RESUMO
The transporter associated with antigen processing (TAP) is a key player in the major histocompatibility class I-restricted antigen presentation and an attractive target for immune evasion by viruses. Bovine herpesvirus 1 impairs TAP-dependent antigenic peptide transport through a two-pronged mechanism in which binding of the UL49.5 gene product to TAP both inhibits peptide transport and triggers its proteasomal degradation. How UL49.5 promotes TAP degradation has, so far, remained unknown. Here, we use high-content siRNA and genome-wide CRISPR-Cas9 screening to identify CLR2KLHDC3 as the E3 ligase responsible for UL49.5-triggered TAP disposal. We propose that the C terminus of UL49.5 mimics a C-end rule degron that recruits the E3 to TAP and engages the cullin-RING E3 ligase in endoplasmic reticulum-associated degradation.
Assuntos
Transportadores de Cassetes de Ligação de ATP , Degrons , Herpesviridae , Apresentação de Antígeno , Citomegalovirus , Degradação Associada com o Retículo Endoplasmático , Proteínas de Membrana Transportadoras , Peptídeos , Ubiquitina-Proteína Ligases/genética , Herpesviridae/fisiologiaRESUMO
Tick-borne encephalitis virus (TBEV), of the genus Flavivirus, is a causative agent of severe encephalitis in regions of endemicity of northern Asia and central and northern Europe. Interferon-induced transmembrane proteins (IFITMs) are restriction factors that inhibit the replication cycles of numerous viruses, including flaviviruses such as West Nile virus, dengue virus, and Zika virus. Here, we demonstrate the role of IFITM1, IFITM2, and IFITM3 in the inhibition of TBEV infection and in protection against virus-induced cell death. We show that the most significant role is that of IFITM3, including the dissection of its functional motifs by mutagenesis. Furthermore, through the use of CRISPR-Cas9-generated IFITM1/3-knockout monoclonal cell lines, we confirm the role and additive action of endogenous IFITMs in TBEV suppression. However, the results of coculture assays suggest that TBEV might partially escape interferon- and IFITM-mediated suppression during high-density coculture infection when the virus enters naive cells directly from infected donor cells. Thus, cell-to-cell spread may constitute a strategy for virus escape from innate host defenses. IMPORTANCE TBEV infection may result in encephalitis, chronic illness, or death. TBEV is endemic in northern Asia and Europe; however, due to climate change, new centers of endemicity have arisen. Although effective TBEV vaccines have been approved, vaccination coverage is low, and due to the lack of specific therapeutics, infected individuals depend on their immune responses to control the infection. IFITM proteins are components of the innate antiviral defenses that suppress cell entry of many viral pathogens. However, no studies on the role of IFITM proteins in TBEV infection have been published thus far. Understanding antiviral innate immune responses is crucial for the future development of antiviral strategies. Here, we show the important role of IFITM proteins in the inhibition of TBEV infection and virus-mediated cell death. However, our data suggest that TBEV cell-to-cell spread may be less prone to both interferon- and IFITM-mediated suppression, potentially facilitating escape from IFITM-mediated immunity.
Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/fisiologia , Encefalite Transmitida por Carrapatos/metabolismo , Encefalite Transmitida por Carrapatos/virologia , Interações Hospedeiro-Patógeno , Interferons/metabolismo , Proteínas de Membrana/metabolismo , Sequência de Aminoácidos , Linhagem Celular , Efeito Citopatogênico Viral , Resistência à Doença/genética , Resistência à Doença/imunologia , Suscetibilidade a Doenças , Encefalite Transmitida por Carrapatos/genética , Encefalite Transmitida por Carrapatos/imunologia , Expressão Gênica , Técnicas de Silenciamento de Genes , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Família Multigênica , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Replicação ViralRESUMO
There is a continued need for effective hemostatic agents that are safe for neurosurgical use. Self-assembling peptide hydrogels have been suggested as novel hemostatic agents. They offer some advantages for neurosurgical hemostasis (e.g., transparency), but their efficacy and safety for neurosurgery have not been established. In this paper, the efficacy and safety of two self-assembling peptides, RADA16 and IEIK13, are explored for hemostasis of oozing bleeding on the rat cerebral cortex (nâ¯=â¯56). Chronic safety was evaluated by neuropathological evaluation at one, four, and twelve weeks after craniotomy (nâ¯=â¯32). An inactive control and oxidized cellulose served as comparators. Mean time-to-hemostasis was significantly shorter for RADA16 and IEIK13 compared to controls, while safety evaluation yielded similar results. Histopathological response consisted primarily of macrophage infiltration at the lesion site in all groups. This study confirms the hemostatic potential and safety of RADA16 and IEIK13 for hemostasis in the rat brain.
Assuntos
Hemostasia , Hemostáticos , Animais , Hemorragia , Hemostáticos/farmacologia , Hidrogéis/farmacologia , Peptídeos/farmacologia , RatosRESUMO
Routine genomic surveillance on samples from COVID-19 patients collected in Poland during summer 2021 revealed the emergence of a SARS-CoV-2 Delta variant with a large 872 nt deletion. This change, confirmed by Sanger and deep sequencing, causes complete loss of ORF7a, ORF7b, and ORF8 genes. The index case carrying the deletion is unknown. The standard pipeline for sequencing may mask this deletion with a long stretch of N's. Effects of this deletion on phenotype or immune evasion needs further study.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , PolôniaRESUMO
Several studies have shown that type IV fibrocytes, located in the spiral ligament, degenerate first after noise exposure. Interestingly, this is the region where Coch expression is most abundant. As it is suggested that cochlin plays a role in our innate immune system, our goal is to investigate hearing thresholds and inner ear inflammation after noise exposure in Coch knockout (Coch-/-) mice compared to Coch wildtype (Coch+/+) mice. Animals were randomly allocated to a noise exposure group and a control group. Vestibular and auditory testing was performed at 48 h and one week after noise exposure. Whole mount staining and cryosectioning of the cochlea was performed in order to investigate hair cells, spiral ganglion neurons, inner ear inflammation, Coch expression and fibrocyte degeneration. Hearing assessment revealed that Coch+/+ mice had significantly larger threshold shifts than Coch-/- mice after noise exposure. We were unable to identify any differences in hair cells, neurons, fibrocytes and influx of macrophages in the inner ear between both groups. Interestingly, Coch expression was significantly lower in the group exposed to noise. Our results indicate that the absence of Coch has a protective influence on hearing thresholds after noise exposure, but this is not related to reduced inner ear inflammation in the knockout.
Assuntos
Envelhecimento/metabolismo , Proteínas da Matriz Extracelular/deficiência , Perda Auditiva Provocada por Ruído/metabolismo , Animais , Cóclea/metabolismo , Orelha Interna/metabolismo , Células Ciliadas Auditivas/metabolismo , Audição/fisiologia , Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , Neurônios/metabolismo , Ruído/efeitos adversosRESUMO
Bovine herpesvirus 1 (BoHV-1)-encoded UL49.5 (a homologue of herpesvirus glycoprotein N) can combine different functions, regulated by complex formation with viral glycoprotein M (gM). We aimed to identify the mechanisms governing the immunomodulatory activity of BoHV-1 UL49.5. In this study, we addressed the impact of gM/UL49.5-specific regions on heterodimer formation, folding and trafficking from the endoplasmic reticulum (ER) to the trans-Golgi network (TGN) - events previously found to be responsible for abrogation of the UL49.5-mediated inhibition of the transporter associated with antigen processing (TAP). We first established, using viral mutants, that no other viral protein could efficiently compensate for the chaperone function of UL49.5 within the complex. The cytoplasmic tail of gM, containing putative trafficking signals, was dispensable either for ER retention of gM or for the release of the complex. We constructed cell lines with stable co-expression of BoHV-1 gM with chimeric UL49.5 variants, composed of the BoHV-1 N-terminal domain fused to the transmembrane region (TM) from UL49.5 of varicella-zoster virus or TM and the cytoplasmic tail of influenza virus haemagglutinin. Those membrane-anchored N-terminal domains of UL49.5 were sufficient to form a complex, yet gM/UL49.5 folding and ER-TGN trafficking could be affected by the UL49.5 TM sequence. Finally, we found that leucine substitutions in putative glycine zipper motifs within TM helices of gM resulted in strong reduction of complex formation and decreased ability of gM to interfere with UL49.5-mediated major histocompatibility class I downregulation. These findings highlight the importance of gM/UL49.5 transmembrane domains for the biology of this conserved herpesvirus protein complex.
Assuntos
Doenças dos Bovinos/virologia , Retículo Endoplasmático/virologia , Complexo de Golgi/virologia , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas do Envelope Viral/metabolismo , Animais , Bovinos , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 1/química , Herpesvirus Bovino 1/genética , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Ligação Proteica , Domínios Proteicos , Transporte Proteico , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genéticaRESUMO
Various types of intercellular connections that are essential for communication between cells are often utilized by pathogens. Recently, a new type of cellular connection, consisting of long, thin, actin-rich membrane extensions named tunneling nanotubes (TNTs), has been shown to play an important role in cell-to-cell spread of HIV and influenza virus. In the present report, we show that TNTs are frequently formed by cells infected by an alphaherpesvirus, bovine herpesvirus 1 (BoHV-1). Viral proteins, such as envelope glycoprotein E (gE), capsid protein VP26, and tegument protein Us3, as well as cellular organelles (mitochondria) were detected by immunofluorescence and live-cell imaging of nanotubes formed by bovine primary fibroblasts and oropharynx cells (KOP cells). Time-lapse confocal studies of live cells infected with fluorescently labeled viruses showed that viral particles were transmitted via TNTs. This transfer also occurred in the presence of neutralizing antibodies, which prevented free entry of BoHV-1. We conclude that TNT formation contributes to successful cell-to-cell spread of BoHV-1 and demonstrate for the first time the participation of membrane nanotubes in intercellular transfer of a herpesvirus in live cells.IMPORTANCE Efficient transmission of viral particles between cells is an important factor in successful infection by herpesviruses. Herpesviruses can spread by the free-entry mode or direct cell-to-cell transfer via cell junctions and long extensions of neuronal cells. In this report, we show for the first time that an alphaherpesvirus can also spread between various types of cells using tunneling nanotubes, intercellular connections that are utilized by HIV and other viruses. Live-cell monitoring revealed that viral transmission occurs between the cells of the same type as well as between epithelial cells and fibroblasts. This newly discovered route of herpesviruses spread may contribute to efficient transmission despite the presence of host immune responses, especially after reactivation from latency that developed after primary infection. Long-range communication provided by TNTs may facilitate the spread of herpesviruses between many tissues and organs of an infected organism.
Assuntos
Extensões da Superfície Celular/virologia , Infecções por Herpesviridae/transmissão , Herpesvirus Bovino 1/fisiologia , Proteínas Virais/metabolismo , Animais , Proteínas do Capsídeo/metabolismo , Bovinos , Comunicação Celular/fisiologia , Linhagem Celular , Imunofluorescência , Proteínas de Fluorescência Verde/genética , Infecções por Herpesviridae/virologia , Junções Intercelulares/metabolismoRESUMO
The ketogenic diet (KD) is a high-fat, adequate-protein, and low-carbohydrate diet that has been used successfully in the treatment of refractory epilepsies for almost 100 years. There has been accumulating evidence to show that the KD may provide a therapeutic benefit in autism spectrum disorders, albeit by a yet-unknown mechanism. We report a case of a 6-year-old patient with high-functioning autism and subclinical epileptic discharges who responded poorly to several behavioural and psychopharmacological treatments. The patient was subsequently placed on the KD due to significant glucose hypometabolism in the brain as revealed by an 18FDG PET. As soon as one month after starting the KD, the patient's behavior and intellect improved (in regard to hyperactivity, attention span, abnormal reactions to visual and auditory stimuli, usage of objects, adaptability to changes, communication skills, fear, anxiety, and emotional reactions); these improvements continued until the end of the observation period at 16 months on the KD. The 18FDG PET, measured at 12 months on the KD, revealed that 18F-FDG uptake decreased markedly and diffusely in the whole cerebral cortex with a relatively low reduction in basal ganglia in comparison to the pre-KD assessment. It warrants further investigation if the 18FDG PET imaging could serve as a biomarker in identifying individuals with autism who might benefit from the KD due to underlying abnormalities related to glucose hypometabolism.
Assuntos
Transtorno Autístico/dietoterapia , Encéfalo/diagnóstico por imagem , Dieta Cetogênica , Transtorno Autístico/diagnóstico por imagem , Criança , Humanos , Masculino , Tomografia por Emissão de Pósitrons , Resultado do TratamentoRESUMO
OBJECTIVE: Introduction: Premature babies account for almost 7% of all newborns and the number of extremely premature infants is increasing. In the European Parliament the problem of premature birth was identified as a priority health task as early as 2011. It is emphasized that the problems of a premature newborn do not end with discharge from hospital. Objective: The aim of the paper was a tentative analysis of the development level of infants born before the 37th week of intrauterine life, taking into account various areas of development and searching for differences in the levels of the development of newborns born prematurely and on time. PATIENTS AND METHODS: Material and methods: The research covered two groups of babies: group I - infants born prematurely (between the 25th and 36th week of their intrauterine life) examined in their 11.5-12.5 month, group II - infants born in due time, examined in their 11.5-12.5 month. Evaluation was carried out in accordance with the Munich Functional Developmental Diagnostics. The analysis comprised 50 questionnaires of prematurely born babies and 30 infants born in due time. Gross and fine motor skills were assessed, as well as autonomy and perception. RESULTS: Results: In our general evaluation, 80% of the children from group I were active in accordance with their birth age. However, as regards the analysis of development in particular areas, 50% of the children from group I undertook activity compliant with their birth age. The analysis of average values indicates the relationship between the level of prematurity and the level of activity presented by the children examined. As the level of prematurity increases, the level of activity presented by the children decreases. The greatest difficulties in group I were noted with regards to perception and autonomy. CONCLUSION: Conclusions: The level of activity presented by the children born prematurely at the age of 12 months depends on their level of prematurity. Newborn babies who were born prematurely require diagnostics specifying different spheres of development.
Assuntos
Desenvolvimento Infantil , Doenças do Prematuro/epidemiologia , Humanos , Lactente , Recém-Nascido Prematuro , Doenças do Prematuro/fisiopatologia , Nascimento PrematuroRESUMO
BACKGROUND: Hepatitis C virus (HCV) infection is a major health problem worldwide, affecting an estimated 2-3 % of human population. An HCV vaccine, however, remains unavailable. High viral diversity poses a challenge in developing a vaccine capable of eliciting a broad neutralizing antibody response against all HCV genotypes. The small surface antigen (sHBsAg) of hepatitis B virus (HBV) has the ability to form highly immunogenic subviral particles which are currently used as an efficient anti-HBV vaccine. It also represents an attractive antigen carrier for the delivery of foreign sequences. In the present study, we propose a bivalent vaccine candidate based on novel chimeric particles in which highly conserved epitope of HCV E2 glycoprotein (residues 412-425) was inserted into the hydrophilic loop of sHBsAg. RESULTS: The expression of chimeric protein was performed in an unconventional, Leishmania tarentolae expression system resulting in an assembly of particles which retained immunogenicity of both HCV epitope and sHBsAg protein. Direct transmission electron microscopy observation and immunogold staining confirmed the formation of spherical particles approximately 22 nm in diameter, and proper foreign epitope exposition. Furthermore, the sera of mice immunized with chimeric particles proved reactive not only to purified yeast-derived sHBsAg proteins but also HCV E2 412-425 synthetic peptide. Most importantly, they were also able to cross-react with E1E2 complexes from different HCV genotypes. CONCLUSIONS: For the first time, we confirmed successful assembly of chimeric sHBsAg virus-like particles (VLPs) in the L. tarentolae expression system which has the potential to produce high-yields of properly N-glycosylated mammalian proteins. We also proved that chimeric Leishmania-derived VLPs are highly immunogenic and able to elicit cross-reactive antibody response against HCV. This approach may prove useful in the development of a bivalent prophylactic vaccine against HBV and HCV and opens up a new and low-cost opportunity for the production of chimeric sHBsAg VLPs requiring N-glycosylation process for their proper functionality and immunogenicity.
Assuntos
Antígenos de Superfície da Hepatite B/imunologia , Leishmania , Proteínas do Envelope Viral/imunologia , Vacinas Virais , Animais , Anticorpos Neutralizantes/imunologia , Epitopos/imunologia , Feminino , Células HEK293 , Hepatite B/imunologia , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/metabolismo , Humanos , Leishmania/genética , Leishmania/imunologia , Leishmania/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Vacinas Virais/biossíntese , Vacinas Virais/imunologia , Vírion/imunologiaRESUMO
Vasculitides in autoimmune diseases are an important cause of secondary headaches. The article discusses the incidence of headache in primary and secondary vasculitides of the central nervous system. The symptoms of primary CNS vasculitis are presented. The occurrence of headache in large-vessel vasculitides, such as Takayasu arteritis and giant cell arteritis; medium-vessel vasculitides, such as polyarteritis nodosa and Kawasaki disease; and small-vessel vasculitides, such as microscopic polyangiitis, granulomatosis with polyangiitis, and eosinophilic granulomatosis with polyangiitis, are characterized. The occurrence of headache in vasculitides of different blood vessels, such as Behcet's disease and Cogan's syndrome, is presented as well. Systemic autoimmune diseases discussed in the paper are systemic lupus erythematosus, antiphospholipid antibody syndrome, rheumatoid arthritis, Sjogren's syndrome, and sarcoidosis. Vasculopathies which can mimic CNS vasculitides were discussed as well. Examples include reversible cerebral vasoconstriction, Susac's symdrome, and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).
Assuntos
Doenças Autoimunes/complicações , Doenças do Sistema Nervoso Central/etiologia , Cefaleia/etiologia , Vasculite/etiologia , Doenças do Sistema Nervoso Central/complicações , Humanos , Vasculite/complicaçõesRESUMO
UNLABELLED: Despite the recent progress in the development of new antiviral agents, hepatitis C virus (HCV) infection remains a major global health problem, and there is a need for a preventive vaccine. We previously reported that adenoviral vectors expressing HCV nonstructural proteins elicit protective T cell responses in chimpanzees and were immunogenic in healthy volunteers. Furthermore, recombinant HCV E1E2 protein formulated with adjuvant MF59 induced protective antibody responses in chimpanzees and was immunogenic in humans. To develop an HCV vaccine capable of inducing both T cell and antibody responses, we constructed adenoviral vectors expressing full-length and truncated E1E2 envelope glycoproteins from HCV genotype 1b. Heterologous prime-boost immunization regimens with adenovirus and recombinant E1E2 glycoprotein (genotype 1a) plus MF59 were evaluated in mice and guinea pigs. Adenovirus prime and protein boost induced broad HCV-specific CD8+ and CD4+ T cell responses and functional Th1-type IgG responses. Immune sera neutralized luciferase reporter pseudoparticles expressing HCV envelope glycoproteins (HCVpp) and a diverse panel of recombinant cell culture-derived HCV (HCVcc) strains and limited cell-to-cell HCV transmission. This study demonstrated that combining adenovirus vector with protein antigen can induce strong antibody and T cell responses that surpass immune responses achieved by either vaccine alone. IMPORTANCE: HCV infection is a major health problem. Despite the availability of new directly acting antiviral agents for treating chronic infection, an affordable preventive vaccine provides the best long-term goal for controlling the global epidemic. This report describes a new anti-HCV vaccine targeting the envelope viral proteins based on adenovirus vector and protein in adjuvant. Rodents primed with the adenovirus vaccine and boosted with the adjuvanted protein developed cross-neutralizing antibodies and potent T cell responses that surpassed immune responses achieved with either vaccine component alone. If combined with the adenovirus vaccine targeting the HCV NS antigens now under clinical testing, this new vaccine might lead to a stronger and broader immune response and to a more effective vaccine to prevent HCV infection. Importantly, the described approach represents a valuable strategy for other infectious diseases in which both T and B cell responses are essential for protection.
Assuntos
Anticorpos Neutralizantes/sangue , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/sangue , Linfócitos T/imunologia , Proteínas do Envelope Viral/imunologia , Vacinas Virais/imunologia , Adenoviridae/genética , Adjuvantes Imunológicos/administração & dosagem , Animais , Feminino , Vetores Genéticos , Cobaias , Hepacivirus/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Polissorbatos/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Esqualeno/administração & dosagem , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/genética , Vacinas Virais/administração & dosagem , Vacinas Virais/genéticaRESUMO
Immunoadhesins are engineered proteins combining the constant domain (Fc) of an antibody with a ligand-binding (adhesion) domain. They have significant potential as therapeutic agents, because they maintain the favourable pharmacokinetics of antibodies with an expanded repertoire of ligand-binding domains: proteins, peptides, or small molecules. We have recently reported that the addition of a cholesterol group to two HIV antibodies can dramatically improve their antiviral potency. Cholesterol, which can be conjugated at various positions in the antibody, including the constant (Fc) domain, endows the conjugate with affinity for the membrane lipid rafts, thus increasing its concentration at the site where viral entry occurs. Here, we extend this strategy to an HIV immunoadhesin, combining a cholesterol-conjugated Fc domain with the peptide fusion inhibitor C41. The immunoadhesin C41-Fc-chol displayed high affinity for Human Embryonic Kidney (HEK) 293 cells, and when tested on a panel of HIV-1 strains, it was considerably more potent than the unconjugated C41-Fc construct. Potentiation of antiviral activity was comparable to what was previously observed for the cholesterol-conjugated HIV antibodies. Given the key role of cholesterol in lipid raft formation and viral fusion, we expect that the same strategy should be broadly applicable to enveloped viruses, for many of which it is already known the sequence of a peptide fusion inhibitor similar to C41. Moreover, the sequence of heptad repeat-derived fusion inhibitors can often be predicted from genomic information alone, opening a path to immunoadhesins against emerging viruses.
Assuntos
Antivirais/química , Colesterol/química , Peptídeos/química , Antivirais/farmacologia , Desenho de Fármacos , Células HEK293 , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Humanos , Peptídeos/farmacologia , Internalização do Vírus/efeitos dos fármacosRESUMO
Despite available treatment, Hepatitis C remains one of most serious burdens to public health. Current therapy based on pegylated interferon-alpha and ribavirin has significant side effects and its effectiveness varies for different genotypes of the virus. Four novel drugs - viral protease inhibitors (telaprevir, boceprevir, simeprevir) and polymerase inhibitor - sofosbuvir have been introduced in last years for use in combination with standard-of-care treatment. For the first time interferon free therapies were approved with the use of combination of sofosbuvir+ribavirin. New therapies improve virological response rates but also increase the cost, side effects and raise the issue of drug resistance. Numerous novel anti-HCV compounds have been evaluated in advanced clinical trials including inhibitors of viral proteins (protease, polymerase and NS5A) and inhibitors of host factors involved in HCV replication (cyclophilin A, microRNA - miR-122). New interferon-free therapies reducing severe side effects are expected to enter the market within few months. At the same time efforts are undertaken to determine the host and viral factors with predictive value for HCV treatment response, enabling personalized therapy approach. The main success in this field was the discovery of interleukin IL28B polymorphism, which correlates with positive standard-of-care treatment response. An effective vaccination may be an alternative for antiviral drugs, but no anti-HCV vaccine is available currently. It is well proved that successful vaccination should induce antibody and T-cell responses specific against a range of HCV genotypes. With this aim, new subunit and genetic candidate vaccines have been evaluated in I and II phase clinical trials. This review summarizes the recent developments in the field of new drug development and vaccine studies against hepatitis C virus.
Assuntos
Antivirais/uso terapêutico , Hepatite C/diagnóstico , Hepatite C/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Inibidores de Proteases/uso terapêutico , Ribavirina/uso terapêutico , Simeprevir/uso terapêutico , Hepacivirus/efeitos dos fármacos , Hepatite C/prevenção & controle , HumanosRESUMO
OBJECTIVE: To assess the efficacy of add-on therapy with tiagabine and cognitive functions in patients with drug-resistant focal epilepsy, when used in everyday clinical practice. MATERIALS AND METHODS: The total number of 437 patients with drug-resistant epilepsy with focal seizures were observed; 436 patients were treated with tiagabine as add-on therapy at a dose of 5-50 mg per day. During the study a number visits were secheduled: Visit V0 - upon enrolment of tiagabine-treated patients into the observational study, visit V1 - four weeks after reaching the initial dose of tiagabine, visit V2 - four weeks after reaching the target dose of tiagabine. The type and number of epileptic seizures, antiepileptic therapy used, concomitant treatment and adverse events were analysed. Analyses were performed using McNemar's, Wilcoxon's, Mann-Whitney's and Fisher's tests. The patients'cognitive functions were assessed using the MM SE scale. RESULTS: The mean observation time was 90 days. Men accounted for 48.3% of the study population and their average age was 41,5±14,0 and women accounted for 51.7% and their average age was 43.4±13.9. About 80% of the patients received valproic acid or carbamazepine before administration of tiagabine. Other most commonly used drugs included acetylsalicylic acid and ramipril. In the group of 185 patients who used drugs inducing liver enzymes before administration of tiagabine, 13% received a dose below 30 mg of tiagabine and 87% above 30 mg. In the group of patients treated with drugs which do not induce liver enzymes, 91.6% received tiagabine in a dose below 30 mg and 8.4% in a dose above 30 mg. The percentage of patients experiencing epileptic seizures was reduced from 72.2% between visits V0-V1 to 58.7% between visits V1-V2 (p<0.001). A decrease in the population of patients who experienced seizures and a reduction of the number of seizures were observed in all age groups. In the youngest age group, the number of seizures since the last visit went down from 5.4 to 3.7 (the average difference amounted to 1.7), in the 40-59 years age group, the number of seizures went down from 4.0 to 3.1 (the average difference amounted to 0.9) and in patients above the age of 60, from 3.0 to 2.1 (the average difference amounted to 0.9) (p<0.001; p=0.001 and p<0.001, respectively). Adverse events occurred in 4 (i.e. 0.9%) patients, dizziness being the most common. The Mini Mental State Examination (MM SE) was performed in 25% of patients. Cognitive functions did not deteriorate. The average MM SE score corresponded to a mild level of cognitive impairment. CONCLUSIONS: Tiagabine is a well tolerated drug providing effective control of focal seizures and in a sub-population of 25% patients whose cognitive functions were evaluated using MM SE, no significant adverse effect of the drug on such functions was observed.
Assuntos
Anticonvulsivantes/uso terapêutico , Resistência a Medicamentos/efeitos dos fármacos , Epilepsias Parciais/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Ácidos Nipecóticos/uso terapêutico , Adulto , Idoso , Relação Dose-Resposta a Droga , Esquema de Medicação , Epilepsias Parciais/prevenção & controle , Feminino , Agonistas GABAérgicos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Tiagabina , Resultado do TratamentoRESUMO
Orf virus (ORFV) strain D1701-V, a Parapoxvirus belonging to the family Poxviridae, became attractive as a novel virus vector system that we successfully used for the generation of recombinant vaccines. Therefore, the identification of viral genes involved in host tropisms or immune modulation is of great interest, as for instance the ORFV-encoded ankyrin-repeat (AR) containing proteins. The present study shows for the first time that the ANK-1 designated gene product of ORFV126 is targeted to mitochondria of ORFV-infected and in ANK-1 transiently expressing cells. Taking advantage of ANK-1 EGFP fusion proteins and confocal fluorescence microscopy mutational and deletion analyses indicated the importance of AR8 and AR9, which may contain a novel class of mitochondria-targeting sequence (MTS) in the central to C-terminal part of this AR-containing protein. The fluorescent findings were corroborated by cell fractionation and Western blotting experiments. The presented results open the avenue for more detailed investigations on cellular binding partners and the function of ANK-1 in viral replication or virulence.
Assuntos
Anquirinas/análise , Mitocôndrias/química , Vírus do Orf/fisiologia , Proteínas Virais/análise , Animais , Repetição de Anquirina , Anquirinas/genética , Fusão Gênica Artificial , Chlorocebus aethiops , Análise Mutacional de DNA , Genes Reporter , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/genética , Microscopia Confocal , Microscopia de Fluorescência , Transporte Proteico , Células Vero , Proteínas Virais/genéticaRESUMO
Multiple sclerosis (MS) is a progressive disease of the central nervous system. It is characterized by disseminated foci of demyelination, which are responsible for the diverse clinical picture of MS. Pain is a frequent but underestimated symptom of multiple sclerosis. It is estimated to affect 29-86% of MS patients in various stages of the disease and severely influences rehabilitation and quality of life. The pain experienced by MS patients is generally caused by nervous system damage during the course of the disease process and can usually be characterized as central neuropathic pain (less frequently as peripheral or nociceptive pain). The most frequent symptoms include dysesthetic extremity pain, painful tonic spasms, Lhermitte's sign, trigeminal neuralgia, headaches and low back pain. This paper discusses the probable mechanisms behind the development of pain in MS, the prevalence, classification, types of pain, as well as the most effective treatment methods.
Assuntos
Esclerose Múltipla/complicações , Neuralgia , Progressão da Doença , Humanos , Neuralgia/classificação , Neuralgia/etiologia , Neuralgia/fisiopatologia , PrevalênciaRESUMO
The article discusses the possible association between multiple sclerosis (MS) and headache. MS has a broad range of neurological symptoms, but headache is not included among them. Research on the link between MS and headache focuses on primary headaches such as migraine, tension-type headache and cluster headache. Studies on the possible association between MS and migraine have had conflicting results and have found a wide range of prevalence rates for migraine in MS patients. The possible mechanisms proposed linking migraine and MS can be unidirectional, bidirectional or involving a common cause. The prevalence of TTH in MS patients is similar to that observed in the general population. Immunotherapy may play a role in inducing headache.
Assuntos
Imunoterapia/efeitos adversos , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/imunologia , Cefaleia do Tipo Tensional/epidemiologia , Adulto , Comorbidade , Humanos , Prevalência , Cefaleia do Tipo Tensional/induzido quimicamenteRESUMO
The glycosylation of viral envelope proteins plays an important role in virus biology and the immune response of the host to infection. Hepatitis C virus (HCV) envelope proteins E1 and E2, key players in virus entry and spread, are highly N-glycosylated and possess 4 (5 in certain genotypes) to 11 conserved glycosylation sites, respectively. Many published results based on recombinant proteins indicate that the glycan shield can mask the epitopes targeted by neutralizing antibodies. Glycan shifting within the conserved linear E2 region (412-423) could be one of the escape strategies used by HCV. In the present report, we isolated E2 genes from samples (collected before the IFN-RBV therapy) originating from pediatric patients infected with HCV gt 1a. We analyzed the biochemical properties of cloned E2 glycoprotein variants and investigated their glycosylation status. The sequencing of E2 genes isolated from patients who did not respond to therapy revealed mutations at N-glycosylation sites, thus leading to a lower molecular weight and a low affinity to both linear and conformational neutralizing antibodies. The loss of the glycosylation site within the conserved epitope (amino acid 417) impaired the binding with AP33, an antibody that potently neutralizes all genotypes of HCV. Our findings, based on clinical samples, confirm the influence of N-glycosylation aberrations on the antigenic and conformational properties of HCV E1/E2, which may possibly correlate with the outcome of therapy in patients.
RESUMO
DFNA9 is a dominantly inherited form of adult-onset progressive hearing impairment caused by mutations in the COCH gene. COCH encodes cochlin, a crucial extracellular matrix protein. We established a genomically humanized mouse model for the Dutch/Belgian c.151C>T founder mutation in COCH. Considering upcoming sequence-specific genetic therapies, we exchanged the genomic murine Coch exons 3-6 for the corresponding human sequence. Introducing human-specific genetic information into mouse exons can be risky. To mitigate unforeseen consequences on cochlin function resulting from the introduction of the human COCH protein-coding sequence, we converted all human-specific amino acids to mouse equivalents. We furthermore optimized the recognition of the human COCH exons by the murine splicing machinery during pre-mRNA splicing. Subsequent observations in mouse embryonic stem cells revealed correct splicing of the hybrid Coch transcript. The inner ear of the established humanized Coch mice displays correctly-spliced wild-type and mutant humanized Coch alleles. For a comprehensive study of auditory function, mice were crossbred with C57BL/6 Cdh23753A>G mice to remove the Cdh23ahl allele from the genetic background of the mice. At 9 months, all humanized Coch genotypes showed hearing thresholds comparable to wild-type C57BL/6 Cdh23753A>G mice. This indicates that both the introduction of human wildtype COCH, and correction of Cdh23ahl in the humanized Coch lines was successful. Overall, our approach proved beneficial in eliminating potential adverse events of genomic humanization of mouse genes, and provides us with a model in which sequence-specific therapies directed against the human mutant COCH alle can be investigated. With the hearing and balance defects anticipated to occur late in the second year of life, a long-term follow-up study is ongoing to fully characterize the humanized Coch mouse model.