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Introduction Virologic failure due to antiretroviral drug resistance is a threat to efforts to control the human immunodeficiency virus (HIV) epidemic. Understanding the factors that influence the genetic and clinical expression of drug resistance is fundamental for infection control. Methods A nested case-control study was conducted on a cohort of adult HIV patients between 2016 and 2022. The cases were defined as patients with a confirmed diagnosis of virologic failure due to drug resistance, as indicated by a viral genotype result. The control group consisted of patients who had not experienced virologic failure or undergone any documented changes to their antiretroviral treatment. The incidence of virologic failure over a defined period was calculated. The characteristics of each group were documented in frequency tables and measures of central tendency. To identify risk factors, multiple logistic regression models were employed, and post hoc tests were conducted. All calculations were performed with 95% confidence intervals, and p-values less than 0.05 were considered significant. Results The incidence of virologic failure over the seven-year study period was 9.2% (95% CI: 7.5-11.2%). Low CD4 T-lymphocyte count (≤200 cells/mm³) at diagnosis (adjOR 14.2, 95% CI: 3.1-64.5), history of opportunistic infections (adjOR 3.5, 95% CI: 1.9-6.4), and late enrollment into an HIV program after diagnosis (>1 year) (adjOR 9.2, 95% CI: 3.8-22.2) were identified as independent predictors of virologic failure. The drugs with the highest rates of resistance were nevirapine (84.6%), efavirenz (82.4%), emtricitabine (81.3%), lamivudine (81.3%), and atazanavir (6.6%). The most prevalent major mutations identified were K103N, M184V, and M46I/M. Approximately 50% of the secondary mutations were identified in protease regions. Conclusions The incidence of virologic failure was low in the study population. The identified risk characteristics allow for the prediction of the profile of patients susceptible to failure and for the early optimization of treatment regimens.
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Chikungunya virus (CHIKV) is an arbovirus causing acute febrile illness with severe joint pain, often leading to chronic arthralgia. This study investigated the adaptive immune responses during the early stages of symptomatic acute CHIKV infection, focusing on the transcription factors and cytokines linked to Th1, Th2, Th17, and Treg cells. Thirty-six individuals were enrolled: nine healthy controls and 27 CHIKV-positive patients confirmed by qRT-PCR. Blood samples were analyzed for the mRNA expression of transcription factors (Tbet, GATA3, FoxP3, STAT3, RORγt) and cytokines (IFN-γ, IL-4, IL-17, IL-22, TGF-ß, IL-10). The results showed the significant upregulation of Tbet, GATA3, FoxP3, STAT3, and RORγt in CHIKV-positive patients, with RORγt displaying the highest increase. Correspondingly, cytokines IFN-γ, IL-4, IL-17, and IL-22 were upregulated, while TGF-ß was downregulated. Principal component analysis (PCA) confirmed the distinct immune profiles between CHIKV-positive and healthy individuals. A correlation analysis indicated that higher Tbet expression correlated with a lower viral load, whereas FoxP3 and TGF-ß were associated with higher viral loads. Our study sheds light on the intricate immune responses during acute CHIKV infection, characterized by a mixed Th1, Th2, Th17, and Treg response profile. These results emphasize the complex interplay between different adaptive immune responses and how they may contribute to the pathogenesis of Chikungunya fever.
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Fiebre Chikungunya , Virus Chikungunya , Citocinas , Linfocitos T Colaboradores-Inductores , Humanos , Fiebre Chikungunya/inmunología , Fiebre Chikungunya/virología , Citocinas/metabolismo , Masculino , Femenino , Virus Chikungunya/inmunología , Adulto , Linfocitos T Colaboradores-Inductores/inmunología , Persona de Mediana Edad , Adulto Joven , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Linfocitos T Reguladores/inmunología , Inmunidad AdaptativaRESUMEN
Mayaro virus (MAYV) is the causative agent of Mayaro fever, which is characterized mainly by acute fever and long-term severe arthralgia, common manifestations of other arbovirus infections, making the correct diagnosis a challenge. Besides, MAYV infections have been reported in South America, especially in Brazil. However, the lack of vaccines or specific antiviral drugs to control these infections makes the search for new antivirals an urgent need. Herein, we evaluated the antiviral potential of synthetic ß-enaminoesters derivatives against MAYV replication and their pharmacokinetic and toxicological (ADMET) properties using in vitro and in silico strategies. For this purpose, Vero cells were infected with MAYV at an MOI of 0.1, treated with compounds (50 µM) for 24 h, and virus titers were quantified by plaque reduction assays. Compounds 2b (83.33%) and 2d (77.53%) exhibited the highest activity with inhibition rates of 83.33% and 77.53%, respectively. The most active compounds 2b (EC50 = 18.92 µM; SI > 52.85), and 2d (EC50 = 14.52 µM; SI > 68.87) exhibited higher potency and selectivity than the control drug suramin (EC50 = 38.97 µM; SI > 25.66). Then, we investigated the mechanism of action of the most active compounds. None of the compounds showed virucidal activity, neither inhibited virus adsorption, but compound 2b inhibited virus entry (62.64%). Also, compounds 2b and 2d inhibited some processes involved with the release of new virus particles. Finally, in silico results indicated good ADMET parameters of the most active compounds and reinforced their promising profile as drug candidates against MAYV.
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Alphavirus , Antivirales , Ésteres , Replicación Viral , Antivirales/farmacología , Antivirales/química , Chlorocebus aethiops , Animales , Células Vero , Ésteres/farmacología , Ésteres/química , Alphavirus/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Simulación por Computador , Brasil , Infecciones por Alphavirus/tratamiento farmacológico , Infecciones por Alphavirus/virologíaRESUMEN
Hepatitis C virus (HCV) belongs to the Flaviviridae family, and is a single-stranded RNA virus with positive polarity. It is the primary cause of hepatocellular carcinoma (HCC) worldwide. The treatment of HCV has entered a new era with the advent of direct-acting antiviral drugs (DAAs) and is associated with cure rates of more than 95 %, making HCV the only curable viral disease. The successful treatment of chronic hepatitis C has greatly reduced, but not eliminated, the risk of HCC. Certain individuals, especially those with cirrhosis already present, remain vulnerable to HCC after achieving a sustained virological response (SVR). This article systematically reviews the recent studies on the risk and mechanisms of HCC development after HCV viral cure, the screening and predictive value of biological markers, and patient surveillance. Factors such as older age, diabetes, hepatic fat accumulation, alcohol use, and lack of fibrosis reversal are linked to increased HCC risk after HCV cure. The mechanism of HCC development after DAAs treatment remains unclear, but the possible mechanisms include immune cell dysfunction during HCV infection, cytokine network imbalance, epigenetic alterations, and host factors. Several biological markers and risk prediction models have been used to monitor the risk of HCC in CHC patients who have achieved SVR, but most still require validation and standardization. The implementation of risk-stratified surveillance programs is becoming urgent from a cost-effective point of view, but the availability of validated biomarkers to predict HCC in cured patients remains an unmet clinical need. Additionally, managing CHC patients who achieve SVR is becoming a growing challenge as an increasing number of HCV patients are cured.
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OBJECTIVE: The role of Non-Alcoholic Fatty Liver Disease (NAFLD) on antiviral response in Chronic Hepatitis B (CHB) remains unclear. Previous studies mainly focus on the impact of the Non-Alcoholic Fatty Liver (NAFL) on antiviral efficacy, whereas the role of Non-Alcoholic Steatohepatitis (NASH) has not been highlighted. The authors aimed to investigate the association of NAFLD (NAFL and NASH), viral and histological characteristics with antiviral response. METHODS: The authors collected data of treatment-naïve CHB patients who underwent liver biopsy. All these patients received antiviral monotherapy and 48-week follow-up. The antiviral response was evaluated by Kaplan-Meier analysis. Cox regression analysis identified the variables associated with antiviral response. RESULTS: Overall, 120 treatment-naïve CHB patients were enrolled, with 49.2 % (59/120) of them were complicated by NAFLD. Male (Odd Ratio [OR = 4.222], 95 % Confidence Interval [95 % CI 1.620-11.003]) and overweight (OR = 8.709, 95 % CI 3.355-22.606) were independent predictors for concurrent NAFLD. After 48-week follow-up, the authors found that the overall antiviral response did not differ between CHB patients with and without concomitant NAFL/NASH (p > 0.05). High viral load (Hazard Ratio [HR = 0.522], 95 % CI 0.286-0.952), advanced fibrosis (HR = 2.426, 95 % CI 1.256-4.686), and moderate-to-severe interface hepatitis (HR = 2.541, 95 % CI 1.406-4.592) were significantly correlated with antiviral response after 8-week follow-up. CONCLUSION: Neither NAFL nor NASH had an impact on antiviral therapy for CHB. It was low hepatitis B load, advanced fibrosis, and moderate-to-severe interface hepatitis that contributed to the virological response.
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Antivirales , Hepatitis B Crónica , Hígado , Enfermedad del Hígado Graso no Alcohólico , Humanos , Masculino , Enfermedad del Hígado Graso no Alcohólico/patología , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/patología , Femenino , Antivirales/uso terapéutico , Adulto , Biopsia , Persona de Mediana Edad , Hígado/patología , Resultado del Tratamiento , Carga Viral , Estimación de Kaplan-Meier , Estudios RetrospectivosRESUMEN
Introduction: Human respiratory syncytial virus (hRSV) is a main cause of bronchiolitis in infants and its persistence has been described in immunocompromised subjects. However, limited evidence has been reported on the gene expression triggered by the hRSV and the effect of recombinant Taenia solium-derived calreticulin (rTsCRT). Methods: Using a comprehensive microarray approach, we analyzed the transcriptome profile of a macrophage cell line that has supported hRSV persistence for over 150 passages. We compared the gene expression of persistently infected and non-infected macrophages. We also evaluated the effect of rTsCRT on hRSV-infected macrophage gene transcription, as well as on cytokine production and number of copies of the persistent hRSV genome. Results: Our analysis showed that hRSV long-term virus infection significantly alters mRNA expression of antiviral, inflammatory, as well as arginine and lipid metabolism-associated genes, revealing a transcriptional signature that suggests a mixed M1/M2 phenotype. The resulting host-virus equilibrium allows for the regulation of viral replication, while evading the antiviral and proinflammatory responses. Interestingly, rTsCRT stimulus upregulated Tnfα, Il6 and Nos2 mRNA. We found increased levels of both proinflammatory cytokines and nitrite levels in the conditioned media of persistent macrophages treated with rTsCRT. This increase was associated with a significant reduction in viral genome copies. Discussion: hRSV persistently infected macrophages retain responsiveness to external stimuli and demonstrate that the profound changes induced by viral persistence are potentially reversible. Our observations contribute to the understanding of the mechanisms related to hRSV persistence in macrophages and have implications for the development of targeted therapies to eliminate persistent infections or reduce the negative effects related with chronic inflammatory diseases associated with hRSV infection.
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Aim: Influenza control demands multifaceted strategies, including antiviral drugs. Baloxavir, a recent addition to influenza treatment, acts as an inhibitor of the Polymerase acid (PA) component of the viral polymerase. However, mutations associated with resistance have been identified. Purpose: This study analyzed PA gene sequences of influenza A and B viruses (IAV and IBV, respectively) reported in the Americas, retrieved from databases published until May 2023, to identify primary markers of resistance to baloxavir. Patients and Methods: PA gene sequences were obtained from the GISAID and NCBI databases, focusing on countries in the Americas with 500 or more sequences for IAV, and 50 or more sequences for IBV. Results: Of the 58,816 PA sequences analyzed for IAV, only 55 (0.1%) harbored resistance markers, representing approximately 1 in 1000 occurrence. The most frequent markers were I38V (21 cases) and I38M (7 cases) at position 38 of PA, followed by E199G (9 cases) at position 199. For IBV, 14,684 sequences were analyzed, of which only eight presented a resistance marker (0.05%). Five sequences had the M34I marker, while the remaining three had the I38V marker. While frequency of resistance markers in PA is comparable to other regions, these results highlight the need for enhanced sequencing efforts, particularly in Latin America. Such efforts would serve to intensify influenza surveillance and inform public health interventions. Conclusion: While baloxavir demonstrates efficacy against influenza, resistance markers have been identified, including pre-existing ones. Our study adds eight (IAV: six and IBV: two) new spontaneously occurring substitutions to the existing literature, highlighting the need for continued surveillance. Among these, I38M stands out due to its significant tenfold reduction in drug susceptibility. Therefore, vigilant monitoring of these resistance markers in IAV and IBV remains crucial for maintaining baloxavir's effectiveness and informing future public health interventions.
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Anacardic acids are natural compounds found in various plant families, such as Anacardiaceae, Geraniaceae, Ginkgoaceae, and Myristicaceae, among others. Several activities have been reported regarding these compounds, including antibacterial, antioxidant, anticancer, anti-inflammatory, and antiviral activities, showing the potential therapeutic applicability of these compounds. From a chemical point of view, they are structurally made up of salicylic acids substituted by an alkyl chain containing unsaturated bonds, which can vary in number and position, determining their bioactivity and differentiating them from the various existing forms. Our work aimed to explore the potential of anacardic acids, based on studies that address the bioactivity of these compounds, as well as to establish a greater understanding of the structure-activity relationship of these compounds through in silico methods, with a focus on the elucidation of a possible drug target through the application of computer-aided drug design, CADD.
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The COVID-19 pandemic has revealed weaknesses in healthcare systems and underscored the need for advanced antimicrobial materials. This study investigates the quaternization of agar, a seaweed-derived polysaccharide, and the development of electrospun membranes for air filtration in facemasks and biomedical applications. Using the betacoronavirus MHV-3 as a model, quaternized agar and membranes achieved a 90-99.99 % reduction in viral load, without associated cytotoxicity. The quaternization process reduced the viscosity of the solution from 1.19 ± 0.005 to 0.64 ± 0.005 Pa.s and consequently the electrospun fiber diameter ranged from 360 to 185 nm. Membranes synthesized based on polyvinyl alcohol and thermally cross-linked with citric acid exhibited lower water permeability. Avoiding organic solvents in the electrospinning technique ensured eco-friendly production. This approach offers a promising way to develop biocompatible and functional materials for healthcare and environmental applications.
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Agar , SARS-CoV-2 , Agar/química , SARS-CoV-2/efectos de los fármacos , COVID-19/virología , COVID-19/prevención & control , Humanos , Inactivación de Virus/efectos de los fármacos , Viscosidad , Membranas Artificiales , Animales , Alcohol Polivinílico/química , Alcohol Polivinílico/farmacología , Pandemias/prevención & control , Chlorocebus aethiops , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacologíaRESUMEN
Antiviral peptides (AVPs) represent a promising strategy for addressing the global challenges of viral infections and their growing resistances to traditional drugs. Lab-based AVP discovery methods are resource-intensive, highlighting the need for efficient computational alternatives. In this study, we developed five non-trained but supervised multi-query similarity search models (MQSSMs) integrated into the StarPep toolbox. Rigorous testing and validation across diverse AVP datasets confirmed the models' robustness and reliability. The top-performing model, M13+, demonstrated impressive results, with an accuracy of 0.969 and a Matthew's correlation coefficient of 0.71. To assess their competitiveness, the top five models were benchmarked against 14 publicly available machine-learning and deep-learning AVP predictors. The MQSSMs outperformed these predictors, highlighting their efficiency in terms of resource demand and public accessibility. Another significant achievement of this study is the creation of the most comprehensive dataset of antiviral sequences to date. In general, these results suggest that MQSSMs are promissory tools to develop good alignment-based models that can be successfully applied in the screening of large datasets for new AVP discovery.
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BACKGROUND: Currently, there is no antiviral licensed to treat chikungunya fever, a disease caused by the infection with Alphavirus chikungunya (CHIKV). Treatment is based on analgesic and anti-inflammatory drugs to relieve symptoms. Our study aimed to evaluate the antiviral activity of sulfadoxine (SFX), an FDA-approved drug, and its derivatives complexed with silver(I) (AgSFX), salicylaldehyde Schiff base (SFX-SL), and with both Ag and SL (AgSFX-SL) against CHIKV. METHODS: The anti-CHIKV activity of SFX and its derivatives was investigated using BHK-21 cells infected with CHIKV-nanoluc, a marker virus-carrying nanoluciferase reporter. Dose-response and time of drug-addition assays were performed in order to assess the antiviral effects of the compounds, as well as in silico data and ATR-FTIR analysis for insights on their mechanisms of action. RESULTS: The SFX inhibited 34% of CHIKV replication, while AgSFX, SFX-SL, and AgSFX-SL enhanced anti-CHIKV activity to 84%, 89%, and 95%, respectively. AgSFX, SFX-SL, and AgSFX-SL significantly decreased viral entry and post-entry to host cells, and the latter also protected cells against infection. Additionally, molecular docking calculations and ATR-FTIR analysis demonstrated interactions of SFX-SL, AgSFX, and AgSFX-SL with CHIKV. CONCLUSIONS: Collectively, our findings suggest that the addition of metal ions and/or Schiff base to SFX improved its antiviral activity against CHIKV.
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Antivirales , Fiebre Chikungunya , Virus Chikungunya , Sulfadoxina , Virus Chikungunya/efectos de los fármacos , Antivirales/farmacología , Antivirales/química , Animales , Línea Celular , Sulfadoxina/farmacología , Fiebre Chikungunya/tratamiento farmacológico , Fiebre Chikungunya/virología , Cricetinae , Bases de Schiff/farmacología , Plata/farmacología , Plata/química , Replicación Viral/efectos de los fármacos , Simulación del Acoplamiento Molecular , Relación Dosis-Respuesta a Droga , Humanos , AldehídosRESUMEN
Dengue, caused by the dengue virus (DENV), is a global health threat transmitted by Aedes mosquitoes, resulting in 400 million cases annually. The disease ranges from mild to severe, with potential progression to hemorrhagic dengue. Current research is focused on natural antivirals due to challenges in vector control. This study evaluates the antiviral potential of peptides derived from the microalgae Phaeodactylum tricornutum, known for its bioactive compounds. Microalgae were cultivated under controlled conditions, followed by protein extraction and hydrolysis to produce four peptide fractions. These fractions were assessed for cytotoxicity via the MTT assay and antiviral activity against DENV serotype 2 using flow cytometry and plaque formation assays. The 10-30 kDa peptide fraction, at 150 and 300 µg/mL concentrations, demonstrated no cytotoxicity and significantly reduced the percentage of infected cells and viral titers. These findings suggest that peptides derived from Phaeodactylum tricornutum exhibit promising antiviral activity against dengue virus serotype 2, potentially contributing to developing new therapeutic approaches for dengue.
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Antivirales , Virus del Dengue , Microalgas , Virus del Dengue/efectos de los fármacos , Antivirales/farmacología , Antivirales/química , Animales , Hidrolisados de Proteína/farmacología , Hidrolisados de Proteína/química , Dengue/tratamiento farmacológico , Dengue/virología , Péptidos/farmacología , Péptidos/química , Serogrupo , Chlorocebus aethiops , Humanos , Aedes/efectos de los fármacos , Células VeroRESUMEN
The treatment of recurrent genital herpes typically involves daily doses of acyclovir for extended periods. Additive manufacturing is an intriguing technique for creating personalised drug delivery systems, which can enhance the effectiveness of treatments for various diseases. The vaginal route offers a viable alternative for the systemic administration of drugs with low oral bioavailability. In this study, we produced different grades of thermoplastic polyurethane (TPU) filaments through hot-melt extrusion, with acyclovir concentrations of 0%, 10%, and 20% by weight. We used fused filament fabrication to manufacture matrix-based devices, including intrauterine devices and intravaginal rings. Our results, obtained through SEM, FTIR, and DSC analyses, confirm the successful incorporation of acyclovir into the matrix. Thermal analysis reveals that the manufacturing process alters the organization of the TPU chains, resulting in a slight reduction in crystallinity. In our in-vitro tests, we observed an initial burst release on the first day, followed by sustained release at reduced rates for up to 145 days, demonstrating their potential for long-term applications. Additionally, cytotoxicity analysis suggests the excellent biocompatibility of the printed devices, and biological assays show a remarkable 99% reduction in HSV-1 replication. In summary, TPU printed devices offer a promising alternative for long-term genital herpes treatment, with the results obtained potentially contributing to the advancement of pharmaceutical manufacturing.
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OBJECTIVE: In this study, we have synthesized 19 Thiazolidine (TZD) derivatives to investigate their potential anti-ZIKV effects. METHODS: Nineteen thiazolidine derivatives were synthesized and evaluated for their cytotoxicity and antiviral activity against the ZIKA virus. RESULTS: Among them, six demonstrated remarkable selectivity against the ZIKV virus, exhibiting IC50 values of <5µM, and the other compounds did not demonstrate selectivity for the virus. Interestingly, several derivatives effectively suppressed the replication of ZIKV RNA copies, with derivatives significantly reducing ZIKV mRNA levels at 24 hours post-infection (hpi). Notably, two derivatives (ZKC-4 and -9) stood out by demonstrating a protective effect against ZIKV cell entry. Informed by computational analysis of binding affinity and intermolecular interactions within the NS5 domain's N-7 and O'2 positions, ZKC-4 and FT-39 displayed the highest predicted affinities. Intriguingly, ZKC-4 and ZKC-9 derivatives exhibited the most favorable predicted binding affinities for the ZIKV-E binding site. CONCLUSION: The significance of TZDs as potent antiviral agents is underscored by these findings, suggesting that exploring TZD derivatives holds promise for advancing antiviral therapeutic strategies.
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Antivirales , Tiazolidinas , Virus Zika , Antivirales/farmacología , Antivirales/química , Antivirales/síntesis química , Tiazolidinas/farmacología , Tiazolidinas/química , Tiazolidinas/síntesis química , Virus Zika/efectos de los fármacos , Humanos , Relación Estructura-Actividad , Estructura Molecular , Replicación Viral/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Relación Dosis-Respuesta a Droga , Animales , Chlorocebus aethiops , Células Vero , Simulación del Acoplamiento MolecularRESUMEN
Foot and mouth disease (FMD) is a highly contagious infection caused by FMD-virus (FMDV) that affects livestock worldwide with significant economic impact. The main strategy for the control is vaccination with FMDV chemically inactivated with binary ethylenimine (FMDVi). In FMDV infection and vaccination, B cell response plays a major role by providing neutralizing/protective antibodies in animal models and natural hosts. Extracellular vesicles (EVs) and small EVs (sEVs) such as exosomes are important in cellular communication. EVs secreted by antigen-presenting cells (APC) like dendritic cells (DCs) participate in the activation of B and T cells through the presentation of native antigen membrane-associated to B cells or by transferring MHC-peptide complexes to T cells and even complete antigens from DCs. In this study, we demonstrate for the first time that APC activated with the FMDVi O1 Campos vaccine-antigens secrete EVs expressing viral proteins/peptides that could stimulate FMDV-specific immune response. The secretion of EVs-FMDVi is a time-dependent process and can only be isolated within the first 24 h post-activation. These vesicles express classical EVs markers (CD9, CD81, and CD63), along with immunoregulatory molecules (MHC-II and CD86). With an average size of 155 nm, they belong to the category of EVs. Studies conducted in vitro have demonstrated that EVs-FMDVi express antigens that can stimulate a specific B cell response against FMDV, including both marginal zone B cells (MZB) and follicular B cells (FoB). These vesicles can also indirectly or directly affect T cells, indicating that they express both B and T epitopes. Additionally, lymphocyte expansion induced by EVs-FMDVi is greater in splenocytes that have previously encountered viral antigens in vivo. The present study sheds light on the role of EVs derived from APC in regulating the adaptive immunity against FMDV. This novel insight contributes to our current understanding of the immune mechanisms triggered by APC during the antiviral immune response. Furthermore, these findings may have practical implications for the development of new vaccine platforms, providing a rational basis for the design of more effective vaccines against FMDV and other viral diseases.
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Células Presentadoras de Antígenos , Antígenos Virales , Linfocitos B , Vesículas Extracelulares , Virus de la Fiebre Aftosa , Fiebre Aftosa , Vacunas Virales , Animales , Virus de la Fiebre Aftosa/inmunología , Vesículas Extracelulares/inmunología , Linfocitos B/inmunología , Fiebre Aftosa/inmunología , Fiebre Aftosa/prevención & control , Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/metabolismo , Antígenos Virales/inmunología , Vacunas Virales/inmunología , Proteínas Virales/inmunología , Activación de Linfocitos/inmunología , Células Dendríticas/inmunología , Presentación de Antígeno/inmunologíaRESUMEN
Since human angiotensin-converting enzyme 2 (ACE2) serves as a primary receptor for SARS-CoV-2, characterizing ACE2 regions that allow SARS-CoV-2 to enter human cells is essential for designing peptide-based antiviral blockers and elucidating the pathogenesis of the virus. We identified and synthesized a 25-mer mimetic peptide (encompassing positions 22-46 of the ACE2 alpha-helix α1) implicated in the S1 receptor-binding domain (RBD)-ACE2 interface. The mimetic (wild-type, WT) ACE2 peptide significantly inhibited SARS-CoV-2 infection of human pulmonary Calu-3 cells in vitro. In silico protein modeling predicted that residues F28, K31, F32, F40, and Y41 of the ACE2 alpha-helix α1 are critical for the original, Delta, and Omicron strains of SARS-CoV-2 to establish the Spike RBD-ACE2 interface. Substituting these residues with alanine (A) or aspartic acid (D) abrogated the antiviral protective effect of the peptides, indicating that these positions are critical for viral entry into pulmonary cells. WT ACE2 peptide, but not the A or D mutated peptides, exhibited significant interaction with the SARS-CoV-2 S1 RBD, as shown through molecular dynamics simulations. Through identifying the critical amino acid residues of the ACE2 alpha-helix α1, which is necessary for the Spike RBD-ACE2 interface and mobilized during the in vitro viral infection of cells, we demonstrated that the WT ACE2 peptide protects susceptible K18-hACE2 mice against in vivo SARS-CoV-2 infection and is effective for the treatment of COVID-19.
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Enzima Convertidora de Angiotensina 2 , COVID-19 , Péptidos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/química , Humanos , Animales , SARS-CoV-2/efectos de los fármacos , COVID-19/virología , Ratones , Glicoproteína de la Espiga del Coronavirus/metabolismo , Glicoproteína de la Espiga del Coronavirus/química , Péptidos/farmacología , Péptidos/química , Péptidos/uso terapéutico , Tratamiento Farmacológico de COVID-19 , Antivirales/farmacología , Antivirales/química , Línea Celular , Neumonía/tratamiento farmacológico , Neumonía/virología , Neumonía/prevención & control , Pulmón/virología , Pulmón/patología , FemeninoRESUMEN
In severe COVID-19 cases, an exacerbated inflammatory response triggers a cytokine storm that can worsen the prognosis. Compounds with both antiviral and anti-inflammatory activities show promise as candidates for COVID-19 therapy, as they potentially act against the SARS-CoV-2 infection regardless of the disease stage. One of the most attractive drug targets among coronaviruses is the main protease (MPro). This enzyme is crucial for cleaving polyproteins into non-structural proteins required for viral replication. The aim of this review was to identify SARS-CoV-2 MPro inhibitors with both antiviral and anti-inflammatory properties. The interactions of the compounds within the SARS-CoV-2 MPro binding site were analyzed through molecular docking when data from crystallographic structures were unavailable. 18 compounds were selected and classified into five different superclasses. Five of them exhibit high potency against MPro: GC-376, baicalein, naringenin, heparin, and carmofur, with IC50 values below 0.2 µM. The MPro inhibitors selected have the potential to alleviate lung edema and decrease cytokine release. These molecules mainly target three critical inflammatory pathways: NF-κB, JAK/STAT, and MAPK, all previously associated with COVID-19 pathogenesis. The structures of the compounds occupy the S1/S2 substrate binding subsite of the MPro. They interact with residues from the catalytic dyad (His41 and Cys145) and/or with the oxyanion hole (Gly143, Ser144, and Cys145), which are pivotal for substrate recognition. The MPro SARS-CoV-2 inhibitors with potential anti-inflammatory activities present here could be optimized for maximum efficacy and safety and be explored as potential treatment of both mild and severe COVID-19.
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Antiinflamatorios , Antivirales , Tratamiento Farmacológico de COVID-19 , Proteasas 3C de Coronavirus , SARS-CoV-2 , Humanos , Antiinflamatorios/farmacología , SARS-CoV-2/efectos de los fármacos , Antivirales/farmacología , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Proteasas 3C de Coronavirus/metabolismo , Simulación del Acoplamiento Molecular , COVID-19 , Síndrome de Liberación de Citoquinas/tratamiento farmacológico , AnimalesRESUMEN
At the end of 2019, the world witnessed the beginning of the COVID-19 pandemic. As an aggressive viral infection, the entire world remained attentive to new discoveries about the SARS-CoV-2 virus and its effects in the human body. The search for new antivirals capable of preventing and/or controlling the infection became one of the main goals of research during this time. New biocompounds from marine sources, especially microalgae and cyanobacteria, with pharmacological benefits, such as anticoagulant, anti-inflammatory and antiviral attracted particular interest. Polysaccharides (PS) and extracellular polymeric substances (EPS), especially those containing sulfated groups in their structure, have potential antiviral activity against several types of viruses including HIV-1, herpes simplex virus type 1, and SARS-CoV-2. We review the main characteristics of PS and EPS with antiviral activity, the mechanisms of action, and the different extraction methodologies from microalgae and cyanobacteria biomass.
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Arboviruses are etiological agents in an extensive group of emerging diseases with great clinical relevance in Brazil, due to the wide distribution of their vectors and the favorable environmental conditions. Among them, the Mayaro virus (MAYV) has drawn attention since its emergence as the etiologic agent of Mayaro fever, a highly debilitating disease. To study viral replication and identify new drug candidates, traditional antiviral assays based on viral antigens and/or plaque assays have been demonstrating low throughput, making it difficult to carry out larger-scale assays. Therefore, we developed and characterized two DNA-launched infectious clones reporter viruses based on the MAYV strain BeAr 20290 containing the reporter genes of firefly luciferase (FLuc) and nanoluciferase (NLuc), designated as MAYV-firefly and MAYV-nanoluc, respectively. The viruses replicated efficiently with similar properties to the parental wild-type MAYV, and luminescence expression levels reflected viral replication. Reporter genes were also preserved during passage in cell culture, remaining stably expressed for one round of passage for MAYV-firefly and three rounds for MAYV-nanoluc. Employing the infectious clone, we described the effect of Rimantadine, an FDA-approved Alzheimer's drug, as a repurposing agent for MAYV but with a broad-spectrum activity against Zika virus infection. Additionally, we validated MAYV-nanoluc as a tool for antiviral drug screening using the compound EIDD-2749 (4'-Fluorouridine), which acts as an inhibitor of alphavirus RNA-dependent RNA polymerase.
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Although the disease caused by chikungunya virus (CHIKV) is of great interest to public health organizations around the world, there are still no authorized antivirals for its treatment. Previously, dihalogenated anti-CHIKV compounds derived from L-tyrosine (dH-Y) were identified as being effective against in vitro infection by this virus, so the objective of this study was to determine the mechanisms of its antiviral action. Six dH-Y compounds (C1 to C6) dihalogenated with bromine or chlorine and modified in their amino groups were evaluated by different in vitro antiviral strategies and in silico tools. When the cells were exposed before infection, all compounds decreased the expression of viral proteins; only C4, C5 and C6 inhibited the genome; and C1, C2 and C3 inhibited infectious viral particles (IVPs). Furthermore, C1 and C3 reduce adhesion, while C2 and C3 reduce internalization, which could be related to the in silico interaction with the fusion peptide of the E1 viral protein. Only C3, C4, C5 and C6 inhibited IVPs when the cells were exposed after infection, and their effect occurred in late stages after viral translation and replication, such as assembly, and not during budding. In summary, the structural changes of these compounds determine their mechanism of action. Additionally, C3 was the only compound that inhibited CHIKV infection at different stages of the replicative cycle, making it a compound of interest for conversion as a potential drug.