Human Immunodeficiency Virus Strains Research Articles

Preventing breast milk HIV transmission using broadly neutralizing monoclonal antibodies: One size does not fit all.

Key messages Passive immunoprophylaxis with broadly neutralizing monoclonal antibodies (bNAbs) could be a game changer in the prevention of human immunodeficiency virus (HIV) acquisition. The prevailing view is that available resources should be focused on identifying a fixed combination of at least three bNAbs for universal use in therapeutic and preventive protocols, regardless of target populations or routes of transmission. HIV transmission through breastfeeding is unique: it involves free viral particles and cell‐associated virus from breast milk and, in the case of acute/recent maternal infection, a viral population with restricted Env diversity. HIV transmission through breastfeeding in high incidence/prevalence areas could potentially be eliminated by subcutaneous administration to all newborns of one or two long‐acting bNAbs with extended breadth, high potency, and effector properties (ADCC, phagocytosis) against circulating HIV strains.

Naphthalene Diimide-Tetraazacycloalkane Conjugates Are G-Quadruplex-Based HIV-1 Inhibitors with a Dual Mode of Action.

Human immunodeficiency virus 1 (HIV-1) therapeutic regimens consist of three or more drugs targeting different steps of the viral life cycle to limit the emergence of viral resistance. In line with the multitargeting strategy, here we conjugated a naphthalene diimide (NDI) moiety with a tetraazacycloalkane to obtain novel naphthalene diimide (NDI)-tetraazacycloalkane conjugates. The NDI inhibits the HIV-1 promoter activity by binding to LTR G-quadruplexes, and the tetraazacycloalkane mimics AMD3100, which blocks HIV entry into cells by interfering with the CXCR4 coreceptor. We synthesized, purified, and tested the metal-free NDI-tetraazacycloalkane conjugate and the two derived metal-organic complexes (MOCs) that incorporate Cu2+ and Zn2+. The NDI-MOCs showed enhanced binding to LTR G4s as assessed by FRET and CD assays in vitro. They also showed enhanced activity in cells where they dose-dependently reduced LTR promoter activity and inhibited viral entry only of the HIV-1 strain that exploited the CXCR4 coreceptor. The time of addition assay confirmed the dual targeting at the different HIV-1 steps. Our results indicate that the NDI-MOC conjugates can simultaneously inhibit viral entry, by targeting the CXCR4 coreceptor, and LTR promoter activity, by stabilizing the LTR G-quadruplexes. The approach of combining multiple targets in a single compound may streamline treatment regimens and improve the overall patient outcomes.

Changes in Primary HIV-1 Drug Resistance Due to War Migration from Eastern Europe

In recent years, especially as a result of war in Ukraine, enormous movements of migration to Poland from eastern European countries have been reported, including people living with Human Immunodeficiency Virus (HIV). We have conducted multi-center, prospective study, which aimed to establish HIV-1 subtype and assess the presence of primary drug resistance mutations to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors in antiretroviral treatment naïve patients. The clinical trial recruited 117 individuals during 2 years period (2020–2022). The prevalence of HIV-1 subtype A was statistically significantly more frequent in Ukrainian, and HIV-1 subtype B in Polish patients (p < 0.05). Drug resistance mutations were detected in 44% of all cases and the comparison of presence of mutations in the analyzed groups, as well as in the subgroups of subtype A and B HIV-1 has not revealed any significant differences (p > 0.05), nevertheless Polish patients had multidrug resistance mutations more frequent (p < 0.05). The results from our trial show no increased risk of transmission of multidrug resistant HIV strains in our cohort of Ukrainian migrants.Clinical trials. Gov number NCT04636736; date of registration: November 19, 2020.

Global Research Output Human Immunodeficiency Virus From 1954-2022: Literature Review

HIV (human immunodeficiency virus) have two primary HIV strains are HIV-1 and HIV-2. Both can lead to AIDS and our work is explained to easily find out the data about HIV. We conducted the research work of HIV between the years of 1954-2022. We classified the models by their mathematical structure and research question. The amount of information that researchers are analyzing from etiology, pathogenesis, in-vivo, in-vitro, and human trials grows daily. As compared data for the HIV research and review work the research will perform moderately with the review work. The In-vivo and the In-vitro work are performed little lower than the other work. This is the useful research review source for the HIV research work. We created a segregation of desirable features of models, reviewed and classified the articles to inform our conclusions.

In Vitro and In Silico Antiviral Activity of Di-Halogenated Compounds Derived from L-Tyrosine against Human Immunodeficiency Virus 1 (HIV-1).

HIV-1 infection is considered one of the major public health problems worldwide. Due to the limited access to antiretroviral therapy, the associated side effects, and the resistance that the virus can generate, it has become necessary to continue the development of new antiviral agents. The study aimed to identify potential antiviral agents for HIV-1 by evaluating the in vitro and in silico activity of 16 synthetic di-halogenated compounds derived from L-Tyrosine. The compounds were tested for cytotoxicity, which was determined using MTT, and a combined antiviral screening strategy (pre- and post-infection treatment) was performed against R5 and X4 strains of HIV-1. The most promising compounds were evaluated against a pseudotyped virus (HIV-GFP-VSV-G), and the effectiveness of these compounds was measured through GFP flow cytometry. Also, the antiviral effect of these compounds was evaluated in PBMCs using flow cytometry and ELISA for p24. The TODB-2M, TODC-2M, TODC-3M, and YDC-3M compounds showed low toxicity and significant inhibitory activity against HIV-1. In silico docking and molecular dynamics assays suggest that the compounds' antiviral activity may be due to interaction with reverse transcriptase, viral protease, or envelope gp120.

Combined Nano-Vector Mediated-Transfer to Suppress HIV-1 Infection with Targeted Antibodies in-vitro.

Broadly neutralizing antibodies (bNAbs) have the ability to neutralize a considerable breadth of genetically diverse human immunodeficiency virus (HIV) strains. Passive immunization can potentially provide protection against HIV infection in animal models. However, the direct antibody infusion effect is limited due to the short half-life and deficient immunogenicity of the antibody. As an alternative strategy, we propose the use of nano viral vectors, specifically the adeno-associated virus (AAV), to continuously and systematically produce bNAbs against HIV. Plasmids expressing bNAbs PG9, PG16, 10E8, and NIH45-46 antibodies were constructed, targeting three different epitopes of HIV. Additionally, the bNAbs gene mediated by rAAV8 was administered to generate long-term expression with a single injection. We established both single and combined immunization groups. The neutralizing activity of antibodies expressed in mice sera was subsequently evaluated. The expression of bNAbs in BALB/c mice can last for >24 weeks after a single intramuscular injection of rAAV8. Further studies show that neutralization of the HIV pseudovirus by sera from co-immunized mice with rAAV8 expressing 10E8 and PG16 was enhanced compared with mice immunized with 10E8 or PG16 alone. The prolonged expression of neutralizing antibodies can be maintained over long periods in BALB/c mice. This combined immunization is a promising candidate strategy for HIV treatment.

Design, synthesis, and biological evaluation of benzo[4,5]thieno[2,3-d]pyrimidine derivatives as novel HIV-1 NNRTIs

Inspired by our previous studies to discover novel human immunodeficiency virus-1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs) by targeting the tolerant region II of the NNRTIs binding pocket (NNIBP), a series of novel benzo[4,5]thieno[2,3-d]pyrimidine derivatives were designed through structure-based drug design as novel potent HIV-1 NNRTIs. The results showed that compound 16b was the most active inhibitor, exhibiting 50% effective concentration (EC50) values from 0.021 µmol/L to 0.298 µmol/L against wild-type (WT) and a panel of NNRTIs-resistant HIV-1 strains. Moreover, 16b was demonstrated with a significantly low 50% cytotoxicity concentration (CC50) value (>200 µmol/L) and high selectivity index (SI) values. In addition, 16b yielded moderate reverse transcriptase (RT) enzyme inhibition with a 50% inhibition concentration (IC50) value of 0.183 µmol/L, which demonstrated that it acted as HIV-1 NNRTIs. The binding mode of 16b with RT was also illustrated via molecular docking. Overall, this work provided a novel lead compound for developing potent HIV-1 NNRTIs.

HIV Pre-Exposure Prophylaxis, Blood Donor Deferral, Occult Infection, and Risk of HIV Transmission by Transfusion: A Fine Balance Between Evidence-Based Donor Selection Criteria and Transfusion Safety.

Pre- and postexposure prophylaxis for human immunodeficiency virus (HIV) are key to reducing the transmission of this virus. Furthermore, low-toxicity, long-acting formulations provide additional clinical benefits, in particular easier adherence to treatment and prevention. However, breakthrough HIV infections can occur despite the use of pre-exposure prophylaxis (PrEP), mainly due to suboptimal adherence or multi-drug resistant HIV strains. Albeit rare, PrEP breakthrough infections have also been reported in fully adherent patients. Should such breakthrough infection occur in an eligible blood donor, PrEP might suppress viremia and delay antibody seroconversion, thereby masking the infection and increasing the risk of transfusion transmission. This possibility has raised concerns in the blood transfusion community but remains little documented. Therefore, a literature search was performed to assess the state of knowledge on the risk of PrEP breakthrough infection, with a particular focus on the risk of HIV entering the blood supply. Evidently, PrEP breakthrough infections are rare, although the risk is not zero. Moreover, a fraction of individuals - including blood donors - do not disclose PrEP use according to various surveys and measurements of HIV PrEP analytes. Additionally, viremia and seroconversion may remain undetectable or close to the limit of detection for a long time after cessation of PrEP, particularly with long-acting antiretrovirals. Therefore, current recommendations to defer donors for at least 3 months after the last dose of oral PrEP or 2 years for long-acting PrEP appear justified, as they safeguard the blood supply and public trust toward the system. These recommendations help to safeguard blood safety and public trust in the blood supply.

HIV-1 Transmission among Injecting Drug Users is Principally Derived from Local Circulating Strains in Guangxi, China

ObjectiveThe mode of human immunodeficiency virus (HIV) transmission via injection drug use (IDU) still exists, and the recent shift in IDU-related transmission of HIV infection is largely unknown. The purpose of this study was to analyze the spatiotemporal sources and dynamics of HIV-1 transmission through IDU in Guangxi. MethodsWe performed a molecular epidemiological investigation of infections across Guangxi from 2009 to 2019. Phylogenetic and Bayesian time-geographic analyses of HIV-1 sequences were performed to confirm the characteristics of transmission between IDUs in combination with epidemiological data. ResultsAmong the 535 subjects, CRF08_BC (57.4%), CRF01_AE (28.4%), and CRF07_BC (10.7%) were the top 3 HIV strains; 72.6% of infections were linked to other provinces in the transmission network; 93.6% of sequence-transmitted strains were locally endemic, with the rest coming from other provinces, predominantly Guangdong and Yunnan; 92.1% of the HIV transmission among people who inject drugs tended to be transmitted between HIV-positive IDUs. ConclusionHIV recombinants were high diversity, and circulating local strains were the transmission sources among IDUs in Guangxi. However, there were still cases of IDUs linked to other provinces. Coverage of traditional prevention strategies should be expanded, and inter-provincial collaboration between Guangxi, Yunnan, and Guangdong provinces should be strengthened.

A Rapid and Sensitive Detection of HIV-1 with a One-Pot Two-Stage Reverse Transcription Recombinase Aided Real-Time PCR Assay.

Human immunodeficiency virus 1 (HIV-1) attacks the immune system, making people susceptible to various diseases, thus increasing their risk of death. Comprehensive detection of major HIV-1 strains circulating in China is vital for effective HIV-1 infection prevention and treatment. HIV-1 nucleic acid detection is considered effective for HIV-1 diagnosis since traditional immunological testing may fail to detect HIV-1 infection during the window period. This work demonstrates a one-pot two-stage amplification assay (RT-RAP), a combination of reverse transcription recombinase (RT- RAA), and quantitative real-time polymerase chain reaction (qRT-PCR). The turn-around time of the assay is only 50 min and can be performed with commonly available laboratory equipment, the qPCR devices. The RT-RAP assay could detect approximately 5 and 14 copies/reaction of HIV-1 DNA and RNA using recombinant plasmids and standard reference strains, respectively. Additionally, we found that the clinical performance of RT-RAP (detected 169 samples out of 170 specimens) was consistent with that of qRT-PCR. The sensitivity and specificity of RT-RAP were 100.00% (99/99) and 98.59% (70/71), respectively, while its positive and negative predictive values were 99.00% (99/100) and 100.00% (70/70), respectively. The total coincidence rate of the RT-RAP was 99.41% (169/170), with a kappa value of 0.988 (p < 0.05). We demonstrated that RT-RAP could rapidly detect the common HIV-1 subtypes commonly circulating in China with comparable sensitivity and specificity to qRT-PCR.

Adaptation to HLA-associated immune pressure over the course of HIV infection and in circulating HIV-1 strains.

Adaptation to human leukocyte antigen (HLA)-associated immune pressure represents a major driver of human immunodeficiency virus (HIV) evolution at both the individual and population level. To date, there has been limited exploration of the impact of the initial cellular immune response in driving viral adaptation, the dynamics of these changes during infection and their effect on circulating transmitting viruses at the population level. Capturing detailed virological and immunological data from acute and early HIV infection is challenging as this commonly precedes the diagnosis of HIV infection, potentially by many years. In addition, rapid initiation of antiretroviral treatment following a diagnosis is the standard of care, and central to global efforts towards HIV elimination. Yet, acute untreated infection is the critical period in which the diversity of proviral reservoirs is first established within individuals, and associated with greater risk of onward transmissions in a population. Characterizing the viral adaptations evident in the earliest phases of infection, coinciding with the initial cellular immune responses is therefore relevant to understanding which changes are of greatest impact to HIV evolution at the population level. In this study, we utilized three separate cohorts to examine the initial CD8+ T cell immune response to HIV (cross-sectional acute infection cohort), track HIV evolution in response to CD8+ T cell-mediated immunity over time (longitudinal chronic infection cohort) and translate the impact of HLA-driven HIV evolution to the population level (cross-sectional HIV sequence data spanning 30 years). Using next generation viral sequencing and enzyme-linked immunospot interferon-gamma recall responses to peptides representing HLA class I-specific HIV T cell targets, we observed that CD8+ T cell responses can select viral adaptations prior to full antibody seroconversion. Using the longitudinal cohort, we uncover that viral adaptations have the propensity to be retained over time in a non-selective immune environment, which reflects the increasing proportion of pre-adapted HIV strains within the Western Australian population over an approximate 30-year period.

The anti-HIV potential of imidazole, oxazole and thiazole hybrids: A mini-review

Human immunodeficiency virus (HIV) especially HIV-1 infection and its progression to acquired immune deficiency syndrome (AIDS) remains a significant global health challenge. The advent of the highly active antiretroviral therapy (HAART) has greatly extended the life expectancy of patients living with HIV, but it has become evident that long-term HAART will not eliminate the HIV reservoir and cure the infection. Moreover, the drug resistance and undesirable side effects hamper efficacious therapy, creating an urgent need to develop novel, more effective and less toxic anti-HIV therapeutics. Imidazole, oxazole and thiazole with two heteroatoms at meta-position of five-membered rings are fascinating structures and constitute an important class of heterocycles in drug discovery. Their derivatives could exert the anti-HIV activity through diverse mechanisms and possess promising antiviral activity against both drug-sensitive and drug-resistant HIV strains. This review summarizes the research progress made regarding the anti-HIV potential of imidazole, oxazole and thiazole hybrids, and the structure–activity relationships (SARs) are also discussed to facilitate further rational design of more effective candidates, covering articles published from 2012 to 2022.

HIV-1 Infection of Long-Lived Hematopoietic Precursors In Vitro and In Vivo.

Latent reservoirs in human-immunodeficiency-virus-1 (HIV-1)-infected individuals represent a major obstacle in finding a cure for HIV-1. Hematopoietic stem and progenitor cells (HSPCs) have been described as potential HIV-1 targets, but their roles as HIV-1 reservoirs remain controversial. Here we provide additional evidence for the susceptibility of several distinct HSPC subpopulations to HIV-1 infection in vitro and in vivo. In vitro infection experiments of HSPCs were performed with different HIV-1 Env-pseudotyped lentiviral particles and with replication-competent HIV-1. Low-level infection/transduction of HSPCs, including hematopoietic stem cells (HSCs) and multipotent progenitors (MPP), was observed, preferentially via CXCR4, but also via CCR5-mediated entry. Multi-lineage colony formation in methylcellulose assays and repetitive replating of transduced cells provided functional proof of susceptibility of primitive HSPCs to HIV-1 infection. Further, the access to bone marrow samples from HIV-positive individuals facilitated the detection of HIV-1 gag cDNA copies in CD34+ cells from eight (out of eleven) individuals, with at least six of them infected with CCR5-tropic HIV-1 strains. In summary, our data confirm that primitive HSPC subpopulations are susceptible to CXCR4- and CCR5-mediated HIV-1 infection in vitro and in vivo, which qualifies these cells to contribute to the HIV-1 reservoir in patients.

A Literature Review on Recent Advancements in the Treatment of Human Immunodeficiency Virus

Abstract: The aim of this study is to conduct an extensive literature review on recent advancements in the treatment of human immunodeficiency virus (HIV). This is because in extant studies, the care of the HIV infected patient has changed dramatically in the last few years. Potent new antiretroviral drugs combined with updated treatment strategies have now achieved efficient inhibition of HIV replication in most patients. Classes of drugs include both nucleoside and non-nucleoside inhibitors of the viral enzyme reverse transcriptase (RT) and inhibitors of the viral protease and integrase enzymes. The methodology used in this study was reviewed from secondary sources of information including journals, articles, newspaper, and textbooks. In this study, authors found that a major drawback of the highly active antiretroviral therapy (HAART) is the selection of resistant mutants under suboptimal dosage, in advanced stages of disease or after pre-treatment with mono- or double-combination regimens. In addition, monitoring of antiretroviral therapy is achieved by measurement of viral load using nucleic acid amplification techniques. Strict adherence to HIV drug regimens was reported to be essential for reaching and maintaining therapeutic levels of anti-retro-virals and avoiding development of drug-resistant HIV strains. This strict dosage-taking adherence makes HIV therapies among the most challenging treatments with which to adhere. Future researchers are encouraged to adopt a scientific approach in investigating the various constructs that have emerged in this study in other to provide more generalized findings for the research community and public policy makers. Keywords: Antiretroviral Drugs: Combination Therapy: Medication: Transmission: Inhibitors: Immune System.

Closing the Door with CRISPR: Genome Editing of CCR5 and CXCR4 as a Potential Curative Solution for HIV.

Human immunodeficiency virus (HIV) infection can be controlled by anti-retroviral therapy. Suppressing viral replication relies on life-long medication, but anti-retroviral therapy is not without risks to the patient. Therefore, it is important that permanent cures for HIV infection are developed. Three patients have been described to be completely cured from HIV infection in recent years. In all cases, patients received a hematopoietic stem cell (HSC) transplantation due to a hematological malignancy. The HSCs were sourced from autologous donors that expressed a homozygous mutation in the CCR5 gene. This mutation results in a non-functional receptor, and confers resistance to CCR5-tropic HIV strains that rely on CCR5 to enter host cells. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas) system is one of the methods of choice for gene editing, and the CRISPR/Cas system has been employed to target loci of interest in the context of HIV. Here, the current literature regarding CRISPR-mediated genome editing to render cells resistant to HIV (re)-infection by knocking out the co-receptors CCR5 and CXCR4 is summarized, and an outlook is provided regarding future (research) directions.

The effect of human immunodeficiency virus and human papillomavirus strain diversity on the progression of anal squamous intraepithelial lesions

Anal squamous cell carcinoma (SCC) is a human papillomavirus (HPV)-mediated malignancy with increasing incidence. Human immunodeficiency virus (HIV) infection is a significant risk factor for anal SCC; however, it is unknown if HIV infection alters anal lesion progression and HPV strain profile. This study aims to determine whether HIV coinfection is associated with progression of HPV-mediated anal lesions and on their HPV strain diversity. This is a retrospective cohort study of adults with anal squamous intraepithelial lesion (SIL) who presented for anorectal sampling between 2010 and 2019. Using the full cohort, we performed clinicopathologic epidemiologic analysis of HIV coinfection on lesion progression. Using a subset of patients, we conducted molecular analysis of HPV strain diversity as related to HIV status and progression. Our cohort included 2203 individuals, of which 940 (43%) were HIV+. HIV+ status was associated with faster progression at all levels of dysplasia. Our molecular cohort included 329 adults, of which 190 (57.8%) were HIV+. HIV+status was associated with higher HPV strain diversity (median: 7 [5-9] versus median: 4 [4-6], P<.001). Latent class analysis identified specific HPV strain signatures associated with progression. We demonstrate that HIV+ individuals had faster rates of anal SIL progression and that almost all HPV strains were more prevalent in anal samples from HIV+ adults. Our results imply that HIV+ adults with anal SIL should undergo more frequent screening and obtain HPV genotyping at initial presentation, as it shows value as a biomarker of lesion progression.

Transmission and Drug Resistance Characteristics of Human Immunodeficiency Virus-1 Strain Using Medical Information Data Retrieval System.

This study was aimed at exploring the transmission and drug resistance characteristics of acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus-1 (HIV-1). The query expansion algorithm based on Candecomp Parafac (CP) decomposition was adopted to construct a data information retrieval system for semantic web and tensor decomposition. In the latent variable model based on tensor decomposition, the three elements in the triples generated feature vectors to calculate the training samples. The HIV patient data set was selected to evaluate the performance of the system, and then, the HIV gene resistance of 213 patients was retrospectively analyzed based on the electronic medical records. 43 cases showed failure of ribonucleic acid drug resistance, the ART virological failure rate was 24.43% (43/213), and one case was not reported. There was 1 case of RNA hemolysis that could not be detected. There were 50 resistant cases of nonnucleotide reverse transcriptase inhibitors (NNRTI), accounting for 29.94% (50/167), and there were 17 resistant cases of nucleotide reverse transcriptase inhibitors (NRTI), accounting for 10.18% (17/167) of all mutation cases. Among the HIV-1 strains, 19 cases failed the detection of drug resistance sites in the integrase region, and mutations in the integrase region were significantly more than those in the protease region. There were 12 types of HIV-1 strains with drug-resistant mutations. The fusion technical scheme constructed in this study showed excellent performance in medical information retrieval. In this study, the characteristics of HIV-1 of AIDS patients were analyzed from different directions, and effective treatment was performed for patients, so as to provide reference for clinical diagnosis of AIDS patients.

Deciphering gp120 sequence variation and structural dynamics in HIV neutralization phenotype by molecular dynamics simulations and graph machine learning.

Human immunodeficiency virus (HIV) exploits the sequence variation and structural dynamics of the envelope glycoprotein gp120 to evade the immune attack of neutralization antibodies, contributing to various HIV neutralization phenotypes. Although the HIV neutralization phenotype has been experimentally characterized, the roles of rapid sequence variability and significant structural dynamics of gp120 are not well understood. Here, 45 prefusion gp120 from different HIV strains belong to three tiers of sensitive, moderate, and resistant neutralization phenotype are structurally modeled by homology modeling and then investigated by molecular dynamics (MD) simulations and graph machine learning (ML). Our results show that the structural deviations, population distribution, and conformational flexibility of gp120 are related to the HIV neutralization phenotype. Per-residue dynamics indicate the local regions especially in the second structural elements with high-flexibility, may be responsible for the HIV neutralization phenotype. Moreover, a graph ML model with the attention mechanism was trained to explore inherent representation related to the classification of the HIV neutralization phenotype, further distinguishing the strong related gp120 sequence variation together with structural dynamics in the HIV neutralization phenotype. Our study not only deciphers gp120 sequence variation and structural dynamics in the HIV neutralization phenotype but also explores complex relationships between the sequence, structure, and dynamics of protein by combining MD simulations and ML.

Repurposing FDA-approved drugs as HIV-1 integrase inhibitors: an in silico investigation

The Human Immunodeficiency Virus (HIV) infection is a global pandemic that has claimed 33 million lives to-date. One of the most efficacious treatments for naïve or pretreated HIV patients is the HIV integrase strand transfer inhibitors (INSTIs). However, given that HIV treatment is life-long, the emergence of HIV strains resistant to INSTIs is an imminent challenge. In this work, we showed two best regression QSAR models that were constructed using a boosted Random Forest algorithm (r2 = 0.998, q2 10CV = 0.721, q2 external_test = 0.754) and a boosted K* algorithm (r2 = 0.987, q2 10CV = 0.721, q2 external_test = 0.758) to predict the pIC50 values of INSTIs. Subsequently, the regression QSAR models were deployed against the Drugbank database for drug repositioning. The top-ranked compounds were further evaluated for their target engagement activity using molecular docking studies and accelerated Molecular Dynamics simulation. Lastly, their potential as INSTIs were also evaluated from our literature search. Our study offers the first example of a large-scale regression QSAR modelling effort for discovering highly active INSTIs to combat HIV infection. Communicated by Ramaswamy H. Sarma

CD8 T Cell Virus Inhibition Assay Protocol.

The human immunodeficiency virus (HIV)-1 viral inhibition assay (VIA) measures CD8+ T cell-mediated inhibition of HIV replication in CD4+ T cells and is increasingly used for clinical testing of HIV vaccines and immunotherapies. Different VIAs that differ in length of CD8:CD4 T cell culture periods (6-13 days), purity of CD4 cultures [isolated CD4+ T cells or CD8+ depleted peripheral blood mononuclear cells (PBMCs)], HIV strains (laboratory strains, isolates, reporter viruses) and read-outs of virus inhibition (p24 ELISA, intracellular measurement of p24, luciferase reporter expression, and viral gag RNA) have been reported. Here, we describe multiple modifications to a 7-day VIA protocol, the most impactful being the introduction of independent replicate cultures for both HIV infected-CD4 (HIV-CD4) and HIV-CD4:CD8 T cell cultures. Virus inhibition was quantified using a ratio of weighted averages of p24+ cells in replicate cultures and the corresponding 95% confidence intervals. We identify methodological and analysis changes that could be incorporated into other protocols to improve assay reproducibility. We found that in people living with HIV (PLWH) on antiretroviral therapy (ART), CD8 T cell virus inhibition was largely stable over time, supporting the use of this assay and/or analysis methods to examine therapeutic interventions. Graphic abstract.