Antiretroviral Agents Research Articles

Optimising Paediatric HIV Treatment: Recent Developments and Future Directions.

Treatment options for children living with HIV have historically been less effective, less practical and more difficult to implement compared with those for adults, as the research and development of new drugs for children has lagged behind. Significant progress has been achieved in response to the paediatric HIV epidemic over the last decade. Several optimised paediatric antiretroviral formulations are currently available or in development, including fixed-dose combination tablets containing a complete World Health Organization-recommended regimen. Despite these advancements, virological suppression rates in children are generally lower than in adults. Even when oral fixed-dose combinations with the optimal target profiles are developed, for some children virological suppression is not achievable for reasons such as adherence challenges, intolerance, toxicity and genotypic resistance. New safe, effective, well-tolerated antiretroviral agents from existing and novel classes, as well as innovative administration strategies are essential. To achieve the UNAIDS target of virological suppression in 95% of children receiving antiretroviral therapy, concerted efforts are required. This includes identifying priority drugs in line with latest developments, focusing drug development studies on these priorities, ensuring a timely technical knowledge transfer between originator and generic companies, accelerating regulatory approvals and facilitating procurement and implementation in countries. Success in these efforts depends on collaboration among all stakeholders, including communities, researchers, pharmaceutical companies, guideline and policymakers, governments, funders, regulators and healthcare providers. This review outlines which paediatric antiretroviral therapies are currently available, those which are under development and the future directions of paediatric HIV treatment.

The structural and mechanistic bases for the viral resistance to allosteric HIV-1 integrase inhibitor pirmitegravir.

Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are investigational antiretroviral agents that potently impair virion maturation by inducing hyper-multimerization of IN and inhibiting its interaction with viral genomic RNA. The pyrrolopyridine-based ALLINI pirmitegravir (PIR) has recently advanced into phase 2a clinical trials. Previous cell culture-based viral breakthrough assays identified the HIV-1(Y99H/A128T IN) variant that confers substantial resistance to this inhibitor. Here, we have elucidated the unexpected mechanism of viral resistance to PIR. Although both Tyr99 and Ala128 are positioned within the inhibitor binding V-shaped cavity at the IN catalytic core domain (CCD) dimer interface, the Y99H/A128T IN mutations did not substantially affect the direct binding of PIR to the CCD dimer or functional oligomerization of full-length IN. Instead, the drug-resistant mutations introduced a steric hindrance at the inhibitor-mediated interface between CCD and C-terminal domain (CTD) and compromised CTD binding to the CCDY99H/A128T + PIR complex. Consequently, full-length INY99H/A128T was substantially less susceptible to the PIR-induced hyper-multimerization than the WT protein, and HIV-1(Y99H/A128T IN) conferred >150-fold resistance to the inhibitor compared with the WT virus. By rationally modifying PIR, we have developed its analog EKC110, which readily induced hyper-multimerization of INY99H/A128T in vitro and was ~14-fold more potent against HIV-1(Y99H/A128T IN) than the parent inhibitor. These findings suggest a path for developing improved PIR chemotypes with a higher barrier to resistance for their potential clinical use.IMPORTANCEAntiretroviral therapies save the lives of millions of people living with HIV (PLWH). However, the evolution of multi-drug-resistant viral phenotypes is a major clinical problem, and there are limited or no treatment options for heavily treatment-experienced PLWH. Allosteric HIV-1 integrase inhibitors (ALLINIs) are a novel class of antiretroviral compounds that work by a unique mechanism of binding to the non-catalytic site on the viral protein and inducing aberrant integrase multimerization. Accordingly, ALLINIs potently inhibit both wild-type HIV-1 and all drug-resistant viral phenotypes that have so far emerged against currently used therapies. Pirmitegravir, a highly potent and safe investigational ALLINI, is currently advancing through clinical trials. Here, we have elucidated the structural and mechanistic bases behind the emergence of HIV-1 integrase mutations in infected cells that confer resistance to pirmitegravir. In turn, our findings allowed us to rationally develop an improved ALLINI with substantially enhanced potency against the pirmitegravir-resistant virus.

The impact of Medicaid expansion under the Affordable Care Act on HIV care continuum outcomes across the United States.

HIV care continuum outcome disparities by health insurance status have been noted among people with HIV (PWH). We therefore examined associations between state Medicaid expansion and HIV outcomes in the United States. Adults (≥18 years) with ≥1 visit in NA-ACCORD clinical cohorts from 2012-2017 contributed person-time annually between first and final visit or death; in each calendar year, clinical retention was ≥2 completed visits > 90 days apart, antiretroviral therapy (ART) receipt was receipt of ≥3 antiretroviral agents, and viral suppression was last measured HIV-1 RNA < 200 copies/mL. CD4 at enrollment was obtained within 6 months of enrollment in cohort. Difference-in-difference (DID) models quantified associations between Medicaid expansion changes (by state of residence) and HIV outcomes. Across 50 states, 87 290 PWH contributed 325 113 person-years of follow-up. Medicaid expansion had a substantial positive effect on CD4 at enrollment (DID = 93.5, 95% CI: 52.9, 134 cells/mm3), a small negative effect on proportions clinically retained (DID = -0.19, 95% CI: -0.037, -0.01), and no effects on ART receipt (DID = 0.001, 95% CI: -0.003, 0.005) or viral suppression (DID = -0.14, 95% CI: -0.34, 0.07). Medicaid expansion had a positive effect on CD4 at entry, suggesting more timely HIV testing and care linkage, but generally null effects on downstream HIV care continuum measures.

Efficacy and safety of two fixed doses of ibalizumab plus optimized background regimen in treatment-experienced HIV-positive individuals.

Sustained viral suppression in patients with multidrug-resistant (MDR) human immunodeficiency virus (HIV) infection remains difficult; accordingly, agents targeting different steps in the HIV life cycle are needed. Ibalizumab, a humanized immunoglobulin G4 monoclonal antibody, is a cluster of differentiation (CD4)-directed post-attachment inhibitor. In this Phase IIb study, 113 individuals with MDR HIV-1 and limited treatment options were assigned an optimized background regimen (OBR) and randomized to either 800 mg ibalizumab every two weeks (q2wk; n=59) or 2,000 mg ibalizumab every four weeks (q4wk; n=54) up to Week 24. Viral loads (VL) below the detection limit were achieved in 44% and 28% of patients in the 800 mg q2wk and 2,000 mg q4wk groups, respectively, at Week 24. Mean (standard deviation) VL (log10 copies/mL) decreased from Baseline (4.6(0.8), 800 mg q2wk; 4.7(0.7), 2,000 mg q4wk) to Week 2, with the reduction maintained through Week 24 (2.9(1.5), 800 mg q2wk; 3.2(1.4), 2,000 mg q4wk). Baseline CD4+ counts were 80.5 and 54.0 cells/μL in the 800 mg q2wk and 2,000 mg q4wk groups, respectively. Mean CD4+ T-cell count was increased at Week 24 in both groups. No serious adverse events were related to ibalizumab. In heavily treatment-experienced patients with HIV (PWH) at a more advanced baseline disease severity, clinically significant response rates at Week 24 were achieved with ibalizumab plus OBR. Ibalizumab's unique mechanism of action and lack of cross-resistance to other antiretroviral agents make it an important component of combination treatment regimens for PWH with limited treatment options.

An Integrative Computational Approach for Design and Evaluation of Novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole Analogues as Dual-Action Anti-Retroviral and Anti-Bacterial Agents: Insights into Rational Drug Design Strategies

The development of effective antiretroviral inhibitors (HIV-1 Reverse Transcriptase) and glucosamine-6-phosphate (GlcN6P) agents represent a significant challenge for combating viral infections and related diseases. In this study, we employed a multidisciplinary approach to design and evaluate a series of novel triazole analogs as potential candidates for anti-retroviral and glucosamine-6-phosphate agents. Using molecular docking, we explored the binding interactions between the RSA3 analog and the target proteins implicated in viral replication and glucosamine metabolism. Density functional theory (DFT) employing the 6-311++G(d,p) basis set was utilized for computational analysis, with a subsequent examination of the electronic parameters. The HOMO and LUMO orbitals as well as the molecular electrostatic potential map were investigated using DFT to characterize the reactivity of our molecule. Molecular dynamics simulations were performed to investigate the stability and dynamic behavior of the ligand-protein complex (RSA3) over time (300 ns). Furthermore, we employed MM-GBSA calculations of the compound RSA3 (molecular mechanics generalized band surface area) to estimate the binding free energies (−71.30 ± 7.26 kcal/mol and −67.86 ± 7.09 kcal/mol, respectively) and identified the most promising compounds with high affinity for the target proteins. Additionally, predictive absorption, distribution, metabolism, excretion and toxicity (ADMET) studies of compound RSA3 were conducted to assess its drug-like properties and potential safety profiles of the selected compound. Our results revealed that RSA3 has favorable binding interactions, is a stable complex and has significant binding affinity for target proteins. Moreover, predictive ADMET studies indicated that RSA3 possesses desirable drug-like properties, suggesting its potential for further investigation as an anti-retroviral agent and glucosamine-6-phosphate agent. Overall, this integrative computational approach combining molecular docking, DFT analysis, dynamics simulations, MM-GBSA and predictive ADMET studies provides valuable insights into the design and evaluation of novel triazole analogs with potential therapeutic applications, highlighting the importance of rational drug design strategies in the field of antiretroviral and glucosamine research.

Treatment Management Challenges in Naïve and Experienced HIV-1-Infected Individuals Carrying the M184V Mutation.

M184V is a single-base mutation in the YMDD domain of reverse transcriptase (RT). The M184V resistance-associated mutation (RAM) is related to virological unresponsiveness to lamivudine (3TC) and emtricitabine (FTC) and induces high-level resistance to these two antiretroviral agents. M184V is rapidly selected in the setting of non-suppressive antiretroviral therapy (ART) and accumulates in the HIV reservoir. There were continuous efforts to evaluate the impact of the M184V mutation on the treatment outcomes in people living with HIV (PLWH). Since 3TC remains an extensively used part of recommended antiretroviral combinations, M184V is commonly detected in patients with virological failure (VF). ART guidelines do not recommend the use of drugs impacted by RAMs as they have been confirmed to comprise a risk factor for VF. However, there is evidence that 3TC/FTC can remain active even in the presence of M184V. Given the potential benefits of 3TC in ART combinations, the investigation of M184V remains of high interest to clinicians and researchers, especially in certain regions with limited resources, and especially for its unusual effects. This is a review of the literature on the challenges in treating both naïve and experienced individuals carrying the M184V mutation, including virological failure, virological suppression, and resistance to ART.

HIV-1 Integrase T218I/S Polymorphisms Do Not Reduce HIV-1 Integrase Inhibitors' Phenotypic Susceptibility.

The recently Food and Drug Administration (FDA)-approved cabotegravir (CAB) has demonstrated efficacy as an antiretroviral agent for HIV treatment and prevention, becoming an important tool to stop the epidemic in the United States of America (USA). However, the effectiveness of CAB can be compromised by the presence of specific integrase natural polymorphisms, including T97A, L74M, M50I, S119P, and E157Q, particularly when coupled with the primary drug-resistance mutations G140S and Q148H. CAB's recent approval as a pre-exposure prophylaxis (PrEP) may increase the number of individuals taking CAB, which, at the same time, could increase the number of epidemiological implications. In this context, where resistance mutations, natural polymorphisms, and the lack of drug-susceptibility studies prevail, it becomes imperative to comprehensively investigate concerns related to the use of CAB. We used molecular and cell-based assays to assess the impact of T218I and T218S in the context of major resistance mutations G140S/Q148H on infectivity, integration, and resistance to CAB. Our findings revealed that T218I and T218S, either individually or in combination with G140S/Q148H, did not significantly affect infectivity, integration, or resistance to CAB. Notably, these polymorphisms also exhibited neutrality concerning other widely used integrase inhibitors, namely raltegravir, elvitegravir, and dolutegravir. Thus, our study suggests that the T218I and T218S natural polymorphisms are unlikely to undermine the effectiveness of CAB as a treatment and PrEP strategy.

Intracellular islatravir-triphosphate half-life supports extended dosing intervals.

Antiretroviral therapy has substantially reduced morbidity, mortality, and disease transmission in people living with HIV. Islatravir is a nucleoside reverse transcriptase translocation inhibitor that inhibits HIV-1 replication by multiple mechanisms of action, and it is in development for the treatment of HIV-1 infection. In preclinical and clinical studies, islatravir had a long half-life (t½) of 3.0 and 8.7 days (72 and 209 hours, respectively); therefore, islatravir is being investigated as a long-acting oral antiretroviral agent. A study was conducted to definitively elucidate the terminal t½ of islatravir and its active form islatravir-triphosphate (islatravir-TP). A single-site, open-label, non-randomized, single-dose phase 1 study was performed to evaluate the pharmacokinetics and safety of islatravir in plasma and the pharmacokinetics of islatravir-TP in peripheral blood mononuclear cells after administration of a single oral dose of islatravir 30 mg. Eligible participants were healthy adult males without HIV infection between the ages of 18 and 65 years. Fourteen participants were enrolled. The median time to maximum plasma islatravir concentration was 1 hour. Plasma islatravir concentrations decreased in a biphasic manner, with a t½ of 73 hours. The t½ (percentage geometric coefficient of variation) of islatravir-TP in peripheral blood mononuclear cells through 6 weeks (~1008 hours) after dosing was 8.1 days or 195 hours (25.6%). Islatravir was generally well tolerated with no drug-related adverse events observed. Islatravir-TP has a long intracellular t½, supporting further clinical investigation of islatravir administered at an extended dosing interval.

Integrated Population Exposure-Response of Dolutegravir in HIV-1 Supports Bridging of Clinical Response Influenced by Relevant Intrinsic and Extrinsic Patient Characteristics.

Dolutegravir (DTG) is a human immunodeficiency virus type 1 (HIV-1) integrase strand transfer inhibitor indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric subjects aged at least 4 weeks. The present work aimed to characterize the viral response based on a pooled analysis of exposure-response (E-R) from five studies in treatment-experienced and integrase-resistant (INI-r) patients infected with HIV-1. Importantly, model-based simulations of the E-R relationships with DTG provided insight into the clinical relevance of known intrinsic (e.g., sub-population with Q148-driven integrase mutation) and extrinsic (food, enzyme inducers, and metal cation-containing products) factors expected to influence the DTG E-R relationship. Model-based post hoc exposure metrics (C min and C avg) were incorporated into a mechanistic population viral dynamic model describing the short-term effect of DTG on log10 HIV-1 RNA viral load over 8 or 10 days. In addition, the impact of DTG in combination with background ARTs on the 24-week HIV RNA response was also assessed using logistic regression. There was good concordance between model-based predictions and observed virologic response on day 10 and week 24. The E-R model-based simulations exploring the potential impact of a higher dose (100 mg b.i.d.) of DTG in subpopulations experiencing exposure changes due to covariates did not show clinically relevant changes in virological response compared with the approved 50 mg b.i.d. clinical dose. Overall, our study confirmed the current recommendation of dolutegravir 50 mg b.i.d. in the integrase inhibitor-resistant (INI-r) population.

COGNITIVE FUNCTION ASPECTS IN HIV-ASSOCIATED CEREBRAL TOXOPLASMOSIS: A CASE REPORT

HIV-associated cerebral toxoplasmosis may lead to cognitive function impairment through accumulation of β-amyloid plaques and Tau protein which cause damage, inflammatory and oxidative processes in the brain. A 40-year-old, Balinese, right-handed female patient, came with chief complaint of three times of seizure before admission. After the seizures stopped, the patient was fully conscious again. Since the last 2 months, the patient seemed more confused and spoke a little slower. The patient also often repeated a story about something and forgot that she had already told it. The patient has a known history of HIV infection in the past 3 months before admission, she had taken anti-retroviral agents but she stopped them by herself since last 1 month. Anti-Toxoplasma IgG antibody showed reactive results and CD-4 of 62 cells/µL. The results of the overall cognitive function examination found mild cognitive impairment with activities that required mild assistance. HIV-associated neurocognitive disorders (HAND) are still a challenge to study, and the importance of improving patient cognitive function to maintain or increase aspects of independence and quality of life is a target in the care of HIV patients, especially patients with HIV-associated cerebral toxoplasmosis infection.

Exploration of carboxamide hybrid indolyl aryl sulfones as antiretroviral agents by HIV-1 reverse transcriptase inhibition and antioxidant effects: Synthesis, biochemical screening and computational analysis

Indolyl aryl sulfones (IASs) have been under investigation as HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) since the discovery of Merck's compound l-737,126. This research work reports the synthesis of a novel series of indolyl aryl sulfonyl carboxamides (11 to 21 and 25 to 28) and their biological evaluation. Among the synthesized compounds, 15 (IC50 = 57.4 ± 10.1 µM) and 26 (IC50 = 34.0 ± 1.9 µM) demonstrated potent inhibitory activity in RNA-dependent DNA polymerization (RDDP) reactions. In addition, radical inhibition activity was performed by reacting the synthesized compounds against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and it was observed that compounds 20 (IC50 = 8.2 ± 0.2 µM) and 21 (IC50 = 9.3 ± 0.5 µM) showed promising antioxidant properties. Additionally, Two-Dimensional Quantitative Structure Activity Relationship (2D-QSAR) and molecular docking studies were employed to provide insight into the molecular mechanism of RDDP inhibition.

First-trimester exposure to newer antiretroviral agents and congenital anomalies in a US cohort.

To characterize associations of exposure to newer antiretroviral medications in the first trimester with congenital anomalies among infants born to persons with HIV in the United States. Longitudinal cohort of infants born 2012-2022 to pregnant persons with HIV enrolled in the Surveillance Monitoring for ART Toxicities (SMARTT) study. First-trimester exposures to newer antiretrovirals (ARVs) were abstracted from maternal medical records. Trained site staff conducted physical exams and abstracted congenital anomalies from infant medical records. Investigators classified anomalies using the Metropolitan Atlanta Congenital Defects Program classification system. The prevalence of major congenital anomalies identified by age one year was estimated for infants exposed and unexposed to each ARV. Generalized estimating equation models were used to estimate the odds ratio (OR) of major congenital anomalies for each ARV exposure, adjusting for potential confounders. Of 2034 infants, major congenital anomalies were identified in 135 [6.6%; 95% confidence interval (CI): 5.6-7.8%]. Cardiovascular ( n = 43) and musculoskeletal ( n = 37) anomalies were the most common. Adjusted ORs (95% CI) of congenital anomalies were 1.03 (0.62-1.72) for darunavir, 0.91 (0.46-1.81) for raltegravir, 1.04 (0.58-1.85) for rilpivirine, 1.31 (0.71-2.41) for elvitegravir, 0.76 (0.37-1.57) for dolutegravir, and 0.34 (0.05-2.51) for bictegravir, compared to those unexposed to each specific ARV. Findings were similar after adjustment for nucleoside/nucleotide backbones. The odds of congenital anomalies among infants with first-trimester exposure to newer ARVs did not differ substantially from those unexposed to these specific ARVs, which is reassuring. Continued evaluation of these ARVs with larger studies will be needed to confirm these findings.

HIV and adipose tissue: A long history linked to therapeutic classes of antiretrovirals

HIV infection has been controlled only since the introduction of triple therapy in 1996, combining, as antiretroviral agents, two nucleoside reverse transcriptase inhibitors (NRTIs) and one protease inhibitor (PI). However, among the NRTIs, the thymidine analogues stavudine and zidovudine led to lipoatrophy, either generalized or associated with visceral fat hypertrophy and buffalo hump. These molecules also increased insulin resistance and the prevalence of diabetes. They were replaced by other NRTIs or non-NRTIs (NNRTIs) that were considered to be free of adipose tissue (AT) toxicity. More recently, the NRTI tenofovir disoproxyfumarate (TDF) and the NNRTI efavirenz have been associated with inhibition of fat gain but not with clear lipoatrophy. Otherwise, the use of PIs led to a phenotype of trunk fat hypertrophy associated with cardiometabolic complications. To avoid their adverse effects, PIs have recently been replaced by a new class of antiretrovirals, the integrase inhibitors (INSTIs), which are well tolerated and effective in controlling HIV. However, this class has been associated with global weight gain, which may be important and concerning for some people living with HIV (PWH). Also, in the NRTI class, TDF has often been replaced by tenofovir alafenamide (TAF) due to bone and renal toxicities, and TAF has been associated with global fat gain. The cardiometabolic consequences of INTIs and TAF are primarily related to the associated weight gain. In the global obesogenic worldwide context, PWH are gaining weight as well in relation to poor health life conditions. Taking in charge obesity uses the same strategies as those used in the general population.

Blood-to-Testis Transport of Ribavirin Involves Carrier-Mediated Processes at the Blood–Testis Barrier

Ribavirin, an antiretroviral agent targeting the hepatitis C virus, causes male reproductive toxicity. This study investigated the mechanism of ribavirin transport at the blood–testis barrier (BTB). In vivo mouse integration plot analysis after intravenous administration revealed that the net influx clearance of [3H]ribavirin in the testis was 3.6-fold greater than that of [14C]D-mannitol, a paracellular transport marker, implying transcellular transport of ribavirin across the BTB. Moreover, [3H]ribavirin uptake by TM4 cells, mouse-derived Sertoli cells, was time- and concentration-dependent, with a Km value of 2.49 mM. S-[(4-nitrophenyl)methyl]-6-thioinosine, an inhibitor of Na+-independent equilibrative nucleoside transporters (ENTs), strongly inhibited the [3H]ribavirin uptake by TM4 cells at 100 µM. Compared to the uptake of [3H]adenosine, a typical endogenous nucleoside, [3H]ribavirin uptake was relatively similar to ENT2 transport. [3H]Ribavirin uptake was also observed in mouse ENT2-expressing Xenopus laevis oocytes, and gene silencing via the transfection of ENT2 small interfering RNA significantly reduced the [3H]ribavirin transport into TM4 cells by 13%. Taken together, these results suggest that ENT2 partially contributes to ribavirin transport at the BTB.

Evaluating Hepatotoxicity: A Comparative Analysis of New Generation versus Historical Antiretroviral Agents.

(1) Background: Since the advent of zidovudine in 1987, antiretroviral therapy has undergone significant evolution, marked by the introduction of 34 antiretroviral drugs and 24 fixed-dose combinations. Despite these advances, hepatotoxicity remains a formidable challenge, influencing morbidity, mortality, and treatment adherence in HIV-infected patients. This study aims to compare the hepatotoxic effects of latest-generation antiretroviral medications with those of older-generation therapies, assessing their long-term impact on liver health in HIV patients. (2) Methods: This retrospective study analyzed data from 304 HIV patients treated with either latest-generation or older-generation antiretroviral drugs over four years. Patients were monitored for hepatotoxicity through liver function tests at diagnosis, six months, and one-year post-treatment initiation. (3) Results: Initial and six-month liver function tests showed no significant differences between the two groups. However, at one-year post-treatment, patients on latest-generation antiretrovirals exhibited significant improvements in ALT, AST, and ALP levels, suggesting a better safety profile regarding hepatotoxicity. Additionally, a significantly lower incidence of splenomegaly was observed in patients treated with newer medications. (4) Conclusions: The findings suggest that the latest-generation antiretroviral medications may offer a safer profile in terms of hepatotoxicity compared to older therapies, with potential benefits for long-term liver health. This study underscores the importance of continuous monitoring and further research to optimize ART strategies, ensuring improved patient outcomes and quality of life for individuals living with HIV.

Expectations of preventative benefits and risk behaviors in a randomized trial evaluating oral HIV preexposure prophylaxis candidates

ABSTRACT When participants enrolled in an HIV prevention trial hold a preventive misconception (PM) – expectations that experimental interventions will confer protection from HIV infection – they may engage in behaviors that increase their risk of acquiring HIV. This can raise ethical concerns about whether those enrolled in the trial understand the nature of participation and their safety. Consequently, we systematically evaluated the prevalence of PM and its association with risk behaviors in a trial examining three candidate regimens for oral HIV pre-exposure prophylaxis in which all participants received at least one antiretroviral agent. Overall, trial participants exhibited relatively high preventive expectations that may be associated with an increase in risk behaviors among men who have sex with men. In addition, we identified substantial site variability in PM that necessitates future research to uncover its source. This will allow appropriate measures to be taken to mitigate PM and help ensure that participants have an accurate understanding of the potential risks and benefits of trial participation throughout the course of a trial.

Advances in Antiretroviral Therapy for Patients with Human Immunodeficiency Virus-Associated Tuberculosis.

Tuberculosis is one of the most common opportunistic infections and a prominent cause of death in patients with human immunodeficiency virus (HIV) infection, in spite of near-universal access to antiretroviral therapy (ART) and tuberculosis preventive therapy. For patients with active tuberculosis but not yet receiving ART, starting ART after anti-tuberculosis treatment can complicate clinical management due to drug toxicities, drug-drug interactions and immune reconstitution inflammatory syndrome (IRIS) events. The timing of ART initiation has a crucial impact on treatment outcomes, especially for patients with tuberculous meningitis. The principles of ART in patients with HIV-associated tuberculosis are specific and relatively complex in comparison to patients with other opportunistic infections or cancers. In this review, we summarize the current progress in the timing of ART initiation, ART regimens, drug-drug interactions between anti-tuberculosis and antiretroviral agents, and IRIS.

Prevention and infection control of HIV infection and AIDS

Background: Although the global incidence of human immunodeficiency virus (HIV) has decreased significantly since modern antiretroviral therapy (ART), new HIV infections steadily occur, in the Republic of Korea. Based on the understanding of the risk factors for HIV infection, combined strategic behavioral and biomedical interventions should be implemented to reduce HIV infection. This paper reviews the strategies for the prevention of HIV infection.Current Concepts: While the consistent use of latex condoms is effective for the prevention of HIV transmission, consistent use of condoms is low among sexually active individuals. ART can be initiated, after exposure, to prevent HIV infection (post-exposure prophylaxis) after occupational or sexual exposure, injection drug use, and other nonoccupational exposures to HIV. There is a negligible risk of sexual transmission of HIV when the HIV-infected sexual partner has durably suppressed viral replication with ART. Antiretroviral agents have been shown to be highly effective when administered prophylactically to HIV-uninfected but at-risk individuals (preexposure prophylaxis). A high-risk group, such as men who have sex with men, is required to be included in health insurance care benefits for pre-exposure prophylaxis, in addition to the current partners of HIV-infected individuals, to ensure its efficacy.Discussion and Conclusion: HIV-related deaths are rapidly decreasing, but new HIV infections continue to occur. In an environment where a cure or the development of vaccines is unlikely, a multifaceted and proactive approach is required to minimize new HIV infections.

Antiretroviral treatment for HIV infection and AIDS

Background: Antiretroviral therapy is the cornerstone treatment for people living with human immunodeficiency virus (HIV). Clinical practice guidelines for antiretroviral therapy have been developed.Current Concepts: After the introduction of zidovudine, more than 30 antiretroviral agents have been approved for the treatment of HIV infection. Since a controlled trial proved the efficacy and safety of combination antiretroviral therapy, virologic suppression, immune reconstitution, and long-term survival of people living with HIV have been achievable goals. Early antiretroviral treatment for all people living with HIV is an effective strategy to maintain individual health and prevent the transmission of HIV infection. Selecting an appropriate combination antiretroviral therapy requires careful consideration of various factors, including regimen characteristics, pretreatment viral load and CD4+ cell counts, comorbid conditions, and the anticipated level of compliance. Ongoing advances in antiretroviral treatment, such as the development of long-acting injectables and medications targeting multidrug-resistant HIV, address challenges in the treatment of HIV infection.Discussion and Conclusion: Although cure of HIV infection is impossible with current antiretroviral treatment, HIV infection has become a chronic disease with long-term survival. Hence, clinicians should have knowledge of antiretroviral treatment guidelines.

Gp120-derived amyloidogenic peptides form amyloid fibrils that increase HIV-1 infectivity.

Apart from mediating viral entry, the function of the free HIV-1 envelope protein (gp120) has yet to be elucidated. Our group previously showed that EP2 derived from one β-strand in gp120 can form amyloid fibrils that increase HIV-1 infectivity. Importantly, gp120 contains ~30 β-strands. We examined whether gp120 might serve as a precursor protein for the proteolytic release of amyloidogenic fragments that form amyloid fibrils, thereby promoting viral infection. Peptide array scanning, enzyme degradation assays, and viral infection experiments in vitro confirmed that many β-stranded peptides derived from gp120 can indeed form amyloid fibrils that increase HIV-1 infectivity. These gp120-derived amyloidogenic peptides, or GAPs, which were confirmed to form amyloid fibrils, were termed gp120-derived enhancers of viral infection (GEVIs). GEVIs specifically capture HIV-1 virions and promote their attachment to target cells, thereby increasing HIV-1 infectivity. Different GAPs can cross-interact to form heterogeneous fibrils that retain the ability to increase HIV-1 infectivity. GEVIs even suppressed the antiviral activity of a panel of antiretroviral agents. Notably, endogenous GAPs and GEVIs were found in the lymphatic fluid, lymph nodes, and cerebrospinal fluid (CSF) of AIDS patients in vivo. Overall, gp120-derived amyloid fibrils might play a crucial role in the process of HIV-1 infectivity and thus represent novel targets for anti-HIV therapeutics.