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Introduction: Influenza A virus (IAV) is one of the leading causes of respiratory tract infections in humans, representing a major public health concern. The various types of cell death have a crucial role in IAV pathogenesis because this virus may trigger both apoptosis and necroptosis in airway epithelial cells in parallel. Macrophages play an important role in the clearance of virus particles, priming the adaptive immune response in influenza. However, the contribution of macrophage death to pathogenesis of IAV infection remains unclear. Methods: In this work, we investigated IAV-induced macrophage death, along with potential therapeutic intervention. We conducted in vitro and in vivo experiments to evaluate the mechanism and the contribution of macrophages death to the inflammatory response induced by IAV infection. Results: We found that IAV or its surface glycoprotein hemagglutinin (HA) triggers inflammatory programmed cell death in human and murine macrophages in a Toll-like receptor-4 (TLR4)- and TNF-dependent manner. Anti-TNF treatment in vivo with the clinically approved drug etanercept prevented the engagement of the necroptotic loop and mouse mortality. Etanercept impaired the IAV-induced proinflammatory cytokine storm and lung injury. Conclusion: In summary, we demonstrated a positive feedback loop of events that led to necroptosis and exacerbated inflammation in IAV-infected macrophages. Our results highlight an additional mechanism involved in severe influenza that could be attenuated with clinically available therapies.
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Virus de la Influenza A , Gripe Humana , Humanos , Animales , Ratones , Etanercept , Inhibidores del Factor de Necrosis Tumoral , Apoptosis , MacrófagosRESUMEN
Human immunodeficiency virus type 1 (HIV-1) is a public health problem that affects over 38 million people worldwide. Although there are highly active antiretroviral therapies, emergence of antiviral resistant strains is a problem which leads to almost a million death annually. Thus, the development of new drugs is necessary. The viral enzyme reverse transcriptase (RT) represents a validated therapeutic target. Because the oxoquinolinic scaffold has substantial biological activities, including antiretroviral, a new series of 4-oxoquinoline ribonucleoside derivatives obtained by molecular hybridization were studied here. All synthesized compounds were tested against human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT), and 9a and 9d displayed the highest antiviral activities, with IC50 values of 1.4 and 1.6 µM, respectively. These compounds were less cytotoxic than AZT and showed CC50 values of 1486 and 1394 µM, respectively. Molecular docking studies showed that the most active compounds bound to the allosteric site of the enzyme, suggesting a low susceptibility to the development of antiviral resistance. In silico pharmacokinetic and toxicological evaluations reinforced the potential of the active compounds as anti-HIV candidates for further exploration. Overall, this work showed that compounds 9a and 9d are promising scaffold for future anti-HIV-1 RT drug design.
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4-Quinolonas/farmacología , Fármacos Anti-VIH/farmacología , Transcriptasa Inversa del VIH/antagonistas & inhibidores , VIH-1/efectos de los fármacos , Inhibidores de la Transcriptasa Inversa/farmacología , Ribonucleósidos/farmacología , 4-Quinolonas/síntesis química , 4-Quinolonas/química , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Transcriptasa Inversa del VIH/metabolismo , VIH-1/metabolismo , Humanos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Estructura Molecular , Inhibidores de la Transcriptasa Inversa/síntesis química , Inhibidores de la Transcriptasa Inversa/química , Ribonucleósidos/síntesis química , Ribonucleósidos/química , Relación Estructura-ActividadRESUMEN
BACKGROUND: Since the influenza virus is the main cause of acute seasonal respiratory infections and pandemic outbreaks, antiviral drugs are critical to mitigate infections and impair chain of transmission. Neuraminidase inhibitors (NAIs) are the main class of anti-influenza drugs in clinical use. Nevertheless, resistance to oseltamivir (OST), the most used NAI, has been detected in circulating strains of the influenza virus. Therefore, novel compounds with anti-influenza activity are necessary. OBJECTIVE: To verify whether the NA from influenza A and B virus is susceptible to the compound 4-(4- phenyl-1H-1,2,3-triazol-1-yl)-2,2,6,6-tetramethylpiperidine-1-oxyl (Tritempo). METHODS: Cell-free neuraminidase inhibition assays were performed with Tritempo, using wild-type (WT) and OST-resistant influenza strains. Cell-based assays in MDCKs were performed to confirm Tritempo`s antiviral activity and cytotoxicity. Multiple passages of the influenza virus in increasing concentrations of our compound, followed by the sequencing of NA gene and molecular docking, were used to identify our Tritempo's target. RESULTS AND DISCUSSION: Indeed, Tritempo inhibited the neuraminidase activity of WT and OSTresistant strains of influenza A and B, at the nanomolar range. Tritempo bound to WT and OST-resistant influenza NA isoforms at the sialic acid binding site with low free binding energies. Cell-free assays were confirmed using a prototypic influenza A infection assay in MDCK cells, in which we found an EC50 of 0.38 µM, along with very low cytotoxicity, CC50 > 2,000 µM. When we passaged the influenza A virus in the presence of Tritempo, a mutant virus with the G248P change in the NA was detected. This mutant was resistant to Tritempo but remained sensitive to OST, indicating no cross-resistance between the studied and reference drugs. CONCLUSION: Our results suggest that Tritempo's chemical structure is a promising one for the development of novel antivirals against influenza.
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Antivirales/farmacología , Inhibidores Enzimáticos/farmacología , Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza B/efectos de los fármacos , Neuraminidasa/antagonistas & inhibidores , Piperidinas/farmacología , Tiazoles/farmacología , Triazoles/farmacología , Antivirales/síntesis química , Antivirales/química , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Virus de la Influenza A/enzimología , Virus de la Influenza B/enzimología , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Estructura Molecular , Neuraminidasa/metabolismo , Piperidinas/síntesis química , Piperidinas/química , Relación Estructura-Actividad , Tiazoles/síntesis química , Tiazoles/química , Triazoles/síntesis química , Triazoles/químicaRESUMEN
BACKGROUND: Neuraminidase inhibitors (NAIs) are the only class of antivirals in clinical use against influenza virus approved worldwide. However, approximately 1-3% of circulating strains present resistance mutations to oseltamivir (OST), the most used NAI. Therefore, it is important to catalogue new molecules to inhibit influenza virus, especially OST-resistant strains. Natural products from tropical plants used for human consumption represent a worthy class of substances. Their use could be stimulated in resource-limited setting where the access to expensive antiviral therapies is restricted. METHODS: We evaluated the anti-influenza virus activity of agathisflavone derived from Anacardium occidentale L. RESULTS: The neuraminidase (NA) activity of wild-type and OST-resistant influenza virus was inhibited by agathisflavone, with IC50 values ranging from 20 to 2.0 µM, respectively. Agathisflavone inhibited influenza virus replication with EC50 of 1.3 µM. Sequential passages of the virus in the presence of agathisflavone revealed the emergence of mutation R249S, A250S and R253Q in the NA gene. These changes are outside the OST binding region, meaning that agathisflavone targets this viral enzyme at a region different than conventional NAIs. CONCLUSION: Altogether our data suggest that agathisflavone has a promising chemical structure for the development of anti-influenza drugs.
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Anacardium/química , Biflavonoides/farmacología , Inhibidores Enzimáticos/farmacología , Neuraminidasa/antagonistas & inhibidores , Orthomyxoviridae/efectos de los fármacos , Fitoquímicos/farmacología , Animales , Biflavonoides/química , Biflavonoides/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Perros , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Células de Riñón Canino Madin Darby/efectos de los fármacos , Células de Riñón Canino Madin Darby/virología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Neuraminidasa/metabolismo , Orthomyxoviridae/enzimología , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacosRESUMEN
BACKGROUND: According to the World Health Organization (WHO), the fight against Acquired Immunodeficiency Syndrome (AIDS) is still one of the most significant challenges facing humanity. Worldwide, it is estimated that 36.7 million people are infected by the Human Immunodeficiency Virus (HIV). Despite the variety of available drugs, the search for new enzymatic inhibitors of HIV is still important due to the presence of adverse effects and the development of resistant strains. Therefore, the present study aimed to design, synthesize, and biologically evaluate novel inhibitors of HIV Reverse Transcriptase (RT). MATERIALS AND METHODS: These compounds were obtained in two series, and compounds in both series contain a 1,2,3-triazole ring in their structures. The compounds in the first series are Efavirenz (EFV) analogues with the N-1 position substituted by another important fragment as described in the medicinal chemistry literature on anti-HIV drugs. The second series has a phosphonate chain similar to that in the structure of Tenofovir Disoproxil Fumarate (TDF). RESULTS AND CONCLUSION: The results of the biological evaluation showed that all compounds presented high RT inhibition values and lower or comparable inhibitory concentrations (the concentration needed to reduce the enzymatic activity by 50%, IC50 values, 0.8-1.9 µM). Among the compounds in the first series, the three with the lowest IC50 values had values between 0.8-0.9 µM, and of those in the second series, the most potent had an IC50 value of 1.1 µM; compounds in both series were equipotent to TDF (1.2 µM). Thus, the new compounds could be considered lead compounds for the development of new antiretroviral compounds.
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Fármacos Anti-VIH/farmacología , Benzoxazinas/farmacología , Transcriptasa Inversa del VIH/antagonistas & inhibidores , VIH-1/efectos de los fármacos , Organofosfonatos/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Triazoles/farmacología , Alquinos , Fármacos Anti-VIH/química , Benzoxazinas/química , Ciclopropanos , Relación Dosis-Respuesta a Droga , Transcriptasa Inversa del VIH/metabolismo , VIH-1/enzimología , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Organofosfonatos/química , Inhibidores de la Transcriptasa Inversa/química , Relación Estructura-Actividad , Triazoles/químicaRESUMEN
Zika virus (ZIKV), an arthropod-born Flavivirus, has been associated with a wide range of neurological diseases in adults, foetuses and neonates. Since no vaccine is available, repurposing of antiviral drugs currently in medical use is necessary. Mefloquine has confirmed anti-ZIKV activity. We used medicinal chemistry-driven approaches to synthesize and evaluate the ability of a series of new 2,8-bis(trifluoromethyl)quinoline derivatives to inhibit ZIKV replication in vitro, in order to improve the potency of mefloquine. We found that quinoline derivatives 3a and 4 were the most potent compounds within this series, both with mean EC50 values of 0.8 µM, which represents a potency 5 times that of mefloquine. These results indicate that new 2,8-bis(trifluoromethyl)quinoline chemical structures may be promising for the development of novel anti-ZIKV drugs.
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Antivirales/química , Antivirales/farmacología , Mefloquina/farmacología , Quinolinas/química , Quinolinas/farmacología , Virus Zika/efectos de los fármacos , Animales , Antivirales/síntesis química , Antivirales/toxicidad , Chlorocebus aethiops , Diseño de Fármacos , Quinolinas/síntesis química , Quinolinas/toxicidad , Relación Estructura-Actividad , Células Vero , Replicación Viral/efectos de los fármacos , Virus Zika/fisiologíaRESUMEN
Zika virus (ZIKV), an emerging Flavivirus, was recently associated with severe neurological complications and congenital diseases. Therefore, development of antiviral agents capable of inhibiting ZIKV replication is urgent. Chloroquine is a molecule with a confirmed safety history for use with pregnant women, and has been found to exhibit anti-ZIKV activity at concentrations around 10 µM. This suggests that modifications to the chloroquine structure could be promising for obtaining more effective anti-ZIKV agents. Here, we report the ability of a series of N-(2-(arylmethylimino)ethyl)-7-chloroquinolin-4-amine derivatives to inhibit ZIKV replication in vitro. We have found that the quinoline derivative, N-(2-((5-nitrofuran-2-yl)methylimino)ethyl)-7-chloroquinolin-4-amine, 40, was the most potent compound within this series, reducing ZIKV replication by 72% at 10 µM. Compound 40 exhibits an EC50 value of 0.8 ± 0.07 µM, compared to that of chloroquine of 12 ± 3.2 µM. Good activities were also obtained for other compounds, including those with aryl groups = phenyl, 4-fluorophenyl, 4-nitrophenyl, 2,6-dimethoxyphenyl, 3-pyridinyl and 5-nitrothien-2-yl. Syntheses of these quinoline derivatives have been obtained both by thermal and ultrasonic means. The ultrasonic method produced comparable yields to the thermal (reflux) method in very much shorter times 30-180 s compared to 30-180 min reactions times. These results indicate that this group of compounds is a good follow-up point for the potential discovery of new drugs against the Zika disease.
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Antivirales/síntesis química , Antivirales/farmacología , Cloroquina/síntesis química , Cloroquina/farmacología , Temperatura , Ondas Ultrasónicas , Virus Zika/efectos de los fármacos , Animales , Antivirales/química , Chlorocebus aethiops , Cloroquina/química , Cloroquina/toxicidad , Células Vero , Replicación Viral/efectos de los fármacos , Virus Zika/fisiologíaRESUMEN
Zika virus (ZIKV) is a member of the Flaviviridae family, along with other agents of clinical significance such as dengue (DENV) and hepatitis C (HCV) viruses. Since ZIKV causes neurological disorders during fetal development and in adulthood, antiviral drugs are necessary. Sofosbuvir is clinically approved for use against HCV and targets the protein that is most conserved among the members of the Flaviviridae family, the viral RNA polymerase. Indeed, we found that sofosbuvir inhibits ZIKV RNA polymerase, targeting conserved amino acid residues. Sofosbuvir inhibited ZIKV replication in different cellular systems, such as hepatoma (Huh-7) cells, neuroblastoma (SH-Sy5y) cells, neural stem cells (NSC) and brain organoids. In addition to the direct inhibition of the viral RNA polymerase, we observed that sofosbuvir also induced an increase in A-to-G mutations in the viral genome. Together, our data highlight a potential secondary use of sofosbuvir, an anti-HCV drug, against ZIKV.
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Antivirales/farmacología , Sofosbuvir/farmacología , Replicación Viral/efectos de los fármacos , Virus Zika/fisiología , Antivirales/uso terapéutico , Línea Celular , Supervivencia Celular/efectos de los fármacos , ARN Polimerasas Dirigidas por ADN/antagonistas & inhibidores , ARN Polimerasas Dirigidas por ADN/metabolismo , Genoma Viral , Humanos , Mutación , Sofosbuvir/uso terapéutico , Proteínas Virales/antagonistas & inhibidores , Proteínas Virales/metabolismo , Virus Zika/genética , Virus Zika/aislamiento & purificación , Infección por el Virus Zika/tratamiento farmacológico , Infección por el Virus Zika/patología , Infección por el Virus Zika/virologíaRESUMEN
The influenza virus causes acute respiratory infections, leading to high morbidity and mortality in groups of patients at higher risk. Antiviral drugs represent the first line of defense against influenza, both for seasonal infections and pandemic outbreaks. Two main classes of drugs against influenza are in clinical use: M2-channel blockers and neuraminidase inhibitors. Nevertheless, because influenza strains that are resistant to these antivirals have been described, the search for novel compounds with different mechanisms of action is necessary. Here, we investigated the anti-influenza activity of a fungi-derived natural product, aureonitol. This compound inhibited influenza A and B virus replication. This compound was more effective against influenza A(H3N2), with an EC50 of 100 nM. Aureonitol cytoxicity was also very low, with a CC50 value of 1426 µM. Aureonitol inhibited influenza hemagglutination and, consequently, significantly impaired virus adsorption. Molecular modeling studies revealed that aureonitol docked in the sialic acid binding site of hemagglutinin, forming hydrogen bonds with highly conserved residues. Altogether, our results indicate that the chemical structure of aureonitol is promising for future anti-influenza drug design.
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Furanos/farmacología , Hemaglutininas/metabolismo , Subtipo H3N2 del Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza B/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Replicación Viral/efectos de los fármacos , Aminoácidos/genética , Animales , Antivirales/farmacología , Muerte Celular/efectos de los fármacos , Simulación por Computador , Secuencia Conservada , Perros , Relación Dosis-Respuesta a Droga , Furanos/química , Células HEK293 , Hemaglutinación/efectos de los fármacos , Hemaglutininas/química , Humanos , Células de Riñón Canino Madin Darby , Neuraminidasa/metabolismo , Factores de Tiempo , Internalización del Virus/efectos de los fármacosRESUMEN
The 2009 pandemic influenza A(H1N1)pdm09 virus emerged and caused considerable morbidity and mortality in the third world, especially in Brazil. Although circulating strains of A(H1N1)pdm09 are A/California/04/2009-like (CA-04-like) viruses, various studies have suggested that some mutations in the viral hemagglutinin (HA) may be associated with enhanced severity and fatality. This phenomenon is particularly challenging for immunocompromised individuals, such as those who have undergone bone marrow transplant (BMT), because they are more likely to display worse clinical outcomes to influenza infection than non-immunocompromised individuals. We studied the clinical and viral aspects of post-BMT patients with confirmed A(H1N1)pdm09 diagnosis in the largest cancer hospital in Brazil. We found a viral strain with K-15E, P83S and Q293H polymorphisms in the HA, which is presumably more virulent, in these individuals. Despite that, these patients showed only mild symptoms of infection. Our findings complement the discovery of mild cases of infection with the A(H1N1)pdm09 virus with the K-15E, P83S and Q293H mutations in Brazil and oppose other studies that have linked these changes with increased disease severity. These results could be important for a better comprehension of the impact of the pandemic influenza in the context of BMT.
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Trasplante de Médula Ósea , Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/patología , Mutación , Adolescente , Adulto , Animales , Estudios de Casos y Controles , Niño , Análisis Mutacional de ADN , Perros , Femenino , Hemaglutininas Virales/genética , Interacciones Huésped-Patógeno , Humanos , Huésped Inmunocomprometido , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/fisiología , Gripe Humana/virología , Células de Riñón Canino Madin Darby , Masculino , Datos de Secuencia Molecular , Filogenia , Polimorfismo Genético , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
Indivíduos infectados pelo HIV têm um risco mais elevado de serem afetados por doenças graves, tais como infecções por vírus respiratórios, incluindo o vírus da influenza. A imunossupressão desses indivíduos pode afetar a sua capacidade de resposta à imunização ativa. A vacinação contra o vírus influenza ainda representa a principal forma de reduzir o impacto deste vírus. Devido à circulação em 2009 do vírus influenza pandêmico A (H1N1) pdm09 e influenza sazonal A (H3N2) e vírus B, a composição atual vacina incluem antígenos destes três agentes em sua formulação. Assim, a análise do impacto da vacina trivalente inativada contra influenza (TIV) em indivíduos infectados pelo HIV merece mais estudos. Uma coorte de 131 indivíduos HIV- 1 positivos, com viremia controlada recebeu duas doses únicas de TIV com 21 dias de intervalo. Os títulos de anti- hemaglutinantes (HA) de seus soros foi avaliada em diferentes pontos de tempo (dias zero, 21 e 42, bem como seis meses pós- vacinação). No que diz respeito à resposta imune ao vírus A(H1N1) pdm09 , observouse que um ano depois de ter recebido a vacina monovalente contra este antígeno , 62,6 por cento dos indivíduos permaneceram soroprotegidos, uma queda de 20 por cento em relação à 6 meses pós vacinação monovalente no ano de 2010. Além disso, após a primeira dose de TIV, títulos soroprotetores foram encontrados em todos os indivíduosA soroproteção de baseline para os antígenos H3N2 e influenza B foi de 67,9 por cento e 27,5 por cento, respectivamente. Em relação à soroconversão, observamos que 19,8 por cento e 21 por cento dos indivíduos apresentavam títulos antihemaglutinantes para o vírus A(H1N1)pdm09, 21 e 42 dias pós-vacinação com TIV, respectivamente...
HIV-infected individuals have a higher risk of being affected by serious illnesses , such as infections by respiratory viruses, including influenza virus . Immunosuppression of theseindividuals can affect their ability to respond to active immunization. Vaccination againstinfluenza is still the main way to reduce the impact of this virus. Due to the movement in2009 pandemic influenza A (H1N1)pdm09 and seasonal influenza A (H3N2) and B viruses,the current vaccine composition include antigens of these three agents in their formulation.Thus, analysis of the impact of trivalent inactivated influenza vaccine (TIV) in HIV-infectedindividuals deserves further study. A cohort of 131 HIV-1 positive individuals with controlledviremia received two single doses of TIV 21 days apart. The titers of anti-hemagglutinant(HA) of their sera was assessed at different time points (zero, 21, 42 days and six monthspost- vaccination). With regard to immune to the virus A (H1N1)pdm09 response , it wasnoted that a year after having received the monovalent vaccine against this antigen , 62.6 percent ofsubjects remained seroprotection , a decrease of 20 percent compared to 6 monovalent monthspost-vaccination in 2010 . Moreover, after the first dose of TIV, seroprotective titers werefound in all individuals. The seroprotection baseline for H3N2 and influenza B antigens was67.9 percent and 27.5 percent , respectively. Regarding to seroconversion, we found that 19.8 percent and 21percent of subjects had anti -hemagglutinin titles for the A (H1N1)pdm09, 21 and 42 days postvaccinationwith TIV, respectively...