RESUMO
Dengue is a mosquito-borne infectious disease that is highly endemic in tropical and subtropical countries. Symptomatic patients can rapidly progress to severe conditions of hemorrhage, plasma extravasation, and hypovolemic shock, which leads to death. The blood tests of patients with severe dengue typically reveal low levels of high-density lipoprotein (HDL), which is responsible for reverse cholesterol transport (RCT) and regulation of the lipid composition in peripheral tissues. It is well known that dengue virus (DENV) depends on membrane cholesterol rafts to infect and to replicate in mammalian cells. Here, we describe the interaction of DENV nonstructural protein 1 (NS1) with apolipoprotein A1 (ApoA1), which is the major protein component of HDL. NS1 is secreted by infected cells and can be found circulating in the serum of patients with the onset of symptoms. NS1 concentrations in plasma are related to dengue severity, which is attributed to immune evasion and an acute inflammatory response. Our data show that the DENV NS1 protein induces an increase of lipid rafts in noninfected cell membranes and enhances further DENV infection. We also show that ApoA1-mediated lipid raft depletion inhibits DENV attachment to the cell surface. In addition, ApoA1 is able to neutralize NS1-induced cell activation and to prevent NS1-mediated enhancement of DENV infection. Furthermore, we demonstrate that the ApoA1 mimetic peptide 4F is also capable of mediating lipid raft depletion to control DENV infection. Taken together, our results suggest the potential of RCT-based therapies for dengue treatment. These results should motivate studies to assess the importance of RCT in DENV infection in vivo. IMPORTANCE DENV is one of the most relevant mosquito-transmitted viruses worldwide, infecting more than 390 million people every year and leading to more than 20 thousand deaths. Although a DENV vaccine has already been approved, its potential side effects have hampered its use in large-scale immunizations. Therefore, new treatment options are urgently needed to prevent disease worsening or to improve current clinical management of severe cases. In this study, we describe a new interaction of the NS1 protein, one of the major viral components, with a key component of HDL, ApoA1. This interaction seems to alter membrane susceptibility to virus infection and modulates the mechanisms triggered by DENV to evade the immune response. We also propose the use of a mimetic peptide named 4F, which was originally developed for atherosclerosis, as a potential therapy for relieving DENV symptoms.
Assuntos
Apolipoproteína A-I/imunologia , Vírus da Dengue/metabolismo , Evasão da Resposta Imune/imunologia , Microdomínios da Membrana/metabolismo , Proteínas não Estruturais Virais/imunologia , Animais , Antivirais/farmacologia , Linhagem Celular , Colesterol/metabolismo , Dengue/patologia , Humanos , Inflamação/prevenção & controle , Camundongos , Peptídeos/farmacologia , Células RAW 264.7 , Ligação Viral/efeitos dos fármacosRESUMO
Lactoferrin is part of the innate immune system, with antiviral activity against numerous DNA and RNA viruses. Rhinoviruses, the leading cause of the common cold, are associated with exacerbation of respiratory illnesses such as asthma. Here, we explored the effect of bovine lactoferrin (BLf) on RV-B14 infectivity. Using different assays, we show that the effect of BLf is strongest during adhesion of the virus to the cell and entry. Tracking the internalisation of BLf and virus revealed a degree of colocalisation, although their interaction was only confirmed in vitro using empty viral particles, indicating a possible additional influence of BLf on other infection steps.
Assuntos
Antivirais/farmacologia , Enterovirus/efeitos dos fármacos , Lactoferrina/farmacologia , Internalização do Vírus/efeitos dos fármacos , Antivirais/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Efeito Citopatogênico Viral/efeitos dos fármacos , Enterovirus/fisiologia , Infecções por Enterovirus/virologia , Células HeLa , Humanos , Lactoferrina/metabolismo , Ligação Viral/efeitos dos fármacosRESUMO
Human respiratory syncytial virus (hRSV) is one of the main etiological agents of diseases of the lower respiratory tract and is often responsible for the hospitalization of children and the elderly. To date, treatments are only palliative and there is no vaccine available. Natural products show exceptional structural diversity and they have played a vital role in drug research. Several investigations focused on applied structural modification of natural products to improved metabolic stability, solubility and biological actions them. Quercetin is a flavonoid that presents several biological activities, including anti-hRSV role. Some works criticize the pharmacological use of Quercetin because it has low solubility and low specificity. In this sense, we acetylated Quercetin structure and we used in vitro and in silico assays to compare anti-hRSV function between Quercetin (Q0) and its derivative molecule (Q1). Q1 shows lower cytotoxic effect than Q0 on HEp-2 cells. In addition, Q1 was more efficient than Q0 to protect HEp-2 cells infected with different multiplicity of infection (0.1-1 MOI). The virucidal effects of Q0 and Q1 suggest interaction between these molecules and viral particle. Dynamic molecular results suggest that Q0 and Q1 may interact with F-protein on hRSV surface in an important region to adhesion and viral infection. Q1 interaction with F-protein showed ΔG= -14.22 kcal/mol and it was more stable than Q0. Additional, MTT and plate assays confirmed that virucidal Q1 effects occurs during adhesion step of cycle hRSV replication. In conclusion, acetylation improves anti-hRSV Quercetin effects because Quercetin pentaacetate could interact with F-protein with lower binding energy and better stability to block viral adhesion. These results show alternative anti-hRSV strategy and contribute to drug discovery and development.
Assuntos
Antivirais/farmacologia , Células Epiteliais/efeitos dos fármacos , Quercetina/análogos & derivados , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Ligação Viral/efeitos dos fármacos , Acetilação , Linhagem Celular , Células Epiteliais/virologia , Humanos , Simulação de Dinâmica Molecular , Quercetina/farmacologia , Vírus Sincicial Respiratório Humano/fisiologia , Proteínas Virais de Fusão/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Mayaro virus (MAYV) is a sublethal arbovirus transmitted by mosquitoes with possible installation of an urban cycle in the Americas. Its infection causes disabling arthralgia, and still, there is no vaccine or treatment to it. We recently investigated nearly 600 compounds by molecular docking and identified epicatechin as a potent antiviral against MAYV. The root extract of Maytenus imbricata showed anti-MAYV activity and two isolated compounds from this plant were also evaluated in vitro. Proanthocyanidin (PAC), a dimer containing epicatechin, showed an effective concentration for 50% of the cells infected by MAYV (EC50) of 37.9⯱â¯2.4⯵M and a selectivity index (SI) above 40. PAC showed significant virucidal activity, inhibiting 100% of the virus proliferation (7 log units), and caused moderate effect during adsorption and virus internalization stage. However, PAC was unable to block the infection when only the cells were pretreated. It was observed a reduction in virus yields when adding PAC at different moments after infection. The set of results indicates that PAC binds to viral and non-cellular elements and may inactivate the MAYV. The inactivation occurs before infection or when the virus reaches the extracellular environment from the 2nd cycle of infection that could block its progression cell-to-cell or to tissues not yet infected.
Assuntos
Alphavirus/efeitos dos fármacos , Antivirais/farmacologia , Proantocianidinas/farmacologia , Infecções por Alphavirus/virologia , Animais , Antivirais/química , Catequina/química , Catequina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Magnoliopsida/química , Estrutura Molecular , Raízes de Plantas/química , Proantocianidinas/química , Células Vero , Ligação Viral/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
Dengue is the most common arboviral disease worldwide with 96 million symptomatic cases annually. Despite its major impact on global human health and huge economic burden there is no antiviral drug available to treat the disease. The first tetravalent dengue virus vaccine was licensed in 2015 for individuals aged 9 to 45, however, most cases are reported in infants and young children. This, together with the limited efficacy of the vaccine to dengue virus (DENV) serotype 2, stresses the need to continue the search for compounds with antiviral activity to DENV. In this report, we describe tomatidine as a novel compound with potent antiviral properties towards all DENV serotypes and the related Zika virus. The strongest effect was observed for DENV-2 with an EC50 and EC90 value of 0.82 and 1.61⯵M, respectively, following infection of Huh7 cells at multiplicity of infection of 1. The selectivity index is 97.7. Time-of-drug-addition experiments revealed that tomatidine inhibits virus particle production when added pre, during and up to 12â¯h post-infection. Subsequent experiments show that tomatidine predominantly acts at a step after virus-cell binding and membrane fusion but prior to the secretion of progeny virions. Tomatidine was found to control the expression of the cellular protein activating transcription factor 4 (ATF4), yet, this protein is not solely responsible for the observed antiviral effect. Here, we propose tomatidine as a candidate for the treatment of dengue given its potent antiviral activity.
Assuntos
Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Tomatina/análogos & derivados , Replicação Viral/efeitos dos fármacos , Fator 4 Ativador da Transcrição/genética , Animais , Linhagem Celular , Chlorocebus aethiops , Dengue/tratamento farmacológico , Descoberta de Drogas , Sorogrupo , Tomatina/farmacologia , Células Vero , Ligação Viral/efeitos dos fármacos , Zika virus/efeitos dos fármacosRESUMO
PURPOSE OF REVIEW: Even in the era of modern HAART, antiretroviral (ARV) failure and emergence of drug resistance is still a problem worldwide. New classes with different mechanisms of action are needed to overcome this challenge. After the integrase inhibitors were launched, more than a decade ago, no new classes were added to the ARV armamentarium. RECENT FINDINGS: Fostemsavir (FTR) is an attachment inhibitor, active regardless of viral tropism, without cross-resistance to any of the existing ARV compounds. A phase 3 study showed a reduction in plasma viral RNA of 1.21-1.73âlog10 copies/ml from baseline after 8 days of functional monotherapy; at 48 weeks, up to 82% of patients treated with FTR and an optimized background ARV regimen achieved virological suppression below 50 copies/ml. SUMMARY: FTR is an investigational HIV drug with a novel mechanism of action that demonstrates virologic activity in HIV-infected treatment-experienced individuals.
Assuntos
Fármacos Anti-HIV/administração & dosagem , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/tratamento farmacológico , HIV/efeitos dos fármacos , Organofosfatos/administração & dosagem , Piperazinas/administração & dosagem , Ligação Viral/efeitos dos fármacos , Fármacos Anti-HIV/farmacologia , Ensaios Clínicos Fase III como Assunto , HIV/fisiologia , Infecções por HIV/virologia , Humanos , Organofosfatos/farmacologia , Piperazinas/farmacologia , Tropismo Viral/efeitos dos fármacosRESUMO
Dengue virus (DENV) is the most prevalent and burdensome arbovirus transmitted by Aedes mosquitoes, against which there is only a limited licensed vaccine and no approved drug treatment. A Chromobacterium species, C. sp. Panama, isolated from the midgut of A. aegypti is able to inhibit DENV replication within the mosquito and in vitro. Here we show that C. sp. Panama mediates its anti-DENV activity through secreted factors that are proteinous in nature. The inhibitory effect occurs prior to virus attachment to cells, and is attributed to a factor that destabilizes the virion by promoting the degradation of the viral envelope protein. Bioassay-guided fractionation, coupled with mass spectrometry, allowed for the identification of a C. sp. Panama-secreted neutral protease and an aminopeptidase that are co-expressed and appear to act synergistically to degrade the viral envelope (E) protein and thus prevent viral attachment and subsequent infection of cells. This is the first study characterizing the anti-DENV activity of a common soil and mosquito-associated bacterium, thereby contributing towards understanding how such bacteria may limit disease transmission, and providing new tools for dengue prevention and therapeutics.
Assuntos
Aminopeptidases/farmacologia , Antivirais/farmacologia , Chromobacterium/enzimologia , Vírus da Dengue/efeitos dos fármacos , Dengue/tratamento farmacológico , Proteínas do Envelope Viral/metabolismo , Proteínas de Bactérias/farmacologia , Dengue/virologia , Vírus da Dengue/fisiologia , Sistema Digestório/virologia , Proteólise , Vírion/efeitos dos fármacos , Ligação Viral/efeitos dos fármacosRESUMO
Rotavirus is the leading worldwide cause of gastroenteritis in children under five years of age. Even though there are some available vaccines to prevent the disease, there are limited strategies for challenging diarrhea induced by rotavirus infection. For this reason, researchers are constantly searching for other approaches to control diarrhea by means of probiotics. In order to demonstrate the ability of some probiotic bacteria to interfere with the in vitro rotavirus infection in MA104 cells, strains of Lactobacillus sp. and Bifidobacterium sp. were tested in MA104 cells before the viral infection. As a preliminary assay, a blocking effect treatment was performed with viable bacteria. In this screening assay, four of initial ten bacteria showed a slight reduction of the viral infection (measured by percentage of infection). L. casei (Lafti L26-DSL), L. fermentum(ATCC 9338), B. adolescentis (DSM 20083), and B. bifidum (ATCC 11863) were used in further experiments. Three different treatments were tested in order to evaluate protein-based metabolites obtained from mentioned bacteria: (i) cell exposure to the protein-based metabolites before viral infection, (ii) exposure to protein-based metabolites after viral infection, and (iii) co-incubation of the virus and protein-based metabolites before viral infection to the cell culture. The best effect performed by protein-based metabolites was observed during the co-incubation assay of the virus and protein-based metabolites before adding them into the cell culture. The results showed 25 and 37% of infection in the presence of L. casei and B. adolescentis respectively. These results suggest that the antiviral effect may be occurring directly with the viral particle instead of making a blocking effect of the cellular receptors that are needed for the viral entrance.
Assuntos
Antivirais/farmacologia , Bifidobacterium adolescentis/fisiologia , Lacticaseibacillus casei/fisiologia , Probióticos/farmacologia , Infecções por Rotavirus/virologia , Rotavirus/efeitos dos fármacos , Ligação Viral/efeitos dos fármacos , Linhagem Celular , Gastroenterite/prevenção & controle , Gastroenterite/virologia , Humanos , Lacticaseibacillus casei/química , Rotavirus/fisiologia , Infecções por Rotavirus/prevenção & controleRESUMO
UNLABELLED: Infectious salmon anemia virus (ISAV) is the etiological agent of the disease by the same name and causes major losses in the salmon industry worldwide. Epizootic ISAV outbreaks have occurred in Norway and, to a lesser degree, in Canada. In 2007, an ISAV outbreak in Chile destroyed most of the seasonal production and endangered the entire Chilean salmon industry. None of the existing prophylactic approaches have demonstrated efficacy in providing absolute protection from or even a palliative effect on ISAV proliferation. Sanitary control measures for ISAV, based on molecular epidemiology data, have proven insufficient, mainly due to high salmon culture densities and a constant presence of a nonpathogenic strain of the virus. This report describes an alternative treatment approach based on interfering peptides selected from a phage display library. The screening of a phage display heptapeptide library resulted in the selection of a novel peptide with significant in vitro antiviral activity against ISAV. This peptide specifically interacted with the viral hemagglutinin-esterase protein, thereby impairing virus binding, with plaque reduction assays showing a significant reduction in viral yields. The identified peptide acts at micromolar concentrations against at least two different pathogenic strains of the virus, without detectable cytotoxic effects on the tested fish cells. Therefore, antiviral peptides represent a novel alternative for controlling ISAV and, potentially, other fish pathogens. IMPORTANCE: Identifying novel methods for the efficient control of infectious diseases is imperative for the future of global aquaculture. The present study used a phage display heptapeptide library to identify a peptide with interfering activity against a key protein of the infectious salmon anemia virus (ISAV). A piscine orthomyxovirus, ISAV is a continuous threat to the commercial sustainability of cultured salmon production worldwide. The complex epidemiological strategy of this pathogen has made prophylactic control extremely difficult. The identified antiviral peptide efficiently impairs ISAV infection in vitro by specifically blocking hemagglutinin-esterase, a pivotal surface protein of this virus. Peptide synthesis could further modify the primary structure of the identified peptide to improve specific activity and stability. The present results form the foundation for developing a new pharmacological treatment against ISAV.
Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Isavirus/efeitos dos fármacos , Peptídeos/síntese química , Peptídeos/farmacologia , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Peixes , Isavirus/fisiologia , Biblioteca de Peptídeos , Spodoptera , Ensaio de Placa Viral , Ligação Viral/efeitos dos fármacosRESUMO
The role of angiotensin II (Ang II) in dengue virus infection remains unknown. The aim of this study was to determine the effect of losartan, an antagonist of the angiotensin II type 1 receptor (AT1 receptor), and enalapril, an inhibitor of angiotensin I-converting enzyme (ACE), on viral antigen expression and IL-1ß production in peritoneal macrophages infected with dengue virus type 2. Mice treated with losartan or enalapril and untreated controls were infected intraperitoneally with the virus, and macrophages were analyzed. Infection resulted in increased IL-1ß production and a high percentage of cells expressing viral antigen, and this was decreased by treatment with anti-Ang II drugs, suggesting a role for Ang II in dengue virus infection.