect of chidamide combined with tenofovir in inducing growth inhibition and apoptosis in EBV-positive BL cells and provide an effective strategy for eliminating EBV and EBV-associated malignancies. SIGNIFICANCE STATEMENT: High levels of Epstein-Barr virus (EBV)-DNA have consistently been associated with unfavorable progression-free survival and overall survival in EBV-associated lymphomas. Therefore, identifying novel strategies to effectively eradicate tumor cells and eliminate EBV is crucial for lymphoma patients. This study confirmed, for the first time, the synergistic effect of chidamide combined with tenofovir in the treatment of Burkitt lymphoma and the eradication of EBV virus.

Treatment-emergent reverse transcriptase resistance during antiretroviral therapy with bictegravir, tenofovir alafenamide, and emtricitabine: A case series

OBJECTIVES

Bictegravir/tenofovir alafenamide/emtricitabine (BIC/TAF/FTC) is a complete regimen for the treatment of HIV with a high barrier to resistance and few reported cases of treatment failure. We present three cases of treatment-emergent resistance to nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) in patients with suboptimal treatment adherence and assess whether the resistance-associated mutations were present before BIC/TAF/FTC initiation or emerged during therapy.

METHODS

We used genotypic drug resistance testing by Sanger sequencing to identify emergent resistance mutations in plasma viral load specimens collected after combination antiretroviral therapy initiation in all participants. Additionally, we performed ultra-deep sequencing by Illumina MiSeq on the earliest available plasma HIV-1 viral load specimen and on any available specimens closest in time to the initiation of BIC/TAF/FTC therapy to identify low-abundance resistance mutations present in the viral quasispecies.

RESULTS

All three participants developed NRTI resistance after prolonged exposure and incomplete adherence to BIC/TAF/FTC. The T69N, K70E, M184I, and/or T215I mutations identified in clinical samples at the time of virological failure were not present on deep sequencing of either baseline samples or samples collected before BIC/TAF/FTC initiation.

CONCLUSIONS

Despite a generally high genetic barrier to resistance, NRTI resistance-associated mutations may emerge during therapy with BIC/TAF/FTC in the setting of suboptimal adherence.

[Research progress on the effect of tenofovir disoproxil fumarate on blood lipid profile]

Tenofovir disoproxil fumarate (TDF) is a novel nucleotide reverse transcriptase inhibitor that is mainly used to treat human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. In recent years, an increasing number of studies have demonstrated that TDF treatment can reduce blood lipid levels in patients with AIDS and chronic hepatitis B and has a close correlation with the severity of the disease and the occurrence of cardiovascular events. This article reviews the research progress on the effect of TDF on blood lipid profiles, with the aim of providing a basis for rational use of TDF.

HIV-1 Resistance to Islatravir/Tenofovir Combination Therapy in Wild-Type or NRTI-Resistant Strains of Diverse HIV-1 Subtypes

Tenofovir disoproxil fumarate (TDF) and islatravir (ISL, 4'-ethynyl-2-fluoro-2'-deoxyadensine, or MK-8591) are highly potent nucleoside reverse transcriptase inhibitors. Resistance to TDF and ISL is conferred by K65R and M184V, respectively. Furthermore, K65R and M184V increase sensitivity to ISL and TDF, respectively. Therefore, these two nucleoside analogs have opposing resistance profiles and could present a high genetic barrier to resistance. To explore resistance to TDF and ISL in combination, we performed passaging experiments with HIV-1 WT, K65R, or M184V in the presence of ISL and TDF. We identified K65R, M184V, and S68G/N mutations. The mutant most resistant to ISL was S68N/M184V, yet it remained susceptible to TDF. To further confirm our cellular findings, we implemented an endogenous reverse transcriptase assay to verify in vitro potency. To better understand the impact of these resistance mutations in the context of global infection, we determined potency of ISL and TDF against HIV subtypes A, B, C, D, and circulating recombinant forms (CRF) 01_AE and 02_AG with and without resistance mutations. In all isolates studied, we found K65R imparted hypersensitivity to ISL whereas M184V conferred resistance. We demonstrated that the S68G polymorphism can enhance fitness of drug-resistant mutants in some genetic backgrounds. Collectively, the data suggest that the opposing resistance profiles of ISL and TDF suggest that a combination of the two drugs could be a promising drug regimen for the treatment of patients infected with any HIV-1 subtype, including those who have failed 3TC/FTC-based therapies.

Biochemical Markers of Calcium and Bone Metabolism during and after Lactation in Ugandan Women with HIV on Universal Maternal Antiretroviral Therapy

We reported accentuated lactational decreases in areal bone mineral density and only partial skeletal recovery after lactation in Ugandan women with HIV (WWH) initiated on tenofovir disoproxil fumarate-based antiretroviral therapy (TDF-based ART) during pregnancy compared to women without HIV (REF). WWH also had higher breast milk calcium in the first months of lactation. To investigate the mechanisms, we measured bone turnover markers (bone resorption: C-terminal telopeptide [CTX]; bone formation: procollagen type 1 N-terminal propeptide [P1NP], bone-specific and total alkaline phosphatase [BALP, TALP]), hormones (parathyroid hormone [PTH], intact fibroblast growth factor 23 [FGF23], 1,25-dihydroxyvitamin D [1,25(OH)2 D]), vitamin D status (25-hydroxyvitamin D [25OHD]), and indices of mineral metabolism and renal function. Blood and urine samples collected at 36 weeks of gestation, 14 and 26 weeks of lactation, and 3-6 months after lactation were analyzed. Mean 25OHD was >50 nmol/L throughout. Both groups experienced similar biochemical changes during pregnancy and lactation to women in other settings, but within these patterns, the two groups differed significantly. Notably, WWH had higher PTH (+31%) and lower 1,25(OH)2 D (-9%) and TmP/GFR (-9%) throughout, lower P1NP (-27%) and plasma phosphate (-10%) in pregnancy, higher CTX (+15%) and BALP (+19%), and lower eGFR (-4%) during and after lactation. P1NP/CTX ratio was lower in WWH than REF in pregnancy (-21%), less so in lactation (-15%), and similar after lactation. Additionally, WWH had lower plasma calcium (-5%), lower FGF23 (-16%) and fasting urinary calcium (-34%) at one or both lactation timepoints, and higher fasting urinary phosphate (+22%) at 26 weeks of lactation and after lactation. These differences resemble reported TDF effects, especially raised PTH, increased bone resorption, decreased bone formation, and decreased renal function, and may explain the observed differences in bone mineral density and breast milk calcium. Further studies are needed to determine whether HIV and TDF-based ART have long-term consequences for maternal bone health and offspring growth. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Bone and Renal Health in Infants With or Without Breastmilk Exposure to Tenofovir-Based Maternal Antiretroviral Treatment in the PROMISE Randomized Trial

BACKGROUND

We assessed bone and kidney outcomes in infants randomized postdelivery as mother-infant pairs within the IMPAACT PROMISE trial to maternal tenofovir disoproxil fumarate-based antiretroviral treatment (mART) or infant nevirapine prophylaxis (iNVP) to prevent breastfeeding HIV transmission.

METHODS

Infants were coenrolled in the P1084s substudy on randomization day and followed through Week 74. Lumbar spine bone mineral content (LS-BMC) was assessed at entry (6-21 age days) and Week 26 by dual-energy x-ray absorptiometry. Creatinine clearance (CrCl) was calculated at entry; Weeks 10, 26, and 74. Student t tests compared mean LS-BMC and CrCl at Week 26 and mean change from entry between arms.

RESULTS

Of 400 enrolled infants, the mean (SD; n) for entry LS-BMC was 1.68 g (0.35; n = 363) and CrCl was 64.2 mL/min/1.73 m 2 (24.6; n = 357). At Week 26, 98% of infants were breastfeeding and 96% on their assigned HIV prevention strategy. The mean (SD) Week 26 LS-BMC was 2.64 g (0.48) for mART and 2.77 g (0.44) for iNVP; mean difference (95% confidence interval [CI]) -0.13 g (-0.22 to -0.04), P = 0.007, n = 375/398 (94%). Mean absolute (-0.14 g [-0.23 to -0.06]) and percent (-10.88% [-18.53 to -3.23]) increase in LS-BMC from entry was smaller for mART than iNVP. At Week 26, the mean (SD) CrCl was 130.0 mL/min/1.73 m 2 (34.9) for mART vs. 126.1 mL/min/1.73 m 2 (30.0) for iNVP; mean difference (95% CI) 3.8 (-3.0 to 10.7), P = 0.27, n = 349/398 (88%).

CONCLUSION

Week 26 mean LS-BMC was lower in infants in the mART group compared with the iNVP group. However, this difference (∼0.23 g) was less than one-half SD, considered potentially clinically relevant. No infant renal safety concerns were observed.

Antiviral supramolecular polymeric hydrogels by self-assembly of tenofovir-bearing peptide amphiphiles

The development of long-acting antiviral therapeutic delivery systems is crucial to improve the current treatment and prevention of HIV and chronic HBV. We report here on the conjugation of tenofovir (TFV), an FDA approved nucleotide reverse transcriptase inhibitor (NRTI), to rationally designed peptide amphiphiles (PAs), to construct antiviral prodrug hydrogelators (TFV-PAs). The resultant conjugates can self-assemble into one-dimensional nanostructures in aqueous environments and consequently undergo rapid gelation upon injection into 1× PBS solution to create a drug depot. The TFV-PA designs containing two or three valines could attain instantaneous gelation, with one displaying sustained release for more than 28 days in vitro. Our studies suggest that minor changes in peptide design can result in differences in supramolecular morphology and structural stability, which impacted in vitro gelation and release. We envision the use of this system as an important delivery platform for the sustained, linear release of TFV at rates that can be precisely tuned to attain therapeutically relevant TFV plasma concentrations.

Study of the Molecular Dynamics Stability in the Inhibitory Interaction of Tenofovir Disoproxil Fumarate against CTLA-4 in Chronic Hepatitis B Patients

Background

Tenofovir disoproxil fumarate (TDF) is a first-line nucleotide analog (NA) drug for hepatitis B therapy. Long-term NA therapy increases peripheral T cell levels to enhance antiviral response, while CTLA-4 inhibits the activation.

Objective

This study analyzed the interaction between TDF and CTLA-4 through molecular docking.

Methods

Target protein and ligand data mining were performed, and proteins were prepared by removing water molecules in the Discovery Studio 2019 software. The energy minimization was performed on ligands using Pyrx v.0.9.8 software. Protein-ligand docking was performed using Autodock Vina integrated with Pyrx v.09.8. Meanwhile, the docking of proteins was accomplished using the Haddock server. The BioVia Discovery Studio 2019 software visualized the interaction between the compound and the docked protein. Molecular dynamics simulations were carried out using the YASARA Dynamic program developed by Biosciences GmbH.

Results

TDF ligand has good and stable inhibitory activity against the CTLA-4/B7-1 and CTLA4/B7-2 complexes. TDF docking has been shown to initiate conformational changes, indicating the ligand's inhibitory activity. The significant conformational changes based on superimposition results were shown by the CTLA-4/TDF/B7-2 and CTLA-4/B7-1/TDF complexes. TDF in all ligands undergoes bonding and displacement of binding sites.

Conclusion

Treatment with TDF was predicted to have inhibitory activity against CTLA-4, especially in its complex form with B7-1 and B7-2.

Interaction of Depot Medroxyprogesterone Acetate and Tenofovir Disoproxil Fumarate/Emtricitabine on Peripheral Blood Mononuclear Cells and Cervical Tissue Susceptibility to HIV Infection and Pharmacokinetics

BACKGROUND

Depot medroxyprogesterone acetate (DMPA) is a widely used contraceptive method. HIV pre-exposure prophylaxis with emtricitabine and tenofovir disoproxil fumarate (F/TDF) is highly effective in reducing HIV acquisition in women. We sought to determine the impact of DMPA on F/TDF pharmacokinetics and pharmacodynamics.

METHODS

Twelve healthy premenopausal cisgender women were enrolled and each completed 4 sequential conditions: (1) baseline, (2) steady-state F/TDF alone, (3) steady-state F/TDF + DMPA, and (4) DMPA alone. Assessments included clinical, pharmacokinetic, viral infectivity (ex vivo challenge of peripheral blood mononuclear cells by X4- and R5-tropic green fluorescent protein pseudoviruses and cervical tissue by HIV BaL ), endocrine, immune cell phenotyping, and renal function.

RESULTS

Compared with baseline, F/TDF (± DMPA) significantly decreased both %R5- and X4-infected CD4 T cells and F/TDF + DMPA decreased cervical explant p24 (all P < 0.05). The %R5- and X4-infected CD4 T cells were higher during DMPA alone than during F/TDF periods and lower than baseline (not statistically significant). Cervical explant p24 fell between baseline and F/TDF values (not statistically significant). There were neither statistically significant differences in F/TDF pharmacokinetics, including total or renal clearance of either antiviral drug, nor changes in glomerular filtration rate with the addition of DMPA. There were few immune cell phenotypic differences across conditions.

CONCLUSIONS

F/TDF decreased HIV infection in both challenge assays, whereas DMPA alone did not enhance HIV infection in either challenge assay. DMPA did not alter F/TDF pharmacokinetics or renal function.

Evaluation of tenofovir disoproxil fumarate loaded silver nanoparticle on testicular morphology in experimental type-2 diabetic rats

Reproductive derangement and metabolic disorders in human immunodeficiency virus (HIV) infected persons require a nanoparticle delivery system to convey antiretroviral drugs to the anatomical sanctuary such as testis. This study investigated the effects of tenofovir disoproxil fumarate (TDF) loaded silver nanoparticles (AgNPs) on the testicular oxidative stress, inflammatory cytokines and histology in male diabetic rats. Thirty-six Sprague-Dawley rats weighing 230 ± 20 g were randomly divided into diabetic and non-diabetic groups (n = 18). Diabetes was induced using the fructose-streptozotocin (Frt-STZ) rat model. Both groups were further divided into three (n = 6) and administered distilled water, TDF, or TDF-AgNP. Results obtained with the TDF-AgNP administration showed a significant increase (p < .05) in the reduced glutathione and catalase levels. Tumour necrosis factor-alpha and interleukin 6 were reduced in diabetic rats administered TDF-AgNP. More so, administration of TDF-AgNP to diabetic rats improved testicular histoarchitecture in diabetic rats. In addition, diabetic rats administered TDF-AgNP showed a significant reduction (p < .05) in blood glucose levels. TDF-AgNP to diabetic rats enhanced testicular antioxidant enzyme, reduced testicular inflammation, and alleviated structural derangements in the testis. Thus, the application of AgNP to deliver TDF may alleviate testicular toxicity and subsequently cater for neglected reproductive dysfunction during the management of HIV infection.

Impact of preexisting nucleos(t)ide reverse transcriptase inhibitor resistance on the effectiveness of bictegravir/emtricitabine/tenofovir alafenamide in treatment experience patients

INTRODUCTION

Few clinical trials and cohort studies have evaluated the efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in people with HIV (PWH) with preexisting M184V/I or other nucleos(t)ide reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs). Real-world data are also scarce.

METHODS

Retrospective review of treatment-experienced patients who started B/F/TAF in a cohort of PWH. HIV-RNA less than 50 copies/ml was analyzed at 48 weeks in an intention-to-treat (ITT) analysis (missing=failure) and per protocol analysis (patients with missing data or changes for reasons other than virological failure were excluded). Results were compared in patients with and without previous NRTI-RAMs.

RESULTS

Five hundred and six PWH were included (16.2% women). Median age and time with HIV infection were 52.3 and 18.9 years, respectively. At baseline, viral load was less than 50 copies/ml in 440 patients (86.6%). Overall, 69 (13.6%) participants had documented preexisting NRTI-RAMs: 57 (11.2%) M184V/I and 30 (5.9%) tenofovir RAMs. In the ITT analysis, 83% (420/506) had HIV-RNA less than 50 copies/ml [82.2% (359/437) and 88.4% (61/69) in persons without and with NRTI-RAMs, respectively ( P  = 0.2)]. In the per protocol analysis 94.2% (420/445) had HIV-RNA less than 50 copies/ml [94.4% (359/380) vs. 93.8% (61/65); P  = 0.2]. A total of 61 participants were excluded from the per protocol analysis (23 missing data, 19 discontinued B/F/TAF because of toxicity, 13 for other reasons, and 6 died).

CONCLUSION

Switching to B/F/TAF is well tolerated and effective in the real-world setting, even in patients with preexisting NRTI RAMs, such as M184V and RAMs conferring resistance to tenofovir. These results confirm the robustness of this combination.

Do anti-HIV drugs pose a threat to photosynthetic microorganisms?

We investigated the occurrence and risk assessment of three anti-HIV drugs [(tenofovir (TNF), lamivudine (LMV) and efavirenz (EFV)] in urban rivers from Curitiba (Brazil), as well as the individual and combined effects of their environmental representative concentrations on the freshwater periphytic species Synechococcus elongatus (Cyanobacteria) and Chlorococcum infusionum (Chlorophyta). The three studied drugs, except TNF, were found in 100% of the samples, and concentrations in samples ranged from 165 to 412 ng TNF L^-1, 173-874 ng LMV L^-1 and 13-1250 ng EFV L^-1. Bioassays using artificial contaminated water showed that at environmental concentrations, TNF and LMV did not represent environmental risks to the studied photosynthetic organisms. However, EFV was shown to be toxic, affecting photosynthesis, respiration, and oxidative metabolism. The studied drugs demonstrated interactive effects. Indeed, when submitted to the combination of TNF and LMV, decreased photosynthesis was observed in C. infusionum cells. Moreover, the toxic effects of EFV were amplified in both species when TNF and/or LMV were added to the media. The simultaneous presence of TNF, LMV and EFV in environmental matrices associated with their interactive effects, lead to increased toxicological effects of water contaminated by anti-HIV drugs and thus to an ecological threat to photosynthetic microorganisms.

Immunomodulation and RNA interference alter hepatitis B virus-specific CD8 T-cell recognition of infected HepG2-NTCP

BACKGROUND AND AIMS

CD8 T cells are essential in controlling HBV infection. Viral control is dependent on efficient recognition of HBV-infected hepatocytes by CD8 T cells, which can induce direct lysis of infected hepatocytes. In addition, CD8 T cells produce interferon (IFN)-γ, which mediates noncytopathic viral clearance. Innate immunomodulators and HBV-targeted RNA interference (RNAi) are being developed to treat chronic hepatitis B (CHB), but may modify HBV antigen presentation and impact CD8 T-cell recognition, in addition to their primary mechanisms of action.

APPROACH AND RESULTS

HBV-infected HepG2-NTCP cells were treated with tenofovir disoproxil fumarate (TDF), Toll-like receptor (TLR) 7/8 agonists, TLR7/8 conditioned media (CM) collected from immune cells, or RNAi using short interfering RNAs. The effect of these treatments on antigen presentation was measured through coculture with CD8 T cells recognizing human leukocyte antigen-A0201 restricted epitopes, HBc18-27 or HBs183-191. Cytokine profiles of TLR7/8 CM were measured using a cytometric bead array. TDF reduced viral replication, but not CD8 T-cell recognition, of infected cells. Direct exposure of infected HepG2-NTCP to TLR7/8 agonists had no impact on T-cell recognition. Exposure of infected HepG2-NTCP to TLR7/8 CM enhanced HBV-specific CD8 T-cell recognition through type 1 interferon (IFN) and IFN-γ-dependent mechanisms. RNAi rapidly suppressed HBV-DNA, HBcAg, and HBsAg expression, impairing recognition by HBV-specific CD8 T cells.

CONCLUSIONS

Immunomodulation and RNAi, but not nucleos(t)ide analogues, alter the recognition of infected HepG2-NTCP by HBV-specific CD8 T cells. Understanding these changes will inform combination treatments for CHB.

Tenofovir disoproxil fumarate-mediated γ-globin induction is correlated with the suppression of trans-acting factors in CD34+ progenitor cells: A role in the reactivation of fetal hemoglobin

Sickle-cell disease (SCD) and β-thalassemia are public health issues that affect people all over the world. Fetal hemoglobin (HbF) induction is a molecular intervention, including hydroxyurea, which has made an effort to improve current treatment. Tenofovir disoproxil fumarate (TDF) is formerly reported with improving levels of hemoglobin, mean corpuscular hemoglobin (MCH), and mean corpuscular volume (MCV). Hence, in this preclinical investigation, human peripheral whole blood-derived CD34⁺ progenitor cells were cultured to prove the efficacy of TDF on erythroid proliferation, differentiation, γ-globin gene expression regulation, and ultimately HbF production. We observed that TDF increased the proliferation of immature erythroid cells, delayed the terminal erythroid maturation without cytotoxicity as correlated with other HbF inducers. Here, the presented data show that TDF can induce HbF expression by up-regulating the γ-globin gene transcription up to 7.1 ± 0.46-fold and subsequently increased the F-cells (10.79 ± 1.9-fold) population in terminally differentiated erythroid cells. Furthermore, our findings demonstrated that TDF-mediated γ-globin gene induction and HbF production was associated with down-fold regulation of BCL11A and SOX6, and their corresponding trans-acting regulators, FOP, KLF1, and GATA1. Collectively, our findings suggest TDF as an effective inducer of HbF in CD34⁺ cells and pave the way to put forward the assessment of TDF as a new potential therapy in treating β-hemoglobinopathies.

An artificial intelligence model to predict hepatocellular carcinoma risk in Korean and Caucasian patients with chronic hepatitis B

BACKGROUND & AIMS

Several models have recently been developed to predict risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). Our aims were to develop and validate an artificial intelligence-assisted prediction model of HCC risk.

METHODS

Using a gradient-boosting machine (GBM) algorithm, a model was developed using 6,051 patients with CHB who received entecavir or tenofovir therapy from 4 hospitals in Korea. Two external validation cohorts were independently established: Korean (5,817 patients from 14 Korean centers) and Caucasian (1,640 from 11 Western centers) PAGE-B cohorts. The primary outcome was HCC development.

RESULTS

In the derivation cohort and the 2 validation cohorts, cirrhosis was present in 26.9%-50.2% of patients at baseline. A model using 10 parameters at baseline was derived and showed good predictive performance (c-index 0.79). This model showed significantly better discrimination than previous models (PAGE-B, modified PAGE-B, REACH-B, and CU-HCC) in both the Korean (c-index 0.79 vs. 0.64-0.74; all p <0.001) and Caucasian validation cohorts (c-index 0.81 vs. 0.57-0.79; all p <0.05 except modified PAGE-B, p = 0.42). A calibration plot showed a satisfactory calibration function. When the patients were grouped into 4 risk groups, the minimal-risk group (11.2% of the Korean cohort and 8.8% of the Caucasian cohort) had a less than 0.5% risk of HCC during 8 years of follow-up.

CONCLUSIONS

This GBM-based model provides the best predictive power for HCC risk in Korean and Caucasian patients with CHB treated with entecavir or tenofovir.

LAY SUMMARY

Risk scores have been developed to predict the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B. We developed and validated a new risk prediction model using machine learning algorithms in 13,508 antiviral-treated patients with chronic hepatitis B. Our new model, based on 10 common baseline characteristics, demonstrated superior performance in risk stratification compared with previous risk scores. This model also identified a group of patients at minimal risk of developing HCC, who could be indicated for less intensive HCC surveillance.

Tenofovir disoproxil fumarate directly ameliorates liver fibrosis by inducing hepatic stellate cell apoptosis via downregulation of PI3K/Akt/mTOR signaling pathway

Background

Antifibrotic agent for the treatment of liver fibrosis has not been developed so far. Long term treatment of chronic hepatitis B patients with antiviral drugs tenofovir disoproxil fumarate (TDF) and entecavir (ETV) results in the regression of liver fibrosis, but the underlying mechanism has not been clarified. Therefore, we aimed to investigate the direct impact of TDF and ETV on liver fibrosis.

Methods

Activated hepatic stellate cell (HSC) cell lines were used to evaluate the effects of TDF and ETV. After treatment with each antiviral agent, cell viability, morphology, apoptotic features, autophagy and antifibrosis signalling pathways were examined. Then, collagen deposition, fibrosis markers and activated HSCs were measured in liver tissues of the liver fibrosis model mice.

Results

After TDF treatment, the viabilities of LX2 and HSC-T6 cells were decreased, and the cells exhibited apoptotic features, but ETV did not induce these effects. Cleavage of PARP and Caspase-3 and the inhibition of the antiapoptotic gene Bcl-xl indicated activated HSC apoptosis following TDF treatment. TDF simultaneously increased autophagy, which also regulated apoptosis through crosstalk. TDF inactivated the PI3K/Akt/mTOR signalling pathway, which was associated with the activation of both apoptosis and autophagy. In the liver fibrosis mouse model, the fibrotic area and activated HSC markers were decreased by TDF but not ETV treatment. Additionally, apoptotic cells were concentrated in the periportal fibrotic area after TDF treatment, which indicated the specific antifibrotic effect of TDF.

Conclusions

TDF directly ameliorates liver fibrosis by downregulating the PI3K/Akt/mTOR signalling pathway, which results in the apoptosis of activated HSCs. The antifibrotic effects of TDF indicate that it may be a therapeutic agent for the treatment of liver fibrosis.

Effectiveness of tenofovir alafenamide for chronic hepatitis B patients with a poor response to the previously used nucleos(t)ide analogs

BACKGROUND

Few studies have demonstrated the potency of tenofovir alafenamide (TAF) in patients with poor response to other nucleos(t)ide analogs (NAs).

METHODS

We conducted a retrospective study comprising consecutive 40 patients exhibiting a poor response to other NAs, who subsequently received TAF-containing regimens. The primary outcome was the prevalence of virological response (VR) at each time and maintained virological response (MVR) under TAF-containing regimens until week 96.

RESULTS

In the entire cohort, the prevalence of MVR was 71.1% (27/38). Further, poor tenofovir disoproxil fumarate (TDF) response was significantly associated with a lower prevalence of MVR (p = 0.014). In TDF-naïve patients, the prevalence of MVR was 92.3% (12/13) and 62.5% (5/8) in patients with lamivudine resistance (LAM-r) and entecavir resistance (ETV-r), respectively. Further, viral load and HBeAg status at baseline were associated with a lower prevalence of MVR (p = 0.013). Among the seven patients with prior TDF exposure, 2 patients achieved MVR. Among them, one patient with development of viral breakthrough during TDF/LAM achieved MVR after switching to TAF/ETV. In contrast, one of the five patients with non-MVR had three substitutions (rtS106C, rtD134N/S, and rtL269I) of quadruple mutations in addition to ETV-r. Other patients with rtA181T + rtN236T also could not achieve MVR.

CONCLUSION

TAF exhibited high antiviral potency in patients with LAM-r and ETV-r. However, TAF potency was associated with previous TDF response, viral load, and HBeAg status at baseline. Additionally, a quadruple mutation may impact tenofovir resistance; however, further studies are needed to verify this.

Tenofovir Modulates Semaphorin 4D Signaling and Regulates Bone Homeostasis, Which Can Be Counteracted by Dipyridamole and Adenosine A2A Receptor

Semaphorin 4D (Sema4D) is a neurotrophin that is secreted by osteoclasts and binds to its receptor PlexinB1 on osteoblasts to inhibit their differentiation and function. Adenosine A2A activation inhibits osteoclast Sema4D-mediated secretion, diminishes inflammatory osteolysis and prevents bone loss following tenofovir (one of the most used antivirals in HIV). Therefore, tenofovir might activate Sema4D signaling to alter bone turnover. Female C57Bl/6/A2AKO mice were ovariectomized and treated with saline (control), tenofovir 75 mg/Kg/day, dipyridamole 25 mg/Kg/day or a combination for 5 weeks and long bones were prepared for histology. Primary murine-induced osteoclast/osteoblast were challenged with tenofovir/dipyridamole 1 μM each, and the expression of Sema4D/PlexinB1, RhoA/ROCK/IGF1R was studied by RT-PCR, Western blot and immunostaining. In vivo tenofovir showed an increased expression of Sema4D when compared to control mice, and dipyridamole reverted the expression in an A2A-dependent manner. In vitro, tenofovir increases Sema4D expression and secretion in osteoclast precursors, and pre-treatment with dipyridamole reverted this effect. pRhoA and ROCK1 activation were increased and IRS1/IGF1R expression was diminished by tenofovir in the Vav3/ARHGAP18 mechanism in osteoblast precursors and reverted by dipyridamole in an A2A-dependent manner. This suggests that tenofovir increases bone loss by activation of Sema4D/PlexinB1 signaling, which inhibits osteoblast differentiation. Agents that increase local adenosine concentrations, such as dipyridamole, might prevent bone loss following the inhibition of this pathway.

Transformation of tenofovir into stable ProTide nanocrystals with long-acting pharmacokinetic profiles

Treatment and prevention of human immunodeficiency virus type one (HIV-1) infection was transformed through widespread use of antiretroviral therapy (ART). However, ART has limitations in requiring life-long daily adherence. Such limitations have led to the creation of long-acting (LA) ART. While nucleoside reverse transcriptase inhibitors (NRTI) remain the ART backbone, to the best of our knowledge, none have been converted into LA agents. To these ends, we transformed tenofovir (TFV) into LA surfactant stabilized aqueous prodrug nanocrystals (referred to as NM1TFV and NM2TFV), enhancing intracellular drug uptake and retention. A single intramuscular injection of NM1TFV, NM2TFV, or a nanoformulated tenofovir alafenamide (NTAF) at 75 mg/kg TFV equivalents to Sprague Dawley rats sustains active TFV-diphosphate (TFV-DP) levels ≥ four times the 90% effective dose for two months. NM1TFV, NM2TFV and NTAF elicit TFV-DP levels of 11,276, 1,651, and 397 fmol/g in rectal tissue, respectively. These results are a significant step towards a LA TFV ProTide.

ω-Functionalized Lipid Prodrugs of HIV NtRTI Tenofovir with Enhanced Pharmacokinetic Properties

Tenofovir (TFV) is the cornerstone nucleotide reverse transcriptase inhibitor (NtRTI) in many combination antiretroviral therapies prescribed to patients living with HIV/AIDS. Due to poor cell permeability and oral bioavailability, TFV is administered as one of two FDA-approved prodrugs, both of which metabolize prematurely in the liver and/or plasma. This premature prodrug processing depletes significant fractions of each oral dose and causes toxicity in kidney, bone, and liver with chronic administration. Although TFV exalidex (TXL), a phospholipid-derived prodrug of TFV, was designed to address this issue, clinical pharmacokinetic studies indicated substantial hepatic extraction, redirecting clinical development of TXL toward HBV. To circumvent this metabolic liability, we synthesized and evaluated ω-functionalized TXL analogues with dramatically improved hepatic stability. This effort led to the identification of compounds 21 and 23, which exhibited substantially longer t1/2 values than TXL in human liver microsomes, potent anti-HIV activity in vitro, and enhanced pharmacokinetic properties in vivo.

Combination Treatment with the Vimentin-Targeting Antibody hzVSF and Tenofovir Suppresses Woodchuck Hepatitis Virus Infection in Woodchucks

Current treatment options for patients infected with hepatitis B virus (HBV) are suboptimal, because the approved drugs rarely induce cure due to the persistence of the viral DNA genome in the nucleus of infected hepatocytes, and are associated with either severe side effects (pegylated interferon-alpha) or require life-long administration (nucleos(t)ide analogs). We report here the evaluation of the safety and therapeutic efficacy of a novel, humanized antibody (hzVSF) in the woodchuck model of HBV infection. hzVSF has been shown to act as a viral entry inhibitor, most likely by suppressing vimentin-mediated endocytosis of virions. Targeting the increased vimentin expression on liver cells by hzVSF after infection with HBV or woodchuck hepatitis virus (WHV) was demonstrated initially. Thereafter, hzVSF safety was assessed in eight woodchucks naïve for WHV infection. Antiviral efficacy of hzVSF was evaluated subsequently in 24 chronic WHV carrier woodchucks by monotreatment with three ascending doses and in combination with tenofovir alafenamide fumarate (TAF). Consistent with the proposed blocking of WHV reinfection, intravenous hzVSF administration for 12 weeks resulted in a modest but transient reduction of viral replication and associated liver inflammation. In combination with oral TAF dosing, the antiviral effect of hzVSF was enhanced and sustained in half of the woodchucks with an antibody response to viral proteins. Thus, hzVSF safely but modestly alters chronic WHV infection in woodchucks; however, as a combination partner to TAF, its antiviral efficacy is markedly increased. The results of this preclinical study support future evaluation of this novel anti-HBV drug in patients.

A Mechanistic In Vivo/Ex Vivo Pharmacokinetic-Pharmacodynamic Model of Tenofovir for HIV Prevention

Defining tissue and plasma-specific prophylactic drug concentrations is central to pre-exposure prophylaxis product development for sexual transmission of HIV-1. Pharmacokinetic (PK) data from study RMP-02/MTN-006 comparing single dose oral tenofovir disoproxil fumarate with single and multiple dose rectal tenofovir (TFV) gel administration in HIV-1 seronegative adults was used to construct a multicompartment plasma-rectal tissue population PK model for TFV and tenofovir-diphosphate (TFVdp) in plasma and rectal tissue. PK data were collected in five matrices: TFV (plasma, rectal tissue homogenate), TFVdp (peripheral blood mononuclear cells, rectal mononuclear cells (MMCs), rectal tissue homogenate). A viral growth compartment and a delayed effect compartment for p24 antigen expression measured from an ex vivo explant assay described HIV-1 infection and replication. Using a linear PK/pharmacodynamic model, MMC TFVdp levels over 9,000 fmol/million cells in the explant assay provided apparent viral replication suppression down to 1%. Parameters were estimated using NONMEM version 7.4.

Distinctive HBV Replication Capacity and Susceptibility to Tenofovir Induced by a Polymerase Point Mutation in Hepatoma Cell Lines and Primary Human Hepatocytes

Tenofovir disoproxil fumarate (TDF) has been regarded as the most potent drug for treating patients with chronic hepatitis B (CHB). However recently, viral mutations associated with tenofovir have been reported. Here, we found a CHB patient with suboptimal response after more than 4 years of TDF treatment. Clonal analysis of hepatitis B virus (HBV) isolated from sequential sera of this patient identified the seven previously reported TDF-resistant mutations (CYELMVI). Interestingly, a threonine to alanine mutation at the 301 amino acid position of the reverse-transcriptase (RT) domain, (rtT301A), was commonly accompanied with CYELMVI at a high rate (72.7%). Since the rtT301A mutation has not been reported yet, we investigated the role of this naturally occurring mutation on the viral replication and susceptibility to tenofovir in various liver cells (hepatoma cells as well as primary human hepatocytes). A cell-based phenotypic assay revealed that the rtT301A mutation dramatically impaired the replication ability with meaningful reduction in sensitivity to tenofovir in hepatoma cell lines. However, attenuated viral replication by the rtT301A mutation was significantly restored in primary human hepatocytes (PHHs). Our findings suggest that the replication capability and drug sensitivity of HBV is different between hepatoma cell lines and PHHs. Therefore, our study emphasizes that validation studies should be performed not only in the liver cancer cell lines but also in the PHHs to understand the exact viral fitness under antiviral pressure in patients.

A New Approach to Developing Long-Acting Injectable Formulations of Anti-HIV Drugs: Poly(Ethylene Phosphoric Acid) Block Copolymers Increase the Efficiency of Tenofovir against HIV-1 in MT-4 Cells

Despite the world’s combined efforts, human immunodeficiency virus (HIV), the causative agent of AIDS, remains one of the world’s most serious public health challenges. High genetic variability of HIV complicates the development of anti-HIV vaccine, and there is an actual clinical need for increasing the efficiency of anti-HIV drugs in terms of targeted delivery and controlled release. Tenofovir (TFV), a nucleotide-analog reverse transcriptase inhibitor, has gained wide acceptance as a drug for pre-exposure prophylaxis or treatment of HIV infection. In our study, we explored the potential of tenofovir disoproxil (TFD) adducts with block copolymers of poly(ethylene glycol) monomethyl ether and poly(ethylene phosphoric acid) (mPEG-b-PEPA) as candidates for developing a long-acting/controlled-release formulation of TFV. Two types of mPEG-b-PEPA with numbers of ethylene phosphoric acid (EPA) fragments of 13 and 49 were synthesized by catalytic ring-opening polymerization, and used for preparing four types of adducts with TFD. Antiviral activity of [mPEG-b-PEPA]TFD or tenofovir disoproxil fumarate (TDF) was evaluated using the model of experimental HIV infection in vitro (MT-4/HIV-1_IIIB). Judging by the values of the selectivity index (SI), TFD exhibited an up to 14-fold higher anti-HIV activity in the form of mPEG-b-PEPA adducts, thus demonstrating significant promise for further development of long-acting/controlled-release injectable TFV formulations.

Global Occurrence of Clinically Relevant Hepatitis B Virus Variants as Found by Analysis of Publicly Available Sequencing Data

Several viral factors impact the natural course of hepatitis B virus (HBV) infection, the sensitivity of diagnostic tests, or treatment response to interferon-α and nucleos(t)ide analogues. These factors include the viral genotype and serotype but also mutations affecting the HBV surface antigen, basal core promoter/pre-core region, or reverse transcriptase. However, a comprehensive overview of the distribution of HBV variants between HBV genotypes or different geographical locations is lacking. To address this, we performed an in silico analysis of publicly available HBV full-length genome sequences. We found that not only the serotype frequency but also the majority of clinically relevant mutations are primarily associated with specific genotypes. Distinct mutations enriched in certain world regions are not explained by the local genotype distribution. Two HBV variants previously identified to confer resistance to the nucleotide analogue tenofovir in vitro were not identified, questioning their translational relevance. In summary, our work elucidates the differences in the clinical manifestation of HBV infection observed between genotypes and geographical locations and furthermore helps identify suitable diagnostic tests and therapies.

Computational drug re-purposing targeting the spike glycoprotein of SARS-CoV-2 as an effective strategy to neutralize COVID-19

COVID-19 has intensified into a global pandemic with over a million deaths worldwide. Experimental research analyses have been implemented and executed with the sole rationale to counteract SARS-CoV-2, which has initiated potent therapeutic strategy development in coherence with computational biology validation focusing on the characterized viral drug targets signified by proteomic and genomic data. Spike glycoprotein is one of such potential drug target that promotes viral attachment to the host cellular membrane by binding to its receptor ACE-2 via its Receptor-Binding Domain (RBD). Multiple Sequence alignment and relative phylogenetic analysis revealed significant sequential disparities of SARS-CoV-2 as compared to previously encountered SARS-CoV and MERS-CoV strains. We implemented a drug re-purposing approach wherein the inhibitory efficacy of a cluster of thirty known drug candidates comprising of antivirals, antibiotics and phytochemicals (selection contingent on their present developmental status in underway clinical trials) was elucidated by subjecting them to molecular docking analyses against the spike protein RBD model (developed using homology modelling and validated using SAVES server 5.0) and the composite trimeric structures of spike glycoprotein of SARS-CoV-2. Our results indicated that Camostat, Favipiravir, Tenofovir, Raltegravir and Stavudine showed significant interactions with spike RBD of SARS-CoV-2. Proficient bioavailability coupled with no predicted in silico toxicity rendered them as prospective alternatives for designing and development of novel combinatorial therapy formulations for improving existing treatment regimes to combat COVID-19.

Knowledge and barriers of PrEP delivery among diverse groups of potential PrEP users in Central Uganda

BACKGROUND

Scale-up of oral pre-exposure prophylaxis (PrEP) for HIV prevention in Uganda began with serodiscordant couples (SDC) and has expanded to other most at-risk populations (MARPs). We explored knowledge, acceptability, barriers and facilitators of PrEP use among potential PrEP users in four MARPs (SDC; men who have sex with men [MSM]; female sex workers [FSW], and fisher folk).

METHODS

We administered quantitative surveys to potential PrEP users in multiple settings in Central Uganda at baseline and approximately 9 months after healthcare worker (HCW) training on PrEP.

RESULTS

The survey was completed by 250 potential PrEP users at baseline and 125 after HCW training; 55 completed both surveys. For these 250 participants, mean age was 28.5 years (SD 6.9), 47% were male and 6% were transgender women, with approximately even distribution across MARPs and recruitment locations (urban, peri-urban, and rural). Most (65%) had not heard about PrEP. After HCW training, 24% of those sampled were aware of PrEP, and the proportion of those who accurately described PrEP as "antiretrovirals to be used before HIV exposure" increased from 54% in the baseline survey to 74% in the second survey (p<0.001). The proportion of participants who reported HCW as a source of PrEP information increased after training (59% vs 91%, p<0.001). In both surveys, nearly all participants indicated they were willing to take PrEP if offered. The most common anticipated barriers to PrEP were stigma, transportation, accessibility, busy schedules, and forgetfulness. Closeness to home was a common facilitator for all participant categories.

CONCLUSIONS

Initial awareness of PrEP was low, but PrEP knowledge and interest increased among diverse MARPs after HCW training. Demand creation and HCW training will be critical for increasing PrEP awareness among key populations, with support to overcome barriers to PrEP use. These findings should encourage the acceleration of PrEP rollout in Uganda.

Continuation of emtricitabine/lamivudine within combination antiretroviral therapy following detection of the M184V/I HIV-1 resistance mutation

OBJECTIVES

The aim of the study was to investigate whether lamivudine (3TC) or emtricitabine (FTC) use following detection of M184V/I is associated with better virological outcomes.

METHODS

We identified people with viruses harbouring the M184V/I mutation in UK multicentre data sets who had treatment change/initiation within 1 year. We analysed outcomes of viral suppression (< 200 HIV-1 RNA copies/mL) and appearance of new major drug resistance mutations (DRMs) using Cox and Poisson models, with stratification by new drug regimen (excluding 3TC/FTC) and Bayesian implementation, and estimated the effect of 3TC/FTC adjusted for individual and viral characteristics.

RESULTS

We included 2597 people with the M184V/I resistance mutation, of whom 665 (25.6%) were on 3TC and 458 (17.6%) on FTC. We found a negative adjusted association between 3TC/FTC use and viral suppression [hazard ratio (HR) 0.84; 95% credibility interval (CrI) 0.71-0.98]. On subgroup analysis of individual drugs, there was no evidence of an association with viral suppression for 3TC (n = 184; HR 0.94; 95% CrI 0.73-1.15) or FTC (n = 454; HR 0.99; 95% CrI 0.80-1.19) amongst those on tenofovir-containing regimens, but we estimated a reduced rate of viral suppression for people on 3TC amongst those without tenofovir use (n = 481; HR 0.71; 95% CrI 0.54-0.90). We found no association between 3TC/FTC and detection of any new DRM (overall HR 0.92; 95% CrI 0.64-1.18), but found inconclusive evidence of a lower incidence rate of new DRMs (overall incidence rate ratio 0.69; 95% CrI 0.34-1.11).

CONCLUSIONS

We did not find evidence that 3TC or FTC use is associated with an increase in viral suppression, but it may reduce the appearance of additional DRMs in people with M184V/I. 3TC was associated with reduced viral suppression amongst people on regimens without tenofovir.

Uptake, engagement, and adherence to pre-exposure prophylaxis offered after population HIV testing in rural Kenya and Uganda: 72-week interim analysis of observational data from the SEARCH study

BACKGROUND

Optimal strategies for pre-exposure prophylaxis (PrEP) engagement in generalised HIV epidemics are unknown. We aimed to assess PrEP uptake and engagement after population-level HIV testing and universal PrEP access to characterise gaps in the PrEP cascade in rural Kenya and Uganda.

METHODS

We did a 72-week interim analysis of observational data from the ongoing SEARCH (Sustainable East Africa Research in Community Health) study. Following community sensitisation and PrEP education, we did HIV testing and offered PrEP at health fairs and facilities in 16 rural communities in western Kenya, eastern Uganda, and western Uganda. We provided enhanced PrEP counselling to individuals 15 years and older who were assessed as having an elevated HIV risk on the basis of serodifferent partnership or empirical risk score, or who otherwise self-identified as being at high risk but were not in serodifferent partnerships or identified by the risk score. PrEP follow-up visits were done at facilities, homes, or community locations. We assessed PrEP uptake within 90 days of HIV testing, programme engagement (follow-up visit attendance at week 4, week 12, and every 12 weeks thereafter), refills, self-reported adherence up to 72 weeks, and concentrations of tenofovir in hair samples from individuals reporting HIV risk and adherence during follow-up, and analysed factors associated with uptake and adherence. This study is registered with ClinicalTrials.gov, NCT01864603.

FINDINGS

Between June 6, 2016, and June 23, 2017, 70 379 community residents 15 years or older who had not previously been diagnosed with HIV were tested during population-level HIV testing. Of these individuals, 69 121 tested HIV-negative, 12 935 of whom had elevated HIV risk (1353 [10%] serodifferent partnership, 6938 [54%] risk score, 4644 [36%] otherwise self-identified risk). 3489 (27%) initiated PrEP, 2865 (82%) of whom did so on the same day as HIV testing and 1733 (50%) of whom were men. PrEP uptake was lower among individuals aged 15-24 years (adjusted odds ratio 0·55, 95% CI 0·45-0·68) and mobile individuals (0·61, 0·41-0·91). At week 4, among 3466 individuals who initiated PrEP and did not withdraw or die before the first visit, 2215 (64%) were engaged in the programme, 1701 (49%) received medication refills, and 1388 (40%) self-reported adherence. At week 72, 1832 (56%) of 3274 were engaged, 1070 (33%) received a refill, and 900 (27%) self-reported adherence. Among participants reporting HIV risk at weeks 4-72, refills (89-93%) and self-reported adherence (70-76%) were high. Among sampled participants self-reporting adherence at week 24, the proportion with tenofovir concentrations in the hair reflecting at least four doses taken per week was 66%, and reflecting seven doses per week was 44%. Participants who stopped PrEP accepted HIV testing at 4274 (83%) of 5140 subsequent visits; half of these participants later restarted PrEP. 29 participants of 3489 who initiated PrEP had serious adverse events, including seven deaths. Five adverse events (all grade 3) were assessed as being possibly related to the study drug.

INTERPRETATION

During population-level HIV testing, inclusive risk assessment (combining serodifferent partnership, an empirical risk score, and self-identification of HIV risk) was feasible and identified individuals who could benefit from PrEP. The biggest gap in the PrEP cascade was PrEP uptake, particularly for young and mobile individuals. Participants who initiated PrEP and had perceived HIV risk during follow-up reported taking PrEP, but one-third had drug concentrations consistent with poor adherence, highlighting the need for novel approaches and long-acting formulations as PrEP roll-out expands.

FUNDING

National Institutes of Health, President's Emergency Plan for AIDS Relief, Bill & Melinda Gates Foundation, and Gilead Sciences.

Changes in Bone Mass After Discontinuation of Preexposure Prophylaxis With Tenofovir Disoproxil Fumarate/Emtricitabine in Young Men Who Have Sex With Men: Extension Phase Results of Adolescent Trials Network Protocols 110 and 113

Human immunodeficiency virus-seronegative men aged 15-22 years who lost bone mineral density (BMD) during tenofovir disoproxil fumarate/emtricitabine preexposure prophylaxis (PrEP) showed BMD recovery 48 weeks following PrEP discontinuation. Lumbar spine and whole body BMD z-scores remained below baseline 48 weeks off PrEP in participants aged 15-19 years. Clinical Trials Registration. NCT01772823 (ATN 110) and NCT01769456 (ATN 113).

Changes in kidney function among men having sex with men starting on demand tenofovir disoproxil fumarate - emtricitabine for HIV pre-exposure prophylaxis

INTRODUCTION

Daily pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is associated with a small but statistically significant decrease in estimated glomerular filtration rate (eGFR). We assessed the renal safety of on-demand PrEP with TDF/FTC in HIV-1 uninfected men.

METHODS

We used data from the randomized double-blind placebo-controlled ANRS-IPERGAY trial and its open-label extension conducted between February 2012 and June 2016 among HIV-uninfected MSM starting on-demand PrEP. Using linear mixed model, we evaluated the mean eGFR decline from baseline over time and determined risks factors associated with eGFR decline during the study.

RESULTS

During the blind phase, with a median follow-up of 9.4 months, the mean decline slope of eGFR from baseline was -0.88 and -1.53 mL/min/1.73 m2 per year in the placebo (n = 201) and the TDF/FTC group (n = 198) respectively, with a slope difference of 0.65 mL/min/1.73 m2 per year (p = 0.27). Including both phases, 389 participants started on-demand TDF/FTC with a median follow-up of 19.2 months and a mean decline of eGFR from baseline of -1.14 mL/min/1.73 m2 per year (p < 0.001). The slope of eGFR reduction was not significantly different in participants with baseline eGFR ≤ 90 mL/min/1.73 m2 (p = 0.44), age >40 years (p = 0.24) or hypertension (p = 0.21). There was a dose-response relationship between recent tenofovir exposure and lower eGFR when considering the number of pills taken in the two months prior the visit (eGFR difference of -0.88 mL/min/1.73 m2 between >15 pills/month vs. ≤15 pills/month, p < 0.01) or plasma tenofovir concentrations at the visit (eGFR difference compared to ≤2 ng/mL: >2 to ≤10ng/mL: -0.98 mL/min/1.73 m2 , >10 to ≤40ng/mL: -1.28 mL/min/1.73 m2 , >40 ng/mL: -1.82 mL/min/1.73 m2 , p < 0.001). Three participants discontinued TDF/FTC for eGFR < 60 mL/min/1.73 m2 during the OLE phase. No case of Fanconi syndrome was reported.

CONCLUSIONS

The renal safety of on-demand PrEP with TDF/FTC was good. The overall reduction and intermittent exposure to TDF/FTC may explain this good renal safety.

Reciprocal Modulation of Antiretroviral Drug and Steroid Receptor Function In Vitro

Millions of women are exposed simultaneously to antiretroviral drugs (ARVs) and progestin-based hormonal contraceptives. Yet the reciprocal modulation by ARVs and progestins of their intracellular functions is relatively unexplored. We investigated the effects of tenofovir disoproxil fumarate (TDF) and dapivirine (DPV), alone and in the presence of select steroids and progestins, on cell viability, steroid-regulated immunomodulatory gene expression, activation of steroid receptors, and anti-HIV-1 activity in vitro Both TDF and DPV modulated the transcriptional efficacy of a glucocorticoid agonist via the glucocorticoid receptor (GR) in the U2OS cell line. In TZM-bl cells, DPV induced the expression of the proinflammatory interleukin 8 (IL-8) gene while TDF significantly increased medroxyprogesterone acetate (MPA)-induced expression of the anti-inflammatory glucocorticoid-induced leucine zipper (GILZ) gene. However, peripheral blood mononuclear cell (PBMC) and ectocervical explant tissue viability and gene expression results, along with TZM-bl HIV-1 infection data, are reassuring and suggest that TDF and DPV, in combination with dexamethasone (DEX) or MPA, do not reciprocally modulate key biological effects in primary cells and tissue. We show for the first time that TDF induces progestogen-independent activation of the progesterone receptor (PR) in a cell line. The ability of TDF and DPV to influence GR and PR activity suggests that their use may be associated with steroid receptor-mediated off-target effects. This, together with cell line and individual donor gene expression responses in the primary models, raises concerns that reciprocal modulation may cause side effects in a cell- and donor-specific manner in vivo.

Pharmacological Modulation of the Wnt/β-Catenin Pathway Inhibits Proliferation and Promotes Differentiation of Long-Lived Memory CD4+ T Cells in Antiretroviral Therapy-Suppressed Simian Immunodeficiency Virus-Infected Macaques

The major obstacle to human immunodeficiency type 1 virus (HIV-1) eradication is a reservoir of latently infected cells that persists despite long-term antiretroviral therapy (ART) and is maintained through cellular proliferation. Long-lived memory CD4+ T cells with high self-renewal capacity, such as central memory (CM) T cells and stem cell memory (SCM) T cells, are major contributors to the viral reservoir in HIV-infected individuals on ART. The Wnt/β-catenin signaling pathway regulates the balance between self-renewal and differentiation of SCM and CM T cells, and pharmacological manipulation of this pathway offers an opportunity to interfere with the proliferation of latently infected cells. Here, we evaluated in vivo a novel approach to inhibit self-renewal of SCM and CM CD4+ T cells in the rhesus macaque (RM) model of simian immunodeficiency (SIV) infection. We used an inhibitor of the Wnt/β-catenin pathway, PRI-724, that blocks the interaction between the coactivator CREB-binding protein (CBP) and β-catenin, resulting in the cell fate decision to differentiate rather than proliferate. Our study shows that PRI-724 treatment of ART-suppressed SIVmac251-infected RMs resulted in decreased proliferation of SCM and CM T cells and modified the SCM and CM CD4+ T cell transcriptome toward a profile of more differentiated memory T cells. However, short-term treatment with PRI-724 alone did not significantly reduce the size of the viral reservoir. This work demonstrates for the first time that stemness pathways of long-lived memory CD4+ T cells can be pharmacologically modulated in vivo, thus establishing a novel strategy to target HIV persistence.IMPORTANCE Long-lasting CD4+ T cell subsets, such as central memory and stem cell memory CD4+ T cells, represent critical reservoirs for human immunodeficiency virus (HIV) persistence despite suppressive antiretroviral therapy. These cells possess stem cell-like properties of enhanced self-renewal/proliferation, and proliferation of latently infected memory CD4+ T cells plays a key role in maintaining the reservoir over time. Here, we evaluated an innovative strategy targeting the proliferation of long-lived memory CD4+ T cells to reduce viral reservoir stability. Using the rhesus macaque model, we tested a pharmacological inhibitor of the Wnt/β-catenin signaling pathway that regulates T cell proliferation. Our study shows that administration of the inhibitor PRI-724 decreased the proliferation of SCM and CM CD4+ T cells and promoted a transcriptome enriched in differentiation genes. Although the viral reservoir size was not significantly reduced by PRI-724 treatment alone, we demonstrate the potential to pharmacologically modulate the proliferation of memory CD4+ T cells as a strategy to limit HIV persistence.

Clinical pharmacology of the single tablet regimen bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF)

The fourth HIV strand-transfer integrase inhibitor (INSTI) has been released into the market as part of a single-tablet-regimen (STR) consisting of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). The newest component is thus BIC, a booster-free INSTI with pharmacological characteristics similar to those of dolutegravir (DTG), including high intrinsic antiretroviral potency. The BIC-containing STR underwent clinical development in both treatment-naive and virologically suppressed patients and was found non-inferior to DTG-based comparator arms. In the currently evolving therapeutic scenario, the BIC/FTC/TAF STR regimen represents the smartest response on the side of triple conventional regimens, while new 2-drug regimens have received regulatory approval and nowadays epitomize the search for simpler and lighter antiretroviral regimens. The overall characteristics of BIC/FTC/TAF, however, make this therapeutic option quite comparable in terms of simplicity to the newly approved dual regimens, and the main reasons (e.g., toxicity) accounting in the past for the search of regimens consisting of less than three drugs are no longer in place.

Drug Resistance During HIV Pre-Exposure Prophylaxis

Clinical studies have demonstrated that use of tenofovir disoproxil fumarate with or without emtricitabine as antiretroviral pre-exposure prophylaxis (PrEP) can decrease the risk of human immunodeficiency virus (HIV) acquisition when medication adherence is high. However, the potential for PrEP to promote antiretroviral resistance remains an important public health consideration. We performed a search of the medical literature to identify studies that address HIV drug resistance during PrEP use. In this review, we summarize findings about emergent drug resistance during clinical trials of PrEP, case reports of seroconversions in patients adherent to PrEP, and animal studies of PrEP effectiveness against drug-resistant viral strains. We also discuss the potential utility of novel PrEP formulations for protection against drug-resistant HIV, the impact of drug resistance on HIV treatment options, and mathematical models that estimate the potential contribution of PrEP to population-level drug resistance. Evidence suggests that selection for HIV drug resistance with PrEP use is infrequent and most likely to occur when PrEP is used during undiagnosed acute HIV infection. Breakthrough infections during PrEP use with high adherence are possible, but appear to be rare. The prevalence of drug-resistant HIV strains needs to be monitored as PrEP is scaled up. However, the benefit of a decreased HIV incidence with wider PrEP use is likely to outweigh the risk of harms from possible increases in the prevalence of HIV drug resistance.

TAF and TDF attenuate liver fibrosis through NS5ATP9, TGFβ1/Smad3, and NF-κB/NLRP3 inflammasome signaling pathways

BACKGROUND

This study aimed to investigate the roles and mechanisms of tenofovir alafenamide fumarate (TAF)/tenofovir disoproxil fumarate (TDF) in treating liver fibrosis.

METHODS

The effects of TAF/TDF on carbon tetrachloride (CCl₄)-induced liver fibrosis in C57BL/6 wild-type or nonstructural protein 5A transactivated protein 9 (NS5ATP9) knockout mice were studied. The differentiation, activation, and proliferation of LX-2 cells after TAF/TDF treatment were tested in vitro. The expression of NS5ATP9 and activities of transforming growth factor-β1 (TGFβ1)/Sekelsky mothers against decapentaplegic homolog 3 (Smad3) and NF-κB/NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome signaling pathways were detected in TAF/TDF-treated mice and LX-2 cells. The genes related to extracellular matrix accumulation were detected in vivo and in vitro after NS5ATP9 silencing or knockout.

RESULTS

TAF/TDF significantly inhibited CCl₄-induced liver fibrosis in mice, and regulated the differentiation, activation, and proliferation of hepatic stellate cells (HSCs). Furthermore, TAF/TDF suppressed the activities of TGFβ1/Smad3 and NF-κB/NLRP3 inflammasome signaling pathways in vivo and in vitro. NS5ATP9 inhibited liver fibrosis through TGFβ1/Smad3 and NF-κB signaling pathways. TAF/TDF upregulated the expression of NS5ATP9 in vivo and in vitro. Finally, TAF/TDF could only show marginal therapeutic effects when NS5ATP9 was silenced and knocked out in vivo and in vitro.

CONCLUSIONS

TAF/TDF prevented progression and promoted reversion of liver fibrosis through assembling TGFβ1/Smad3 and NF-κB/NLRP3 inflammasome signaling pathways via upregulating the expression of NS5ATP9. TAF/TDF also regulated the differentiation, activation, and proliferation of HSCs. The findings provided strong evidence for the role of TAF/TDF as a new promising therapeutic strategy in liver fibrosis.

Transgender women on oral HIV pre-exposure prophylaxis have significantly lower tenofovir and emtricitabine concentrations when also taking oestrogen when compared to cisgender men

INTRODUCTION

Oral HIV Pre-Exposure Prophylaxis (PrEP) with tenofovir (TFV) disoproxil fumarate (TDF)/emtricitabine (FTC) is highly effective. Transgender women (TGW) have increased HIV risk, but have been underrepresented in trials. For TGW on oestrogens for gender-affirming hormone treatment (GAHT), TDF/FTC-oestrogen interactions may negatively affect HIV prevention or gender-affirming goals. Our aim was to evaluate any pharmacokinetic drug-drug interaction between GAHT and TDF/FTC.

METHODS

We performed a pharmacokinetic study, in an urban outpatient setting in 2016 to 2018, of the effects of GAHT on TFV, FTC and the active forms TFV diphosphate (TFV-DP) and FTC triphosphate (FTC-TP) in eight TGW and eight cisgender men (CGM). At screening, participants were HIV negative. TGW were to maintain their GAHT regimens and have plasma oestradiol concentrations >100 pg/mL. Under direct observation, participants took oral TDF/FTC daily for seven days. At the last dose, blood was collected pre-dose, one, two, four, six, eight and twenty-four hours, and colon biopsies were collected at 24 hours to measure drug concentration. TGW versus CGM concentration comparisons used non-parametric tests. Blood and colon tissue were also obtained to assess kinase expression.

RESULTS

Plasma TFV and FTC C24 (trough) concentrations in TGW were lower by 32% (p = 0.010) and 32% (p = 0.038) respectively, when compared to CGM. Plasma TFV and FTC 24-hr area under the concentration-time curve in TGW trended toward and was significantly lower by 27% (p = 0.065) and 24% (p = 0.028) respectively. Peak plasma TFV and FTC concentrations, as well as all other pharmacokinetic measures, were not statistically significant when comparing TGW to CGM. Oestradiol concentrations were not different comparing before and after TDF/FTC dosing. Plasma oestrogen concentration, renal function (estimated creatinine clearance and glomerular filtration rate), and TFV and FTC plasma concentrations (trough and area under the concentration-time curve) were all correlated.

CONCLUSIONS

GAHT modestly reduces both TFV and FTC plasma concentrations. In TGW taking GAHT, it is unknown if this reduction will impact the HIV protective efficacy of a daily PrEP regimen. However, the combination of an on demand (2 + 1 + 1) PrEP regimen and GAHT may result in concentrations too low for reliable prevention of HIV infection.

Tenofovir is a more suitable treatment than entecavir for chronic hepatitis B patients carrying naturally occurring rtM204I mutations

BACKGROUND

Hepatitis B virus (HBV) DNA polymerase mutations usually occur to long term use of nucleos(t)ide analogues (NAs), but they can occur spontaneously in treatment-naïve chronic hepatitis B (CHB) patients. The naturally occurring HBV DNA polymerase mutations might complicate antiviral therapy with NAs, leading to the generation of drug-resistant viral mutants and disease progression. The most common substitutions are known to be YMDD-motif mutations, but their prevalence and the influence on antiviral therapy is unclear.

AIM

To investigate prevalence of the naturally occurring rtM204I mutations in treatment-naïve CHB genotype C2 patients and their influence on antiviral therapy.

METHODS

A total of 410 treatment-naïve CHB patients infected with HBV genotype C2 strains were enrolled in this retrospective study. Among the 410 patients, 232 were treated with NAs for at least 12 mo. Significant fibrosis was defined as fibrosis-4 index > 3.25 or aspartate aminotransferase to platelet ratio index > 1.5. Complete viral response (CVR) during NAs was defined as undetectable serum HBV DNA (< 24 IU/mL). The rtM204I variants were analyzed by a newly developed locked nucleotide probe (LNA probe) based real-time PCR (LNA-RT-PCR) method.

RESULTS

The LNA-RT-PCR could discriminate rtM204I mutant-type (17 patients, 4.2%) from rtM204 wild-type (386 patients, 95.8%) in 403 of 410 patients (98.3% sensitivity). Multivariate analysis showed that naturally occurring rtM204I variants were more frequently detected in patients with significant fibrosis [odd-ratio (OR) 3.397, 95% confidence-interval (CI) 1.119-10.319, P = 0.031]. Of 232 patients receiving NAs, multivariate analysis revealed that achievement of CVR was reversely associated with naturally occurring rtM204I variants prior to NAs treatment (OR 0.014, 95%CI 0.002-0.096, P < 0.001). Almost patients receiving tenofovir achieved CVR at 12 mo of tenofovir, irrespective of pre-existence of naturally occurring rtM204I mutations (CVR rates: patients with rtM204I, 100%; patients without rtM204I, 96.6%), whereas, pre-existence of naturally-occurring rtM204I-mutations prior to NAs significantly affects CVR rates in patients receiving entecavir (at 12 mo: Patients with rtM204I, 16.7%; patients without rtM204I, 95.6%, P < 0.001).

CONCLUSION

The newly developed LNA-RT-PCR method could detect naturally occurring rtM204I mutations with high-sensitivity. Theses mutations were more frequent in patients with liver fibrosis. Tenofovir is a more suitable treatment than entecavir for CHB patients carrying the naturally occurring rtM204I mutations.

Cell-type specific differences in antiretroviral penetration and the effects of HIV-1 Tat and morphine among primary human brain endothelial cells, astrocytes, pericytes, and microglia

The inability to achieve adequate intracellular antiretroviral concentrations may contribute to HIV persistence within the brain and to neurocognitive deficits in opioid abusers. To investigate, intracellular antiretroviral concentrations were measured in primary human astrocytes, microglia, pericytes, and brain microvascular endothelial cells (BMECs), and in an immortalized brain endothelial cell line (hCMEC/D3). HIV-1 Tat and morphine effects on intracellular antiretroviral concentrations also were evaluated. After pretreatment for 24 h with vehicle, HIV-1 Tat, morphine, or combined Tat and morphine, cells were incubated for 1 h with equal concentrations of a mixture of tenofovir, emtricitabine, and dolutegravir at one of two concentrations (5 μM or 10 μM). Intracellular drug accumulation was measured using LC-MS/MS. Drug penetration differed depending on the drug, the extracellular concentration used for dosing, and cell type. Significant findings included: 1) Dolutegravir (at 5 μM or 10 μM) accumulated more in HBMECs than other cell types. 2) At 5 μM, intracellular emtricitabine levels were higher in microglia than other cell types; while at 10 μM, emtricitabine accumulation was greatest in HBMECs. 3) Tenofovir (5 or 10 μM extracellular dosing) displayed greater accumulation inside HBMECs than in other cell types. 4) After Tat and/or morphine pretreatment, the relative accumulation of antiretroviral drugs was greater in morphine-exposed HBMECs compared to other treatments. The opposite effect was observed in astrocytes in which morphine exposure decreased drug accumulation. In summary, the intracellular accumulation of antiretroviral drugs differed depending on the particular drug involved, the concentration of the applied antiretroviral drug, and the cell type targeted. Moreover, morphine, and to a lesser extent Tat, exposure also had differential effects on antiretroviral accumulation. These data highlight the complexity of optimizing brain-targeted HIV therapeutics, especially in the setting of chronic opioid use or misuse.

Rectal Douching Practices Associated with Anal Intercourse: Implications for the Development of a Behaviorally Congruent HIV-Prevention Rectal Microbicide Douche

Tenofovir administration via rectal douching results in higher rectal-mucosa drug concentration than oral administration. Many who engage in receptive anal intercourse (RAI) use cleansing rectal douches. To inform development of a behaviorally-congruent tenofovir douche, 4751 individuals ≥ 18 years-old, born male, from all US states/territories, who engaged in anal intercourse responded to an online survey. Of those who reported RAI in the prior 3 months, 80% douched beforehand, 82% within 1 h, mean 2.9 consecutive applications; 27% douched afterwards, 83% within 1 h, mean 1.7 consecutive applications. Among multidose users, 78% applied doses within 2 min, and 76% retained liquid < 1 min. Most used tap water (89%) in an enema bottle (50%) or rubber bulb (43%), and douched for cleanliness (97%), to avoid smelling bad (65%), and to enhance pleasure (24%). 98% reported high likelihood of using an HIV-prevention douche. An ideal product will protect within a user's typical number of applications, within 1 h, and be dissolvable in tap water.

Treatment with a fixed dose combination antiretroviral therapy drug containing tenofovir, emtricitabine and efavirenz is associated with cardioprotection in high calorie diet-induced obese rats

HIV-infection, certain antiretroviral drug classes, especially protease inhibitors (PI), and obesity are associated with increased ischaemic heart disease (IHD) risk. However, the effect of PI-free fixed dose combination (FDC) antiretroviral therapy (ART) on hearts exposed to ischaemia-reperfusion injury (I/R) is unknown, particularly in obesity. This is becoming relevant as World Health Organisation guidelines recommend a FDC ART containing (non-) nucleoside reverse transcriptase inhibitors (tenofovir (TDF), emtricitabine (FTC) and efavirenz (EFV)) as first-line HIV treatment. Additionally, obesity rates are rising in HIV-infected populations, not only in ART-experienced individuals, but also at the time of ART initiation, which may further increase the risk of IHD. Therefore, we investigated the effects of PI-free FDC ART in myocardial I/R-exposed hearts from obese rats. Obesity was induced in male wistar rats via a 16-week high calorie diet. At week 10, treatment with a FDC ART drug containing TDF/FTC/EFV was initiated. Biometric and metabolic parameters, as well as myocardial functional recovery and infract size (IS), and myocardial signalling proteins following I/R were assessed after 16 weeks. Obese rats presented with increased body and intraperitoneal fat mass, elevated triglyceride and TBARS levels, whilst the hearts responded to I/R with impaired functional performance and increased IS. The FDC ART treatment did not alter biometric and metabolic parameters in obese rats. In a novel finding, ART protected obese hearts against I/R as shown by improved functional performance and smaller IS vs. untreated obese hearts. Cardioprotection was underscored by increased myocardial phosphorylated endothelial nitric oxide synthase (eNOS) and reduced AMP-kinase levels. In conclusion, these results demonstrate for the first time, that 6-weeks treatment of obese rats with a FDC ART drug specifically containing TDF/FTC/EFV conferred cardioprotection against I/R. The FDC ART-induced cardioprotection was seemingly unrelated to metabolic changes, but rather due to direct cardiac mechanisms including the up-regulation of myocardial eNOS.

Efficacy of tenofovir in preventing perinatal transmission of HBV infection in pregnant women with high viral loads

Mother-to-child transmission is the major cause of chronic hepatitis B virus (HBV) infection. This double-blind trial tested the effect of tenofovir disoproxil fumarate (TDF) in preventing vertical transmission. Pregnant women who were HBsAg/HBeAg-positive with a HBV DNA titer ≥ 2×106 IU/mL were randomly assigned to the control (n = 60) and TDF-treated (n = 60) groups. TDF treatment (oral dose 300 mg/day) was initiated at 24 weeks of gestation and continued to 4 weeks after delivery. The subjects were followed up to 28 weeks postpartum. The effects of TDF on vertical transmission, outcomes of the mothers and infants and virological changes were monitored. TDF dynamically reduced the serum HBV DNA level of the mothers, particularly during the first 4 weeks of treatment. The lower viral loads were maintained in the pregnancies until delivery. Approximately 90% and 33.9% of the TDF-treated mothers had viral loads ≤2000 IU/mL after delivery and at 28 weeks postpartum, respectively. No cervical transmission or adverse effects were observed in the TDF-treated individuals, whereas 13.5% of the infants were infected with HBV in the control group. We conclude that TDF treatment initiated at 24 weeks of gestation in high-viremia, HBsAg/HBeAg-positive mothers efficiently prevents mother-to-child HBV transmission without adverse events in mothers and infants.

Regulation of human placental drug transporters in HCV infection and their influence on direct acting antiviral medications

INTRODUCTION

The objectives of this study were to determine how HCV infection affects placental drug transporters, and to determine the role of drug transporters on the cellular accumulation of direct-acting antiviral drugs in human trophoblasts.

METHODS

Eighty-four ABC and SLC transporter genes were first screened in normal and HCV infected pregnant women using PCR profiler array. The changes in expression were confirmed by qPCR and Western blot. The impact of selected drug transporters on the cellular accumulation of radiolabeled antiviral drugs sofosbuvir, entecavir, and tenofovir was measured in primary human trophoblasts (PHT) and BeWo b30 cells in the presence or absence of transporter-specific inhibitors. PHT were then treated with CL097, ssRNA40, and imquimod to determine the impact of Toll-like receptor (TLR) 7/8 activation on drug transporter expression.

RESULTS

The expression of the ABC efflux transporters ABCB1/P-gp and ABCG2/BCRP was increased in placenta of women with HCV, while the nucleoside transporters SLC29A1/ENT1 and SLC29A2/ENT2 remained unchanged. The accumulation of sofosbuvir and tenofovir was unaffected by inhibition of these transporters in trophoblast cells. Entecavir accumulation was decreased by the inhibition of ENT2. P-gp and BCRP inhibition enhanced entecavir accumulation in BeWo b30, but not PHT. Overall, there was little effect of TLR7/8 activation on these drug transporters, and the accumulation of entecavir in PHT.

DISCUSSION

The data suggest that expression of placental drug transporters and selection of antiviral drug may impact fetal drug exposure in pregnancies complicated by HCV infections.

Development of tenofovir disoproxil fumarate resistance after complete viral suppression in a patient with treatment-naïve chronic hepatitis B: A case report and review of the literature

Tenofovir disoproxil fumarate (TDF) is a potent nucleotide analogue that is recommended as first-line therapy for patients with chronic hepatitis B. The results of a longitudinal study of TDF treatment demonstrated no development of resistance. We observed one treatment-naïve chronic hepatitis B (CHB) patient who developed TDF resistance after complete viral suppression during long-term TDF treatment. A 37-year-old HBeAg-positive man received TDF 300 mg/d for 43 mo. The hepatitis B virus (HBV) DNA titer was 8 log₁₀ copies/mL at baseline and became undetectable at 16 mo after treatment. However, the HBV DNA titer rebounded to 7.5 log₁₀ copies/mL at 43 mo after treatment. We performed full sequencing to find mutation sites associated with virologic breakthrough. The results showed 9 mutation sites, most of which had not been well-known as mutation sites. We changed the therapy from tenofovir to entecavir with a regimen of 0.5 mg once daily. After 4 mo, the HBV DNA titer decreased to 267 copies/mL, and the liver enzyme levels were normalized.