Design of Vif-Derived Peptide Inhibitors with Anti-HIV-1 Activity by Interrupting Vif-CBFß Interaction.

One of the major functions of the accessory protein Vif of human immunodeficiency virus type 1 (HIV-1) is to induce the degradation of APOBEC3 (A3) family proteins by recruiting a Cullin5-ElonginB/C-CBFß E3 ubiquitin ligase complex to facilitate viral replication. Therefore, the interactions between Vif and the E3 complex proteins are promising targets for the development of novel anti-HIV-1 drugs. Here, peptides are designed for the Vif-CBFß interaction based on the sequences of Vif mutants with higher affinity for CBFß screened by a yeast surface display platform. We identified two peptides, VMP-63 and VMP-108, that could reduce the infectivity of HIV-1 produced from A3G-positive cells with IC50 values of 49.4 µM and 55.1 µM, respectively. They protected intracellular A3G from Vif-mediated degradation in HEK293T cells, consequently increasing A3G encapsulation into the progeny virions. The peptides could rapidly enter cells after addition to HEK293T cells and competitively inhibit the binding of Vif to CBFß. Homology modeling analysis demonstrated the binding advantages of VMP-63 and VMP-108 with CBFß over their corresponding wild-type peptides. However, only VMP-108 effectively restricted long-term HIV-1 replication and protected A3 functions in non-permissive T lymphocytes. Our findings suggest that competitive Vif-derived peptides targeting the Vif-CBFß interaction are promising for the development of novel therapeutic strategies for acquired immune deficiency syndrome.

Resistencia transmitida de VIH-1 en pacientes sin exposición a tratamiento antirretroviral: Guatemala / Transmitted HIV-1 resistance in patients without exposure to antiretroviral treatment: Guatemala / Resistência transmitida ao HIV-1 em pacientes sem exposição ao tratamento antirretroviral: Guatemala

El objetivo del estudio fue describir los niveles de resistencia transmitida de VIH-1 en adultos atendidos en Unidades de Atención Integral de Guatemala. El estudio incluyó registros de 185 pacientes adultos VIH-1 positivo, de reciente diagnóstico sin antecedente de uso de TAR, de noviembre del 2019 a noviembre del 2020. El análisis se realizó en el software DeepChek® v2.0, para la clasificación de la resistencia se siguió el algoritmo de Stanford HIVdb (v9.4 - 07/12/2022). Se encontró 18.4% (IC 95% 13.1 - 24.7%) de resistencia general a alguna familia de ARVs. Se evidenció 15.1% (IC 95% 10.3 - 21.1%) de resistencia individual a la familia de INNTR afectando principalmente a NVP y EFV; 2.2% (IC 95% 0.6 - 5.4%) de resistencia a INTR, mayormente a FTC/3TC; y 2.7% (IC 95% 0.9 - 6.2%) de resistencia intermedia y baja los IP NFV y LPV/r. Tres casos presentaron resistencia múltiple a los INTR + INNTR. Las mutaciones más frecuentemente encontradas fueron K103N (41.2%), M184V/I (8.8%) y M46I (5.9%). La elevada resistencia transmitida del VIH-1 en pacientes atendidos en distintas Unidades de Atención Integral del VIH, demuestra la importancia de analizar periódicamente la tendencia de la resistencia en personas que no han estado expuestas a ARVs, lo cual a su vez es un marcador indirecto de presencia de resistencia adquirida en el país, datos que evidencian la necesidad de acciones e intervenciones prontas y efectivas dado su impacto en la salud pública.

The objective of this study was to describe the levels of transmitted HIV-1 resistance in patients with a recent HIV diagnosis before starting ART, treated in Comprehensive Care Units in Guatemala during the years 2019 and 2020. The study included records of 185 HIV-positive adult patients, recently diagnosed with HIV without a history of ART use. The analysis was carried out in the DeepChek® v2.0 software, the Stanford HIVdb algorithm (v9.4 - 07/12/2022) was followed to classify resistance. 18.4% (95% CI 13.1 - 24.7%) of general resistance to some family of ARVs was found. There was evidence of 15.1% (95% CI 10.3 - 21.1%) of individual resistance to the NNRTI family, mainly affecting NVP and EFV; 2.2% (95% CI 0.6 - 5.4%) resistance to INTR, mostly to FTC/3TC; and 2.7% (95% CI 0.9 - 6.2%) of intermediate and low resistance IP NFV and LPV/r. Three cases presented multiple resistance to NRTIs + NNRTIs. The most frequently found mutations were K103N (41.2%), M184V/I (8.8%) and M46I (5.9%). The high transmitted resistance of HIV-1 in patients treated in different Comprehensive HIV Care Units demonstrates the importance of periodically analyzing the trend of resistance in people who have not been exposed to ARVs, which in turn is an indirect marker. of the presence of acquired resistance in the country, data that demonstrate the need for prompt and effective actions and interventions given its impact on public health.

O objetivo deste estudo foi descrever os níveis de resistência transmitida ao HIV-1 em adultos tratados em Unidades de Cuidados Integrais na Guatemala. O estudo incluiu prontuários de 185 pacientes adultos HIV-1 positivos, recentemente diagnosticados sem histórico de uso de TARV, no período de novembro de 2019 a novembro de 2020. A análise foi realizada no software DeepChek® v2.0, para classificação da resistência, O algoritmo Stanford HIVdb (v9.4 - 07/12/2022) foi seguido. Foi encontrada 18.4% (IC 95% 13.1 - 24.7%) de resistência geral a alguma família de ARVs. Houve evidência de 15.1% (IC 95% 10.3 - 21.1%) de resistência individual à família de NNRTI, afetando principalmente NVP e EFV; 2.2% (IC 95% 0.6 - 5.4%) resistência ao INTR, principalmente ao FTC/3TC; e 2.7% (IC 95% 0.9 - 6.2%) de resistência intermediária e baixa ao IP NFV e LPV/r. Três casos apresentaram resistência múltipla a NRTIs + NNRTIs. As mutações mais frequentemente encontradas foram K103N (41.2%), M184V/I (8.8%) e M46I (5.9%). A elevada resistência transmitida do HIV-1 em pacientes atendidos em diferentes Unidades de Cuidados Integrados ao HIV demonstra a importância de analisar periodicamente a tendência de resistência em pessoas que não foram expostas aos ARVs, o que por sua vez é um marcador indireto da presença de ARVs adquiridos. resistência no país, dados que demonstram a necessidade de ações e intervenções rápidas e eficazes dado o seu impacto na saúde pública.

Learning from cerebrospinal fluid drug-resistant HIV escape-associated encephalitis: a case report.

BACKGROUND: In the era of antiretroviral therapy (ART), central nervous system (CNS) complications in patients with human immunodeficiency virus (HIV) infection are sometimes associated with cerebrospinal fluid (CSF) viral escape. Here, we reported a case of persistent CNS viral escape with recurrent symptomatic encephalitis, which had ultimate stabilization achieved by a combination of ART adjustment and corticosteroids. CASE PRESENTATION: A 27-year-old man with HIV infection complained of recurrent headaches during the last year. His magnetic resonance imaging (MRI) presented diffused bilateral white matter lesions, and laboratory tests confirmed elevated CSF protein level, lymphocytic pleocytosis, and detectable CSF HIV RNA (774 copies/mL). Plasma HIV RNA was well suppressed with tenofovir, lamivudine, and lopinavir/ritonavir. Prednisone 60 mg once daily was initiated to reduce intracranial inflammation, followed by a good clinical response, with CSF HIV RNA still detectable (31.1 copies/mL). During the gradual tapering of prednisone, his headache relapsed, and booming viral loads were detected in both CSF (4580 copies/mL) and plasma (340 copies/mL) with consistent drug-resistant mutations. Thereupon, prednisone was resumed and the ART regimen was switched to zidovudine, lamivudine, and dolutegravir according to drug resistance tests. Persistent clinical recovery of symptoms, neuroimaging, and laboratory abnormalities were observed in the follow-up visits. CONCLUSION: CSF and plasma HIV RNA and further drug resistance tests should be monitored in HIV-infected patients with neurologic symptoms, as opportunistic infections or tumors can be ruled out. ART optimization using a sensitive regimen may be crucial for addressing CSF viral escape and the related encephalitis.

HIV Pre-Exposure Prophylaxis: New and Upcoming Drugs to Address the HIV Epidemic.

Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) provides a critical intervention toward ending the HIV epidemic and protecting people with reasons to utilize PrEP. PrEP options continue to expand as new administration modalities offer the potential to tailor PrEP use for individual success. We have provided the evidence for new and emerging antiretroviral agents for PrEP (cabotegravir, lenacapavir, dapivirine, and broadly neutralizing antibodies), divided into pharmacology, animal model, and human data, accompanied by a summary and suggested place in therapy. Cabotegravir is a US Food and Drug Administration (FDA)-approved intramuscular injection given every 2 months with a strong body of evidence demonstrating efficacy for HIV PrEP, lenacapavir administered subcutaneously every 6 months is currently under investigation for HIV PrEP, dapivirine vaginal ring is an available PrEP option for women in certain areas of Africa, and broadly neutralizing monoclonal antibodies have been challenged in demonstrating efficacy in phase 1-2 study for HIV PrEP to date. Clinical literature for individual agents is discussed with data from major studies summarized in tables. This review provides a detailed overview of recently available and premier candidate PrEP drugs.

Lipid nanocarrier targeting activated macrophages for antiretroviral therapy of HIV reservoir.

Aim: To develop lipid nano-antiretrovirals (LNAs) for the treatment of HIV-infected macrophages. Materials & methods: LNAs were prepared with docosahexaenoic acid to facilitate brain penetration and surface-decorated with folate considering that infected macrophages often overexpress folate receptors. Results: Folate-decorated LNAs loading rilpivirine (RPV) were efficiently taken up by folate receptor-expressing cell types including activated macrophages. The intracellular Cmax of the RPV-LNAs in activated macrophages was 2.54-fold and the area under the curve was 3.4-fold versus free RPV, translating to comparable or higher (p < 0.01; RPV ≤6.5 ng/ml) activities against HIV infectivity and superior protection (p < 0.05) against HIV cytotoxicity. LNAs were also effective in monocyte-derived macrophages. Conclusion: These findings demonstrate the potential of LNAs for the treatment of infected macrophages, which are key players in HIV reservoirs.

HIV can infect and hide inside certain types of white blood cells that make up the immune system and help defend our body, such as macrophages. Because these infected cells tend to carry the virus to certain organs where antiviral drugs have a hard time reaching, the virus is able to avoid treatment from the drug. In this study, the authors developed very small devices known as nanocarriers to carry antiviral drugs. These nanocarriers were designed to seek out infected macrophages. The nanocarriers were successfully built with oils and lipids that are safe for patients and could easily deliver antiviral drugs to macrophages infected by HIV. Excellent anti-HIV effects were observed using these nanocarriers. In summary, the authors developed a promising device with the potential to fight HIV in a smart and safe manner.

Lipophilic Nucleoside Triphosphate Prodrugs of Anti-HIV Active Nucleoside Analogs as Potential Antiviral Compounds.

Nucleoside analogs require three phosphorylation steps catalyzed by cellular kinases to give their triphosphorylated metabolites. Herein, the synthesis of two types of triphosphate prodrugs of different nucleoside analogs is disclosed. Triphosphates comprising: i) a γ-phosphate or γ-phosphonate bearing a bioreversible acyloxybenzyl group and a long alkyl group and ii) γ-dialkyl phosphate/phosphonate modified nucleoside triphosphate analogs. Almost selective conversion of the former TriPPPro-compounds into the corresponding γ-alkylated nucleoside triphosphate derivatives is demonstrated in CEM/0 cell extracts that proved to be stable toward further hydrolysis. The latter γ-dialkylated triphosphate derivatives lead to the slow formation of the corresponding NDPs. Both types of TriPPPro-compounds are highly potent in wild-type CEM/0 cells and more importantly, they exhibit even better activities against HIV-2 replication in CEM/TK- cell cultures. A finding of major importance is that, in primer extension assays, γ-phosphate-modified-NTPs, γ-mono-alkylated-triphosphates, and NDPs prove to be substrates for HIV-RT but not for cellular DNA-polymerases α,γ.

Heart transplantation and human immunodeficiency virus-navigating drug-drug interactions: a case report.

BACKGROUND: Antiretroviral therapy (ART) has led to a decline in human immunodeficiency virus (HIV)-related mortality, but comorbidities, including organ dysfunction, are increasingly the focus of care. Heart transplant (HT) is a very effective therapeutic strategy for end-stage heart failure (HF); however, clinicians may be hesitant due to concerns of complex drug-drug interactions (DDIs) between ART and HT immunosuppressive regimens and the potential impact of ART on long-term HT outcomes. In this report, we describe long-term (76-month) follow-up of a patient with HIV-positive status who underwent orthotopic HT with special emphasis on complex drug interactions. CASE PRESENTATION: A 58-year-old man with HIV-1 developed ischemic cardiomyopathy, progressed to end-stage HF and underwent orthotopic HT. To avoid DDIs with planned immunosuppressive therapies, the ART regimen was modified to consist of lamivudine, tenofovir disoproxil fumarate, rilpivirine, and raltegravir. Following HT, the patient's immunosuppression consisted of tacrolimus and mycophenolate mofetil. He has had normal cardiac function and no opportunistic infections and was subsequently switched to tenofovir alafenamide, emtricitabine, and bictegravir in combination for convenience. Serial HIV-1 RNA blood levels were constantly below the limit of quantification, and his CD4 count remained above 200 cells/mm3 (30-35%). Several DDIs were identified and addressed; however, his long-term post-HT complications included one episode of asymptomatic acute cellular rejection, adenocarcinoma of the prostate, basal cell carcinoma, cardiac allograft vasculopathy, and peripheral neuropathy. CONCLUSION: The clinical outcome of this case supports the conclusion of previously published reports, summarized here within, demonstrating that HIV-1 positive status should not preclude HT in carefully selected individuals. Both addressing potential DDIs prior to HT and long-term monitoring for routine post-transplant complications and secondary and incidental malignancies are imperative.

Repurposing of rilpivirine for preventing platelet ß3 integrin-dependent thrombosis by targeting c-Src active autophosphorylation.

BACKGROUND: HIV-infected individuals are known to be at higher risk for thrombotic cardiovascular disease (CVD), which may also be differentially affected by components of anti-HIV drugs. To identify the effects of a series of FDA-approved anti-HIV drugs on platelet aggregation in humans, focusing on the novel pharmacological effects of rilpivirine (RPV), a reverse transcriptase inhibitor, on platelet function both in vitro and in vivo and the mechanisms involved. METHODS AND RESULTS: In vitro studies showed that RPV was the only anti-HIV reagent that consistently and efficiently inhibited aggregation elicited by different agonists, exocytosis, morphological extension on fibrinogen, and clot retraction. Treatment of mice with RPV significantly prevented thrombus formation in FeCl3-injured mesenteric vessels, postcava with stenosis surgery, and ADP -induced pulmonary embolism models without defects in platelet viability, tail bleeding, and coagulation activities. RPV also improved cardiac performance in mice with post-ischemic reperfusion. A mechanistic study revealed that RPV preferentially attenuated fibrinogen-stimulated Tyr773 phosphorylation of ß3-integrin by inhibiting Tyr419 autophosphorylation of c-Src. Molecular docking and surface plasmon resonance analyses showed that RPV can bind directly to c-Src. Further mutational analysis showed that the Phe427 residue of c-Src is critical for RPV interaction, suggesting a novel interaction site for targeting c-Src to block ß3-integrin outside-in signaling. CONCLUSION: These results demonstrated that RPV was able to prevent the progression of thrombotic CVDs by interrupting ß3-integrin-mediated outside-in signaling via inhibiting c-Src activation without hemorrhagic side effects, highlighting RPV as a promising reagent for the prevention and therapy of thrombotic CVDs.

An Artificial Peptide-Based Bifunctional HIV-1 Entry Inhibitor That Interferes with Viral Glycoprotein-41 Six-Helix Bundle Formation and Antagonizes CCR5 on the Host Cell Membrane.

Human immunodeficiency virus type 1 (HIV-1) is characterized by high variability and drug resistance. This has necessitated the development of antivirals with a new chemotype and therapy. We previously identified an artificial peptide with non-native protein sequence, AP3, with the potential to inhibit HIV-1 fusion through targeting hydrophobic grooves on the N-terminal heptad repeat trimer of viral glycoprotein gp41. Here, a small-molecule HIV-1 inhibitor targeting chemokine coreceptor CCR5 on the host cell was integrated into the AP3 peptide, producing a novel dual-target inhibitor with improved activity against multiple HIV-1 strains including those resistant to the currently used anti-HIV-1 drug enfuvirtide. Its superior antiviral potency in comparison with the respective pharmacophoric moieties is in consonance with the dual binding of viral gp41 and host factor CCR5. Therefore, our work provides a potent artificial peptide-based bifunctional HIV-1 entry inhibitor and highlights the multitarget-directed ligands approach in the development of novel therapeutic anti-HIV-1 agents.

A comprehensive overview on the role of phytocompounds in human immunodeficiency virus treatment.

Acquired immune deficiency syndrome (AIDS) is a worldwide epidemic caused by human immunodeficiency virus (HIV) infection. Newer medicines for eliminating the viral reservoir and eradicating the virus are urgently needed. Attempts to locate relatively safe and non-toxic medications from natural resources are ongoing now. Natural-product-based antiviral candidates have been exploited to a limited extent. However, antiviral research is inadequate to counteract for the resistant patterns. Plant-derived bioactive compounds hold promise as powerful pharmacophore scaffolds, which have shown anti-HIV potential. This review focuses on a consideration of the virus, various possible HIV-controlling methods and the recent progress in alternative natural compounds with anti-HIV activity, with a particular emphasis on recent results from natural sources of anti-HIV agents. Please cite this article as: Mandhata CP, Sahoo CR, Padhy RN. A comprehensive overview on the role of phytocompounds in human immunodeficiency virus treatment. J Integr Med. 2023; 21(4):332-353.

The CARD8 inflammasome in HIV infection.

The biggest challenge to immune control of HIV infection is the rapid within-host viral evolution, which allows selection of viral variants that escape from T cell and antibody recognition. Thus, it is impossible to clear HIV infection without targeting "immutable" components of the virus. Unlike the adaptive immune system that recognizes cognate epitopes, the CARD8 inflammasome senses the essential enzymatic activity of the HIV-1 protease, which is immutable for the virus. Hence, all subtypes of HIV clinical isolates can be recognized by CARD8. In HIV-infected cells, the viral protease is expressed as a subunit of the viral Gag-Pol polyprotein and remains functionally inactive prior to viral budding. A class of anti-HIV drugs, the non-nucleoside reverse transcriptase inhibitors (NNRTIs), can promote Gag-pol dimerization and subsequent premature intracellular activation of the viral protease. NNRTI treatment triggers CARD8 inflammasome activation, which leads to pyroptosis of HIV-infected CD4+ T cells and macrophages. Targeting the CARD8 inflammasome can be a potent and broadly effective strategy for HIV eradication.

Virtual screening identifies tipranavir as a SIRT1 inhibitor with anti-hepatocarcinoma effect.

Aim: To identify novel inhibitors of SIRT1 and to understand their mechanism of action in hepatocellular carcinoma. Materials & methods: Molecular docking and dynamic simulations were conducted to identify potential SIRT1 inhibitors. The in vitro efficacy of the inhibitors was evaluated by methyl thiazolyl tetrazolium assays, flow cytometry and western blot analysis. Additionally, the in vivo antitumor activity of the inhibitor was evaluated. Results: Tipranavir, a US FDA-approved anti-HIV-1 medication, was found to possess potential as a SIRT1 inhibitor. Tipranavir selectively inhibited HepG2 cell proliferation without causing toxicity to normal human hepatic cells. Additionally, tipranavir treatment resulted in a reduction of SIRT1 expression and induction of apoptosis in HepG2 cells. Furthermore, tipranavir was found to suppress tumorigenesis in a xenograft mouse model and decreased the expression of SIRT1 in vivo. Conclusion: Tipranavir holds desirable potential as a promising therapeutic agent against hepatoma.

Enzyme-Triggered l-α/d-Peptide Hydrogels as a Long-Acting Injectable Platform for Systemic Delivery of HIV/AIDS Drugs.

Eradicating HIV/AIDS by 2030 is a central goal of the World Health Organization. Patient adherence to complicated dosage regimens remains a key barrier. There is a need for convenient long-acting formulations that deliver drugs over sustained periods. This paper presents an alternative platform, an injectable in situ forming hydrogel implant to deliver a model antiretroviral drug (zidovudine [AZT]) over 28 days. The formulation is a self-assembling ultrashort d or l-α peptide hydrogelator, namely phosphorylated (naphthalene-2-ly)-acetyl-diphenylalanine-lysine-tyrosine-OH (NapFFKY[p]-OH), covalently conjugated to zidovudine via an ester linkage. Rheological analysis demonstrates phosphatase enzyme instructed self-assembly, with hydrogels forming within minutes. Small angle neutron scattering data suggest hydrogels form narrow radius (≈2 nm), large length fibers closely fitting the flexible cylinder elliptical model. d-Peptides are particularly promising for long-acting delivery, displaying protease resistance for 28 days. Drug release, via hydrolysis of the ester linkage, progress under physiological conditions (37 °C, pH 7.4, H2 O). Subcutaneous administration of Napffk(AZT)Y[p]G-OH in Sprague Dawley rats demonstrate zidovudine blood plasma concentrations within the half maximal inhibitory concentration (IC50 ) range (30-130 ng mL-1 ) for 35 days. This work is a proof-of-concept for the development of a long-acting combined injectable in situ forming peptide hydrogel implant. These products are imperative given their potential impact on society.

Evolution of Antiretroviral Drug Rilpivirine and Approach to Oncology.

Rilpivirine is an antiretroviral drug used to treat AIDS worldwide. The drug is a non-nucleoside reverse transcriptase inhibitor that halts the cDNA elongation process and, thus, the capacity of the HIV-1 virus to replicate. With the new wave of drug repurposing in recent years, rilpivirine has been studied in this regard. This drug is useful in Zika virus treatment, with in vivo results indicating regression in neuronal effects often associated with this infection. Several cancer types have also been researched, from breast to leukemia and pancreatic cancer, and rilpivirine has proved to have inhibitory effects in various cell lines with low concentrations, causing cellular death, apoptosis, and cell cycle arrest. The pathways are not yet established, but some works have hypothesized and demonstrated that rilpivirine causes inhibition of Aurora A kinase and has effects on the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway and the vascular endothelial growth factors-receptors (VEGFs-VEGFRs) pathway, which are known to be altered in cancer and tumors and can be targeted for cancer treatment. Further testing and clinical trials are needed, but this review demonstrates the potential of rilpivirine's repurposing for cancer treatment.

CD4/CD8 Ratio Outcome According to the Class of the Third Active Drug in Antiretroviral Therapy Regimens: Results From the Quebec Human Immunodeficiency Virus Cohort Study.

BACKGROUND: The impact of different therapeutic classes of drugs in antiretroviral therapy (ART) regimens on the CD4/CD8 ratio is not well documented in people treated for HIV. The objective of this study was to analyze the long-term effect of exposure to integrase strand transfer inhibitor (INSTI) on CD4/CD8 ratio compared with nonnucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI) among ART-treated persons with HIV (PWH). METHODS: Data from the Quebec HIV Cohort collected from 31 August 2017 were used. Our analysis included all patients in the cohort who received a first or subsequent ART regimen composed of 2 nucleoside reverse transcriptase inhibitors (NRTIs) and a third active drug of a different class (NNRTI, PI, or INSTI) for at least 16 weeks. Marginal structural Cox models were constructed to estimate the effect of different therapeutic classes on the CD4/CD8 ratio outcome. RESULTS: Among the 3907 eligible patients, 972 (24.9%), 1996 (51.1%), and 939 (24.0%) were exposed to an ART regimen whose third active agent was an NNRTI, PI, or INSTI, respectively. The total follow-up time was 13 640.24 person-years. The weighted hazard ratio for the association between the third active class and CD4/CD8 ratio ≥1 was .56 (95% confidence interval [CI]: .48-.65) for patients exposed to NNRTI + 2 NRTIs and .41 (95% CI: .35-.47) for those exposed to PI + 2 NRTIs, compared with those exposed INSTI + 2 NRTIs. CONCLUSIONS: For people treated for HIV, INSTI-based ART appears to be associated with a higher CD4/CD8 ratio than NNRTI and PI-based ART.

Intrinsic resistance of HIV-2 and SIV to the maturation inhibitor GSK2838232.

GSK2838232 (GSK232) is a novel maturation inhibitor that blocks the proteolytic cleavage of HIV-1 Gag at the junction of capsid and spacer peptide 1 (CA/SP1), rendering newly-formed virions non-infectious. To our knowledge, GSK232 has not been tested against HIV-2, and there are limited data regarding the susceptibility of HIV-2 to other HIV-1 maturation inhibitors. To assess the potential utility of GSK232 as an option for HIV-2 treatment, we determined the activity of the compound against a panel of HIV-1, HIV-2, and SIV isolates in culture. GSK232 was highly active against HIV-1 isolates from group M subtypes A, B, C, D, F, and group O, with IC50 values ranging from 0.25-0.92 nM in spreading (multi-cycle) assays and 1.5-2.8 nM in a single cycle of infection. In contrast, HIV-2 isolates from groups A, B, and CRF01_AB, and SIV isolates SIVmac239, SIVmac251, and SIVagm.sab-2, were highly resistant to GSK232. To determine the role of CA/SP1 in the observed phenotypes, we constructed a mutant of HIV-2ROD9 in which the sequence of CA/SP1 was modified to match the corresponding sequence found in HIV-1. The resulting variant was fully susceptible to GSK232 in the single-cycle assay (IC50 = 1.8 nM). Collectively, our data indicate that the HIV-2 and SIV isolates tested in our study are intrinsically resistant to GSK232, and that the determinants of resistance map to CA/SP1. The molecular mechanism(s) responsible for the differential susceptibility of HIV-1 and HIV-2/SIV to GSK232 require further investigation.

The Use of Zidovudine Pharmacophore in Multi-Target-Directed Ligands for AIDS Therapy.

The concept of polypharmacology embraces multiple drugs combined in a therapeutic regimen (drug combination or cocktail), fixed dose combinations (FDCs), and a single drug that binds to different targets (multi-target drug). A polypharmacology approach is widely applied in the treatment of acquired immunodeficiency syndrome (AIDS), providing life-saving therapies for millions of people living with HIV. Despite the success in viral load suppression and patient survival of combined antiretroviral therapy (cART), the development of new drugs has become imperative, owing to the emergence of resistant strains and poor adherence to cART. 3'-azido-2',3'-dideoxythymidine, also known as azidothymidine or zidovudine (AZT), is a widely applied starting scaffold in the search for new compounds, due to its good antiretroviral activity. Through the medicinal chemistry tool of molecular hybridization, AZT has been included in the structure of several compounds allowing for the development of multi-target-directed ligands (MTDLs) as antiretrovirals. This review aims to systematically explore and critically discuss AZT-based compounds as potential MTDLs for the treatment of AIDS. The review findings allowed us to conclude that: (i) AZT hybrids are still worth exploring, as they may provide highly active compounds targeting different steps of the HIV-1 replication cycle; (ii) AZT is a good starting point for the preparation of co-drugs with enhanced cell permeability.

Tigliane-Type Diterpene Esters from the Fruits of Shirakiopsis indica and Their Anti-HIV Activity.

Four new diterpene esters, shirakindicans A-D (1-4), along with eight related known diterpene esters (5-12), were isolated from the fruits of the Bangladeshi medicinal plant Shirakiopsis indica. The structures of 1-4 were elucidated by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Shirakindican A (1) was assigned as a tigliane-type diterpene ester possessing an unusual 6ß-hydroxy-1,7-dien-3-one structure, while shirakindican B (2) exhibits a tiglia-1,5-dien-3,7-dione structure. The anti-HIV activities of the isolated diterpene esters were evaluated and showed significant activities for sapintoxins A (5) and D (11), with EC50 values of 0.0074 and 0.044 µM, respectively, and TI values of 1 100 and 5 290. Sapatoxin A (12) also exhibited anti-HIV activity with an EC50 value of 0.13 µM and a TI value of 161.

Spray-dried tenofovir alafenamide-chitosan nanoparticles loaded oleogels as a long-acting injectable depot system of anti-HIV drug.

The development of suitable drug delivery systems for prolonged action against HIV receives great attention in recent research. Herein, a long-acting injectable (LAI) of Tenofovir alafenamide-chitosan polymeric nanoparticles loaded oleogels developed with sesame oil and ethyl cellulose for prolonged release of the drug is reported for the first time. The research resulted with unique long-acting parenteral formulation for chronic anti-retroviral therapy, based on our experimental in-vitro and ex-vivo studies. The chitosan nanoparticles with 49 % drug content were produced through the spray-drying technique and characterized for their size (106-540 nm) and the other physico-chemical features through SEM, FT-IR, XRD, TGA, and DSC. The ethyl cellulose and sesame oil oleogels were developed through a heat-cool process by incorporating the drug-loaded chitosan nanoparticles. The oleogels exhibited extended release (56 %) of the drug for 16 days, which could be prolonged further to achieve the maximum drug release. Also, the ex-vivo permeation studies of the nanoparticles loaded oleogels demonstrated about 10-fold decrease in the flux and the permeation of the drug due to prolonged release of the drug across dual barriers of chitosan nanoparticles and ethyl cellulose gel matrix. The result provided proof-of-evidence that the developed Tenofovir alafenamide-chitosan polymeric nanoparticles loaded with ethyl cellulose oleogels could be potentially used as the long-acting injectable system for the treatment of patients infected with HIV/AIDS.

Improved induced innate immune response after cART initiation in people with HIV.

Introduction: Impairment of the innate immune function may contribute to the increased risk of bacterial and viral infections in people with HIV (PWH). In this study we aimed to investigate the induced innate immune responses in PWH prior to and after initiation of combinational antiretroviral therapy (cART). Furthermore, we aimed to investigate if the induced innate immune responses before initiation of cART were associated with CD4+ T-cell recovery one year after initiating cART. Material and method: The induced innate immune response was assessed by the TruCulture® whole blood technique in 32 PWH before cART initiation and after 1, 6 and 12 months. To mimic bacterial and viral infections we used a panel of three stimuli (lipopolysaccharide (LPS), resiquimod (R848), and polyinosinic:polycytidylic acid (Poly I:C)) to stimulate the extracellular Toll-like receptor (TLR) 4 and the intracellular TLR7/8 and TLR3, respectively. The following cytokine responses were analyzed by Luminex 200: Tumor Necrosis Factor (TNF)-α, Interleukin (IL)-1b, IL-6, IL-8, IL-10, IL-12p40, IL17A, Interferon (IFN)-α, and IFN-γ. Results: At baseline PWH with nadir CD4+ T-cell count <350 cell/µL had lower levels of LPS-, R848-, and Poly I:C-induced IL-6 and IFN-γ, LPS- and R848-induced TNF-α and IL-12, LPS induced IL-1b, and R848-induced IL-10 than PWH with nadir CD4+ T-cell count >350 cells/µL. The majority (>50%) had induced cytokine concentrations below the reference intervals at baseline which was most pronounced for the LPS- and Poly I:C-induced responses. The induced responses in the whole population improved after 12 months of cART, and more PWH had induced cytokine concentrations within the reference intervals after 12 months. However, the majority of PWH still had LPS-induced INF-α, INF-γ and Poly I:C-induced TNF-α and IL-6 below the reference interval. The induced innate immune responses before cART initiation were not associated with the CD4+ T-cell recovery after 12 months of cART. Conclusion: The innate immune response was impaired in PWH, with a more pronounced impairment in PWH with low nadir CD4+ T-cell count. Initiation of cART improved the innate immune response, but compared to the reference intervals, some impairment remained in PWH without viral replication.