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1.
J Infect Dis ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38547499

RESUMO

Enterovirus D68 (EV-D68) infections are associated with severe respiratory disease and acute flaccid myelitis (AFM). The European Non-Polio Enterovirus Network (ENPEN) aimed to investigate the epidemiological and genetic characteristics of EV-D68 and its clinical impact during the fall-winter season of 2021/22. From 19 European countries, 58 institutes reported 10,481 (6.8%) EV-positive samples of which 1,004 (9.6%) were identified as EV-D68 (852 respiratory samples). Clinical data was reported for 969 cases. 78.9% of infections were reported in children (0-5 years); 37.9% of cases were hospitalised. Acute respiratory distress was commonly noted (93.1%) followed by fever (49.4%). Neurological problems were observed in 6.4% of cases with six reported with AFM. Phylodynamic/Nextstrain and phylogenetic analyses based on 694 sequences showed the emergence of two novel B3-derived lineages, with no regional clustering. In conclusion, we describe a large-scale EV-D68 European upsurge with severe clinical impact and the emergence of B3-derived lineages.

2.
Vaccine ; 41(5): 1059-1066, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36599736

RESUMO

BACKGROUND: Hepatitis E virus (HEV) is a major cause of acute viral hepatitis worldwide and it contributes to considerable maternal and neonatal mortality and morbidity in many low-income countries like Bangladesh. A three-dose regimen of a vaccine against HEV (HEV 239) has shown promising results in China. The effects and safety of this vaccine in other populations and with different dosing regimens remains uncertain. OBJECTIVES: Investigate the immune response and safety of a two-dose regimen with the HEV 239 vaccine among healthy adults. Examine the feasibility of conducting a larger HEV 239 vaccine trial in rural Bangladesh. METHODS: One-hundred healthy men and non-pregnant women 16-39 years old were randomized in a 1:1 ratio to receive two doses of either the study (HEV) or control (Hepatitis B virus, HBV) vaccine (at 0, 1 month). Blood samples were collected at day 0, day 60 and 2 years after vaccination. The primary endpoints were the proportion and severity of adverse events up to 2 months after dose one and the longitudinal shift in anti-HEV IgG levels from day 0 to day 60 and 2 years after vaccination. RESULTS: Adverse events to HEV 239 were comparable to the control vaccine, mild in severity and resolved within one to nine days. All participants in the study group seroconverted and achieved high levels of HEV IgG antibodies that remained positive for two years in all but one. A T-cell response was detected one month after HEV 239 vaccination. CONCLUSION: Our results show that two doses of the HEV 239 vaccine produces broad and likely functional immune responses against HEV that remain for at least two years. The safety profile was acceptable and a phase four study of HEV 239 in rural Bangladesh is feasible. CLINICALTRIALS: gov Identifier: NCT02759991.


Assuntos
Vírus da Hepatite E , Vacinas , Masculino , Feminino , Recém-Nascido , Humanos , Adulto , Adolescente , Adulto Jovem , Bangladesh , Projetos Piloto , Anticorpos Anti-Hepatite , Imunoglobulina G , Método Duplo-Cego , Imunogenicidade da Vacina , Anticorpos Antivirais
3.
Viruses ; 14(11)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36423134

RESUMO

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. In many low-income countries it causes large outbreaks and disproportionally affects pregnant women and their offspring. Surveillance studies to find effective preventive interventions are needed but are hampered by the lack of funding and infrastructure. Dried blood spots (DBS) offer an easier and more robust way to collect, transport, and store blood samples compared to plasma/serum samples, and could ease some of the barriers for such studies. In this study we optimize an HEV IgG ELISA for DBS samples and validate it on 300 paired DBS and plasma samples collected in rural areas of Bangladesh from participants in a HEV vaccine study. We demonstrate that HEV IgG in blood stored as DBS is stable for two months at up to 40 °C, and for five freeze-thaw cycles. The specificity was 97% and the overall sensitivity of the DBS assay was 81%. The sensitivity was higher in samples from vaccinated participants (100%) compared to previously infected participants (59%), reflecting a positive correlation between IgG titer and sensitivity. We found a strong correlation between DBS and plasma samples with an r2 of 0.90, but with a higher degree of difference between individual paired samples. Our study shows that DBS offers a stable alternative to plasma/serum for HEV IgG measurements and can facilitate serological studies, particularly in resource limited areas.


Assuntos
Vírus da Hepatite E , Feminino , Humanos , Gravidez , Estudos de Viabilidade , Anticorpos Anti-Hepatite , Testes Hematológicos , Imunoglobulina G
4.
Viruses ; 15(1)2022 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-36680103

RESUMO

HEV is the most common cause of acute hepatitis globally. This review summarizes the latest knowledge on the epidemiology, clinical characteristics, testing, and treatment of HEV infection. We also focused on Bangladesh to highlight the distinct challenges and the possible remedies. In low-income settings, the virus is mainly transmitted between people by fecal contamination of drinking water causing large outbreaks, and sporadic cases. The disease is usually mild and self-limiting acute hepatitis. Still, pregnant women and their offspring in low-income countries are at particular risk for severe disease, with up to 20% maternal mortality. Despite the high burden of the disease, HEV remains a relatively neglected virus, with detection hampered by costly tests and a lack of suitable treatments. Molecular PCR diagnostics, together with ELISA antibody tests, remain the preferred methods for diagnosis of HEV; however, rapid bedside diagnostics are available and could offer a practical alternative, especially in low-income countries. One vaccine (HEV 239) is only available in China and Pakistan, as efficacy against the other genotypes remains uncertain. The effectiveness trial conducted in Bangladesh might lead the way in gathering more efficacy data and could, together with improved surveillance and raised awareness, dramatically reduce the global burden of HEV.


Assuntos
Vírus da Hepatite E , Hepatite E , Humanos , Feminino , Gravidez , Vírus da Hepatite E/genética , Bangladesh/epidemiologia , Hepatite E/diagnóstico , Hepatite E/epidemiologia , Hepatite E/prevenção & controle , Surtos de Doenças , Genótipo , Doença Aguda
5.
Euro Surveill ; 26(45)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34763750

RESUMO

We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe.


Assuntos
COVID-19 , Enterovirus Humano D , Infecções por Enterovirus , Enterovirus , Mielite , Infecções Respiratórias , Controle de Doenças Transmissíveis , Surtos de Doenças , Enterovirus Humano D/genética , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/epidemiologia , Europa (Continente)/epidemiologia , Humanos , Mielite/epidemiologia , SARS-CoV-2
6.
Front Med (Lausanne) ; 8: 712326, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34660624

RESUMO

Objective: The objectives of this study were to describe the incidence and genetic diversity of Rotavirus (RV) infection among children up to 3 years of age in a community in Nepal. Methods: We investigated community-acquired cases of asymptomatic and symptomatic RV infections in children from birth to 36 months of age in a community-based birth cohort in Bhaktapur, Nepal. Monthly surveillance and diarrheal stool samples were collected from 240 children enrolled at birth, of which 238 completed the 3 years of follow-up. Samples were screened for rotavirus by Enzyme Immuno Assay (EIA). All RV screened positives were further genotyped by reverse transcription-polymerase chain reaction for the capsid genes VP7 and VP4. Results: In total, 5,224 stool samples were collected from 238 children, followed from birth to 36 months of age. Diarrhea occurred in 92.4% (230/238) of all children in the cohort. During the 3 years study period, RV was more frequently seen in children with symptoms (7.6%) than in non-symptomatic children (0.8%). The highest RV detection rate was found in younger children between 3 and 21 months of age. Although rotavirus is known as winter diarrhea, it was detected throughout the year except in August. The highest positivity rate was observed in the months between December and March, with a peak in January. Four common G types were seen: G2 (30%), G1 (29%), G12 (19%), and G9 (16%). The most predominant genotypes seen were G2P[4] (30%), followed by G1P[8] (27.0%), G12P[6] (14.0%), G9P[8] (10%), and remaining were mixed, partial, and untyped. Conclusion: Our study confirms that rotavirus is a common cause of gastroenteritis in young children in the community. The prevalence and pathogenicity of rotavirus infection differed by age. There was substantial variability in circulating strains in the community samples compared to samples collected from hospitals. This shows the importance of including community-based surveillance systems to monitor the diversity of circulating rotavirus strains in Nepal.

7.
Emerg Infect Dis ; 27(6): 1616-1626, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34013874

RESUMO

In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.


Assuntos
Infecções por Echovirus , Infecções por Enterovirus , Enterovirus Humano B/genética , Europa (Continente) , Genótipo , Humanos , Epidemiologia Molecular , Filogenia , Análise de Sequência de DNA
8.
Biosaf Health ; 2(3): 113-114, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32838283

RESUMO

The non-specific beneficial effects of Bacille Calmette-Guérin (BCG) vaccination suggest that this vaccine might play a role in protecting individuals against severe coronavirus disease 2019 (COVID-19). Several studies propose that BCG vaccination may increase the body's immunity, thereby preventing respiratory infections caused by other respiratory pathogens. As the number of deaths due to COVID-19 is increasing rapidly and there is no specific treatment available to date, scientists are evaluating the effectiveness of already approved drugs as therapies against COVID-19, and the results were found to vary widely: from no significant effect being observed to a reduction in the time taken for clinical improvement. This study thus aims to evaluate whether it is worth performing clinical trials to examine the effects of the BCG vaccine on COVID-19. We herein emphasize the need to conduct phase III randomized controlled trials with adequate sample size and quality to investigate the effects of the BCG vaccine on COVID-19. In the event that BCG vaccination provides non-specific protection against COVID-19, administering it could be helpful in controlling the transmission of COVID-19 and other infectious diseases during future pandemics.

9.
J Med Virol ; 92(12): 3151-3156, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32410230

RESUMO

Acute gastroenteritis (AGE) is a common illness in both adults and children worldwide and is caused by several microorganisms including viruses, bacteria, and parasites. Rotavirus (RV), which is the main cause of AGE, can occur as a mixed infection with other viruses. The aim of this study is to assess the molecular epidemiology of viral enteric viruses and assess RV coinfections with other enteric viruses and their influence on disease severity before and after RV vaccine introduction in children under 5 years of age. A total of 600 samples collected from children hospitalized for AGE in five large hospitals in Norway, and were analyzed for viral gastroenteritis agents by enzyme immunoassay and quantitative real-time polymerase chain reaction (qRT-PCR). Positive results confirmed either by Sanger sequencing or genotyped by multiplex semi-nested RT-PCR. In total, 243 of the 300 (81%) samples, collected from the prevaccine cohort, were positive for at least one of the four viruses tested in this study. RV was most frequently identified in 82.6% of the samples. In the postvaccine cohort, 114 of the 300 (38%) samples were positive for at least one of the viruses tested. RV found in 36.5% of the samples. Coinfections found less frequently in the postvaccine cohort. Among circulating enteric viruses in Norway, RV is the most important cause of viral gastrointestinal infection. As expected, there were fewer RV positive and fewer coinfections after RV vaccine implementation. The results provide valuable data that can aid in further evaluation of the vaccine impact.

10.
Front Microbiol ; 11: 588707, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33613461

RESUMO

Objective: This study describes the types of Human astroviruses detected in stool samples collected from a birth cohort of children in Nepal. Methods: Using a commercial kit (ProSpecT), a total of 5,224 diarrheal and non-diarrheal stool samples were screened for Human astrovirus by ELISA. RT-PCR was performed on ELISA positive samples (2.8%) for further confirmation. The primary RT-PCR assay used targets the ORF2 region and detects human astrovirus type 1-8. Samples that were negative in this assay were further analyzed using primers that target the ORF1b region of human astrovirus which detect both classical type (HAstV 1-8) and novel types (MLB1-5, VA 1-5). PCR positive samples were analyzed by Sanger sequencing to determine the genotype. Results: A total of 148 available ELISA positive stool samples were analyzed by RT-PCR and further genotyped. RT-PCR analysis of these samples using the ORF2 and ORF1b assay revealed that 124 (84%) were positive for classical human types (HAstV 1-8). Seven different classical HAstV genotypes based on ORF2 and ORF1a were identified (HAstV 1- HAstV 8) with the greatest prevalence of HAstV 5 genotype (42.2%), followed by HAstV 1 (34.7%), HAstV 2 and HAstV 8 (7.4%), HAstV 4 (4.1%), HAstV 3 (3.3%), and HAstV 6 (0.8%). Non-classical types were not detected in our study. Conclusion: A high diversity of circulating Astrovirus strains were detected in young children, both with and without symptoms of gastroenteritis. HAstV 5 and HAstV 1 were the most common genotypes in young children in Nepal.

11.
Nutrients ; 11(3)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866564

RESUMO

Preschool children in Addis Ababa, Ethiopia, are highly exposed to influenza viruses. Factors related to infections, nutrition, and environmental conditions that might explain the burden of influenza among these children were investigated. Ninety-five preschool children, 48 girls and 47 boys, were followed clinically for 12 months. Illness and immune responses to influenza; three other respiratory viruses; five airway pathogenic bacteria; and levels of vitamins D, A, and B12 were assessed. Most of the children had antibodies to numerous respiratory viral and bacterial agents at study start, and many were infected during follow-up. Twenty-five girls and 25 boys fell ill during the study, and were treated with one or more courses of systemic antimicrobials. Ninety percent of both girls and boys had 25-hydroxyvitamin D [25(OH)D] levels below the recommended levels. While there was no overall difference in the levels of vitamins D, A, and B12 between girls and boys, treated girls had significantly lower 25(OH)D levels than non-treated girls and treated boys. There was a considerable number of short for age children, but only the short treated girls had significantly lower 25(OH)D levels than the non-treated children. Preschool girls with low 25(OH)D levels were more vulnerable to pathogenic microbes than boys.


Assuntos
Anti-Infecciosos/uso terapêutico , Prescrições de Medicamentos/estatística & dados numéricos , Deficiência de Vitamina D/epidemiologia , Pré-Escolar , Estudos Transversais , Etiópia/epidemiologia , Feminino , Humanos , Masculino , Infecções Respiratórias/tratamento farmacológico
12.
PLoS One ; 12(11): e0188055, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29145441

RESUMO

Maternal influenza infection during pregnancy is associated with increased risk of morbidity and mortality. However, the link between the anti-influenza immune responses and health-related risks during infection is not well understood. We have analyzed memory T and NK cell mediated immunity (CMI) responses in pandemic influenza A(H1N1)pdm09 (pdm09) virus infected non-vaccinated pregnant women participating in the Norwegian Influenza Pregnancy Cohort (NorFlu). The cohort includes information on immunization, self-reported health and disease status, and biological samples (plasma and PBMC). Infected cases (N = 75) were defined by having a serum hemagglutination inhibition (HI) titer > = 20 to influenza pdm09 virus at the time of delivery, while controls (N = 75) were randomly selected among non-infected pregnant women (HI titer <10). In ELISpot assays cases had higher frequencies of IFNγ+ CD8+ T cells responding to pdm09 virus or conserved CD8 T cell-restricted influenza A virus epitopes, compared to controls. Within this T cell population, frequencies of CD95+ late effector (CD45RA+CCR7-) and naive (CD45RA+CCR7+) CD8+ memory T cells correlated inversely with self-reported influenza illness (ILI) symptoms. ILI symptoms in infected women were also associated with lower numbers of poly-functional (IFNγ+TNFα+, IL2+IFNγ+, IL2+IFNγ+TNFα+) CD4+ T cells and increased frequencies of IFNγ+CD3-CD7+ NK cells compared to asymptomatic cases, or controls, after stimulation with the pdm09 virus. Taken together, virus specific and functionally distinct T and NK cell populations may serve as cellular immune correlates of clinical outcomes of pandemic influenza disease in pregnant women. Our results may provide information important for future universal influenza vaccine design.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/imunologia , Células Matadoras Naturais/imunologia , Complicações Infecciosas na Gravidez/imunologia , Linfócitos T/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Memória Imunológica , Influenza Humana/complicações , Interferon gama/metabolismo , Noruega , Gravidez , Linfócitos T/metabolismo
13.
Open Forum Infect Dis ; 4(1): ofx026, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28480294

RESUMO

BACKGROUND: Influenza in children who reside in tropical and subtropical regions has until recently been regarded as insignificant. However, new evidence suggests that it significantly impacts hospitalization and promotes secondary bacterial coinfections. Ethiopia is situated in a subtropical area where influenza viruses are likely to circulate year round. METHODS: Clinical data were recorded in a cohort of 103 healthy preschool children recruited in Addis Ababa, Ethiopia. Humoral and cellular immune responses to influenza virus were determined by hemagglutination inhibition (HI) and interferon-γ enzyme-linked immunospot assays. RESULTS: Ninety-six percent of the children (2-5 years old) had pre-existing HI antibody responses to 1 or more of the circulating influenza A subtypes, H1N1 (51%), H3N2 (86%), or influenza B (51%) strains. At the age of 4, all children had been infected with at least 1 strain, and 75% had been infected with 2-4 different viral strains. CD4+ and CD8+ T-cell responses against conserved viral antigens increased with repeated exposures, indicating boosting of cross-reactive cellular immunity. Malnutrition did not seem to affect these immune responses to influenza. CONCLUSIONS: Influenza is highly prevalent among children in this area of Ethiopia. Due to the risk of secondary bacterial pneumonia, increased influenza awareness might benefit child health.

14.
Immunology ; 147(2): 165-77, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26489873

RESUMO

Pre-existing human CD4(+) and CD8(+) T-cell-mediated immunity may be a useful correlate of protection against severe influenza disease. Identification and evaluation of common epitopes recognized by T cells with broad cross-reactivity is therefore important to guide universal influenza vaccine development, and to monitor immunological preparedness against pandemics. We have retrieved an optimal combination of MHC class I and class II restricted epitopes from the Immune Epitope Database (www.iedb.org), by defining a fitness score function depending on prevalence, sequence conservancy and HLA super-type coverage. Optimized libraries of CD4(+) and CD8(+) T-cell epitopes were selected from influenza antigens commonly present in seasonal and pandemic influenza strains from 1934 to 2009. These epitope pools were used to characterize human T-cell responses in healthy donors using interferon-γ ELISPOT assays. Upon stimulation, significant CD4(+) and CD8(+) T-cell responses were induced, primarily recognizing epitopes from the conserved viral core proteins. Furthermore, the CD4(+) and CD8(+) T cells were phenotypically characterized regarding functionality, cytotoxic potential and memory phenotype using flow cytometry. Optimized sets of T-cell peptide epitopes may be a useful tool to monitor the efficacy of clinical trials, the immune status of a population to predict immunological preparedness against pandemics, as well as being candidates for universal influenza vaccines.


Assuntos
Antígenos Virais/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Imunidade Celular , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/virologia , Células Cultivadas , Biologia Computacional , Bases de Dados de Proteínas , Desenho de Fármacos , ELISPOT , Interações Hospedeiro-Patógeno , Humanos , Imunidade Celular/efeitos dos fármacos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/patogenicidade , Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Interferon gama/imunologia , Interferon gama/metabolismo , Testes de Liberação de Interferon-gama , Ativação Linfocitária , Biblioteca de Peptídeos , Fenótipo
15.
PLoS One ; 10(4): e0123684, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25860483

RESUMO

BACKGROUND: Pancreatic adenocarcinoma is a lethal disease with 5-year survival of less than 5%. 5-fluorouracil (5-FU) is a principal first-line therapy, but treatment only extends survival modestly and is seldom curative. Drug resistance and disease recurrence is typical and there is a pressing need to overcome this. To investigate acquired 5-FU resistance in pancreatic adenocarcinoma, we established chemoresistant monoclonal cell lines from the Panc 03.27 cell line by long-term exposure to increasing doses of 5-FU. RESULTS: 5-FU-resistant cell lines exhibited increased expression of markers associated with multidrug resistance explaining their reduced sensitivity to 5-FU. In addition, 5-FU-resistant cell lines showed alterations typical for an epithelial-to-mesenchymal transition (EMT), including upregulation of mesenchymal markers and increased invasiveness. Microarray analysis revealed the L1CAM pathway as one of the most upregulated pathways in the chemoresistant clones, and a significant upregulation of L1CAM was seen on the RNA and protein level. In pancreatic cancer, expression of L1CAM is associated with a chemoresistant and migratory phenotype. Using esiRNA targeting L1CAM, or by blocking the extracellular part of L1CAM with antibodies, we show that the increased invasiveness observed in the chemoresistant cells functionally depends on L1CAM. Using esiRNA targeting ß-catenin and/or Slug, we demonstrate that in the chemoresistant cell lines, L1CAM expression depends on Slug rather than ß-catenin. CONCLUSION: Our findings establish Slug-induced L1CAM expression as a mediator of a chemoresistant and migratory phenotype in pancreatic adenocarcinoma cells.


Assuntos
Regulação Neoplásica da Expressão Gênica , Molécula L1 de Adesão de Célula Nervosa/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Fatores de Transcrição/metabolismo , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos/genética , Transição Epitelial-Mesenquimal/genética , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Invasividade Neoplásica , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Fatores de Transcrição da Família Snail , Transcrição Gênica , Regulação para Cima , beta Catenina/metabolismo
16.
J Virol Methods ; 207: 232-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25025814

RESUMO

The use of live virus in the laboratory requires additional precautions, such as personnel training and special equipment, in order to limit the transmission risk. This is a requirement which not all laboratories can fulfill. In this study, a viral inactivation method is introduced using hydrogen peroxide (H2O2), which maintains antigenicity. Three strains of influenza viruses were inactivated and the ex vivo cellular and humoral immune responses were further analyzed, by comparing them to live viruses, in ELISpot, Multiplex and ELISA assays. In all assays, the H2O2 inactivated viruses displayed comparable responses to the live viruses, suggesting that the inactivated viruses still elicited immunogenic responses even though inactivation was confirmed by lack of viral replication in MDCK cells. Taken together, this study demonstrates that influenza viruses inactivated with H2O2 retain immunogenicity and are able to both detect humoral and elicit cellular immune responses in vitro, which could reduce the need to handle live viruses in the laboratory.


Assuntos
Antígenos Virais/efeitos dos fármacos , Antígenos Virais/imunologia , Desinfetantes/metabolismo , Peróxido de Hidrogênio/metabolismo , Orthomyxoviridae/efeitos dos fármacos , Orthomyxoviridae/imunologia , Inativação de Vírus , Animais , Cães , Ensaio de Imunoadsorção Enzimática , ELISPOT , Células Madin Darby de Rim Canino , Viabilidade Microbiana/efeitos dos fármacos , Orthomyxoviridae/fisiologia , Cultura de Vírus , Replicação Viral/efeitos dos fármacos
17.
Cytotherapy ; 15(1): 20-32, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23260083

RESUMO

BACKGROUND AIMS: Many ovarian cancers originate from ovarian surface epithelium, where they develop from cysts intermixed with stroma. The stromal layer is critical to the progression and survival of the neoplasm and consequently is recruited into the tumor microenvironment. METHODS: Using both syngeneic mouse tumors (ID8-R) and human xenograft (OVCAR3, SKOV3) tumor models, we first confirmed that intraperitoneally injected circulating mesenchymal stem cells (MSCs) could target, preferentially engraft and differentiate into α-smooth muscle actin-positive myofibroblasts, suggesting their role as "reactive stroma" in ovarian carcinoma development and confirming their potential as a targeted delivery vehicle for the intratumoral production of interferon-ß (IFN-ß). Mice with ovarian carcinomas then received weekly intraperitoneal injections of IFN-ß expressing MSCs. RESULTS: Intraperitoneal injections of IFN-ß expressing MSCs resulted in complete eradication of tumors in 70% of treated OVCAR3 mice (P = 0.004) and an increased survival of treated SKOV3 mice compared with controls (P = 0.01). Similar tumor growth control was observed using murine IFN-ß delivered by murine MSCs in ID8-R ovarian carcinoma. As a potential mechanism of tumor killing, MSCs produced IFN-ß-induced caspase-dependent tumor cell apoptosis. CONCLUSIONS: Our results demonstrate that ovarian carcinoma engrafts MSCs to participate in myofibrovascular networks and that IFN-ß produced by MSCs intratumorally modulates tumor kinetics, resulting in prolonged survival.


Assuntos
Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Neoplasias Ovarianas/terapia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Células Cultivadas , Feminino , Terapia Genética/métodos , Humanos , Imuno-Histoquímica , Interferon beta/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ensaios Antitumorais Modelo de Xenoenxerto
18.
J Chromatogr A ; 1255: 291-7, 2012 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-22410154

RESUMO

Oxysterols are important in numerous biological processes, including cell signaling. Here we present an automated filtration/filter backflush-solid phase extraction-liquid chromatography-tandem mass spectrometry (AFFL-SPE-LC-MS/MS) method for determining 24-hydroxysterol and the isomers 25-hydroxycholesterol and 22S-hydroxycholesterol that enables simplified sample preparation, high sensitivity (~25 pg/mL cell lysis sample) and low sample variability. Only one sample transfer step was required for the entire process of cell lysis, derivatization and determination of selected oxysterols. During the procedure, autoxidation of cholesterol, a potential/common problem using standard analytical methods, was found to be negligible. The reversed phase AFFL-SPE-LC-MS/MS method utilizing a 1mm inner diameter column was validated, and used to determine levels of the oxysterol analytes in mouse fibroblast cell lines SSh-LII and NIH-3T3, and human cancer cell lines, BxPC3, HCT-15 and HCT-116. In BxPC3 cells, the AFFL-SPE-LC-MS/MS method was used to detect significant differences in 24S-OHC levels between vimentin+ and vimentin- heterogenous sub-populations. The methodology also allowed monitoring of significant alterations in 24S-OHC levels upon delivery of the Hedgehog (Hh) antagonist MS-0022 in HCT-116 colorectal carcinoma cell lines.


Assuntos
Cromatografia Líquida/métodos , Hidroxicolesteróis/análise , Hidroxicolesteróis/metabolismo , Espectrometria de Massas/métodos , Extração em Fase Sólida/métodos , Animais , Benzamidas/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular/química , Filtração , Proteínas Hedgehog , Humanos , Hidroxicolesteróis/química , Hidroxicolesteróis/isolamento & purificação , Isomerismo , Camundongos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Transdução de Sinais/efeitos dos fármacos
19.
PLoS One ; 6(6): e19904, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21698280

RESUMO

BACKGROUND: Hedgehog (Hh) signaling is over-activated in several solid tumors where it plays a central role in cell growth, stroma recruitment and tumor progression. In the Hh signaling pathway, the Smoothened (SMO) receptor comprises a primary drug target with experimental small molecule SMO antagonists currently being evaluated in clinical trials. PRINCIPAL FINDINGS: Using Shh-Light II (Shh-L2) and alkaline phosphatase (AP) based screening formats on a "focused diversity" library we identified a novel small molecule inhibitor of the Hh pathway, MS-0022 (2-bromo-N-(4-(8-methylimidazo[1,2-a]pyridin-2-yl)phenyl)benzamide). MS-0022 showed effective Hh signaling pathway inhibition at the level of SMO in the low nM range, and Hh pathway inhibition downstream of Suppressor of fused (SUFU) in the low µM range. MS-0022 reduced growth in the tumor cell lines PANC-1, SUIT-2, PC-3 and FEMX in vitro. MS-0022 treatment led to a transient delay of tumor growth that correlated with a reduction of stromal Gli1 levels in SUIT-2 xenografts in vivo. SIGNIFICANCE: We document the in vitro and in vivo efficacy and bioavailability of a novel small molecule SMO antagonist, MS-0022. Although MS-0022 primarily interferes with Hh signaling at the level of SMO, it also has a downstream inhibitory effect and leads to a stronger reduction of growth in several tumor cell lines when compared to related SMO antagonists.


Assuntos
Adenocarcinoma/patologia , Antineoplásicos/farmacologia , Benzamidas/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Modelos Animais de Doenças , Neoplasias Pancreáticas/patologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Adenocarcinoma/metabolismo , Animais , Antineoplásicos/farmacocinética , Benzamidas/farmacocinética , Disponibilidade Biológica , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Divisão Celular/efeitos dos fármacos , Proteínas Hedgehog/metabolismo , Camundongos , Neoplasias Pancreáticas/metabolismo , Transdução de Sinais , Receptor Smoothened , Transplante Heterólogo
20.
Cancer Res ; 71(1): 197-205, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21199802

RESUMO

Canonical Wnt signaling is deregulated in several types of human cancer where it plays a central role in tumor cell growth and progression. Here we report the identification of 2 new small molecules that specifically inhibit canonical Wnt pathway at the level of the destruction complex. Specificity was verified in various cellular reporter systems, a Xenopus double-axis formation assay and a gene expression profile analysis. In human colorectal cancer (CRC) cells, the new compounds JW67 and JW74 rapidly reduced active ß-catenin with a subsequent downregulation of Wnt target genes, including AXIN2, SP5, and NKD1. Notably, AXIN2 protein levels were strongly increased after compound exposure. Long-term treatment with JW74 inhibited the growth of tumor cells in both a mouse xenograft model of CRC and in Apc(Min) mice (multiple intestinal neoplasia, Min). Our findings rationalize further preclinical and clinical evaluation of these new compounds as novel modalities for cancer treatment.


Assuntos
Divisão Celular/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Oxidiazóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Triazóis/farmacologia , Proteínas Wnt/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Humanos , Camundongos , Proteínas Wnt/metabolismo
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