The current study analyzed the intersecting biophysical, biochemical, and functional properties of extracellular particles (EPs) with the human immunodeficiency virus type-1 (HIV-1) beyond the currently accepted size range for HIV-1. We isolated five fractions (Frac-A through Frac-E) from HIV-infected cells by sequential differential ultracentrifugation (DUC). All fractions showed a heterogeneous size distribution with median particle sizes greater than 100 nm for Frac-A through Frac-D but not for Frac-E, which contained small EPs with an average size well below 50 nm. Synchronized and released cultures contained large infectious EPs in Frac-A, with markers of amphisomes and viral components. Additionally, Frac-E uniquely contained EPs positive for CD63, HSP70, and HIV-1 proteins. Despite its small average size, Frac-E contained membrane-protected viral integrase, detectable only after SDS treatment, indicating that it is enclosed in vesicles. Single particle analysis with dSTORM further supported these findings as CD63, HIV-1 integrase, and the viral surface envelope (Env) glycoprotein (gp) colocalized on the same Frac-E particles. Surprisingly, Frac-E EPs were infectious, and infectivity was significantly reduced by immunodepleting Frac-E with anti-CD63, indicating the presence of this protein on the surface of infectious small EPs in Frac-E. To our knowledge, this is the first time that extracellular vesicle (EV) isolation methods have identified infectious small HIV-1 particles (smHIV-1) that are under 50 nm. Collectively, our data indicate that the crossroads between EPs and HIV-1 potentially extend beyond the currently accepted biophysical properties of HIV-1, which may have further implications for viral pathogenesis.

Factor VIII and IX clotting factor concentrates manufactured from pooled plasma have been identified as potent sources of virus infection in persons with hemophilia (PWHs) in the 1970s and 1980s. To investigate the range and diversity of viruses over this period, we analysed 24 clotting factor concentrates for several blood-borne viruses. Nucleic acid was extracted from 14 commercially produced clotting factors and 10 from nonremunerated donors, preserved in lyophilized form (expiry dates: 1974-1992). Clotting factors were tested by commercial and in-house quantitative PCRs for blood-borne viruses hepatitis A, B, C and E viruses (HAV, HBV, HCV, HEV), HIV- types 1/2, parvoviruses B19V and PARV4, and human pegiviruses types 1 and 2 (HPgV-1,-2). HCV and HPgV-1 were the most frequently detected viruses (both 14/24 tested) primarily in commercial clotting factors, with frequently extremely high viral loads in the late 1970s-1985 and a diverse range of HCV genotypes. Detection frequencies sharply declined following introduction of virus inactivation. HIV-1, HBV, and HAV were less frequently detected (3/24, 1/24, and 1/24 respectively); none were positive for HEV. Contrastingly, B19V and PARV4 were detected throughout the study period, even after introduction of dry heat treatment, consistent with ongoing documented transmission to PWHs into the early 1990s. While hemophilia treatment is now largely based on recombinant factor VIII/IX in the UK and elsewhere, the comprehensive screen of historical plasma-derived clotting factors reveals extensive exposure of PWHs to blood-borne viruses throughout 1970s-early 1990s, and the epidemiological and manufacturing parameters that influenced clotting factor contamination.

The Gag-Pol polyprotein in human immunodeficiency virus type I (HIV-1) encodes enzymes that are essential for virus replication: protease (PR), reverse transcriptase (RT), and integrase (IN). The mature forms of PR, RT and IN are homodimer, heterodimer and tetramer, respectively. The precise mechanism underlying the formation of dimer or tetramer is not yet understood. Here, to gain insight into the dimerization of PR and RT in the precursor, we prepared a model precursor, PR-RT, incorporating an inactivating mutation at the PR active site, D25A, and including two residues in the p6* region, fused to a SUMO-tag, at the N-terminus of the PR region. We also prepared two mutants of PR-RT containing a dimer dissociation mutation either in the PR region, PR(T26A)-RT, or in the RT region, PR-RT(W401A). Size exclusion chromatography showed both monomer and dimer fractions in PR-RT and PR(T26A)-RT, but only monomer in PR-RT(W401A). SEC experiments of PR-RT in the presence of protease inhibitor, darunavir, significantly enhanced the dimerization. Additionally, SEC results suggest an estimated PR-RT dimer dissociation constant that is higher than that of the mature RT heterodimer, p66/p51, but slightly lower than the premature RT homodimer, p66/p66. Reverse transcriptase assays and RT maturation assays were performed as tools to assess the effects of the PR dimer-interface on these functions. Our results consistently indicate that the RT dimer-interface plays a crucial role in the dimerization in PR-RT, whereas the PR dimer-interface has a lesser role.

BACKGROUND: Although sex hormones are recognized to induce immune variations, the effect of hormonal therapy use on immunity is only poorly understood. Here, we quantified how hormonal therapy use affects HIV-1 immune markers in cis women (CW) and trans women and non-binary people (TNBP) with HIV.
METHODS: We considered CD4, CD8 and lymphocyte measurements from cis men (CM), CW and TNBP in the Swiss HIV Cohort Study. We modelled HIV-1 markers using linear mixed-effects models with an interaction between \'gender\' (CW, TNBP) and \'hormonal therapy use\' (yes/no). Models were adjusted on age, ethnicity, education level, time since start of antiretroviral therapy and use of intravenous drugs. We assessed the inflammatory effect of hormonal therapy use in 31 TNBP using serum proteomics measurements of 92 inflammation markers.
RESULTS: We included 54 083 measurements from 3092 CW and 83 TNBP, and 147 230 measurements from 8611 CM. Hormonal therapy use increased CD4 count and CD4:CD8 ratio in TNBP more than in CW (pinteraction = 0.02 and 0.007, respectively). TNBP with hormonal therapy use had significantly higher CD4 counts [median = 772 cells/μL, interquartile range (IQR): 520-1006] than without (617 cells/μL, 426-892). This was similar to the effect of CW versus CM on CD4 T cells. Hormonal therapy use did not affect serum protein concentrations in TNBP.
CONCLUSIONS: This study highlights the potential role of hormonal therapy use in modulating the immune system among other biological and social factors, especially in TNBP with HIV.

Nanotechnology offers promising avenues for enhancing drug delivery systems, particularly in HIV-1 treatment. This study investigates a nanoemulsified formulation combining epigallocatechin gallate (EGCG) with dolutegravir (DTG) for managing HIV-1 infection. The combinatorial interaction between EGCG and DTG was explored through cellular, enzymatic, and molecular studies. In vitro assays demonstrated the potential of a dual drug-loaded nanoemulsion, NE-DTG-EGCG, in inhibiting HIV-1 replication, with EGCG serving as a supplementary treatment containing DTG. In silico molecular interaction studies highlighted EGCG\'s multifaceted inhibitory potential against HIV-1 integrase and reverse transcriptase enzymes. Further investigations are needed to validate the formulation\'s efficacy across diverse contexts. Overall, by integrating nanotechnology into drug delivery systems, this study represents a significant advancement in managing HIV-1 infection.

Broadly neutralizing antibodies are proposed as therapeutic and prophylactic agents against HIV-1, but their potency and breadth are less than optimal. This study describes the immunization of a llama with the prefusion-stabilized HIV-1 envelope (Env) trimer, BG505 DS-SOSIP, and the identification and improvement of potent neutralizing nanobodies recognizing the CD4-binding site (CD4bs) of vulnerability. Two of the vaccine-elicited CD4bs-targeting nanobodies, G36 and R27, when engineered into a triple tandem format with llama IgG2a-hinge region and human IgG1-constant region (G36×3-IgG2a and R27×3-IgG2a), neutralized 96% of a multiclade 208-strain panel at geometric mean IC80s of 0.314 and 0.033 µg mL-1, respectively. Cryo-EM structures of these nanobodies in complex with Env trimer revealed the two nanobodies to neutralize HIV-1 by mimicking the recognition of the CD4 receptor. To enhance their neutralizing potency and breadth, nanobodies are linked to the light chain of the V2-apex-targeting broadly neutralizing antibody, CAP256V2LS. The resultant human-llama bispecific antibody CAP256L-R27×3LS exhibited ultrapotent neutralization and breadth exceeding other published HIV-1 broadly neutralizing antibodies, with pharmacokinetics determined in FcRn-Fc mice similar to the parent CAP256V2LS. Vaccine-elicited llama nanobodies, when combined with V2-apex broadly neutralizing antibodies, may therefore be able to fulfill anti-HIV-1 therapeutic and prophylactic clinical goals.

OBJECTIVE: To study the prevalence of low-level viraemia (LLV) and its association with virological failure (VF).
METHODS: We conducted a retrospective analysis of 3498 participants at YRG CARE, Chennai, India (2013-2018) on antiretroviral therapy (ART) for ≥6 months with two or more plasma viral load (pVL) measurements. Results were stratified for those with pVL <1000 copies/mL: fully suppressed (FS) (pVL <40), low-LLV (pVL 40-199), mid-LLV (pVL 200-399), and high-LLV (pVL 400-999). The study assessed the association with VF (pVL >1000 copies/mL) using Cox proportional hazard model.
RESULTS: Among 3498 participants, 2965 (84.8%) were FS and 533 (15.2%) were LLV. During the follow-up, 348 (10%) experienced VF, with 222 (6.3%) experienced after LLV (42% of LLV) and 126 (3.6%) experienced after FS (4.3% of FS). When compared with FS, those with LLV had a greater risk of VF [adjusted hazard ratio (aHR) = 12.7; 95% confidence interval (CI): 10.2-15.9]. First-line participants had a higher VF incidence (aHR = 15.8, 95% CI: 11.4-21.9) than second-line participants (aHR = 5.6, 95% CI: 4.1-7.7). Those with high-LLV had the highest VF risk (aHR = 22.856, 95% CI: 15.204-34.359 vs. aHR = 8.186, 95% CI: 5.564-12.043, for first-line vs. second-line participants, respectively), followed by those with mid-LLV (aHR = 13.375, 95% CI: 8.327-21.483 vs. aHR = 6.261, 95% CI: 4.044-9.695) and low-LLV (aHR = 12.976, 95% CI: 7.974-21.118 vs. aHR = 4.158, 95% CI: 2.826-6.119).
CONCLUSIONS: The prevalence of LLV was intermediate in our study population. There was a higher risk of VF among individuals with LLV, and this risk increased with the increasing levels of LLV. Close monitoring of individuals experiencing LLV could help in the early identification of VF.

Nucleic acid amplification, the bedrock of biotechnology and molecular diagnostics, surges in applications-especially isothermal approaches-heightening the demand for advanced and precisely engineered methods. Here, a novel approach for amplifying DNA with multiarm priming and looping optimization of nucleic acid (AMPLON) is presented. AMPLON relies on a novel polymeric material with unique set of multiarm polyethylene glycol-DNA primers for efficient DNA amplification under isothermal conditions. Each arm carries single-stranded DNA complementing the sense or antisense sequence of the target DNA. The amplification reaction begins with antisense arms binding to the target DNA, forming a template for sense-carrying arms to direct multiarm large DNA amplicon synthesis through successive DNA looping and unlooping steps. Using human immunodeficiency virus type 1 (HIV-1) as a model clinical target, AMPLON exhibits high sensitivity, detecting target concentrations as low as 100 copies mL-1. Compared to a quantitative real-time polymerase chain reaction assay using sensitive primers, AMPLON reliably identifies HIV-1 RNA in plasma samples (n = 20) with a significant agreement rate of 95%. With its ability to achieve highly specific and sensitive target amplification within 30 min, AMPLON holds immense potential to transform the field of nucleic acid research and unleashing new possibilities in medicine and biotechnology.

Since the identification of human immunodeficiency virus type 1 (HIV-1) in 1983, many improvements have been made to control viral replication in the peripheral blood and to treat opportunistic infections. This has increased life expectancy but also the incidence of age-related central nervous system (CNS) disorders and HIV-associated neurodegeneration/neurocognitive impairment and depression collectively referred to as HIV-associated neurocognitive disorders (HAND). HAND encompasses a spectrum of different clinical presentations ranging from milder forms such as asymptomatic neurocognitive impairment or mild neurocognitive disorder to a severe HIV-associated dementia (HAD). Although control of viral replication and suppression of plasma viral load with combination antiretroviral therapy has reduced the incidence of HAD, it has not reversed milder forms of HAND. The objective of this review, is to describe the mechanisms by which HIV-1 invades and disseminates in the CNS, a crucial event leading to HAND. The review will present the evidence that underlies the relationship between HIV infection and HAND. Additionally, recent findings explaining the role of neuroinflammation in the pathogenesis of HAND will be discussed, along with prospects for treatment and control.

BACKGROUND: This study aimed to investigate mutations associated with, the causes of, and the conditions that contribute to HIV drug resistance (DR). This research provides crucial insights into the mechanisms through which HIV evades antiretroviral drugs and suggests strategies to counter this phenomenon. Our objective was to assess the prevalence and structure of DR in HIV-1 across various regions in Russia and identify the primary factors influencing the development of HIV DR.
METHODS: The study used nucleotide sequences from the HIV-1 pol gene obtained from 1369 patients with a history of therapy and virological failure between 2005 and 2019 to analyze the frequency and structure of DR and the factors associated with it.
RESULTS: The analysed HIV-1 genotypes included viruses resistant to nucleoside reverse transcriptase inhibitors (NRTIs; 11.8%), non-nucleoside reverse transcriptase inhibitors (NNRTIs; 6.4%), and NRTIs + NNRTIs (31.7%). The mutations M184V/I and G190A/S/E were the most prevalent, accounting for 54.5% and 26.6%, respectively. The dominance of multiple DR persisted throughout the entire observation period. The likelihood of encountering drug-resistant variants was increased among men, patients in the late stage of infection, and those with a viral load <30 000 RNA copies/mL. Injection drug use was not associated with DR.
CONCLUSIONS: This study has yielded new insights into HIV DR in Russia, offering valuable information to identify clinical or programmatic events warranting closer attention and support.