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Key HIV cure strategies involve reversing immune dysfunction and limiting the proliferation of infected T cells. We evaluate the safety of sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, in people with HIV (PWH) and study the impact of sirolimus on HIV-1 reservoir size and HIV-1-specific immunity in a single-arm study of 20 weeks of treatment in PWH on antiretroviral therapy (ART). Sirolimus treatment does not impact HIV-1-specific CD8 T cell responses but leads to a significant decrease in CD4+ T cell-associated HIV-1 DNA levels at 20 weeks of therapy in the primary efficacy population (n = 16; 31% decline, p = 0.008). This decline persists for at least 12 weeks following cessation of the study drug. Sirolimus treatment also leads to a significant reduction in CD4+ T cell cycling and PD-1 expression on CD8+ lymphocytes. These data suggest that homeostatic proliferation of infected cells, an important mechanism for HIV persistence, is an intriguing therapeutic target.

The presence of HIV in sequestered reservoirs is a central impediment to a functional cure, allowing HIV to persist despite life-long antiretroviral therapy (ART), and driving a variety of comorbid conditions. Our understanding of the latent HIV reservoir in the central nervous system is incomplete, because of difficulties in accessing human central nervous system tissues. Microglia contribute to HIV reservoirs, but the molecular phenotype of HIV-infected microglia is poorly understood. We leveraged the unique "Last Gift" rapid autopsy program, in which people with HIV are closely followed until days or even hours before death. Microglial populations were heterogeneous regarding their gene expression profiles but showed similar chromatin accessibility landscapes. Despite ART, we detected occasional microglia containing cell-associated HIV RNA and HIV DNA integrated into open regions of the host's genome (∼0.005%). Microglia with detectable HIV RNA showed an inflammatory phenotype. These results demonstrate a distinct myeloid cell reservoir in the brains of people with HIV despite suppressive ART. Strategies for curing HIV and neurocognitive impairment will need to consider the myeloid compartment to be successful.

Determining the label to target ratio, also known as the degree of labeling (DOL), is crucial for quantitative fluorescence microscopy and a high DOL with minimal unspecific labeling is beneficial for fluorescence microscopy in general. Yet robust, versatile and easy-to-use tools for measuring cell-specific labeling efficiencies are not available. Here we present a DOL determination technique named protein-tag DOL (ProDOL), which enables fast quantification and optimization of protein-tag labeling. With ProDOL various factors affecting labeling efficiency, including substrate type, incubation time and concentration, as well as sample fixation and cell type can be easily assessed. We applied ProDOL to investigate how human immunodeficiency virus-1 pathogenesis factor Nef modulates CD4 T cell activation measuring total and activated copy numbers of the adapter protein SLP-76 in signaling microclusters. ProDOL proved to be a versatile and robust tool for labeling calibration, enabling determination of labeling efficiencies, optimization of strategies and quantification of protein stoichiometry.

Drugs that inhibit HIV transcription and/or reactivation of latent HIV have been proposed as a strategy to reduce HIV-associated immune activation or to achieve a functional cure, yet comparative studies are lacking. We evaluated 26 drugs, including drugs previously reported to inhibit HIV transcription (inhibitors of Tat-dependent HIV transcription, Rev, HSF-1/PTEF-b, HSP90, Jak/Stat, or SIRT1/Tat deacetylation) and other agents that were not tested before (inhibitors of PKC, NF-κB, SP-1, or histone acetyltransferase; NR2F1 agonists), elongation (inhibitors of CDK9/ PTEF-b), completion (inhibitors of PolyA-polymerase), or splicing (inhibitors of human splice factors). To investigate if those drugs would vary in their ability to affect different blocks to HIV transcription, we measured levels of initiated, elongated, midtranscribed, completed, and multiply spliced HIV RNA in PBMCs from antiretroviral therapy-suppressed individuals following ex vivo treatment with each drug and subsequent T cell activation. We identified new drugs that prevent HIV reactivation, including CDK and splicing inhibitors. While some drugs inhibited 1 or 2 steps, other drugs (CDK inhibitors, splicing inhibitors, tanespimycin, and triptolide) inhibited multiple stages of HIV transcription and blocked the production of supernatant viral RNA. These drugs and targets deserve further study in strategies aimed at reducing HIV-associated immune activation or achieving a functional cure.

BACKGROUND: HVTN 120 is a phase 1/2a randomized double-blind placebo-controlled human immunodeficiency virus (HIV) vaccine trial that evaluated the safety and immunogenicity of ALVAC-HIV (vCP2438) and MF59- or AS01B-adjuvanted bivalent subtype C gp120 Env protein at 2 dose levels in healthy HIV-uninfected adults. METHODS: Participants received ALVAC-HIV (vCP2438) alone or placebo at months 0 and 1. At months 3 and 6, participants received either placebo, ALVAC-HIV (vCP2438) with 200 μg of bivalent subtype C gp120 adjuvanted with MF59 or AS01B, or ALVAC-HIV (vCP2438) with 40 μg of bivalent subtype C gp120 adjuvanted with AS01B. Primary outcomes were safety and immune responses. RESULTS: We enrolled 160 participants, 55% women, 18-40 years old (median age 24 years) of whom 150 received vaccine and 10 placebo. Vaccines were generally safe and well tolerated. At months 6.5 and 12, CD4+ T-cell response rates and magnitudes were higher in the AS01B-adjuvanted groups than in the MF59-adjuvanted group. At month 12, HIV-specific Env-gp120 binding antibody response magnitudes in the 40 μg gp120/AS01B group were higher than in either of the 200 μg gp120 groups. CONCLUSIONS: The 40 μg dose gp120/AS01B regimen elicited the highest CD4+ T-cell and binding antibody responses. Clinical Trials Registration . NCT03122223.

Engineered reverse hairpin constructs containing a partial C-heptad repeat (CHR) sequence followed by a short loop and full-length N-heptad repeat (NHR) were previously shown to form trimers in solution and to be nanomolar inhibitors of HIV-1 Env mediated fusion. Their target is the in situ gp41 fusion intermediate, and they have similar potency to other previously reported NHR trimers. However, their design implies that the NHR is partially covered by CHR, which would be expected to limit potency. An exposed hydrophobic pocket in the folded structure may be sufficient to confer the observed potency, or they may exist in a partially unfolded state exposing full length NHR. Here we examined their structure by crystallography, CD and fluorescence, establishing that the proteins are folded hairpins both in crystal form and in solution. We examined unfolding in the milieu of the fusion reaction by conducting experiments in the presence of a membrane mimetic solvent and by engineering a disulfide bond into the structure to prevent partial unfolding. We further examined the role of the hydrophobic pocket, using a hairpin-small molecule adduct that occluded the pocket, as confirmed by X-ray footprinting. The results demonstrated that the NHR region nominally covered by CHR in the engineered constructs and the hydrophobic pocket region that is exposed by design were both essential for nanomolar potency and that interaction with membrane is likely to play a role in promoting the required inhibitor structure. The design concepts can be applied to other Class 1 viral fusion proteins.

We evaluated the HIV-1 DNA reservoir in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) in people with HIV (PWH) and associations to cognitive dysfunction. Using the intact proviral DNA assay (IPDA), an emerging technique to identify provirus that may be the source of viral rebound, we assessed HIV DNA in CSF and PBMC in PWH regardless of antiretroviral therapy (ART). CSF was used as a sampling surrogate for the central nervous system (CNS) as opposed to tissue. IDPA results (3' defective, 5' defective, and intact HIV DNA) were analyzed by compartment (Wilcoxon signed rank; matched and unmatched pairs). Cognitive performance, measured via a battery of nine neuropsychological (NP) tests, were analyzed for correlation to HIV DNA (Spearman's rho). 11 CSF and 8 PBMC samples from PWH were evaluated both unmatched and matched. Total CSF HIV DNA was detectable in all participants and was significantly higher than in matched PBMCs (p ​= ​0.0039). Intact CSF HIV DNA was detected in 7/11 participants and correlated closely with those in PBMCs but tended to be higher in CSF than in PBMC. CSF HIV DNA did not correlate with global NP performance, but higher values did correlate with worse executive function (p ​= ​0.0440). Intact HIV DNA is frequently present in the CSF of PWH regardless of ART. This further supports the presence of an HIV CNS reservoir and provides a method to study CNS reservoirs during HIV cure studies. Larger studies are needed to evaluate relationships with CNS clinical outcomes.

HIV-1 Vpr promotes efficient spread of HIV-1 from macrophages to T cells by transcriptionally downmodulating restriction factors that target HIV-1 Envelope protein (Env). Here we find that Vpr induces broad transcriptomic changes by targeting PU.1, a transcription factor necessary for expression of host innate immune response genes, including those that target Env. Consistent with this, we find silencing PU.1 in infected macrophages lacking Vpr rescues Env. Vpr downmodulates PU.1 through a proteasomal degradation pathway that depends on physical interactions with PU.1 and DCAF1, a component of the Cul4A E3 ubiquitin ligase. The capacity for Vpr to target PU.1 is highly conserved across primate lentiviruses. In addition to impacting infected cells, we find that Vpr suppresses expression of innate immune response genes in uninfected bystander cells, and that virion-associated Vpr can degrade PU.1. Together, we demonstrate Vpr counteracts PU.1 in macrophages to blunt antiviral immune responses and promote viral spread.

BACKGROUNDEarly antiretroviral therapy initiation (ARTi) in HIV-1 restricts reservoir size and diversity while preserving immune function, potentially improving opportunities for immunotherapeutic cure strategies. For antibody-based cure approaches, the development of autologous neutralizing antibodies (anAbs) after acute/early ARTi is relevant but is poorly understood.METHODSWe characterized antibody responses in a cohort of 23 participants following ARTi in acute HIV (

Human immunodeficiency virus-1 (HIV-1) infects the central nervous system (CNS) and causes HIV-associated neurocognitive disorders (HAND) in about half of the population living with the virus despite combination anti-retroviral therapy (cART). HIV-1 activates the innate immune system, including the production of type 1 interferons (IFNs) α and β. Transgenic mice expressing HIV-1 envelope glycoprotein gp120 (HIVgp120tg) in the CNS develop memory impairment and share key neuropathological features and differential CNS gene expression with HIV patients, including the induction of IFN-stimulated genes (ISG). Here we show that knocking out IFNβ (IFNβKO) in HIVgp120tg and non-tg control mice impairs recognition and spatial memory, but does not affect anxiety-like behavior, locomotion, or vision. The neuropathology of HIVgp120tg mice is only moderately affected by the KO of IFNβ but in a sex-dependent fashion. Notably, in cerebral cortex of IFNβKO animals presynaptic terminals are reduced in males while neuronal dendrites are reduced in females. The IFNβKO results in the hippocampal CA1 region of both male and female HIVgp120tg mice in an ameliorated loss of neuronal presynaptic terminals but no protection of neuronal dendrites. Only female IFNβ-deficient HIVgp120tg mice display diminished microglial activation in cortex and hippocampus and increased astrocytosis in hippocampus compared to their IFNβ-expressing counterparts. RNA expression for some immune genes and ISGs is also affected in a sex-dependent way. The IFNβKO abrogates or diminishes the induction of MX1, DDX58, IRF7 and IRF9 in HIVgp120tg brains of both sexes. Expression analysis of neurotransmission related genes reveals an influence of IFNβ on multiple components with more pronounced changes in IFNβKO females. In contrast, the effects of IFNβKO on MAPK activities are independent of sex with pronounced reduction of active ERK1/2 but also of active p38 in the HIVgp120tg brain. In summary, our findings show that the absence of IFNβ impairs memory dependent behavior and modulates neuropathology in HIVgp120tg brains, indicating that its absence may facilitate development of HAND. Moreover, our data suggests that endogenous IFNβ plays a vital role in maintaining neuronal homeostasis and memory function.

Here, an in vitro characterization of a family of prazole derivatives that covalently bind to the C73 site on Tsg101 and assay their ability to inhibit viral particle production is presented. Structurally, increased steric bulk on the 4-pyridyl of the prazole expands the prazole site on the UEV domain toward the β-hairpin in the Ub-binding site and is coupled to increased inhibition of virus-like particle production in HIV-1. Increased bulk also increased toxicity, which is alleviated by increasing flexibility. Further, the formation of a novel secondary Tsg101 adduct for several of the tested compounds and the commercial drug lansoprazole. The secondary adduct involved the loss of the 4-pyridyl substituent to form an irreversible species, with implications for increasing the half-life of the active species or its specificity toward Tsg101 UEV. It is also determined that sulfide derivatives display effective viral inhibition, presumably through cellular sulfoxidation, allowing for delayed conversion within the cellular environment, and identify SARS-COV-2 as a target of prazole inhibition. These results open multiple avenues for the design of prazole derivatives for antiviral applications.

Macrophages (MΦ) infected with human immunodeficiency virus (HIV)-1 or activated by its envelope protein gp120 exert neurotoxicity. We found previously that signaling via p38 mitogen-activated protein kinase (p38 MAPK) is essential to the neurotoxicity of HIVgp120-stimulated MΦ. However, the associated downstream pathways remained elusive. Here we show that cysteinyl-leukotrienes (CysLT) released by HIV-infected or HIVgp120 stimulated MΦ downstream of p38 MAPK critically contribute to neurotoxicity. SiRNA-mediated or pharmacological inhibition of p38 MAPK deprives MΦ of CysLT synthase (LTC4S) and, pharmacological inhibition of the cysteinyl-leukotriene receptor 1 (CYSLTR1) protects cerebrocortical neurons against toxicity of both gp120-stimulated and HIV-infected MΦ. Components of the CysLT pathway are differentially regulated in brains of HIV-infected individuals and a transgenic mouse model of NeuroHIV (HIVgp120tg). Moreover, genetic ablation of LTC4S or CysLTR1 prevents neuronal damage and impairment of spatial memory in HIVgp120tg mice. Altogether, our findings suggest a novel critical role for cysteinyl-leukotrienes in HIV-associated brain injury.

Drug resistance in HIV type 1 (HIV-1) is a pervasive problem that affects the lives of millions of people worldwide. Although records of drug-resistant mutations (DRMs) have been extensively tabulated within public repositories, our understanding of the evolutionary kinetics of DRMs and how they evolve together remains limited. Epistasis, the interaction between a DRM and other residues in HIV-1 protein sequences, is key to the temporal evolution of drug resistance. We use a Potts sequence-covariation statistical-energy model of HIV-1 protein fitness under drug selection pressure, which captures epistatic interactions between all positions, combined with kinetic Monte-Carlo simulations of sequence evolutionary trajectories, to explore the acquisition of DRMs as they arise in an ensemble of drug-naive patient protein sequences. We follow the time course of 52 DRMs in the enzymes protease, RT, and integrase, the primary targets of antiretroviral therapy. The rates at which DRMs emerge are highly correlated with their observed acquisition rates reported in the literature when drug pressure is applied. This result highlights the central role of epistasis in determining the kinetics governing DRM emergence. Whereas rapidly acquired DRMs begin to accumulate as soon as drug pressure is applied, slowly acquired DRMs are contingent on accessory mutations that appear only after prolonged drug pressure. We provide a foundation for using computational methods to determine the temporal evolution of drug resistance using Potts statistical potentials, which can be used to gain mechanistic insights into drug resistance pathways in HIV-1 and other infectious agents.

BACKGROUND: Neisseria gonorrheae and Chlamydia trachomatis are associated with mucosal inflammation and human immunodeficiency virus 1 (HIV-1) transmission. We assessed levels of inflammatory cytokines in men who have sex with men (MSM) with and without rectal gonorrhea and/or chlamydia in Lima, Peru. METHODS: We screened 605 MSM reporting condomless receptive anal intercourse for rectal N. gonorrheae/C. trachomatis using nucleic acid testing. We identified 101 cases of gonorrhea and/or chlamydia and randomly selected 50 N. gonorrheae/C. trachomatis positive cases and matched 52 negative controls. We measured levels of IL-1β, IL-6, IL-8, and TNF-α in rectal secretions. Tests for HIV-1, rectal N. gonorrheae/C. trachomatis, and mucosal cytokines were repeated after 3 and 6 months. Cytokine levels in cases and uninfected controls were compared using Wilcoxon rank-sum tests and linear regression. RESULTS: MSM with gonorrhea/chlamydia had elevated levels of all cytokines in rectal mucosa compared with matched controls (all P values .05). DISCUSSION: Rectal gonorrhea/chlamydia infection is associated with transient mucosal inflammation and cytokine recruitment. Our data provide proof of concept for rectal sexually transmitted infection screening as an HIV prevention strategy for MSM. Clinical Trials Registration. NCT03010020.

Interindividual variation of human immunodeficiency virus (HIV) RNA setpoint in cerebrospinal fluid (CSF) and its determinants are poorly understood, but relevant for HIV neuropathology, brain reservoirs, viral escape, and reseeding after antiretroviral interruptions. Longitudinal multicentric study on demographic, clinical, and laboratory correlates of CSF HIV RNA in 2000 follow-up visits from 597 people with HIV (PWH) off antiretroviral therapy (ART) and with plasma HIV RNA > the lower limit of quantification (LLQ). Factors associated with CSF control (CSFC; CSF HIV RNA  LLQ) and with CSF/plasma discordance (CSF > plasma HIV RNA > LLQ) were also assessed through mixed-effects models. Posthoc and sensitivity analyses were performed for persistent CSFC and ART-naïve participants, respectively. Over a median follow-up of 2.1 years, CSF HIV RNA was associated with CD4+ and CD8+ T cells, CSF leukocytes, blood-brain barrier (BBB) integrity, biomarkers of iron and lipid metabolism, serum globulins, past exposure to lamivudine, and plasma HIV RNA (model p

BackgroundThere is limited systematic information available about the perspectives of participants enrolled in intensive combination HIV cure-related trials inclusive of an extended analytical treatment interruption (ATI).ObjectiveTo assess and understand experiences of people with HIV involved in a combination HIV cure-related trial with an extended ATI.MethodsThe trial included five interventions and was followed by an ATI lasting up to 52 wk. From 2022 - 2023, we conducted in-depth interviews with study participants following their extended ATIs. Interviews were audio-recorded, transcribed, and analyzed via conventional thematic analysis.ResultsWe interviewed seven participants. The majority were male, White, and non-Hispanic, with a median age of 37 years. Trust in the research team, scientific altruism and hope of becoming a post-intervention controller were key motivators for joining the trial. Interviewees reported being satisfied with their decision to participate in the trial and the extended ATI. Most recounted feelings of worry related to viral rebound during the ATI. Participants reported both defeat and relief with ART restart. Four faced challenges with protecting partners from HIV during their ATI, such as trying to find out if their partner(s) were using pre-exposure prophylaxis.ConclusionsOur findings demonstrate potential improvements for future ATI trial participant experiences, such as more robust resources for psychosocial support and partner protections. Dedicating greater effort to understanding participant ATI experiences can inform the design of future participant-centered HIV cure trial protocols.

The high incidence of epithelial malignancies in HIV-1 infected individuals is associated with co-infection with oncogenic viruses, such as high-risk human papillomaviruses (HR HPVs), mostly HPV16. The molecular mechanisms underlying the HIV-1-associated increase in epithelial malignancies are not fully understood. A collaboration between HIV-1 and HR HPVs in the malignant transformation of epithelial cells has long been anticipated. Here, we delineated the effects of HIV-1 reverse transcriptase on the in vitro and in vivo properties of HPV16-infected cervical cancer cells. A human cervical carcinoma cell line infected with HPV16 (Ca Ski) was made to express HIV-1 reverse transcriptase (RT) by lentiviral transduction. The levels of the mRNA of the E6 isoforms and of the factors characteristic to the epithelial/mesenchymal transition were assessed by real-time RT-PCR. The parameters of glycolysis and mitochondrial respiration were determined using Seahorse technology. RT expressing Ca Ski subclones were assessed for the capacity to form tumors in nude mice. RT expression increased the expression of the E6*I isoform, modulated the expression of E-CADHERIN and VIMENTIN, indicating the presence of a hybrid epithelial/mesenchymal phenotype, enhanced glycolysis, and inhibited mitochondrial respiration. In addition, the expression of RT induced phenotypic alterations impacting cell motility, clonogenic activity, and the capacity of Ca Ski cells to form tumors in nude mice. These findings suggest that HIV-RT, a multifunctional protein, affects HPV16-induced oncogenesis, which is achieved through modulation of the expression of the E6 oncoprotein. These results highlight a complex interplay between HIV antigens and HPV oncoproteins potentiating the malignant transformation of epithelial cells.

BACKGROUND: There is no systematic review on the prevalence of HIV drug resistance (HIVDR) in Iran. We aimed to estimate the prevalence of HIVDR among people living with HIV (PLHIV) in Iran. We assessed HIVDR prevalence in antiretroviral therapy (ART) naïve PLHIV (i.e., those without a history of ART) and PLHIV receiving ART. METHOD: We systematically searched Scopus, PubMed, Web of Science, Embase, Iranian databases (Iranian Medical Research Information System, Magiran, and Scientific Information Database), the references of studies, and Google Scholar until March 2023. A random-effects model was used to calculate a point estimate and 95% confidence interval (95% CI) for the prevalence of HIVDR in PLHIV. RESULTS: Among 461 potential publications, 22 studies were included in the meta-analysis. The pooled prevalence of acquired HIVDR in PLHIV receiving ART was 34% (95% CI: 19, 50) for nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), 27% (95% CI: 15, 41) for non-nucleoside reverse transcriptase inhibitors (NNRTIs), and 9% (95% CI: 3, 18) for protease inhibitors (PIs). The pooled prevalence of acquired HIVDR in treatment failure PLHIV was 50% (95% CI: 31, 69) for NRTIs, 49% (95% CI: 29, 69) for NNRTIs, 11% (95% CI: 2, 24) for PIs, and 1% (95% CI: 0, 4) for integrase inhibitors (INIs). The pooled prevalence of transmitted HIVDR in ART-naïve people was 3% (95% CI; 1, 6) for NRTIs, 5% (95% CI: 2, 9) for NNRTIs, and 0 for PIs and INIs. CONCLUSION: The prevalence of HIVDR was relatively high in both ART-naïve PLHIV and those receiving ART. Without universal pretreatment HIVDR testing and more frequent routine HIV viral load testing among PLHIV who are on ART, the HIVDR prevalence might increase in PLHIV in Iran.

BackgroundLatency reversing agents (LRAs) such as protein kinase C (PKC) modulators can reduce rebound-competent HIV reservoirs in small animal models. Furthermore, administration of natural killer (NK) cells following LRA treatment improves this reservoir reduction. It is currently unknown why the combination of a PKC modulator and NK cells is so potent and whether exposure to PKC modulators may augment NK cell function in some way.MethodsPrimary human NK cells were treated with PKC modulators (bryostatin-1, prostratin, or the designed, synthetic bryostatin-1 analog SUW133), and evaluated by examining expression of activation markers by flow cytometry, analyzing transcriptomic profiles by RNA sequencing, measuring cytotoxicity by co-culturing with K562 cells, assessing cytokine production by Luminex assay, and examining the ability of cytokines and secreted factors to independently reverse HIV latency by co-culturing with Jurkat-Latency (J-Lat) cells.ResultsPKC modulators increased expression of proteins involved in NK cell activation. Transcriptomic profiles from PKC-treated NK cells displayed signatures of cellular activation and enrichment of genes associated with the NFκB pathway. NK cell cytotoxicity was unaffected by prostratin but significantly decreased by bryostatin-1 and SUW133. Cytokines from PKC-stimulated NK cells did not induce latency reversal in J-Lat cell lines.ConclusionsAlthough PKC modulators have some significant effects on NK cells, their contribution in "kick and kill" strategies is likely due to upregulating HIV expression in CD4+ T cells, not directly enhancing the effector functions of NK cells. This suggests that PKC modulators are primarily augmenting the "kick" rather than the "kill" arm of this HIV cure approach.

Chronic Human Immunodeficiency Virus (HIV) infection remains a significant challenge to global public health. Despite advances in antiretroviral therapy (ART), which has transformed HIV infection from a fatal disease into a manageable chronic condition, a definitive cure remains elusive. One of the key features of HIV infection is chronic immune activation and inflammation, which are strongly associated with, and predictive of, HIV disease progression, even in patients successfully treated with suppressive ART. Chronic inflammation is characterized by persistent inflammation, immune cell metabolic dysregulation, and cellular exhaustion and dysfunction. This review aims to summarize current knowledge of the interplay between chronic inflammation, immune metabolism, and T cell dysfunction in HIV infection, and also discusses the use of humanized mice models to study HIV immune pathogenesis and develop novel therapeutic strategies.

CD4 T follicular helper cells (Tfh) are essential for establishing serological memory and have distinct helper attributes that impact both the quantity and quality of the antibody response. Insights into Tfh subsets that promote antibody persistence and functional capacity can critically inform vaccine design. Based on the Tfh profiles evoked by the live attenuated measles virus vaccine, renowned for its ability to establish durable humoral immunity, we investigated the potential of a Tfh1/17 recall response during the boost phase to enhance persistence of HIV-1 Envelope (Env) antibodies in rhesus macaques. Using a DNA-prime encoding gp160 antigen and Tfh polarizing cytokines (interferon protein-10 (IP-10) and interleukin-6 (IL-6)), followed by a gp140 protein boost formulated in a cationic liposome-based adjuvant (CAF01), we successfully generated germinal center (GC) Tfh1/17 cells. In contrast, a similar DNA-prime (including IP-10) followed by gp140 formulated with monophosphoryl lipid A (MPLA) +QS-21 adjuvant predominantly induced GC Tfh1 cells. While the generation of GC Tfh1/17 cells with CAF01 and GC Tfh1 cells with MPLA +QS-21 induced comparable peak Env antibodies, the latter group demonstrated significantly greater antibody concentrations at week 8 after final immunization which persisted up to 30 weeks (gp140 IgG ng/ml- MPLA; 5500; CAF01, 2155; p

The HIV-1 accessory protein Nef hijacks clathrin adaptors to degrade or mislocalize host proteins involved in antiviral defenses. Here, using quantitative live-cell microscopy in genome-edited Jurkat cells, we investigate the impact of Nef on clathrin-mediated endocytosis (CME), a major pathway for membrane protein internalization in mammalian cells. Nef is recruited to CME sites on the plasma membrane, and this recruitment is associated with an increase in the recruitment and lifetime of the CME coat protein AP-2 and the late-arriving CME protein dynamin2. Furthermore, we find that CME sites that recruit Nef are more likely to recruit dynamin2 and transferrin, suggesting that Nef recruitment to CME sites promotes site maturation to ensure high efficiency in host protein downregulation. Implications of these observations for HIV-1 infection are discussed.

Introduction: For many therapeutic drugs, including antiretroviral drugs used to treat people living with HIV-1 (PLWH), we have little data on the potential effects on the developing human brain due to limited access to tissue and historical constraints on the inclusion of pregnant populations in clinical trials. Human induced pluripotent stem cells (iPSCs) offer a new avenue to gain insight on how drugs may impact human cell types representative of the developing central nervous system. To prevent vertical transmission of HIV and promote the health of pregnant PLWH, antiretroviral therapy must be initiated and/or maintained throughout pregnancy. However, many antiretroviral drugs are approved for widespread use following clinical testing only in non-pregnant populations and there may be limited information on potential teratogenicity until pregnancy outcomes are evaluated. The integrase strand transfer inhibitor dolutegravir (DTG) is a frontline antiretroviral drug that is effective in viral suppression of HIV but was previously reported to be associated with a slight increase in the risk for neural tube defects in one study, although this has not been replicated in other cohorts. Methods: To directly investigate the potential impact of DTG on human cortical neurogenesis, we measured the effects of daily drug exposure on the early stages of corticogenesis in a human iPSC-based forebrain organoid model. We quantified organoid size and structure and analyzed gene and protein expression to evaluate the impact of several doses of DTG on organoid development. Results: We observed deficits in organoid structure and impaired neurogenesis in DTG-treated organoids compared to vehicle-treated control organoids after 20 or 40 days in culture. Our highest dose of DTG (10 μM) resulted in significantly smaller organoids with a reduced density of neural rosette structures compared to vehicle-treated controls. Mechanistically, RNA-sequencing and immunohistological analysis suggests dysregulated amino acid transport and activation of the integrated stress response in the DTG-treated organoids, and functionally, a small molecule integrated stress response inhibitor (ISRIB) could partially rescue increased expression of proteins related to cell cycle regulation. Discussion: Together, these results illustrate the potential for human iPSC-based strategies to reveal biological processes during neurogenesis that may be affected by therapeutic drugs and provide complementary data in relevant human cell types to augment preclinical investigations of drug safety during pregnancy. [ABSTRACT FROM AUTHOR]

Human leukocyte antigen (HLA) class I/killer cell immunoglobulin-like receptor (KIR) genotypes influence human immunodeficiency virus type 1 (HIV-1) disease progression and viral load, but their role in primary infection is uncertain. Inconsistent results from previous studies suggest that the inoculum size and transmission route—parenteral versus sexual—may influence this association. We conducted a genome-wide association study in a population of people with HIV-1 and HIV-1–exposed seronegative individuals exposed to the virus through the sexual route. Our data do not support any role of the HLA/KIR system in susceptibility to sexually transmitted HIV-1 infection. The genetics basis of HIV-1 viral load and disease progression are distinct from the genetics of HIV resistance, a paradox worth exploring. [ABSTRACT FROM AUTHOR]

The prevalence of AIDS and mortality rates among HIV-infected individuals in Guangxi remain relatively high, potentially due to impaired CD4 + cell recovery. This study aims to identify factors hindering CD4 + cell recovery in people living with HIV. We conducted a retrospective study on people living with HIV in Guangxi, China, with data collection extending to the end of 2023. CD4 + T cells were categorized into "immunological responders" and "non-responders" based on CD4 + cell recovery after treatment. Multivariate logistic regression was used to analyze factors associated with the development of immunological non-responders. Recovery of CD4 + T lymphocytes was assessed using the Generalized Additive Mixed Model (GAMM) and Generalized Estimating Equations (GEE). Additionally, multivariate Cox regression identified factors influencing survival rates. Our findings indicated a 52.44% incidence of immunological non-responders after two years of treatment. Factors such as age, sex, education, occupation, infection route, pre-treatment CD4 + T cell count, HIV subtype, and treatment regimen were linked to immunological non-response. Specifically, male gender, education up to high school, farming occupation, heterosexual transmission, CRF01_AE subtype, pre-treatment CD4 + T cell count < 200/µL, and the 3TC + EFV + TDF regimen were identified as significant risk factors. Statistically significant differences in CD4 + T lymphocyte recovery rates were observed among different HIV subtypes (P < 0.05). Beyond age, sex, ethnicity, occupation, subtype, and treatment regimen, being an immunological non-responder was found to be a risk factor for both mortality and accelerated disease progression. The study highlights the complexity of factors affecting CD4 + cell recovery post-HIV treatment in Guangxi and underscores the need for vigilant clinical monitoring of people living with HIV, particularly those with low pre-treatment CD4 + T cell levels. [ABSTRACT FROM AUTHOR]

The sulfane sulfur pool, comprised of persulfide (RS‐SH) and polysulfide (RS‐SnH) derived from hydrogen sulfide (H2S), has emerged as a major player in redox biochemistry. Mitochondria, besides energy generation, serve as significant cellular redox hubs, mediate stress response and cellular health. However, the effects of endogenous mitochondrial sulfane sulfur (MSS) remain largely uncharacterized as compared with their cytosolic counterparts, cytosolic sulfane sulfur (CSS). To investigate this, we designed a novel artificial substrate for mitochondrial 3‐mercaptopyruvate sulfurtransferase (3‐MST), a key enzyme involved in MSS biosynthesis. Using cells expressing a mitochondrion‐localized persulfide biosensor, we demonstrate this tool's ability to selectively enhance MSS. While H2S was previously known to suppress human immunodeficiency virus (HIV‐1), we found that MSS profoundly affected the HIV‐1 life cycle, mediating viral reactivation from latency. Additionally, we provide evidence for the role of the host's mitochondrial redox state, membrane potential, apoptosis, and respiration rates in managing HIV‐1 latency and reactivation. Together, dynamic fluctuations in the MSS pool have a significant and possibly conflicting effect on HIV‐1 viral latency. The precision tools developed herein allow for orthogonal generation of persulfide within both mitochondria and the cytosol and will be useful in interrogating disease biology. [ABSTRACT FROM AUTHOR]

HIV-1 capsids cross nuclear pore complexes (NPCs) by engaging with the nuclear import machinery. To identify compounds that inhibit HIV-1 nuclear import, we screened drugs in silico on a three-dimensional model of a CA hexamer bound by Transportin-1 (TRN-1). Among hits, compound H27 inhibited HIV-1 with a low micromolar IC50. Unlike other CA-targeting compounds, H27 did not alter CA assembly or disassembly, inhibited nuclear import specifically, and retained antiviral activity against PF74- and Lenacapavir-resistant mutants. The differential sensitivity of divergent primate lentiviral capsids, capsid stability and H27 escape mutants, together with structural analyses, suggest that H27 makes multiple low affinity contacts with assembled capsid. Interaction experiments indicate that H27 may act by preventing CA from engaging with components of the NPC machinery such as TRN-1. H27 exhibited good metabolic stability in vivo and was efficient against different subtypes and circulating recombinant forms from treatment-naïve patients as well as strains resistant to the four main classes of antiretroviral drugs. This work identifies compounds that demonstrate a novel mechanism of action by specifically blocking HIV-1 nuclear import. Synopsis: A major unresolved challenge to curing HIV-1 is its presence in the nucleus of infected cells. This study reports on new compounds that specifically block HIV-1 nuclear import by targeting the viral capsid. Graphical abstract by Sophie Desgraupes. The virtual screening of the HIV-1 CA hexamer - Transportin-1/TNPO1/TRN-1 interface identified a single antiviral hit, H27. H27 makes multiple low affinity contacts with assembled capsid. H27 inhibits HIV-1 nuclear import without disrupting reverse transcription, CA assembly or disassembly and has negligible toxicity in vivo. Divergent primate lentiviruses are differentially sensitive to H27. Structural analogues of H27 improved the IC50 to ~0.5 µM. A major unresolved challenge to curing HIV-1 is its presence in the nucleus of infected cells. This study reports on new compounds that specifically block HIV-1 nuclear import by targeting the viral capsid. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus (HIV-1) remains a persistent global health crisis. Even while successfully virologically suppressed, people with HIV (PWH) experience a higher risk for inflammatory disorders such as HIV-associated neurocognitive disorder (HAND). Tobacco use puts PWH at higher risk for neurocognitive symptoms resulting from HIV-associated neuroinflammation. The NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome has been implicated as a driver of HIV-associated inflammation, including HAND. Nicotine, the psychoactive component of tobacco smoke, has also been shown to signal through the NLRP3 inflammasome and modulate inflammatory signaling in the CNS. Here, we explore the impacts of nicotine and tobacco on the complex neurobiology of HAND, including effects on cognition, inflammation, viral latency, and blood-brain barrier integrity. We outline nicotine's role in the establishment of active and latent infection in the brain and posit the NLRP3 inflammasome as a common pathway by which HIV-1 and nicotine promote neuroinflammation in PWH. [ABSTRACT FROM AUTHOR]

HIV-1 infection cannot be cured due to long-lived viral reservoirs formed by latently infected CD4+ T cells. "Shock and Kill" strategy has been considered to eliminate the viral reservoir and achieve a functional cure but the stimulation of cytotoxic immunity is necessary. Ponatinib is a tyrosine kinase inhibitor (TKI) clinically used against chronic myeloid leukemia (CML) that has demonstrated to be effective against HIV-1 infection in vitro. Several TKIs may induce a potent cytotoxic response against cancer cells that makes possible to discontinue treatment in people with CML who present long-term deep molecular response. In this longitudinal study, we analyzed the capacity of ponatinib to induce an antiviral response against HIV-1 infection in peripheral blood mononuclear cells (PBMCs) obtained from people with CML previously treated with imatinib for a median of 10 years who changed to ponatinib for 12 months to boost the anticancer response before discontinuing any TKI as part of the clinical trial NCT04043676. Participants were followed-up for an additional 12 months in the absence of treatment. PBMCs were obtained at different time points and then infected in vitro with HIV-1. The rate of infection was determined by quantifying the intracellular levels of p24-gag in CD4+ T cells. The levels of p24-gag+ CD4+ T−cells were lower when these cells were obtained during and after treatment with ponatinib in comparison with those obtained during treatment with imatinib. Cytotoxicity of PBMCs against HIV-infected target cells was significantly higher during treatment with ponatinib than during treatment with imatinib, and it was maintained at least 12 months after discontinuation. There was a significant negative correlation between the lower levels of p24-gag+ CD4+ T−cells and the higher cytotoxicity induced by PBMCs when cells were obtained during and after treatment with ponatinib. This cytotoxic immunity was mostly based on higher levels of Natural Killer and Tγδ cells seemingly boosted by ponatinib. In conclusion, transient treatment with immunomodulators like ponatinib along with ART could be explored to boost the antiviral activity of cytotoxic cells and contribute to the elimination of HIV-1 reservoir. [ABSTRACT FROM AUTHOR]

Asparagus racemosus (AR), an Ayurvedic botanical, possesses various biological characteristics, yet its impact on HIV-1 replication remains to be elucidated. This study aimed to investigate the inhibitory effects of AR root extracts and its principal bioactive molecule, Shatavarin IV (Shatavarin), on HIV-1 replication and their role in mitigating mitochondrial dysfunction during HIV-1 infection, utilizing both in vitro and in silico methodologies. The cytotoxicity of the extracts was evaluated using MTT and ATPlite assays. In vitro anti-HIV-1 activity was assessed in TZM-bl cells against X4 and R5 subtypes, and confirmed in peripheral blood mononuclear cells using HIV-1 p24 antigen capture ELISA and viral copy number assessment. Mechanistic insights were obtained through enzymatic assays targeting HIV-1 Integrase, Protease and Reverse Transcriptase. Shatavarin's activity was also validated via viral copy number and p24 antigen capture assays, along with molecular interaction studies against key HIV-1 replication enzymes. HIV-1 induced mitochondrial dysfunction was evaluated by detecting mitochondrial reactive oxygen species (ROS), calcium accumulation, mitochondrial potential, and caspase activity within the infected cells. Non-cytotoxic concentrations of both aqueous and hydroalcoholic extracts derived from Asparagus racemosus roots displayed dose-dependent inhibition of HIV-1 replication. Notably, the hydroalcoholic extract exhibited superior Reverse Transcriptase activity, complemented by moderate activity observed in the Protease assay. Molecular interaction studies revealed that Shatavarin IV, the key bioactive constituent of AR, formed hydrogen bonds within the active binding pocket site residues crucial for HIV replication enzyme catalysis, suggesting its potential in attenuating HIV-1 infection. Mitochondrial dysfunction induced by HIV-1 infection, marked by increased oxidative stress, mitochondrial calcium overload, loss of mitochondrial membrane potential, and elevated caspase activity, was effectively mitigated by treatment with AR extracts and Shatavarin IV. These findings underscore the potential of AR extracts and Shatavarin IV as antiviral agents, while enhancing mitochondrial function during HIV-1 infection. In conclusion, Asparagus racemosus extracts, particularly Shatavarin IV, demonstrate promising inhibitory effects against HIV-1 replication while concurrently ameliorating mitochondrial dysfunction induced by the virus. These findings suggest the therapeutic potential of AR extracts and Shatavarin in combating HIV-1 infection and improving mitochondrial health. [ABSTRACT FROM AUTHOR]

The unintegrated HIV-1 DNAs formed by reverse transcription in the early hours after infection are subject to profound transcriptional silencing. The repression of expression of foreign DNA, as an aspect of the innate immune system, serves to restrict the activity of many invading pathogens. Newly formed retroviral DNAs are rapidly loaded with histones upon entry into the nucleus, and the repression of their expression is mediated by an array of host proteins that introduce histone modifications characteristic of heterochromatin, including histone methylation and histone deacetylation. Knockout or knockdown of expression or inhibition of these host factors can relieve the silencing, allowing for viral gene expression even in settings where HIV-1 DNA integration is blocked. When viral DNA integration is allowed, forming the integrated provirus, the silencing in most cases is dramatically relieved, leading to high levels of expression and formation of progeny virus. In some settings and cell types, silencing of the integrated DNA is maintained, or re-established, such that the infected cells retain a silent copy of the viral DNA without production of progeny virus. The basis for the typical switch from silent DNA to actively expressed DNA upon integration is not yet fully clear. This review will summarize the current understanding of the regulation of expression of unintegrated HIV-1 DNAs and the nature of the chromatin that is formed on the viral DNA, and will especially focus on the host machinery that establishes repressive heterochromatin-like structures on the unintegrated DNA. The activation of expression that normally occurs upon integration, and the special circumstances when viral DNA expression is not activated, will also be discussed. These cases can result in the formation of populations of infected cells carrying silent proviruses, which persist for decades in infected individuals in spite of antiviral therapy. This pool of latently infected cells can be stochastically reactivated to give rise to spreading virus whenever antiviral drugs are withdrawn, and constitute the barrier to a true "cure" of AIDS. The hope is that a deeper understanding of the regulation of expression of viral DNAs will lead to new means to prevent or control viremia and disease. [ABSTRACT FROM AUTHOR]

In clinical trials, once-daily oral tenofovir-based pre-exposure prophylaxis (PrEP) significantly reduced HIV-1 acquisition risk; however, this was highly dependent on medication adherence and persistence. We report clinical characteristics, PrEP usage patterns, first evidence of HIV-1, and associated risk factors among adults with commercial insurance using oral PrEP in the United States using health plan claims from the IQVIA PharMetrics® Plus database between January 1, 2015, and March 31, 2020, from individuals who newly initiated emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) or FTC/tenofovir alafenamide (TAF) for daily PrEP. Overall, 25,419 individuals were included (FTC/TDF, n = 24,232; FTC/TAF, n = 1187), with generally similar characteristics reported during the 6-month baseline period across cohorts. Mean follow-up length was 504 and 77 days for FTC/TDF and FTC/TAF, respectively, corresponding with the 2019 approval of FTC/TAF for PrEP. Similarly, mean PrEP use duration was 354 and 68 days for FTC/TDF and FTC/TAF, respectively. PrEP breaks (>90-day gap) were observed in 11.1% of individuals using FTC/TDF, with a mean break duration of 249 days; 20.0% of individuals using FTC/TDF and 7.3% using FTC/TAF had ≥1 sexually transmitted infection diagnosis during follow-up. From 6 to 12 months of follow-up, mean FTC/TDF proportion of days covered (PDC; 0.74 vs. 0.67) and persistence (70.2% vs. 57.4%) decreased; real-world PDC and persistence were lower than reported in globally conducted clinical trials. First evidence of HIV-1 was infrequent among individuals using FTC/TDF (0.6%), though 60.3% had PrEP on hand when HIV-1 definition was met; high-risk sexual behavior, syphilis, and gonorrhea were the most important risk factors. [ABSTRACT FROM AUTHOR]

BackgroundMethodsResultsConclusionMost of the investigations related to inflammasome activation during HIV infection have focused on the receptor NLRP3 and innate immune cells such as monocytes/macrophages. However, during the past years, inflammasome activation has also been explored in lymphocytes, and novel sensors, other than the NLRP3, have been shown to play a role in the biology of these cells. Here, we hypothesized that NLRP1 may be involved in CD4+ T cell dysregulation in people living with HIV (PLWH), therefore contributing to chronic inflammation and to the pathogenesis of non-HIV-associated diseases.The activation of NLRP1 in CD4+ T cells was assessed ex-vivo and in-vitro by the meaning of anti-CD3/anti-CD28 and Talabostat/Val-boroPro (VbP) response.Our results showed that the NLRP1 inflammasome was activated in PLWH CD4+ T cells, and that the stimulation of CD4+ T cells resulted in increased response to anti-CD3/anti-CD28 and VbP. Functional variants in NLRP1 significantly affected the level of inflammatory dysregulation of CD4+ T cells, therefore explaining at least in part the association with CD4+ T-mediated diseases.PLWH CD4+ T cells are more prone to IL-1β release and pyroptosis, therefore contributing to chronic inflammation. [ABSTRACT FROM AUTHOR]

Current medical research suggests that latently infected cells are the primary source of the virus's resistance to elimination. Moreover, these cells can participate in cell–cell transmission. Human immunodeficiency virus type 1 (HIV-1) can transmit to CD4 + T cells by three transmission modes, cell-free, latent cell–cell and active cell–cell. Incorporating the effect of latent infection, weakened humoral and CTL responses as well as three transmission modes, we investigate two generalized HIV-1 dynamics models. Three general incidence functions are used to represent the three viral transmission modes. Our proposed models extend and generalize many viral infection models presented in the virology literature. We begin by demonstrating the solutions' boundedness and nonnegativity which guarantee the model's wellposedness. We calculate the model's basic reproduction ratio (ℜ 0). We establish that the model admits two steady-states, namely, virus-free steady-state and virus-persistence steady-state. Through application of Lyapunov's approach and LaSalle's invariance principle, we demonstrate the global stability of each state-state. For two special forms of the general incidence functions, Holling type-II incidence and Crowley–Martin incidence, we provide numerical simulations to validate our theoretical findings. We illustrate how time delay and weakened adaptive immunity affect HIV-1 dynamics. More specifically, numerical data support our theoretical conclusions on the stability of steady-states. To demonstrate the impact of the parameter values on ℜ 0 , we examine the sensitivity analysis. We have demonstrated that each of the three viral transmission modes adds to ℜ 0 , and that ℜ 0 would be underestimated if any one of them were ignored. This might lead to inadequate medication effectiveness that aims to remove the viruses from the body. The effects of weakened adaptive immunity and time delay on HIV-1 progression are examined. As per our findings, reduced adaptive immunity plays a crucial role in the proliferation of the infection. Weaken adaptive immunity can lead to the acquired immune deficiency syndrome (AIDS) and give a chance for opportunistic infections. We showed that ℜ 0 fall as a function of both medication efficacy and delay parameter. If a model with time delays is used, fewer treatment efficacies will be required to maintain the system at the virus-free steady-state and eradicate HIV-1 from the body. Our study's findings can help us better understand HIV-1 dynamics in the host and can also guide the development of new pharmacological therapies. [ABSTRACT FROM AUTHOR]

Background: Transmitted drug resistance (TDR) increases the risk of antiretroviral therapy (ART) failure in HIV-1 patients. This study investigated the molecular epidemiology of TDR and its transmission networks among newly diagnosed HIV-1 patients in Wenzhou, China. Methods: We enrolled 1878 ART-naive HIV-1 patients from January 2020 to October 2023. TDR was evaluated using the Stanford University HIV Drug Resistance Database. We performed phylogenetic analysis, genotyping, transmission clustering, and population-based TDR-related factor analysis. Results: Among 1782 patients with successful genotyping, TDR prevalence was 5.7%. Multivariable analysis identified CRF08_BC subtype (adjusted odds ratio [aOR] 18.59, 95% CI 3.79-336.18, p = 0.004), CD4 > 500 cells/mm³ (aOR 2.19, 95% CI 1.16–4.03, p = 0.013), and year 2023 (aOR 1.83, 95% CI 1.11–4.89, p = 0.039) as factors associated with higher TDR risk. The most prevalent NNRTI mutations were K103N, E138A, and V179E. Seven TDR transmission clusters were identified, notably one with V179D that expanded during 2020–2023. Conclusions: While TDR prevalence in Wenzhou remained lower than in other Chinese regions, an upward trend was observed. Most resistant individuals were in transmission clusters, predominantly middle-aged and elderly. NNRTI resistance was severe and concentrated in efavirenz, nevirapine, and rilpivirine. Enhanced HIV surveillance and wider free antiretroviral options are crucial to control drug-resistant HIV spread in Wenzhou. [ABSTRACT FROM AUTHOR]

Human myxovirus resistance 2 (MX2) can restrict HIV-1 and herpesviruses at a post-entry step through a process requiring an interaction between MX2 and the viral capsids. The involvement of other host cell factors, however, remains poorly understood. Here, we mapped the proximity interactome of MX2, revealing strong enrichment of phenylalanine-glycine (FG)-rich proteins related to the nuclear pore complex as well as proteins that are part of cytoplasmic ribonucleoprotein granules. MX2 interacted with these proteins to form multiprotein cytoplasmic biomolecular condensates that were essential for its anti-HIV-1 and anti-herpes simplex virus 1 (HSV-1) activity. MX2 condensate formation required the disordered N-terminal region and MX2 dimerization. Incoming HIV-1 and HSV-1 capsids associated with MX2 at these dynamic cytoplasmic biomolecular condensates, preventing nuclear entry of their viral genomes. Thus, MX2 forms cytoplasmic condensates that likely act as nuclear pore decoys, trapping capsids and inducing premature viral genome release to interfere with nuclear targeting of HIV-1 and HSV-1. [Display omitted] • Interferon-induced antiviral protein MX2 forms cytoplasmic condensates with FG Nups • MX2's N-terminal domain and dimerization are required for condensate formation • Restriction of HIV-1 and HSV-1 by MX2 requires condensate formation • MX2 condensates trap HIV-1 capsids and cause premature release of HSV-1 genomes MX2 restricts HIV-1 and herpes simplex virus 1 (HSV-1) through a poorly understood mechanism. Moschonas et al. reveal that MX2 assembles FG nucleoporins into cytoplasmic biomolecular condensates that interact with incoming capsids to trap them or induce premature viral genome release. MX2's N-terminal domain controls condensate formation, which is essential for HIV-1 and HSV-1 restriction. [ABSTRACT FROM AUTHOR]

Despite the efficacy of highly active antiretroviral therapy in controlling the incidence and mortality of AIDS, effective interventions for HIV-1-induced neurological damage and cognitive impairment remain elusive. In this study, we found that HIV-1 infection can induce proteolytic cleavage and aberrant aggregation of TAR DNA-binding protein 43 (TDP-43), a pathological protein associated with various severe neurological disorders. The HIV-1 accessory protein Vpu was found to be responsible for the cleavage of TDP-43, as ectopic expression of Vpu alone was sufficient to induce TDP-43 cleavage, whereas HIV-1 lacking Vpu failed to cleave TDP-43. Mechanistically, the cleavage of TDP-43 at Asp89 by HIV-1 relies on Vpu-mediated activation of Caspase 3, and pharmacological inhibition of Caspase 3 activity effectively suppressed the HIV-1-induced aggregation and neurotoxicity of TDP-43. Overall, these results suggest that TDP-43 is a conserved host target of HIV-1 Vpu and provide evidence for the involvement of TDP-43 dysregulation in the neural pathogenesis of HIV-1. Synopsis: HIV-1 Vpu triggers the cleavage of TDP-43 by stimulating Caspase 3 activation. The cleavage products generated can induce the cytoplasmic aggregation and inactivation of TDP-43, thereby exerting neurotoxic effects. HIV-1 infection promotes the cleavage and cytoplasmic aggregation of TDP-43 proteins. Vpu contributes to HIV-1-mediated cleavage of TDP-43 by enhancing Caspase 3 activity. TDP-43 fragments function as dominant-negative mutants and promote the aggregation of full-length TDP-43. Vpu serves as a neurotoxic factor during HIV-1 infection by inactivating TDP-43. HIV-1 Vpu triggers the cleavage of TDP-43 by stimulating Caspase 3 activation. The cleavage products generated can induce the cytoplasmic aggregation and inactivation of TDP-43, thereby exerting neurotoxic effects. [ABSTRACT FROM AUTHOR]

Introduction Methods Results Conclusion Treatment for people with HIV‐1 and end‐stage kidney disease (ESKD) on haemodialysis (HD) has previously required complex dose‐adjusted regimens, with limited data on the use of a single‐tablet regimen in this population. Our aim was to assess the efficacy and safety of once‐daily bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) and to evaluate the pharmacokinetics of bictegravir (BIC) in adults with HIV‐1 and ESKD on HD.We performed an open‐label extension (OLE) of an open‐label, multicentre, single‐group phase 3b study (NCT02600819) of adults with ESKD on HD and HIV‐1 with virological suppression. Participants switched to elvitegravir/cobicistat/F/TAF (E/C/F/TAF) 150/150/200/10 mg for 96 weeks, following which a subgroup of US participants entered an OLE phase in which they switched to B/F/TAF 50/200/25 mg for 48 weeks, returning for study visits at weeks 4 and 12, and every 12 weeks thereafter. Study assessments included virological response, safety and pharmacokinetic analysis of BIC.Ten participants entered the OLE (median age, 55 years). Virological suppression (HIV‐1 RNA <50 copies/mL) was maintained in all participants over 48 weeks of B/F/TAF treatment. B/F/TAF was well tolerated, with no treatment discontinuations. Mean BIC trough concentrations were lower than those previously reported for people with HIV‐1 with normal kidney function, but remained four‐ to seven‐fold higher than the established protein‐adjusted 95% effective concentration against wild‐type HIV‐1.These findings support the use of the once‐daily B/F/TAF single‐tablet regimen for people with HIV‐1 and ESKD on HD. This regimen offers a convenient treatment option for this population as it reduces the need for dose adjustment, eases pill burden and avoids potential drug–drug interactions associated with alternatives that may impact individuals on multiple medications or awaiting transplantation. [ABSTRACT FROM AUTHOR]

HIV-1 drug resistance (HIVDR) impedes treatment and control of HIV-1, especially in high-prevalence settings such as KwaZulu-Natal (KZN) province, South Africa. This study merged routine HIV-1 genotypic resistance test (GRT) data with Geographic Information Systems coordinates to assess patterns and geographic distribution of HIVDR in KZN, among ART-experienced adults with virological failure. We curated 3133 GRT records generated between 1 January 2018 and 30 June 2022, which includes the early phase of dolutegravir (DTG) rollout, of which 2735 (87.30%) had HIVDR. Of the 2735, major protease, nucleoside, and non-nucleoside reverse transcriptase inhibitor mutations were detected in 41.24%, 84.97% and 88.08% of GRTs, respectively. Additional genotyping of HIV-1 integrase for 41/3133 (1.31%) GRTs showed that 17/41 (41.46%) had integrase strand transfer inhibitor resistance. Notably, of 26 patients on DTG with integrase genotyping, 9 (34.62%) had DTG-associated resistance mutations. Dual- or triple-class resistance was observed in four of every five GRTs. The odds of HIVDR increased significantly with age, with ≥60 years having 5 times higher odds of HIVDR compared to 18–29 years (p = 0.001). We identified geospatial differences in the burden of HIVDR, providing proof of concept that this could be used for data-driven public health decision making. Ongoing real-time HIVDR surveillance is essential for evaluating the outcomes of the updated South African HIV treatment programme. [ABSTRACT FROM AUTHOR]

Expansion microscopy has recently emerged as an alternative technique for achieving high-resolution imaging of biological structures. Improvements in resolution are achieved by physically expanding samples through embedding in a swellable hydrogel before microscopy. However, expansion microscopy has been rarely used in the field of virology. Here, we evaluate and characterize the ultrastructure expansion microscopy (U-ExM) protocol, which facilitates approximately four-fold sample expansion, enabling the visualization of different post-entry stages of the HIV-1 life cycle, focusing on nuclear events. Our findings demonstrate that U-ExM provides robust sample expansion and preservation across different cell types, including cell-culture-adapted and primary CD4+ T-cells as well as monocyte-derived macrophages, which are known HIV-1 reservoirs. Notably, cellular targets such as nuclear bodies and the chromatin landscape remain well preserved after expansion, allowing for detailed investigation of HIV-1–cell interactions at high resolution. Our data indicate that morphologically distinct HIV-1 capsid assemblies can be differentiated within the nuclei of infected cells and that U-ExM enables detection of targets that are masked in commonly used immunofluorescence protocols. In conclusion, we advocate for U-ExM as a valuable new tool for studying virus–host interactions with enhanced spatial resolution. [ABSTRACT FROM AUTHOR]

Nonhuman primate (NHP) studies that utilize simian immunodeficiency virus (SIV) to model human immunodeficiency virus (HIV-1) infection have proven to be powerful, highly informative research tools. However, there are substantial differences between SIV and HIV-1. Accordingly, there are numerous research questions for which SIV-based models are not well suited, including studies of certain aspects of basic HIV-1 biology, and pre-clinical evaluations of many proposed HIV-1 treatment, prevention, and vaccination strategies. To overcome these limitations of NHP models of HIV-1 infection, several groups have pursued the derivation of a minimally modified HIV-1 (mmHIV-1) capable of establishing pathogenic infection in macaques that authentically recapitulates key features of HIV-1 in humans. These efforts have focused on three complementary objectives: (1) engineering HIV-1 to circumvent species-specific cellular restriction factors that otherwise potently inhibit HIV-1 in macaques, (2) introduction of a C chemokine receptor type 5 (CCR5)-tropic envelope, ideally that can efficiently engage macaque CD4, and (3) correction of gene expression defects inadvertently introduced during viral genome manipulations. While some progress has been made toward development of mmHIV-1 variants for use in each of the three macaque species (pigtail, cynomolgus, and rhesus), model development progress has been most promising in pigtail macaques (PTMs), which do not express an HIV-1-restricting tripartite motif-containing protein 5 α (TRIM5α). In our work, we have derived a CCR5-tropic mmHIV-1 clone designated stHIV-A19 that comprises 94% HIV-1 genome sequence and replicates to high acute-phase titers in PTMs. In animals treated with a cell-depleting CD8α antibody at the time of infection, stHIV-A19 maintains chronically elevated plasma viral loads with progressive CD4+ T-cell loss and the development of acquired immune-deficiency syndrome (AIDS)-defining clinical endpoints. However, in the absence of CD8α+ cell depletion, no mmHIV-1 model has yet displayed high levels of chronic viremia or AIDS-like pathogenesis. Here, we review mmHIV-1 development approaches, the phenotypes, features, limitations, and potential utility of currently available mmHIV-1s, and propose future directions to further advance these models. [ABSTRACT FROM AUTHOR]

Tsg101, a component of the endosomal sorting complex required for transport (ESCRT), is responsible for recognition of events requiring the machinery, as signaled by cargo tagging with ubiquitin (Ub), and for recruitment of downstream acting subunits to the site. Although much is known about the latter function, little is known about its role in the earlier event. The N-terminal domain of Tsg101 is a structural homologue of Ub conjugases (E2 enzymes) and the protein associates with Ub ligases (E3 enzymes) that regulate several cellular processes including virus budding. A pocket in the domain recognizes a motif, PT/SAP, that permits its recruitment. PT/SAP disruption makes budding dependent on Nedd4L E3 ligases. Using HIV-1 encoding a PT/SAP mutation that makes budding Nedd4L-dependent, we identified as critical for rescue the residues in the catalytic (HECT) domain of the E3 enzyme that lie in proximity to sites in Tsg101 that bind Ub non-covalently. Mutation of these residues impaired rescue by Nedd4L but the same mutations had no apparent effect in the context of a Nedd4 isomer, Nedd4-2s, whose N-terminal (C2) domain is naturally truncated, precluding C2-HECT auto-inhibition. Surprisingly, like small molecules that disrupt Tsg101 Ub-binding, small molecules that interfered with Nedd4 substrate recognition arrested budding at an early stage, supporting the conclusion that Tsg101–Ub–Nedd4 interaction promotes enzyme activation and regulates Nedd4 signaling for viral egress. Tsg101 regulation of E3 ligases may underlie its broad ability to function as an effector in various cellular activities, including viral particle assembly and budding. [ABSTRACT FROM AUTHOR]

During HIV-1 virus assembly, the genomic RNA (vRNA) is selected for packaging by the viral protein Gag because it contains a specific packaging signal, Psi. While there have been numerous studies of Gag–Psi interactions, there is almost no information on the kinetic aspects of this interaction. We investigated the kinetics of Gag binding to different RNAs using switchSENSE DRX2 technology. We measured the association rate of Gag binding to monomeric Psi, to a "Multiple Binding Site Mutant" Psi that is inactive for genome packaging in vivo, and to a scrambled Psi. We discovered that Gag binds more rapidly to Psi RNA than to the mutant or scrambled RNAs. Furthermore, rapid Gag association kinetics are retained within sub-regions of Psi: Gag associates more rapidly with RNA containing only the 3′ two of the three Psi stem-loops than with monomeric RNA containing the 5′ two stem-loops or a scrambled RNA. No differences were detectable with individual Psi stem-loops. Interestingly, the rate of binding of Gag molecules to Psi increases with increasing Gag concentration, suggesting cooperativity in binding. The results are consistent with the hypothesis that selectivity in packaging derives from kinetic differences in initiation of particle assembly. [ABSTRACT FROM AUTHOR]

CD4-mimetics (CD4mcs) are small molecule compounds that mimic the interaction of the CD4 receptor with HIV-1 envelope glycoproteins (Env). Env from primary viruses normally samples a "closed" conformation that occludes epitopes recognized by CD4-induced (CD4i) non-neutralizing antibodies (nnAbs). CD4mcs induce conformational changes on Env resulting in the exposure of these otherwise inaccessible epitopes. Here, we evaluated the capacity of plasma from a cohort of 50 people living with HIV to recognize HIV-1-infected cells and eliminate them by antibody-dependent cellular cytotoxicity (ADCC) in the presence of a potent indoline CD4mc. We observed a marked heterogeneity among plasma samples. By measuring the levels of different families of CD4i Abs, we found that the levels of anti-cluster A, anti-coreceptor binding site, and anti-gp41 cluster I antibodies are responsible for plasma-mediated ADCC in the presence of CD4mc. [ABSTRACT FROM AUTHOR]

The majority of naturally elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs) because they are unable to recognize the Env trimer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have the potential to eliminate HIV-1-infected cells by antibody-dependent cellular cytotoxicity (ADCC) provided that Env is present on the cell surface in its "open" conformation. This is because most nnAbs recognize epitopes that become accessible only after Env interaction with CD4 and the exposure of epitopes that are normally occluded in the closed trimer. HIV-1 limits this vulnerability by downregulating CD4 from the surface of infected cells, thus preventing a premature encounter of Env with CD4. Small CD4-mimetics (CD4mc) sensitize HIV-1-infected cells to ADCC by opening the Env glycoprotein and exposing CD4-induced (CD4i) epitopes. There are two families of CD4i nnAbs, termed anti-cluster A and anti-CoRBS Abs, which are known to mediate ADCC in the presence of CD4mc. Here, we performed Fab competition experiments and found that anti-gp41 cluster I antibodies comprise a major fraction of the plasma ADCC activity in people living with HIV (PLWH). Moreover, addition of gp41 cluster I antibodies to cluster A and CoRBS antibodies greatly enhanced ADCCmediated cell killing in the presence of a potent indoline CD4mc, CJF-III-288. This cocktail outperformed broadly neutralizing antibodies and even showed activity against HIV-1-infected monocyte-derived macrophages. Thus, combining CD4i antibodies with different specificities achieves maximal ADCC activity, which may be of utility in HIV cure strategies. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus (HIV) type 2 is known to be less pathogenic than HIV-1, possibly due to more effective immune control mechanisms. The mechanism of innate sensing of HIV-2 by T cells is at present unclear. In this study, we show that several primary isolates of HIV-2 (CBL20 and CI85) and HIV-1 (A8 and D2), similar to the molecular clone HIV-1 NL4.3-GFP-I, induce a significant type I interferon response in its main target, activated CD4+ T cells. However, they are unable to do so after shRNA-mediated knock-down of cGAS. In addition, both HIV-1- and HIV-2-induced type I interferon response in CD4+ T cells was dependent on productive infection and integration, as the presence of RT or integrase inhibitor dramatically suppressed the sensing. Our findings collectively showed that the cGAS-dependent type I interferon response of CD4+ T cells to HIV infection is conserved over HIV types and critically depends on productive infection. [ABSTRACT FROM AUTHOR]

VRC01-class broadly neutralizing antibodies (bnAbs) have been isolated from people with HIV-1, but they have not yet been elicited by vaccination. They are extensively somatically mutated and sometimes accumulate CDRL1 deletions. Such indels may allow VRC01-class antibodies to accommodate the glycans expressed on a conserved N276 N-linked glycosylation site in loop D of the gp120 subunit. These glycans constitute a major obstacle in the development of VRC01-class antibodies, as unmutated antibody forms are unable to accommodate them. Although immunizations of knock-in mice expressing human VRC01-class B-cell receptors (BCRs) with specifically designed Env-derived immunogens lead to the accumulation of somatic mutations in VRC01-class BCRs, CDRL1 deletions are rarely observed, and the elicited antibodies display narrow neutralizing activities. The lack of broad neutralizing potential could be due to the absence of deletions, the lack of appropriate somatic mutations, or both. To address this point, we modified our previously determined prime-boost immunization with a germline-targeting immunogen nanoparticle (426c.Mod.Core), followed by a heterologous core nanoparticle (HxB2.WT.Core), by adding a final boost with a cocktail of various stabilized soluble Env trimers. We isolated VRC01-like antibodies with extensive somatic mutations and, in one case, a seven-amino acid CDRL1 deletion. We generated chimeric antibodies that combine the vaccine-elicited somatic mutations with CDRL1 deletions present in human mature VRC01 bnAbs. We observed that CDRL1 indels did not improve the neutralizing antibody activities. Our study indicates that CDRL1 length by itself is not sufficient for the broadly neutralizing phenotype of this class of antibodies. [ABSTRACT FROM AUTHOR]

Cells naturally produce vesicles that bud from different lipid membranes using dedicated molecular machineries. Enveloped RNA viruses, including human immunodeficiency virus type 1 (HIV-1), also generate particles that bud from host cell membranes by hijacking cellular factors and signaling pathways similar to those involved in the budding of extracellular vesicles. HIV-1 buds from the host cell plasma membrane mainly via the self-assembly of Gag, a structural protein. Gag is a polyprotein that forms assembly complexes containing viral genomic RNA (gRNA), host cell lipids and proteins. HIV-1 Gag binds and segregates host cell plasma membrane lipids while self-assembling simultaneously on the gRNA and the plasma membrane. This self-assembly causes membrane bending and formation of a new viral particle with the help of host cell proteins, likely including cortical actin-associated factors. However, it is unclear whether the energy of Gag self-assembly is sufficient to generate new HIV-1 particles. In this Review, we discuss these processes in the light of the past and recent virology literature, incorporating lessons from studies on the quantitative biophysics of viral self-assembly, and explore how Gag might reorganize the plasma membrane and divert host cell membrane curving proteins and cortical actin-related factors to achieve particle assembly and budding. [ABSTRACT FROM AUTHOR]

Objectives To investigate the epidemic patterns of pretreatment drug resistance (PDR) and acquired drug resistance (ADR) in HIV-1 sequences from China. Methods HIV-1 pol sequences and associated epidemiological data were collected from the Los Alamos HIV Sequence Database, NCBI, HIV Gene Sequence Database and PubMed. Genotypic resistance and subtypes were identified using the Stanford HIV Drug Resistance Database. Results A total of 36 263 sequences from ART-naïve individuals and 1548 sequences from ART-experienced individuals with virological failure were evaluated. PDR prevalence was 6.64%, initially decreasing and then increasing to 7.84% (2018–22) due to NNRTI. Pooled ADR prevalence (44.96%) increased, with NNRTI and NRTI aligning with the overall trend. The percentage of multidrug resistance was more than that of single-drug resistance in PDR and especially ADR annually. PDR was most prevalent in Central China followed by Southwest and North. ADR prevalence was highest in North China followed by Northwest and Southwest. In ADR sequences, high-level resistance was more common, especially in NRTI. PDR sequences exhibited low-level or intermediate resistance, especially PI. Drug resistance mutations revealed distinct patterns in PDR and ADR. CRF01_AE, the predominant subtype in China, exhibited the highest proportions among most ART drugs and drug resistance mutations, with a few exceptions where CRF07_BC (prominent in the Northwest), CRF55_01B and CRF08_BC (prominent in the Southwest) showed the highest proportions. Conclusions HIV-1 PDR and ADR prevalence in China exhibited diverse epidemiological characteristics, underscoring the importance of ongoing national monitoring of PDR, ADR and subtype; patient education on adherence; and personalized regimens. [ABSTRACT FROM AUTHOR]