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1.
Arch Virol ; 164(11): 2715-2724, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31456086

RESUMO

Bovine coronavirus (BCoV) is a recognized cause of severe neonatal calf diarrhea, with a negative impact on animal welfare, leading to economic losses to the livestock industry. Cattle production is one of the most important economic sectors in Uruguay. The aim of this study was to determine the frequency of BCoV infections and their genetic diversity in Uruguayan calves and to describe the evolutionary history of the virus in South America. The overall detection rate of BCoV in Uruguay was 7.8% (64/824): 7.7% (60/782) in dairy cattle and 9.5% (4/42) in beef cattle. The detection rate of BCoV in samples from deceased and live calves was 10.0% (6/60) and 7.6% (58/763), respectively. Interestingly, there was a lower frequency of BCoV detection in calves born to vaccinated dams (3.3%, 8/240) than in calves born to unvaccinated dams (12.2%, 32/263) (OR: 4.02, 95%CI: 1.81-8.90; p = 0.00026). The frequency of BCoV detection was higher in colder months (11.8%, 44/373) than in warmer months (1.5%, 3/206) (OR: 9.05, 95%CI: 2.77-29.53, p = 0.000013). Uruguayan strains grouped together in two different lineages: one with Argentinean strains and the other with Brazilian strains. Both BCoV lineages were estimated to have entered Uruguay in 2013: one of them from Brazil (95%HPD interval: 2011-2014) and the other from Argentina (95%HPD interval: 2010-2014). The lineages differed by four amino acid changes, and both were divergent from the Mebus reference strain. Surveillance should be maintained to detect possible emerging strains that can clearly diverge at the antigenic level from vaccine strains.


Assuntos
Antígenos Virais/genética , Doenças dos Bovinos/epidemiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/veterinária , Coronavirus Bovino/isolamento & purificação , Animais , Antígenos Virais/imunologia , Argentina/epidemiologia , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/virologia , Infecções por Coronavirus/prevenção & controle , Coronavirus Bovino/genética , DNA Viral/genética , Disenteria/epidemiologia , Disenteria/veterinária , Disenteria/virologia , Variação Genética/genética , Uruguai/epidemiologia , Vacinação
2.
Vet Microbiol ; 235: 10-20, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282366

RESUMO

African Swine Fever Virus (ASFV) causes a hemorrhagic disease in swine and wild boars with a fatality rate close to 100%. Less virulent strains cause subchronic or chronic forms of the disease. The virus is endemic in sub-Saharan Africa and an outbreak in Georgia in 2007 spread to Armenia, Russia, Ukraine, Belarus, Poland, Lithuania, and Latvia. In August 2018, there was an outbreak in China and in April 2019, ASFV was reported in Vietnam and Cambodia. Since no vaccine or treatment exists, a vaccine is needed to safeguard the swine industry. Previously, we evaluated immunogenicity of two adenovirus-vectored cocktails containing ASFV antigens and demonstrated induction of unprecedented robust antibody and T cell responses, including cytotoxic T lymphocytes. In the present study, we evaluated protective efficacy of both cocktails by intranasal challenge of pigs with ASFV-Georgia 2007/1. A nine antigen cocktail-(I) formulated in BioMize adjuvant induced strong IgG responses, but when challenged, the vaccinees had more severe reaction relative to the controls. A seven antigen cocktail-(II) was evaluated using two adjuvants: BioMize and ZTS-01. The BioMize formulation induced stronger antibody responses, but 8/10 vaccinees and 4/5 controls succumbed to the disease or reached experimental endpoint at 17 days post-challenge. In contrast, the ZTS-01 formulation induced weaker antibody responses, but 4/9 pigs succumbed to the disease while the 5 survivors exhibited low clinical scores and no viremia at 17 days post-challenge, whereas 4/5 controls succumbed to the disease or reached experimental endpoint. Overall, none of the immunogens conferred statistically significant protection.


Assuntos
Febre Suína Africana/prevenção & controle , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Vacinas Virais/imunologia , Adenoviridae , Administração Intranasal , Febre Suína Africana/imunologia , Vírus da Febre Suína Africana , Animais , Antígenos Virais/genética , Imunoglobulina G/sangue , Suínos , Linfócitos T Citotóxicos/imunologia , Vacinas de Subunidades/imunologia , Proteínas Virais/genética , Proteínas Virais/imunologia , Vacinas Virais/genética , Viremia , Virulência
3.
Virol J ; 16(1): 75, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159841

RESUMO

Porcine parvovirus (PPV) is a DNA virus that causes reproductive failure in gilts and sows, resulting in embryonic and fetal losses worldwide. Epitope mapping of PPV is important for developing new vaccines. In this study, we used spot synthesis analysis for epitope mapping of the capsid proteins of PPV (NADL-2 strain) and correlated the findings with predictive data from immunoinformatics. The virus was exposed to three conditions prior to inoculation in pigs: native (untreated), high hydrostatic pressure (350 MPa for 1 h) at room temperature and high hydrostatic pressure (350 MPa for 1 h) at - 18 °C, and was compared with a commercial vaccine produced using inactivated PPV. The screening of serum samples detected 44 positive spots corresponding to 20 antigenic sites. Each type of inoculated antigen elicited a distinct epitope set. In silico prediction located linear and discontinuous epitopes in B cells that coincided with several epitopes detected in spot synthesis of sera from pigs that received different preparations of inoculum. The conditions tested elicited antibodies against the VP1/VP2 antigen that differed in relation to the response time and the profile of structurally available regions that were recognized.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Epitopos/imunologia , Parvovirus Suíno/imunologia , Animais , Antígenos Virais/química , Mapeamento de Epitopos , Epitopos/química , Masculino , Testes de Neutralização , Peptídeos/genética , Peptídeos/imunologia , Suínos
4.
Arch Virol ; 164(7): 1793-1803, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31079211

RESUMO

Numerous studies have shown that immunostimulatory complexes containing Quil-A saponin and various antigens are effective in stimulating the immune response and can be used as vaccine preparations for animals and humans. However, Quil-A saponin possesses toxicity and haemolytic activity. In the present work, a saponin-containing preparation named "Glabilox" was isolated from the roots of a Glycyrrhiza glabra L. plant by high-performance liquid chromatography (HPLC). The results showed that Glabilox has no toxicity or haemolytic activity and can form stable immunostimulatory complexes. Subcutaneous immunization of mice with an immunostimulating complex containing Glabilox and H7N1 influenza virus antigens stimulated high levels of humoral and cellular immunity. Vaccination of chickens with the same immunostimulating complex protected 100% of the animals after experimental infection with a homologous virus. Comparative studies showed that the immunogenic and protective activity of immunostimulatory complexes containing Quil-A and immunostimulatory complexes containing Glabilox are comparable to each other. The results of these studies indicated that Glycyrrhiza glabra saponins show great promise as safe and effective adjuvants.


Assuntos
Adjuvantes Imunológicos/farmacologia , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Glycyrrhiza/imunologia , Vírus da Influenza A Subtipo H7N1/imunologia , Influenza Aviária/prevenção & controle , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , Cães , Glicoproteínas/imunologia , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Influenza Aviária/imunologia , Lipídeos/imunologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Raízes de Plantas/imunologia , Saponinas de Quilaia/imunologia , Saponinas/imunologia , Vacinação
5.
BMC Vet Res ; 15(1): 165, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31118053

RESUMO

BACKGROUND: Feline infectious peritonitis (FIP) is considered highly fatal in its naturally occurring form, although up to 36% of cats resist disease after experimental infection, suggesting that cats in nature may also resist development of FIP in the face of infection with FIP virus (FIPV). Previous experimental FIPV infection studies suggested a role for cell-mediated immunity in resistance to development of FIP. This experimental FIPV infection study in specific pathogen free (SPF) kittens describes longitudinal antiviral T cell responses and clinical outcomes ranging from rapid progression, slow progression, and resistance to disease. RESULTS: Differences in disease outcome provided an opportunity to investigate the role of T cell immunity to FIP determined by T cell subset proliferation after stimulation with different viral antigens. Reduced total white blood cell (WBC), lymphocyte and T cell counts in blood were observed during primary acute infection for all experimental groups including cats that survived without clinical FIP. Antiviral T cell responses during early primary infection were also similar between cats that developed FIP and cats remaining healthy. Recovery of antiviral T cell responses during the later phase of acute infection was observed in a subset of cats that survived longer or resisted disease compared to cats showing rapid disease progression. More robust T cell responses at terminal time points were observed in lymph nodes compared to blood in cats that developed FIP. Cats that survived primary infection were challenged a second time to pathogenic FIPV and tested for antiviral T cell responses over a four week period. Nine of ten rechallenged cats did not develop FIP or T cell depletion and all cats demonstrated antiviral T cell responses at multiple time points after rechallenge. CONCLUSIONS: In summary, definitive adaptive T cell responses predictive of disease outcome were not detected during the early phase of primary FIPV infection. However emergence of antiviral T cell responses after a second exposure to FIPV, implicated cellular immunity in the control of FIPV infection and disease progression. Virus host interactions during very early stages of FIPV infection warrant further investigation to elucidate host resistance to FIP.


Assuntos
Coronavirus Felino/imunologia , Peritonite Infecciosa Felina/imunologia , Imunidade Celular , Linfócitos T/imunologia , Animais , Antígenos Virais/imunologia , Gatos , Resistência à Doença/imunologia , Organismos Livres de Patógenos Específicos
6.
Arch Virol ; 164(8): 2107-2117, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31144039

RESUMO

Species A rotavirus still remains a major cause of acute gastroenteritis in infants and young children. Globally, six genotypes (G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]) account for >90% of circulating strains; however, genotype G12 in combination with P[6] or P[9] has been detected at increasing rates. We sought to broaden our knowledge about the rotavirus strains circulating during the early post-vaccine-introduction period. Stool samples were obtained from children hospitalised for acute gastroenteritis in Belém, Northern Brazil, from May 2008 to May 2011 and examined by reverse transcription polymerase chain reaction and nucleotide sequencing. A total of 122 out of the original 1076 rotavirus strains were judged to be non-typeable in the first analysis and were therefore re-examined. G2P[4] was the most prevalent genotype (58.0%), followed by G1P[8] (16.9%), and G12P[6] (7.5%). G12P[6] strains were identified at similar rates during the first (2.5%) and second (3.9%) years, and the rate jumped to 15.6% in the third year. Analysis of VP7 sequences of the G12P[6] strains showed that they belonged to lineage III. In addition, co-circulating G12P[6] strains displaying long and short RNA patterns were found to belong to the Wa-like and DS-1-like constellation, respectively. Additional unusual circulating strains G12P[9] and G3P[9] were also identified. This hospital-based study showed a high prevalence of G12P[6] strains in the third year of surveillance. Our results highlight the need for continuous longitudinal monitoring of circulating rotavirus strains after introduction of rotavirus vaccines in Brazil and elsewhere.


Assuntos
Gastroenterite/virologia , Rotavirus/genética , Antígenos Virais/imunologia , Brasil , Criança , Criança Hospitalizada , Gastroenterite/imunologia , Genótipo , Humanos , Epidemiologia Molecular/métodos , Filogenia , Prevalência , RNA Viral/genética , Rotavirus/imunologia , Infecções por Rotavirus/imunologia , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus/imunologia , Análise de Sequência de DNA/métodos
7.
Int J Mol Sci ; 20(9)2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31064083

RESUMO

Avian infectious bronchitis virus (IBV) causes considerable economic losses in the poultry industry worldwide, including Taiwan. IBV is among the most important pathogens in chickens, and it spreads rapidly among flocks. In addition to dozens of known serotypes, new viral variants have emerged due to the viral evolution and antigenic variation in IBVs. Therefore, the development of a sensitive, specific, and easily performed assay is crucial for the rapid detection and surveillance of IBV infections. A rapid and simple immunochromatographic strip (ICS) was developed in this study by employing monoclonal antibodies against spike and nucleocapsid proteins of IBV as the tracer and the capture antibody. The ICS showed high specificity in detecting IBV antigens, including several IBV genotypes and novel variants, as opposed to three other common avian respiratory viruses. The detection limit of the strip reached 104.4 50% embryo-infective dose. Moreover, in the experimental chicken model, the strip test demonstrated consistency in detecting IBV with RT-PCR gene detection. Taken together, this antigen detection strip has the potential to serve as an on-farm rapid test for IBV; therefore, it may facilitate surveillance and control of the disease.


Assuntos
Infecções por Coronavirus/diagnóstico , Vírus da Bronquite Infecciosa/imunologia , Técnicas de Diagnóstico Molecular/veterinária , Doenças das Aves Domésticas/diagnóstico , Animais , Antígenos Virais/imunologia , Galinhas , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Feminino , Imunoensaio/métodos , Imunoensaio/normas , Imunoensaio/veterinária , Camundongos , Camundongos Endogâmicos BALB C , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Doenças das Aves Domésticas/virologia , Fitas Reagentes/normas
8.
Ticks Tick Borne Dis ; 10(4): 935-941, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31072731

RESUMO

Tick-borne encephalitis virus (TBEV) is a member of the Flavivirus genus and is the main pathogenic arbovirus circulating in Europe, Russia and China. The envelope (E) protein is exposed on the viral surface and is the main antigen that is employed in diagnostic tests based on the detection of protein-specific antibodies from serum samples of infected individuals. The high degree of similarity among the E proteins of flaviviruses can, in some cases, lead to cross-reactivity and false-positive results in serological tests. Increased specificity in the detection of positive sera for different Flavivirus infections is often obtained by using a portion of the E protein, namely, the DIII domain. Different strategies and expression systems have been described for E and DIII protein production. Here, we present the optimization of an easy and fast method for TBEV E and DIII antigen production and partial purification from E. coli inclusion bodies. The antigenic properties of the produced antigens are retained, as validated by ELISAs with anti-TBEV murine sera as well as sera from infected human patients. The potential applications of both proteins as diagnostic reagents were confirmed.


Assuntos
Antígenos Virais/imunologia , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Escherichia coli/genética , Proteínas Recombinantes/biossíntese , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/biossíntese , Antígenos Virais/genética , Clonagem Molecular , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/imunologia , Ensaio de Imunoadsorção Enzimática , Infecções por Flavivirus/diagnóstico , Infecções por Flavivirus/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas do Envelope Viral/biossíntese , Proteínas do Envelope Viral/genética
9.
World J Gastroenterol ; 25(15): 1899-1906, 2019 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-31057303

RESUMO

BACKGROUND: Cytomegalovirus (CMV) remains a critical complication after solid-organ transplantation. The CMV antigenemia (AG) test is useful for monitoring CMV infection. Although the AG-positivity rate in CMV gastroenteritis is known to be low at onset, almost all cases become positive during the disease course. We treated a patient with transverse colon perforation due to AG-negative CMV gastroenteritis, following a living donor liver transplantation (LDLT). CASE SUMMARY: The patient was a 52-year-old woman with decompensated liver cirrhosis as a result of autoimmune hepatitis who underwent a blood-type compatible LDLT with her second son as the donor. On day 20 after surgery, upper and lower gastrointestinal endoscopy (GE) revealed multiple gastric ulcers and transverse colon ulcers. The biopsy tissue immunostaining confirmed a diagnosis of CMV gastroenteritis. On day 28 after surgery, an abdominal computed tomography revealed transverse colon perforation, and simple lavage and drainage were performed along with an urgent ileostomy. Although the repeated remission and aggravation of CMV gastroenteritis and acute cellular rejection made the control of immunosuppression difficult, the upper GE eventually revealed an improvement in the gastric ulcers, and the biopsy samples were negative for CMV. The CMV-AG test remained negative, therefore, we had to evaluate the status of the CMV infection on the basis of the clinical symptoms and GE. CONCLUSION: This case report suggests a monitoring method that could be useful for AG-negative CMV gastroenteritis after a solid-organ transplantation.


Assuntos
Doenças do Colo/diagnóstico , Infecções por Citomegalovirus/complicações , Gastroenterite/complicações , Perfuração Intestinal/diagnóstico , Transplante de Fígado/efeitos adversos , Antígenos Virais/sangue , Antígenos Virais/imunologia , Colo/diagnóstico por imagem , Colo/virologia , Doenças do Colo/etiologia , Citomegalovirus/imunologia , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Doença Hepática Terminal/imunologia , Doença Hepática Terminal/patologia , Doença Hepática Terminal/cirurgia , Endoscopia Gastrointestinal , Feminino , Gastroenterite/sangue , Gastroenterite/imunologia , Gastroenterite/virologia , Hepatite Autoimune/imunologia , Hepatite Autoimune/patologia , Hepatite Autoimune/cirurgia , Humanos , Perfuração Intestinal/etiologia , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
10.
Appl Microbiol Biotechnol ; 103(12): 4977-4986, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31037380

RESUMO

Dengue virus (DENV) and Japanese encephalitis virus (JEV) are closely related mosquito-borne flaviviruses. Together, they caused most arthropod-borne diseases in the world. Previously, we had demonstrated that both live attenuated and inactivated JE vaccines elicited cross-protection against DENV infection, and a DNA vaccine candidate expressing JEV prM-E protein (named pCAG-JME) could provide effective protection against JEV infection in mice. In this study, we examined whether the same pCAG-JME could elicit cross-protection against DENV infection. Our results showed that pCAG-JME indeed induced cross-reactive antibodies and cross-protection against four different serotypes of DENV in mice. Interestingly, pCAG-JME-immunized mice also generated both Th1 and Th2 responses when stimulated by all four different serotypes of DENV antigens. Moreover, cross-primed CD8+ T cell response was also detected following the stimulation of DENV proteins using intracellular cytokine staining. In addition, sera from pCAG-JME-immunized mice significantly reduced the mortality caused by DENV2 infection in severe combination immunodeficiency mouse. These results suggest that both JE and DENV cross-reactive antibodies and cross-primed T cells might play important roles in the cross-protection. The findings of this study also indicate a possibility of developing novel multivalent genetically engineered vaccines against both JEV and DENV.


Assuntos
Antígenos Virais/imunologia , Proteção Cruzada , Vacinas contra Dengue/imunologia , Dengue/prevenção & controle , Vírus da Encefalite Japonesa (Espécie)/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Vacinas contra Dengue/genética , Vírus da Dengue/classificação , Vírus da Dengue/imunologia , Vírus da Encefalite Japonesa (Espécie)/genética , Feminino , Imunização , Imunização Passiva , Camundongos , Camundongos Endogâmicos BALB C , Sorogrupo , Imunodeficiência Combinada Severa , Células Th1/imunologia , Células Th2/imunologia , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Proteínas do Envelope Viral/genética
11.
PLoS Negl Trop Dis ; 13(4): e0007239, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30943193

RESUMO

Fever is a regulated increase of the body temperature resulting from both infectious and non-infectious causes. Fever is known to play a role in modulating immune responses to infection, but the potential of febrile temperatures in regulating antigen binding affinity to antibodies has not been explored. Here we investigated this process under in vitro conditions using Isothermal titration calorimetry and ELISA. We used selected malarial and dengue antigens against specific monoclonal antibodies, and observed a marked increase in the affinity of these antibody-antigen complexes at 40°C, compared to physiological (37°C) or pathophysiological temperatures (42°C). Induced thermal equilibration of the protein partners at these temperatures in vitro, prior to measurements, further increased their binding affinity. These results suggest another positive and adaptive role for fever in vivo, and highlight the favourable role of thermal priming in enhancing protein-protein affinity for samples with limited availability.


Assuntos
Anticorpos Antivirais/imunologia , Afinidade de Anticorpos , Antígenos Virais/imunologia , Febre/imunologia , Temperatura Ambiente , Anticorpos Monoclonais/imunologia , Complexo Antígeno-Anticorpo/imunologia , Temperatura Corporal , Calorimetria , Dengue/imunologia , Vírus da Dengue , Ensaio de Imunoadsorção Enzimática , Interações Hospedeiro-Patógeno , Humanos , Malária/imunologia , Plasmodium vivax
12.
MBio ; 10(2)2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967460

RESUMO

The effectiveness of influenza vaccines against circulating A(H1N1)pdm09 viruses was modest for several seasons despite the absence of antigenic drift of hemagglutinin (HA), the primary vaccine component. Since antibodies against HA and neuraminidase (NA) contribute independently to protection against disease, antigenic changes in NA may allow A(H1N1)pdm09 viruses to escape from vaccine-induced immunity. In this study, analysis of the specificities of human NA-specific monoclonal antibodies identified antigenic sites that have changed over time. The impact of these differences on in vitro inhibition of enzyme activity was not evident for polyclonal antisera until viruses emerged in 2013 without a predicted glycosylation site at amino acid 386 in NA. Phylogenetic and antigenic cartography demonstrated significant antigenic changes that in most cases aligned with genetic differences. Typical of NA drift, the antigenic difference is observed in one direction, with antibodies against conserved antigenic domains in A/California/7/2009 (CA/09) continuing to inhibit NA of recent A(H1N1)pdm09 viruses reasonably well. However, ferret CA/09-specific antiserum that inhibited the NA of A/Michigan/45/2015 (MI/15) very well in vitro, protected mice against lethal MI/15 infection poorly. These data show that antiserum against the homologous antigen is most effective and suggest the antigenic properties of NA should not be overlooked when selecting viruses for vaccine production.IMPORTANCE The effectiveness of seasonal influenza vaccines against circulating A(H1N1)pdm09 viruses has been modest in recent years, despite the absence of antigenic drift of HA, the primary vaccine component. Human monoclonal antibodies identified antigenic sites in NA that changed early after the new pandemic virus emerged. The reactivity of ferret antisera demonstrated antigenic drift of A(H1N1)pdm09 NA from 2013 onward. Passive transfer of serum raised against A/California/7/2009 was less effective than ferret serum against the homologous virus in protecting mice against a virus with the NA of more recent virus, A/Michigan/45/2015. Given the long-standing observation that NA-inhibiting antibodies are associated with resistance against disease in humans, these data demonstrate the importance of evaluating NA drift and suggest that vaccine effectiveness might be improved by selecting viruses for vaccine production that have NAs antigenically similar to those of circulating influenza viruses.


Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Deriva Genética , Vírus da Influenza A Subtipo H1N1/imunologia , Neuraminidase/imunologia , Proteínas Virais/imunologia , Animais , Anticorpos Monoclonais/imunologia , Modelos Animais de Doenças , Furões , Evasão da Resposta Imune , Imunização Passiva , Vírus da Influenza A Subtipo H1N1/genética , Camundongos , Neuraminidase/genética , Infecções por Orthomyxoviridae/prevenção & controle , Análise de Sobrevida , Resultado do Tratamento , Proteínas Virais/genética
13.
Nat Commun ; 10(1): 1660, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30971703

RESUMO

Influenza A viruses evolve rapidly to escape host immunity, causing reinfection. The form and duration of protection after each influenza virus infection are poorly understood. We quantify the dynamics of protective immunity by fitting individual-level mechanistic models to longitudinal serology from children and adults. We find that most protection in children but not adults correlates with antibody titers to the hemagglutinin surface protein. Protection against circulating strains wanes to half of peak levels 3.5-7 years after infection in both age groups, and wanes faster against influenza A(H3N2) than A(H1N1)pdm09. Protection against H3N2 lasts longer in adults than in children. Our results suggest that influenza antibody responses shift focus with age from the mutable hemagglutinin head to other epitopes, consistent with the theory of original antigenic sin, and might affect protection. Imprinting, or primary infection with a subtype, has modest to no effect on the risk of non-medically attended infections in adults.


Assuntos
Anticorpos Antivirais/sangue , Proteção Cruzada/imunologia , Memória Imunológica/imunologia , Influenza Humana/imunologia , Modelos Biológicos , Adolescente , Adulto , Fatores Etários , Idoso , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Antígenos Virais/isolamento & purificação , Criança , Pré-Escolar , Feminino , Seguimentos , Hemaglutininas/imunologia , Hong Kong/epidemiologia , Humanos , Incidência , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Tempo , Adulto Jovem
14.
Artigo em Inglês | MEDLINE | ID: mdl-30961813

RESUMO

A cross-sectional study was conducted in 274 cats for determination of FeLV antigenemia and FIV seropositivity and factors associated with those infections in cats presented at the Veterinary Hospital of the Santa Catarina State University - UDESC (Brazil). Apparent prevalence for sick cats at the hospital population was 28.41% (95%CI 21.88-34.94%) for FeLV, 7.65% (95%CI 3.71-11.50%) for FIV and 2.18% (95%CI 0.56-5.47%) for both viruses. For healthy cats, the apparent prevalence was 9.89% (95%CI 3.75-16.02%) for FeLV, 2.20% (95%CI 0.34-7.75%) for FIV by immunoassay (ELISA). Average age for FeLV- and FIV-positive individuals was 38.32 and 64.25 months, respectively. Behavior such as aggressiveness and sex (male) were both associated with increased odds of result positivity test for FeLV and FIV; older animals were also associated with FIV test results. A very small proportion of the animals were vaccinated against FeLV and none against FIV. Most of the animals were adopted from shelters or rescued from streets, living with multiple cats that had access to outdoors. The high prevalence of FeLV suggests a need for better control strategies against this disease.


Assuntos
Doenças do Gato/epidemiologia , Síndrome de Imunodeficiência Adquirida Felina/epidemiologia , Vírus da Imunodeficiência Felina/imunologia , Vírus da Leucemia Felina/imunologia , Leucemia Felina/epidemiologia , Infecções Tumorais por Vírus/veterinária , Animais , Antígenos Virais/sangue , Antígenos Virais/imunologia , Comportamento Animal/fisiologia , Brasil/epidemiologia , Doenças do Gato/virologia , Gatos , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/veterinária , Síndrome de Imunodeficiência Adquirida Felina/virologia , Feminino , Leucemia Felina/virologia , Masculino , Prevalência , Fatores de Risco
15.
Int J Mol Sci ; 20(8)2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-31013832

RESUMO

B cell superantigens, also called immunoglobulin superantigens, bind to the variable regions of either the heavy or light chain of immunoglobulins mirroring the lymphocyte-activating properties of classical T cell superantigens. Protein A of Staphylococcus aureus, protein L of Peptostreptococcus magnus, and gp120 of HIV are typical immunoglobulin superantigens. Mast cells are immune cells expressing the high-affinity receptor for IgE (FcεRI) and are strategically located in the human heart, where they play a role in several cardiometabolic diseases. Here, we investigated whether immunoglobulin superantigens induced the activation of human heart mast cells (HHMCs). Protein A induced the de novo synthesis of cysteinyl leukotriene C4 (LTC4) from HHMCs through the interaction with IgE VH3+ bound to FcεRI. Protein L stimulated the production of prostaglandin D2 (PGD2) from HHMCs through the interaction with κ light chains of IgE. HIV glycoprotein gp120 induced the release of preformed (histamine) and de novo synthesized mediators, such as cysteinyl leukotriene C4 (LTC4), angiogenic (VEGF-A), and lymphangiogenic (VEGF-C) factors by interacting with the VH3 region of IgE. Collectively, our data indicate that bacterial and viral immunoglobulin superantigens can interact with different regions of IgE bound to FcεRI to induce the release of proinflammatory, angiogenic, and lymphangiogenic factors from human cardiac mast cells.


Assuntos
Mastócitos/imunologia , Mastócitos/metabolismo , Miocárdio/imunologia , Miocárdio/metabolismo , Superantígenos/imunologia , Antígenos de Bactérias/imunologia , Antígenos Virais/imunologia , Biomarcadores , Liberação de Histamina , Humanos , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/patologia
16.
Clin Lab ; 65(4)2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30969068

RESUMO

BACKGROUND: The aim of this study was to prove the difference between 37°C water incubation method and the BEP III automated immunoassay analyzer incubation method in anti-EBNA1-IgA antibody detection and to find the best way to improve the consistency of the two incubation methods. METHODS: The 37°C water incubation method and BEP III analyzer incubation method were used with the same panel of samples (n = 39) in anti-EBNA1-IgA antibody detection. Except for incubation, the rest of the steps were performed by the BEP III analyzer in both groups. All the data were analyzed by SPSS 17.0 software. Line charts and bar charts were used to compare the difference between the two incubation methods in anti-EBNA1-IgA antibody detection. We planned to find the best incubation scheme for BEP III analyzer, consistent with the water incubation method, using three groups of prolonged incubation time experiments. RESULTS: A sample panel of 39 outpatients were analyzed by two incubation methods. The results showed by line charts that the water incubation method had higher S/CO values than the BEP III analyzer incubation method. Meanwhile the water incubation group had more positive results (61.5%) and less borderline positive results (35.9%) than that of the BEP III analyzer incubation group which were 43.5% and 51.2%, respectively, in the stacked bar charts. We found that by prolonging the incubation time in the BEP III analyzer for 6 minutes in the first and second incubation steps the S/CO values we increased and achieved statistically coincident results with water incubation group. CONCLUSIONS: There were biases between the 37°C water incubation method and the BEP III analyzer incubation method in anti-EBNA1-IgA antibody detection. The water incubation method had higher S/CO values than the BEP III analyzer incubation method in paired groups and led partly to a difference in test results. By prolonging the BEP III analyzer incubation time properly, it can reduce the difference to some extent resulting in statistically similar results with the water incubation method.


Assuntos
Anticorpos Antivirais/isolamento & purificação , Infecções por Vírus Epstein-Barr/imunologia , Antígenos Nucleares do Vírus Epstein-Barr/imunologia , Imunoensaio/métodos , Imunoglobulina A/isolamento & purificação , Antígenos Virais/imunologia , Automação , Proteínas do Capsídeo/imunologia , Ensaio de Imunoadsorção Enzimática , Herpesvirus Humano 4/imunologia , Humanos , Pacientes Ambulatoriais , Controle de Qualidade , Reprodutibilidade dos Testes , Manejo de Espécimes
17.
BMC Res Notes ; 12(1): 214, 2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30961645

RESUMO

OBJECTIVE: Dengue haemorrhagic fever (DHF) is a major public health concern responsible for significant morbidity in both adult and paediatric populations in Sri Lanka. This study examined if persistent non structural protein 1 (NS1) antigen positivity beyond day 3 was predictive of the occurrence of dengue haemorrhagic fever. The patients were followed up during their in-hospital stay and the severity of the illness was classified according to the WHO classification. The NS1 antigen test was repeated after day 3 of the onset of illness, at least 2 days after the initial test. RESULTS: One hundred and fifty-seven patients were enrolled. Persistent NS1 antigen test positivity after day 3 of the illness was not predictive of subsequent development of DHF. Out of multiple other demographic and illness related factors assessed, only having a secondary dengue infection was associated with a high risk of DHF (relative risk = 3.077, 95% CI 1.361, 6.954). Persistent NS1 positivity on day 3 may not be indicative of disease severity. However results need to be confirmed by a larger study with quantitative NS1 testing.


Assuntos
Antígenos Virais/sangue , Coinfecção/diagnóstico , Vírus da Dengue/imunologia , Dengue Grave/diagnóstico , Proteínas não Estruturais Virais/sangue , Adolescente , Antígenos Virais/imunologia , Criança , Pré-Escolar , Coinfecção/imunologia , Coinfecção/patologia , Coinfecção/virologia , Vírus da Dengue/patogenicidade , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos , Dengue Grave/imunologia , Dengue Grave/patologia , Dengue Grave/virologia , Índice de Gravidade de Doença , Sri Lanka , Proteínas não Estruturais Virais/imunologia
19.
Virol Sin ; 34(3): 306-314, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31020574

RESUMO

Previous studies have indicated that two monoclonal antibodies (mAbs; A1-10 and H1-84) of the hemagglutinin (HA) antigen on the H1N1 influenza virus cross-react with human brain tissue. It has been proposed that there are heterophilic epitopes between the HA protein and human brain tissue (Guo et al. in Immunobiology 220:941-946, 2015). However, characterisation of the two mAbs recognising the heterophilic epitope on HA has not yet been performed. In the present study, the common antigens of influenza virus HA were confirmed using indirect enzyme-linked immunosorbent assays and analysed with DNAMAN software. The epitopes were localized to nine peptides in the influenza virus HA sequence and the distribution of the peptides in the three-dimensional structure of HA was determined using PyMOL software. Key amino acids and variable sequences of the antibodies were identified using abYsis software. The results demonstrated that there were a number of common antigens among the five influenza viruses studied that were recognised by the mAbs. One of the peptides, P2 (LVLWGIHHP191-199), bound both of the mAbs and was located in the head region of HA. The key amino acids of this epitope and the variable regions in the heavy and light chain sequences of the mAbs that recognised the epitope are described. A heterophilic epitope on H1N1 influenza virus HA was also introduced. The existence of this epitope provides a novel perspective for the occurrence of nervous system diseases that could be caused by influenza virus infection, which might aid in influenza prevention and control.


Assuntos
Antígenos Heterófilos/imunologia , Antígenos Virais/imunologia , Epitopos/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Mapeamento de Epitopos , Testes de Inibição da Hemaglutinação , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Peptídeos/imunologia , Software
20.
mSphere ; 4(2)2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30867325

RESUMO

This study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n = 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with "suspect" results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated.IMPORTANCE Current measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.


Assuntos
Anticorpos Antivirais/análise , Diarreia/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Coronavirus Respiratório Porcino/imunologia , Vírus da Gastroenterite Transmissível/imunologia , Animais , Antígenos Virais/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/veterinária , Reações Cruzadas , Reações Falso-Positivas , Gastroenterite Suína Transmissível/diagnóstico , Kit de Reagentes para Diagnóstico/normas , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/veterinária , Sensibilidade e Especificidade , Suínos
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