Reverse Transcriptase Enzyme Research Articles

REverse transcriptase ACTivity (REACT) assay for point-of-care measurement of established and emerging antiretrovirals for HIV treatment and prevention.

Maintaining adequate levels of antiretroviral (ARV) medications is crucial for the efficacy of HIV treatment and prevention regimens. Monitoring ARV levels can predict or prevent adverse health outcomes like treatment failure or drug resistance. However, conventional ARV measurement using liquid chromatography-tandem mass spectrometry (LC-MS/MS) is slow, expensive, and centralized delaying clinical and behavioral interventions. We previously developed a rapid enzymatic assay for measuring nucleotide reverse transcriptase inhibitors (NRTIs) - the backbone of HIV treatment and prevention regimens - based on the drugs' termination of DNA synthesis by HIV reverse transcriptase (RT) enzyme. Here, we expand our work to include non-nucleoside reverse transcriptase inhibitors (NNRTIs) - an ARV class used in established and emerging HIV treatment and prevention regimens. We demonstrate that the REverse Transcriptase ACTivity (REACT) assay can detect NNRTIs including medications used in oral and long-acting/extended-release HIV treatment and prevention. We demonstrate that REACT can measure NNRTIs spiked in either buffer or diluted plasma and that fluorescence can be measured on both a traditional plate reader and an inexpensive portable reader that can be deployed in point-of-care (POC) settings. REACT measured clinically relevant concentrations of five NNRTIs spiked in aqueous buffer. REACT measurements showed excellent agreement between the plate reader and the portable reader, with a high correlation in both aqueous buffer (Pearson's r = 0.9807, P < 0.0001) and diluted plasma (Pearson's r = 0.9681, P < 0.0001). REACT has the potential to provide rapid measurement of NNRTIs in POC settings and may help to improve HIV treatment and prevention outcomes.

B-237 Engineered Reverse Transcriptases and Taq DNA Polymerases deliver robust yield in the presence of clinically relevant inhibitors

Abstract Background The past five years has seen explosive growth in molecular diagnostic assays that rely on sensitive and accurate detection of nucleic acids across a wide range of sample types. As the assays are required to become increasingly sensitive, the need for highly functional and purpose-built enzymatic tools has grown. Reverse transcriptase (RT) and Taq DNA Polymerase (Taq DNAP) are commonly used to detect RNA and/or DNA viruses in patient samples for point of care (POC) diagnostics. However, crude patient samples introduce inhibitors that decrease enzyme activity and increase false negative results in POC testing. In addition, there is a need for faster turn-around time for patient diagnosis which can be enabled by engineering more active and sensitive Taq variants. Herein, we present on our engineered RT and Taq DNAP enzymes that were developed to confer greater activity, thermostability, inhibitor tolerance and/or sensitivity. Methods We take a 3-pronged approach to protein engineering: rational design, computational design and directed evolution. Using these techniques, we identified and characterized many RT and Taq DNAP variants. We deeply characterized each RT variant by measuring processivity, inhibitor tolerance and thermostability. First strand synthesis was done at temperatures from 42-65°C in the presence and absence of various clinically relevant inhibitors followed by qPCR to assess cDNA yield. Next, we characterized the inhibitor tolerance of the Taq variants by performing qPCR reactions in the presence of inhibitors. To determine if the Taq variant would be an appropriate fit for fast PCR, the polymerization activity of the Taq DNAP variants were characterized using a primer extension assay. Results Reverse transcriptases termed; StellarScript, StellarScript HT and StellarScript HT+ exhibit high processivity at 42°C. StellarScript HT+ exhibited the highest inhibitor tolerance, processivity and thermostability at temperatures up to 65°C thus making StellarScript HT+ well suited to produce high yields with clinical samples. Taq Pol variants were identified that efficiently amplify DNA in the presence of inhibitors. Conclusions Based on the increased polymerase activity and inhibitor tolerance, WMG Taq variants are well suited to give robust DNA yields with clinical samples. We were successful in engineering RT and Taq DNAP variants that are highly thermostable, active and inhibitor tolerant and thus will enable breakthroughs in existing POC diagnostics.

A Step Towards Optimization of Amide-Linked Coumarin Pharmacophore: As an Anti-HIV Agent.

The aim of the present investigation is to identify effective anti-HIV drugs through the in-silico virtual screening of the coumarin pharmacophore with or without substituents. Virtual screening started with target identification through computation docking and interactions, binding affinity through molecular dynamics, and the ADMET profile through the use of various enzymes. The target study suggests that the target is involved in various stages of HIV replication and in determining the ways in which non-nucleoside reverse transcriptase inhibitors (RTIs) influence it. The interaction pattern and simulation study conclude the specific affinity of coumarin pharmacophore to the HIV's reverse transcriptase enzyme, especially 3HVT. Moreover, the amide linkage worked as a synergistic bridge to provide more interaction to the pharmacophore. The initial results led to the determination of 83 virtual amide-like molecules, which were screened through docking and MD studies (100 ns) on the best-suited enzyme HIV's reverse transcriptase enzyme, such as PDB ID "3HVT". The virtual screening study revealed the high affinity of compounds 7d and 7e with the lowest IC50 values of 0.729 and 0.658 μM; moreover, their metabolism pattern study, toxicity, and QED values in a range of 0.31-0.40 support a good drug candidate. The two compounds were also synthesized and characterized for future in vitro and in vivo studies. The in silico-based descriptor of compounds 7d and 7e indicates the potential future and provides the best two molecules and their synthetic route for the development of a more effective drug to combat HIV/AIDS epidemics.

Generation and Characterization of a variant of Thermostable Moloney Murine Leukemia Virus Reverse Transcriptase (MMLV-RT) Enzyme

Background Reverse Transcriptase (RT) enzymes have been extensively utilized, especially in Polymerase Chain Reaction (PCR). Many viruses that cause infections worldwide contain ribonucleic acid (RNA), and for their molecular detection, it is essential to convert RNA to DNA using RT. This study aimed to create and characterize a thermostable Moloney Murine Reverse Transcriptase (MMLV-RT) enzyme by using consensus sequences from the latest MMLV-RT sequence database. Methodology The six latest sequences encoding MMLV-RT were retrieved from the NCBI website, and the consensus sequence was determined and cloned into the pET28a (+) vector. The vector was overexpressed in an E. coli expression system. The enzyme obtained was purified using Talon accept resin. The purified enzyme was analyzed by SDS-PAGE and Western Blotting. The enzyme performance was evaluated by performing PCR on 89 SARS-CoV 2 positive samples and 40 negative samples both in a concentrated state and at a dilution factor of x10−1. The performance was compared with that of the commercial enzyme, a commercial RT enzyme kit, and Superscript (Invitrogen). Results The enzyme was successfully expressed in E. coli. The concentration of MMLV-RT used was 0.313 mg/mL. The concentrated enzyme detected 98.9% of SARS-CoV-2 RNA, whereas the diluted RT enzyme detected 92.1% of SARS-CoV-2 RNA. In contrast, the diagnostic specificity was 98% for concentrated RT and 95% for diluted RT. This showed that the recombinant in-house MMLV-RT enzyme prototype could be used for the PCR amplification of viral RNA. (Figure 3) Conclusion We successfully produced a recombinant MMLV-RT enzyme whose performance was comparable to that of standard commercial reverse transcriptase (P &lt;0.0001).

Telomerase related molecular subtype and risk model reveal immune activity and evaluate prognosis and immunotherapy response in prostate cancer

BackgroundProstate cancer ranks among the six most lethal malignancies worldwide. Telomerase, a reverse transcriptase enzyme, plays a pivotal role in extending cellular telomeres and is intimately associated with cell proliferation and division. However, the interconnection between prostate cancer and telomerase-related genes (TEASEs) remains unclear.MethodsSomatic mutations and copy number alterations of TEASEs were comprehensively analyzed. Subsequently, the transcripts of prostate cancer patients in TCGA and GEO databases were integrated to delineate new molecular subtypes. Followed by constructing a risk model containing nine characteristic genes through Lasso regression and Cox prognostic analysis among different subtypes. Various aspects including prognosis, tumor microenvironment (TME), landscape of immunity, tumor mutational burden (TMB), stem cell correlation, and median inhibitory concentration amongst different risk groups were compared. Finally, the expression, prognosis, and malignant biological behavior of ZW10 interactor (ZWINT) in vitro was explored.ResultsTEASEs exhibited a notably high mutation frequency. Three distinct molecular subtypes and two gene subclusters based on TEASEs were delineated, displaying significant associations with prognosis, immune function regulation, and clinical characteristics. Low-risk patients demonstrated superior prognosis and better response to immunotherapy. Conversely, high-risk patients exhibited higher TMB and stronger stem cell correlations. It was also found that the patients’ sensitivity to chemotherapy agents was impacted by the risk score. Finally, ZWINT’s potential as a novel diagnostic and prognostic biomarker for prostate cancer was validated.ConclusionsTEASEs play a pivotal role in modulating immune regulation and immunotherapeutic responses, thereby significantly impacting the diagnosis, prognosis, and treatment strategies for affected patients.

Sequence Notes: Near Full-Length Genome Analysis of the First-Reported HIV-1 Circulating Recombinant Form (CRF)_10CD in Uganda.

HIV-1 is characterized by remarkable genetic diversity resulting from its high replication rate, error-prone reverse transcriptase enzyme and recombination events. In Uganda, HIV-1 subtype diversity is mostly dominated by subtypes A, D, and A1/D Unique Recombinant Forms (URFs). In this study, deep sequences of HIV from patients with known antiretroviral therapy (ART) status were analyzed to determine the subtypes and to identify drug-resistance mutations circulating in the study population. Of the 187 participant samples processed for next-generation sequencing (NGS), 137 (73%) were successfully classified. The majority of HIV-1 strains were classified as subtype A (75, 55%), D (43, 31%), with other subtypes including C (3, 2%), A1/D (9, 7%) and CRF10_CD (1, <1%). Recombinant analysis of nine complete A1/D HIV genomes identified novel recombination patterns described herein. Furthermore, we report for the first time in Uganda, an HIV-1 CRF10_CD strain from a fisherfolk in a Lake Victoria Island fishing community.

Productive Growing System of Andrographis paniculata and Inhibitions of Reverse Transcriptase and 3CLpro Enzymes by The Isolated Andrographolide

Productive Growing System of Andrographis paniculata and Inhibitions of Reverse Transcriptase and 3CLpro Enzymes by The Isolated Andrographolide

May I Help You with Your Coat? HIV-1 Capsid Uncoating and Reverse Transcription.

The human immunodeficiency virus type 1 (HIV-1) capsid is a protein core formed by multiple copies of the viral capsid (CA) protein. Inside the capsid, HIV-1 harbours all the viral components required for replication, including the genomic RNA and viral enzymes reverse transcriptase (RT) and integrase (IN). Upon infection, the RT transforms the genomic RNA into a double-stranded DNA molecule that is subsequently integrated into the host chromosome by IN. For this to happen, the viral capsid must open and release the viral DNA, in a process known as uncoating. Capsid plays a key role during the initial stages of HIV-1 replication; therefore, its stability is intimately related to infection efficiency, and untimely uncoating results in reverse transcription defects. How and where uncoating takes place and its relationship with reverse transcription is not fully understood, but the recent development of novel biochemical and cellular approaches has provided unprecedented detail on these processes. In this review, we present the latest findings on the intricate link between capsid stability, reverse transcription and uncoating, the different models proposed over the years for capsid uncoating, and the role played by other cellular factors on these processes.

Potential to use of viral reverse transcriptase inhibitors in oncology

In preparing the review, articles on the functioning of the reverse transcriptase enzyme of endogenous repeat sequences LINE1, the mechanisms of action and antitumor activity of viral reverse transcriptase inhibitors. Articles available in the biomedical literature information databases SciVerse Scopus, PubMed, Web of Science, Russian Science CitationIndex (RSCI) were analyzed. The review used information from 140 publications, of which 95 and 39 were published, respectively, over the last ten and three years, 2 articles present the results of clinical studies, and 45 articles refer to results demonstrating the anticancer properties of the studied compounds in various models in vitro and in vivo. Aim. Based on data on the functional properties of the reverse transcriptase enzyme of endogenous repeat sequences LINE1 (long interspersed nuclear elements 1), analyze the potential use of viral reverse transcriptase inhibitors in oncology, presenting their classification and main mechanisms of action. About 98 % of the human genome consists of repetitive sequences, most of which are represented by mobil genetic elements, the activation of which leads to increased genome instability. These include long (LINE) and short (SINE) interspersed nuclear element repeated DNA sequences interspersed nuclear elements, respectively, which occupy about 45 % of the human genome. Increased expression levels of these sequences in the genome have been identified in many forms of malignant neoplasms. Their transposition occurs due to the expression of LINE1-encoded reverse transcriptase, whichis homologous to viral reverse transcriptase. To date, reverse transcriptase inhibitors of viruses of nucleoside and non-nucleoside structure have been developed and are successfully used in the clinic. These drugs demonstrate an inhibitory effect on both LINE1 reverse transcriptase and telomerase, which provides the tumor cell with the ability to overcome replicative senescence. Due to these properties, these compounds are expected to exhibit both their own antitumor activity and increase the sensitivity of tumor cells to the therapy of malignant neoplasms, which is experimentally confirmed in models of malignant tumors in vitro and in vivo. Use of reverse transcriptase inhibitors in combination therapy seems advisable both to prevent further genome rearrangements caused by LINE1 and to suppress the survival of tumor cells by inhibiting telomerase activity.

Diagnostic accuracy of Dengue NS1 lateral flow immunoassay in comparison to reverse transcriptase polymerase chain reaction and enzyme linked Immunosorbent Assay

The most widely used invitro diagnostic qualitative screening method for dengue virus infection is the lateral flow immunoassay technique. Testing of dengue non-structural antigen NS1 offers specificity in determining the active infection while testing of IgM and IgG helps in differentiating the primary and secondary dengue infections. The ELISA functions as the golden standard for dengue testing and PCR credits for the most accurate determination tool at the genetic level. The RT-PCR endorsed NS1 gene and in ELISA or LFIA NS1 antigen is used as the marker owing to the specificity and lesser chances of mutation effects. This study evaluated the performance of AG-Q Dengue NS1 LFIA kit in comparison with RT-PCR quantification cycle (Cq) Values and ELISA NS1 quantitation. The study also focused on differentiating the samples among dengue serotypes using the RealStar Dengue Type RT-PCR Kit 1.0. Dengue serotype 2 is the prominent viral strain in Kerala region succeeded by serotype 3 and 1 with a prevalence rate of 64 %, 20 % and 6 % respectively. Dengue serotype 4 was not reported during this study period. 10 % co-infection with DENV 1 & DENV 2 was also reported. The AG-Q Dengue NS1 kit stood as efficient in screening by providing positive results with samples having RT-PCR Cq values up to 43 and ELISA NS1 quantification minimum of 14 Panbio units.

Long-range gene editing of LMNA

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Hartstichting (Dutch Heart Foundation) Background Mutations in the LMNA gene commonly affect the cardiac muscle tissue, which leads to the development of a severe dilated cardiomyopathy with life-threatening arrhythmias. The lack of response to conventional heart failure therapy in these patients indicates the urgent need for new therapies. Gene editing has the potential to become a curative treatment for these patients by correcting the genetic cause of the disease. Prime editing is a promising new gene editing technology, which uses a prime editing guide RNA (pegRNA) to target a specific genetic locus and creates edits using a reverse-transcriptase enzyme linked to a Cas9-nickase. Purpose Conventional prime-editing technology targets one mutation per pegRNA. However, with more than 600 disease-causing mutations described in LMNA, the feasibility of applying this technology to each mutation is limited. Therefore, we aim to target not a single, but a set of mutations with one single pegRNA. Methods The pegRNAs are optimised by selecting the optimal target regions, improving their stability and 3D structure. The in vitro editing efficiency is assessed using the fluoPEER reporter plasmid, transfected into HEK293T cells. Using flow cytometry, expression of mCherry fluorescent protein is detected following successful editing of the target mutation. Results Flow-cytometry analysis of treated cells revealed an editing efficiency of 12% with a long-range pegRNA targeting a full exon, compared to 15% with a conventional short pegRNA targeting the same mutation &amp;lt;10bp downstream of the Cas9 nick site. This editing efficiency using the same long-range pegRNA was retained at 9% when editing at a distant position &amp;gt;100bp downstream of the nick site. To increase the editing efficiency, we improved the stability of the pegRNAs by the addition of different 3’ structural motifs. This resulted in an increased editing efficiencies of 15% and 17% for nearby and distant mutations, respectively. Conclusion We show that it is possible to edit different mutations within a range of up to 120 bp with a single pegRNA. By optimisations of the pegRNA 3D structure and optimal selection of target locations we aim to further improve the editing efficiency of this system. This work could eventually provide a prime editing therapy able to cure disease in a subset of patients carrying different mutations in the same genetic region. For LMNA-associated diseases this would substantially reduce the number of pegRNAs that have to be developed to cover all mutations, greatly improving the feasibility of prime editing therapy.

Novel telomerase reverse transcriptase gene mutation in a family with aplastic anaemia.

Telomerase Reverse Transcriptase (TERT) encodes the telomerase reverse transcriptase enzyme and is the most frequently mutated gene in patients with telomeropathies. Heterozygous variants impair telomerase activity by haploinsufficiency and pathogenic variants are associated with bone marrow failure syndrome and predisposition to acute myeloid leukaemia. Owing to their rarity, telomeropathies are often unrecognised and misdiagnosed. Herein, we report a novel TERT gene variant, c.2605G > A p.(Asp869Asn) in a family with hereditary aplastic anaemia. This report emphasises the importance of routine deep genetic screening for rare TERT variants in patients with a family history of cytopenia or aplastic anaemia, which could identify clinically inapparent telomere disorders.

A nanoemulsified formulation of dolutegravir and epigallocatechin gallate inhibits HIV-1 replication in cellular models.

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.

Incorporation of efavirenz inclusion complex In Dissolvable Microneedle for enhanced effectiveness of intravaginal drug delivery: A proof of concept study

Efavirenz (EFV) is one of the first line treatments of HIV infection. EFV is one of non-nucleoside reverse transcriptase inhibitors (NNRTIs) that can inhibit the responsible of reverse transcriptase enzyme for HIV replication. In oral administration, EFV exhibits low bioavailability (30–56 %) problem owing to its poor solubility (0.9 μg/mL). In this research, the poor solubility was overcome by formulating EFV as a complex inclusion (IC)with β-cyclodextrin (β-CD). Furthermore, considering the benefits of vaginal delivery, IC was further incorporated into dissolving microneedle systems (DMN) using polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) as biocompatible and biodegradable polymes. The results showed that EFV successfully formed IC by the change of the molecular shape with β-CD polymer, confirmed by FTIR and XRD. Importantly, the results showed that the formulation did not cause lysis and irritation on erythrocytes and blood vessels, showing the safety of this approach. Following its incorporation into DMN, IC-DMN could permeate the skin ex vivo as 78.70 ± 14.22 μg/cm3, which was about 3-times higher compared to DMN containing pure EFV and patch control. The in vivo pharmacokinetic study showed that the maximum plasma concentration of IC-DMN was 13.74 ± 2.48 μg/cm3, EFV-oral 6.27 ± 1,13 μg/cm3, vaginal gel 14.83 ± 3.65 μg/cm3. AUC values for each treatment was 147.33 ± 26.62 h μg/mL, 22.33 ± 4.03 h μg/mL, 63.33 ± 11.44 h μg/mL, respectively, indicating that the purpose of this study which was to increase the bioavailability of EFV was succefully achieved. Therefore, this combibation approach could be new alternative to HIV treatment using EFV in woman.

In Silico Study of Bioactive Compounds in Herba Sambiloto (Andrographis paniculata Burm. F. Nees) as HIV-1 Reverse Transcriptase Inhibitor

A medicinal plant known as sambiloto (Andrographis paniculata Burm. F. Nees) contains certain active compounds that potentially are anti-HIV. However, it is not yet known which compounds are involved in inhibiting HIV activity. This study aimed to identify potentially active compounds from the sambiloto plant that could inhibit the HIV-1 reverse transcriptase enzyme using the in-silico method. In silico methods that will be carried out are internal validation, molecular docking, ADMET prediction, and molecular dynamics. The molecular docking results showed that the five best compounds have potential as anti-HIV drugs compared to efavirenz with the rerank score -152.119 until -125.177 kcal/mol. In contrast, the rerank score of the comparison ligand is -94.7639 kcal/mol. The ADMET prediction showed that the selected compounds have a good pharmacokinetics profile and are nontoxic. The molecular dynamic results showed that deoxy-11,12-didehydroandrographiside and andropraphiside are stable and have potential as anti-HIV drugs with average RMSD values of 1.88 and 2.02 Å while the comparison ligand is 1.67 Å.

Noncanonical functions of telomerase and telomeres in viruses-associated cancer.

The cause of cancer is attributed to the uncontrolled growth and proliferation of cells resulting from genetic changes and alterations in cell behavior, a phenomenon known as epigenetics. Telomeres, protective caps on the ends of chromosomes, regulate both cellular aging and cancer formation. In most cancers, telomerase is upregulated, with the telomerase reverse transcriptase(TERT) enzyme and telomerase RNA component(TERC) RNA element contributing to the maintenance of telomere length. Additionally, it is noteworthy that two viruses, human papillomavirus (HPV) and Epstein-Barr virus (EBV), utilize telomerase for their replication or persistence in infected cells. Also, TERT and TERC may play major roles in cancer not related to telomere biology. They are involved in the regulation of gene expression, signal transduction pathways, cellular metabolism, or even immune response modulation. Furthermore, the crosstalk between TERT, TERC, RNA-binding proteins, and microRNAs contributes to a greater extent to cancer biology. To understand the multifaceted roles played by TERT and TERC in cancer and viral life cycles, and then to develop effective therapeutic strategies against these diseases, are fundamental for this goal. By investigating deeply, the complicated mechanisms and relationships between TERT and TERC, scientists will open the doors to new therapies. In its analysis, the review emphasizes the significance of gaining insight into the multifaceted roles that TERT and TERC play in cancer pathogenesis, as well as their involvement in the viral life cycle for designing effective anticancer therapy approaches.

Comparison of feline and human immunodeficiency virus reverse transcriptase enzymes through chemical screening and computational analysis.

Feline immunodeficiency virus (FIV) is a common infection found in domesticated and wild cats worldwide. Despite the wealth of therapeutic understanding of the disease in humans, considerably less information exists regarding the treatment of the disease in felines. Current treatment relies on drugs developed for the related human immunodeficiency virus (HIV) and includes compounds of the popular non-nucleotide reverse transcriptase (NNRTI) class. This is despite FIV-RT being only 67% similar to HIV-1 RT at the enzyme level, increasing to 88% for the allosteric pocket targeted by NNRTIs. The goal of this project was to try to quantify how well the more extensive pharmacological knowledge available for human disease translates to felines. To this end we screened known NNRTIs and 10 diverse pyrimidine analogs identified virtually. We use this chemo-centric probe approach to (a) assess the similarity between the two related RT targets based on the observed experimental inhibition values, (b) try to identify more potent inhibitors at FIV, and (c) gain a better appreciation of the structure-activity relationships (SAR). We found the correlation between IC50s at the two targets to be strong (r2 = 0.87) and identified compound 1 as the most potent inhibitor of FIV with IC50 of 0.030 μM ± 0.009. This compared to FIV IC50 values of 0.22 ± 0.17 μM, 0.040 ± 0.010 μM and >160 μM for known anti HIV-1 RT drugs Efavirenz, Rilpivirine, and Nevirapine, respectively. This knowledge, along with an understanding of the structural origin that give rise to any differences could improve the way HIV drugs are repurposed for FIV.

The Global Impact of HIV: A Comprehensive Review

The Human Immunodeficiency Virus (HIV) has been a significant global health challenge since its discovery in the 1980s, leading to the devastating Acquired Immunodeficiency Syndrome (AIDS). Despite advancements in medical research and antiretroviral therapies, HIV/AIDS remains a pressing public health concern, particularly in resource-limited regions. This comprehensive review provides updated data and scientific insights on the global impact of HIV, shedding light on the current state of the epidemic and the challenges faced in combating it. The review highlights the resurgence of HIV cases in Eastern European countries, such as Ukraine, Estonia, and Latvia, with surprising increases in AIDS cases observed in East Asian countries. However, it is in sub-Saharan Africa that the burden of HIV remains most acute, with high prevalence rates and a significant number of affected individuals. The region requires continued attention and resources to address the complex challenges associated with HIV prevention, treatment, and care. The article delves into the classification and structure of HIV, emphasizing its belonging to the Lentivirinae subfamily, specifically HIV-1 and HIV-2. HIV-1, the predominant viral species globally, exhibits a distinct clinical latency phase, contributing to its persistence and infectivity. The high replication rate and genetic variability of HIV, driven by the error-prone reverse transcriptase enzyme, result in the emergence of diverse subtypes and strains across different regions. Furthermore, the article explores the structural components of HIV-1, including the envelope glycoproteins (gp120 and gp41), matrix protein, and various enzymes critical to the viral life cycle. Despite progress in medical research and access to antiretroviral therapies, HIV/AIDS continues to present challenges such as limited resources, drug resistance, and regional disparities.

Brief Histories of Retroviral Integration Research and Associated International Conferences.

The field of retroviral integration research has a long history that started with the provirus hypothesis and subsequent discoveries of the retroviral reverse transcriptase and integrase enzymes. Because both enzymes are essential for retroviral replication, they became valued targets in the effort to discover effective compounds to inhibit HIV-1 replication. In 2007, the first integrase strand transfer inhibitor was licensed for clinical use, and subsequently approved second-generation integrase inhibitors are now commonly co-formulated with reverse transcriptase inhibitors to treat people living with HIV. International meetings specifically focused on integrase and retroviral integration research first convened in 1995, and this paper is part of the Viruses Special Issue on the 7th International Conference on Retroviral Integration, which was held in Boulder Colorado in the summer of 2023. Herein, we overview key historical developments in the field, especially as they pertain to the development of the strand transfer inhibitor drug class. Starting from the mid-1990s, research advancements are presented through the lens of the international conferences. Our overview highlights the impact that regularly scheduled, subject-specific international meetings can have on community-building and, as a result, on field-specific collaborations and scientific advancements.

Use of Recombinant Human Interferon Alpha in felines infected with FeLV

Abstract. The feline leukemia virus (FeLV) is a retrovirus that belongs to the genus Gammaretrovirus and exclusively affects felids. The virus carries the reverse transcriptase enzyme, which integrates into the host's DNA permanently, leading to different clinical conditions. The main complications caused by FeLV are hematopoietic neoplasms, immune-mediated disorders, neurological alterations and immunosuppression, among other ailments. The disease has no effective treatment, but antiviral and immunomodulatory drugs are still under trial. Using Recombinant Human Interferon Alpha has shown to be helpful in reducing clinical symptoms and controlling opportunistic infections, increasing the quality and life expectancy of cats infected with FeLV. Retroviruses are among the main causes of death in domestic cats. The lack of knowledge about the disease among guardians and growing cat population in Brazil are helping to increase the number of FeLV cases. Although the disease lacks a universal veterinary medical protocol, there are new studies and information available that can help to treat infected animals, improving their quality of life and expectancy and, in some cases, potentially eliminating the virus. This fact clashes with another reality: outdated professionals who are not familiar with the guidelines for Feline Retrovirus Testing and Management from the AAFP (American Association of Feline Practitioners), an international entity that since 1971 has been working to improve feline health by providing evidence-based guidelines for veterinary practices. Population growth and diseases that exclusively affect the species also highlight the need to include a deeper understanding of feline health in the curricula of undergraduate courses, preparing these future professionals to meet the demand for updated veterinarians with sufficient knowledge to care for the species.