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1.
Braz J Med Biol Res ; 52(10): e8845, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31576907

RESUMO

Regucalcin is a soluble protein that is principally expressed in hepatocytes. Studies of regucalcin have mainly been conducted in animals due to a lack of commercially available kits. We aimed to develop an enzyme-linked immunosorbent assay (ELISA) to quantify serum regucalcin in patients with hepatitis B virus (HBV)-related disease. High-titer monoclonal antibodies and a polyclonal antibody to regucalcin were produced, a double-antibody sandwich ELISA method was established, and serum regucalcin was determined in 47 chronic hepatitis B (CHB) patients, 91 HBV-related acute-on-chronic liver failure (HBV-ACLF) patients, and 33 healthy controls. The ELISA demonstrated an appropriate linear range, and high levels of reproducibility, sensitivity, specificity, accuracy, and stability. The median serum regucalcin concentrations in HBV-ACLF and CHB patients were 5.46 and 3.76 ng/mL, respectively (P<0.01), which were much higher than in healthy controls (1.72 ng/mL, both P<0.01). For the differentiation of CHB patients and healthy controls, the area under curve (AUC) was 0.86 with a cut-off of 2.42 ng/mL, 85.7% sensitivity, and 78.8% specificity. In contrast, the AUC of alanine aminotransferase (ALT) was lower (AUC=0.80, P=0.01). To differentiate ACLF from CHB, the AUC was 0.72 with a cut-off of 4.26 ng/mL, 77.0% sensitivity, and 61.2% specificity while the AUC of ALT was 0.41 (P=0.07). Thus, we have developed an ELISA that is suitable for measuring serum regucalcin and have shown that serum regucalcin increased with the severity of liver injury due to HBV-related diseases, such that it appears to be more useful than ALT as a marker of liver injury.


Assuntos
Proteínas de Ligação ao Cálcio/sangue , Hepatite B Crônica/sangue , Insuficiência Renal/sangue , Adolescente , Adulto , Idoso , Anticorpos Antivirais/imunologia , Biomarcadores/sangue , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal/virologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Adulto Jovem
2.
J Microbiol ; 57(9): 821-827, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31452045

RESUMO

Most commercialized virus-like particle (VLP) vaccines use aluminum salt as adjuvant, even though VLPs provoke adequate antibody responses without adjuvant. We do not have detailed knowledge of how adjuvant affects the profile of anti-VLP antibodies. Meanwhile, there is evidence that differences between vaccination protocols influence the glycosylation of antibodies, which may alter their effector functions. In the present study a murine model was used to investigate the effects of dosing schedule and adjuvant on the antibody profiles and glycosylation levels of antigen-specific antibody responses to human papillomavirus type 16 L1 (HPV16 L1) VLPs. Mice received subcutaneously 2,000 ng of antigen divided into 4 or 7 doses. The HPV16 L1 VLPs elicited > 4 log10 anti-HPV16 L1 IgG titers without adjuvant, and aluminum hydroxide as adjuvant increased IgG titers 1.3- to 4-fold and reduced the anti-HPV16 L1 IgG2a / anti-HPV16 L1 IgG1 ratio value (use of aluminum hydroxide reduced the ratio of the IgG2a). Immunization with HPV16 L1 VLPs in combination with Freund's adjuvant enhanced IgG titers 5- to 12-fold. Seven-dose immunization markedly increased anti-HPV16 L1 IgM titers compared to four-dose immunization, as well as increasing the proportion of glycosylated antibodies. Our results suggest that antibody glycosylation can be controlled immunologically, and IgG and IgM profiles and glycosylation profiles of the vaccine-induced antibodies can be used as indicators reflecting the vaccine characteristics. These results indicate that the HPV16 L1 VLP dosing schedule can affect the quality of antigen-specific antibody responses. We suggest that dosing schedules should be noted in vaccination protocols for VLP-based vaccines.


Assuntos
Papillomavirus Humano 16/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Infecções por Papillomavirus/virologia , Vacinas contra Papillomavirus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/imunologia , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Papillomavirus Humano 16/genética , Humanos , Esquemas de Imunização , Camundongos , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia
3.
Mem Inst Oswaldo Cruz ; 114: e190098, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31411310

RESUMO

BACKGROUND: Dengue virus (DENV) has circulated in Brazil for over 30 years. During this time, one serotype has cyclically replaced the other, until recently, when all four distinct serotypes began to circulate together. Persistent circulation of DENV for long time periods makes sequential infections throughout a person's life possible. After primary DENV infection, life-long immunity is developed for the infecting serotype. Since DENV and Zika virus (ZIKV) are antigenically similar, the possibility of cross-reactions has attracted attention and has been demonstrated in vitro. OBJECTIVE: The aim of this study was to investigate whether immune-sera from DENV and ZIKV infected patients would cross-react in vitro with other Flaviviridae family members. METHODS: Cross-reaction of the studied samples with yellow fever virus (YFV), West Nile virus (WNV), Rocio virus (ROCV), Saint Louis virus (SLEV) and Ilheus virus (ILHV) has been investigated by plaque reduction neutralisation test (PRNT) and the antibody-dependent enhancement (ADE) by flow-cytometry. FINDINGS: Antibodies against ZIKV and DENV virus cross-reacted with other flaviviruses either neutralising or enhancing the infection. Thus, viral entrance into FcRFcɣRII-expressing cells were influenced by the cross-reactive antibodies. ZIKV or DENV immune sera enhanced cellular infection by WNV, ILHV, ROCV and SLEV. Finally, DENV immune sera presented higher neutralising activity for YFV and SLEV. While ZIKV immune sera neutralised WNV, ILHV and ROCV with high frequencies of positivity. MAIN CONCLUSIONS: The co-circulation of those viruses in the same area represents a risk for the development of severe infections if they spread throughout the country. Successive flavivirus infections may have an impact on disease pathogenesis, as well as on the development of safe vaccine strategies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vírus da Dengue/imunologia , Zika virus/imunologia , Reações Cruzadas/imunologia , Flavivirus/classificação , Flavivirus/imunologia , Citometria de Fluxo , Humanos , Testes de Neutralização
4.
Arch Virol ; 164(8): 2165-2170, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154511

RESUMO

Zika virus (ZIKV) circulation occurs between non-human primates (NHPs) in a sylvatic transmission cycle. To investigate evidence of flavivirus infection in NHPs in Zambia, we performed a plaque reduction neutralization test (PRNT) to quantify neutralizing antibodies. PRNT revealed that sera from NHPs (African green monkeys and baboons) exhibited neutralizing activity against ZIKV (34.4%; 33/96), whereas a PRNT for yellow fever virus using NHP sera showed no neutralization activity. ZIKV genomic RNA was not detected in splenic tissues from NHPs, suggesting that the presence of anti-ZIKV neutralizing antibodies represented resolved infections. Our evidence suggests that ZIKV is maintained in NHP reservoirs in Zambia.


Assuntos
Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia , Zika virus/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Vírus da Dengue/imunologia , Infecções por Flavivirus/imunologia , Infecções por Flavivirus/virologia , Primatas , Testes Sorológicos/métodos , Zâmbia
5.
Dokl Biochem Biophys ; 485(1): 126-128, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201631

RESUMO

We generated a novel human neutralizing human mAb RabD4 against rabies virus glycoprotein using in vitro stimulation of human peripheral B cells produced by immunized donor. The human mAb RabD4 showed a high antigen-binding activity and virus-neutralizing activity in the FAVN test with the CVS-11 rabies virus.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vírus da Raiva/imunologia , Proteínas Virais/imunologia , Humanos
6.
Arch Virol ; 164(9): 2351-2354, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31222429

RESUMO

Porcine bocavirus (PBoV), which belongs the genus Bocaparvovirus, has been identified throughout the world. However, serological methods for detecting anti-PBoV antibodies are presently limited. In the present study, an indirect enzyme-linked immunosorbent assay (PBoV-rNP1 ELISA) based on a recombinant form of nucleoprotein 1 (NP1) of PBoV was established for investigating the seroprevalence of PBoV in 2025 serum specimens collected in north-central China from 2016 to 2018, and 42.3% of the samples tested positive for anti-PBoV IgG antibodies, indicating that the seroprevalence of PBoV is high in pig populations in China.


Assuntos
Anticorpos Antivirais/sangue , Bocavirus/isolamento & purificação , Nucleoproteínas/imunologia , Infecções por Parvoviridae/veterinária , Doenças dos Suínos/virologia , Animais , Anticorpos Antivirais/imunologia , Bocavirus/classificação , Bocavirus/genética , China/epidemiologia , Ensaio de Imunoadsorção Enzimática , Nucleoproteínas/genética , Infecções por Parvoviridae/sangue , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Filogenia , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia
7.
Arch Virol ; 164(9): 2355-2358, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31227892

RESUMO

Equine influenza virus is an important pathogen for the horse industry because of its economic impact, and vaccination is a key control measure. Our previous work suggested that a mutation at position 144 in the hemagglutinin of Florida sublineage clade 2 viruses reduces the cross-neutralizing activity of antiserum against a former vaccine strain. To confirm this suggestion, here, we generated viruses by reverse genetics. Antibody titers against the mutated viruses were one-tenth to one-sixteenth of those against the former vaccine strain. Our findings confirm that this single amino acid substitution reduces the cross-reactivity of antiserum against this former Japanese vaccine.


Assuntos
Anticorpos Antivirais/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Doenças dos Cavalos/imunologia , Vírus da Influenza A/imunologia , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/veterinária , Substituição de Aminoácidos , Animais , Reações Cruzadas , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Doenças dos Cavalos/virologia , Cavalos , Soros Imunes/imunologia , Vírus da Influenza A/genética , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/química , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia
8.
Vet Microbiol ; 233: 102-112, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176394

RESUMO

Pseudorabies virus (PRV) is considered as an infectious agent with a wide of host range, causing considerable economic losses in animal husbandry. Although the commercial vaccine against PRV plays an critical role in control of this disease in swine industry, the potential risk of commercial vaccines against PRV for other host is unclear. Here, we report that the commercial vaccine against PRV is a hidden health risk for dogs. We found that different attenuated PRV strains in commercial vaccines possess different tissue tropism, and that the attenuated PRV strains are lethal to dogs, and that the attenuated PRV strain possesses the ability to spread horizontally among the dogs. Collectively, our findings provide clues that the commercial vaccine against PRV is a hidden risk for dogs, even for the owner of pet dogs to take seriously.


Assuntos
Transmissão de Doença Infecciosa/veterinária , Doenças do Cão/virologia , Herpesvirus Suídeo 1/patogenicidade , Vacinas contra Pseudorraiva/efeitos adversos , Pseudorraiva/prevenção & controle , Animais , Anticorpos Antivirais/imunologia , Cães , Fazendas , Herpesvirus Suídeo 1/imunologia , Animais de Estimação/virologia , Pseudorraiva/transmissão , Vacinas contra Pseudorraiva/imunologia , Fatores de Risco , Vacinas Atenuadas/efeitos adversos , Tropismo Viral , Eliminação de Partículas Virais
9.
Vet Microbiol ; 233: 93-101, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176418

RESUMO

Actinobacillus pleuropneumoniae (APP) and porcine circovirus type 2 (PCV2) are both important pathogens of the porcine respiratory disease complex (PRDC), which results in significant worldwide economic losses. Recently, PCV2 and APP coinfection has been described in the worldwide pork industry, and represents an extremely complex situation in veterinary medicine. However, the mechanism of their coinfection has not been investigated. In this study, we found that PCV2 promoted APP adhesion to and invasion of porcine alveolar macrophages (PAMs) during coinfection. Additionally, PCV2 suppressed reactive oxygen species (ROS) production by inhibiting cytomembrane NADPH oxidase activity, which was beneficial for APP survival in PAMs in vitro. During coinfection, PCV2 weakened the inflammatory response and macrophage antigen presentation by decreasing TNF-α, IFN-γ and IL-4 expression, and reduced clearance of the invading bacteria. The host-cell experimental results were verified in a mouse model. The findings provide a deeper and novel understanding of porcine coinfection, and will be extremely helpful for the design of strategies for PRDC control.


Assuntos
Actinobacillus pleuropneumoniae/fisiologia , Circovirus/fisiologia , Coinfecção/veterinária , Macrófagos Alveolares/microbiologia , Macrófagos Alveolares/virologia , Espécies Reativas de Oxigênio/metabolismo , Infecções por Actinobacillus/imunologia , Infecções por Actinobacillus/veterinária , Animais , Anticorpos Antivirais/imunologia , Apresentação do Antígeno , Aderência Bacteriana , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/veterinária , Citocinas/genética , Citocinas/imunologia , Feminino , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos ICR , Viabilidade Microbiana , NADPH Oxidases/metabolismo , Suínos
10.
Nat Commun ; 10(1): 2699, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221976

RESUMO

Human cytomegalovirus (CMV) causes a wide array of disease to diverse populations of immune-compromised individuals. Thus, a more comprehensive understanding of how CMV enters numerous host cell types is necessary to further delineate the complex nature of CMV pathogenesis and to develop targeted therapeutics. To that end, we establish a vaccination strategy utilizing membrane vesicles derived from epithelial cells to generate a library of monoclonal antibodies (mAbs) targeting cell surface proteins in their native conformation. A high-throughput inhibition assay is employed to screen these antibodies for their ability to limit infection, and mAbs targeting CD46 are identified. In addition, a significant reduction of viral proliferation in CD46-KO epithelial cells confirms a role for CD46 function in viral dissemination. Further, we demonstrate a CD46-dependent entry pathway of virus infection in trophoblasts, but not in fibroblasts, highlighting the complexity of CMV entry and identifying CD46 as an entry factor in congenital infection.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Interações Hospedeiro-Patógeno/imunologia , Proteína Cofatora de Membrana/imunologia , Internalização do Vírus , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/administração & dosagem , Anticorpos Antivirais/imunologia , Linhagem Celular , Infecções por Citomegalovirus/prevenção & controle , Infecções por Citomegalovirus/virologia , Células Epiteliais/imunologia , Células Epiteliais/virologia , Fibroblastos/imunologia , Fibroblastos/virologia , Técnicas de Inativação de Genes , Humanos , Proteína Cofatora de Membrana/genética , RNA Interferente Pequeno/metabolismo , Trofoblastos/imunologia , Trofoblastos/virologia , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia
11.
Emerg Microbes Infect ; 8(1): 841-856, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31169078

RESUMO

The Middle East respiratory syndrome coronavirus (MERS-CoV) has spread through 27 countries and infected more than 2,200 people since its first outbreak in Saudi Arabia in 2012. The high fatality rate (35.4%) of this novel coronavirus and its persistent wide spread infectiousness in animal reservoirs have generated tremendous global public health concern. However, no licensed therapeutic agents or vaccines against MERS-CoV are currently available and only a limited few have entered clinical trials. Among all the potential targets of MERS-CoV, the spike glycoprotein (S) has been the most well-studied due to its critical role in mediating viral entry and in inducing a protective antibody response in infected individuals. The most notable studies include the recent discoveries of monoclonal antibodies and development of candidate vaccines against the S glycoprotein. Structural characterization of MERS-CoV S protein bound with these monoclonal antibodies has provided insights into the mechanisms of humoral immune responses against MERS-CoV infection. The current review aims to highlight these developments and discuss possible hurdles and strategies to translate these discoveries into ultimate medical interventions against MERS-CoV infection.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Coronavirus/prevenção & controle , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
12.
J Vet Sci ; 20(3): e29, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31161747

RESUMO

Vaccination is one of the most effective ways of controlling and preventing foot-and-mouth disease (FMD) outbreaks. The effective prevention of this disease requires the use of high-quality vaccines to meet the criteria that enable customers to use them simply. The administration of FMD vaccines containing oil-based adjuvants in pigs can induce the formation of granuloma in the muscle of the vaccinated, which makes these vaccines a less preferable option. Therefore, it is important to establish an FMD vaccine and vaccine delivery tool that offers better immunity and safer application. This study compared the immune responses of intramuscular and needleless intradermal vaccination in pigs. When the same amount of an FMD virus (FMDV) antigen was administered to pigs, both the intradermally and intramuscularly vaccinated groups were protected completely against a challenge of the homologous FMDV, but the intramuscularly vaccinated group showed an overall higher level of neutralizing antibodies. Importantly, the formation of granuloma in muscle could be excluded in the intradermally vaccinated group. Of the oil-based adjuvants selected in this study, ISA 207 was effective in eliciting immunogenicity in intradermal vaccination. In conclusion, a new vaccine formula can be chosen for the delivery of intradermal route to exclude the possibility of local reactions in the muscle and generate protective immunity against an FMDV challenge.


Assuntos
Anticorpos Antivirais/sangue , Febre Aftosa/imunologia , Absorção Cutânea/imunologia , Doenças dos Suínos/imunologia , Vacinação/veterinária , Vacinas Virais/administração & dosagem , Adjuvantes Imunológicos , Animais , Anticorpos Antivirais/imunologia , Febre Aftosa/prevenção & controle , Vírus da Febre Aftosa/imunologia , Injeções Intramusculares/veterinária , Suínos , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia
13.
Nat Commun ; 10(1): 2073, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-31061402

RESUMO

Isolation of broadly neutralizing human monoclonal antibodies (HmAbs) targeting the E2 glycoprotein of Hepatitis C virus (HCV) has sparked hope for effective vaccine development. Nonetheless, escape mutations have been reported. Ideally, a potent vaccine should elicit HmAbs that target regions of E2 that are most difficult to escape. Here, aimed at addressing this challenge, we develop a predictive in-silico evolutionary model for E2 that identifies one such region, a specific antigenic domain, making it an attractive target for a robust antibody response. Specific broadly neutralizing HmAbs that appear difficult to escape from are also identified. By providing a framework for identifying vulnerable regions of E2 and for assessing the potency of specific antibodies, our results can aid the rational design of an effective prophylactic HCV vaccine.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Hepacivirus/imunologia , Hepatite C/imunologia , Proteínas do Envelope Viral/imunologia , Simulação por Computador , Desenho de Drogas , Mapeamento de Epitopos/métodos , Epitopos/genética , Epitopos/imunologia , Evolução Molecular , Hepacivirus/genética , Hepatite C/prevenção & controle , Hepatite C/virologia , Humanos , Modelos Biológicos , Proteínas do Envelope Viral/genética , Vacinas contra Hepatite Viral/imunologia
14.
Nat Commun ; 10(1): 2105, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068578

RESUMO

The respiratory syncytial virus (RSV) F glycoprotein is a class I fusion protein that mediates viral entry and is a major target of neutralizing antibodies. Structures of prefusion forms of RSV F, as well as other class I fusion proteins, have revealed compact trimeric arrangements, yet whether these trimeric forms can transiently open remains unknown. Here, we perform structural and biochemical studies on a recently isolated antibody, CR9501, and demonstrate that it enhances the opening of prefusion-stabilized RSV F trimers. The 3.3 Å crystal structure of monomeric RSV F bound to CR9501, combined with analysis of over 25 previously determined RSV F structures, reveals a breathing motion of the prefusion conformation. We also demonstrate that full-length RSV F trimers transiently open and dissociate on the cell surface. Collectively, these findings have implications for the function of class I fusion proteins, as well as antibody prophylaxis and vaccine development for RSV.


Assuntos
Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Vírus Sincicial Respiratório Humano/fisiologia , Proteínas Virais de Fusão/metabolismo , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Linfócitos B/virologia , Cercopithecus aethiops , Simulação por Computador , Cristalografia por Raios X , Desenvolvimento de Medicamentos , Células HEK293 , Células HeLa , Humanos , Modelos Moleculares , Multimerização Proteica/fisiologia , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Células Vero , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/imunologia
15.
Vet Res ; 50(1): 36, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31113477

RESUMO

A longitudinal study was performed in three Danish farrow to grower (30 kilos) herds over a 4-month period to investigate the dynamics and clinical impacts of influenza A virus (IAV) infections. In each herd, four batches consisting of four sows each with five ear-tagged piglets were included. Nasal swabs and/or blood were sampled from the sows and/or the piglets prior to farrowing and at weeks 1, 3, and 5 and at the end of the nursery period. Clinical examinations were performed at each sampling time. The sows and piglets were tested for IAV and IAV antibodies in nasal swabs and blood samples, respectively. The results revealed three enzootically infected herds, where the majority of the pigs were infected during the first 5 weeks after birth. Infected piglets of only 3 days of age were detected in the farrowing unit, where the sows were also shedding virus. In all herds, low to moderate numbers of infected pigs (ranging from 3.6 to 20.7%) were found to be virus positive in nasal swabs at two consecutive sampling times. Furthermore, clinical signs of respiratory disease were associated with IAV detection. The findings of this study documented that IAV can persist in herds and that piglets as young as 3 days can be infected despite the presence of maternally derived antibodies.


Assuntos
Anticorpos Antivirais/imunologia , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Animais , Animais Recém-Nascidos/imunologia , Animais Recém-Nascidos/virologia , Feminino , Estudos Longitudinais , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Suínos , Doenças dos Suínos/imunologia
16.
Sensors (Basel) ; 19(9)2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31067666

RESUMO

A new simple electrochemical immunosensor approach for the determination of antibodies to tick-borne encephalitis virus (TBEV) in immunological products was developed and tested. The assay is performed by detecting the silver reduction signal in the bioconjugates with antibodies (Ab@AgNP). Here, signal is read by cathodic linear sweep voltammetry (CLSV) through the detection of silver chloride reduction on a gold-carbon composite electrode (GCCE). Covalent immobilization of the antigen on the electrode surface was performed after thiolation and glutarization of the GCCE. Specific attention has been paid to the selection of conditions for stabilizing both the silver nanoparticles and their Ab@AgNP. A simple flocculation test with NaCl was used to select the concentration of antibodies, and the additional stabilizer bovine serum albumin (BSA) was used for Ab@AgNP preparation. The antibodies to TBEV were quantified in the range from 50 IU·mL-1 to 1600 IU·mL-1, with a detection limit of 50 IU·mL-1. The coefficient of determination (r2) is 0.989. The electrochemical immunosensor was successfully applied to check the quality of immunological products containing IgG antibodies to TBEV. The present work paves the path for a novel method for monitoring TBEV in biological fluids.


Assuntos
Anticorpos Antivirais/imunologia , Técnicas Eletroquímicas/métodos , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/imunologia , Imunoensaio/métodos , Nanopartículas Metálicas/química , Prata/química , Animais , Bovinos , Eletrodos , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Soroalbumina Bovina , Espectrofotometria Ultravioleta
17.
J Immunol Res ; 2019: 6491738, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31089478

RESUMO

Middle East respiratory syndrome coronavirus (MERS-CoV) first emerged in late 2012. Since its emergence, a total of 2279 patients from 27 countries have been infected across the globe according to a World Health Organization (WHO) report (Feb. 12th, 2019). Approximately 806 patients have died. The virus uses its spike proteins as adhesive factors that are proinflammatory for host entry through a specific receptor called dipeptidyl peptidase-4 (DPP4). This receptor is considered a key factor in the signaling and activation of the acquired and innate immune responses in infected patients. Using potent antigens in combination with strong adjuvants may effectively trigger the activation of specific MERS-CoV cellular responses as well as the production of neutralizing antibodies. Unfortunately, to date, there is no effective approved treatment or vaccine for MERS-CoV. Thus, there are urgent needs for the development of novel MERS-CoV therapies as well as vaccines to help minimize the spread of the virus from infected patients, thereby mitigating the risk of any potential pandemics. Our main goals are to highlight and describe the current knowledge of both the innate and adaptive immune responses to MERS-CoV and the current state of MERS-CoV vaccine development. We believe this study will increase our understanding of the mechanisms that enhance the MERS-CoV immune response and subsequently contribute to the control of MERS-CoV infections.


Assuntos
Imunidade Adaptativa , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Imunidade Inata , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Antivirais/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Dipeptidil Peptidase 4/metabolismo , Humanos , Camundongos , Receptores Virais/metabolismo
18.
Emerg Microbes Infect ; 8(1): 787-795, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31132935

RESUMO

Pteropine orthoreoviruses (PRV) are emerging bat-borne viruses with proven zoonotic transmission. We recently demonstrated human exposure to PRV in Singapore, which together with previous reports from Malaysia and Vietnam suggest that human infection of PRV may occur periodically in the region. This raises the question whether bats are the only sources of human infection. In this study, we screened 517 cynomolgus macaques caught in Singapore for evidence of exposure to PRV3M (also known as Melaka virus), which was first isolated from human patients in Melaka, Malaysia. We found that 67 serum samples were PRV3M positive by ELISA and 34 were also positive by virus neutralization assay. To investigate whether monkeys could act as hosts for PRV transmission, we experimentally infected cynomolgus macaques with PRV3M and housed these animals with uninfected monkeys. Although no clinical signs of infection were observed in infected animals, viral RNA was detected in nasal and rectal swabs and all infected macaques seroconverted. Additionally, one of the uninfected animals seroconverted, implying active shedding and transmission of PRV3M. We provide evidence that PRV exposure in the macaque population in Singapore occurs at a relatively high prevalence and this study suggests that cynomolgus macaques may be an intermediate or reservoir host for PRVs.


Assuntos
Macaca fascicularis/virologia , Doenças dos Macacos/virologia , Orthoreovirus/fisiologia , Infecções por Reoviridae/transmissão , Infecções por Reoviridae/veterinária , Zoonoses/transmissão , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Feminino , Humanos , Macaca fascicularis/sangue , Doenças dos Macacos/sangue , Doenças dos Macacos/transmissão , Testes de Neutralização , Orthoreovirus/genética , Infecções por Reoviridae/sangue , Infecções por Reoviridae/virologia , Singapura , Zoonoses/sangue , Zoonoses/virologia
19.
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
20.
Nat Commun ; 10(1): 1943, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-31028263

RESUMO

Zika virus (ZIKV) outbreak in Americas led to extensive efforts to develop vaccines and ZIKV-specific diagnostics. In the current study, we use whole genome phage display library spanning the entire ZIKV genome (ZIKV-GFPDL) for in-depth immune profiling of IgG and IgM antibody repertoires in serum and urine longitudinal samples from individuals acutely infected with ZIKV. We observe a very diverse IgM immune repertoire encompassing the entire ZIKV polyprotein on day 0 in both serum and urine. ZIKV-specific IgG antibodies increase 10-fold between day 0 and day 7 in serum, but not in urine; these are highly focused on prM/E, NS1 and NS2B. Differential antibody affinity maturation is observed against ZIKV structural E protein compared with nonstructural protein NS1. Serum antibody affinity to ZIKV-E protein inversely correlates with ZIKV disease symptoms. Our study provides insight into unlinked evolution of immune response to ZIKV infection and identified unique targets for ZIKV serodiagnostics.


Assuntos
Anticorpos Antivirais/sangue , Infecção por Zika virus/imunologia , Anticorpos Antivirais/imunologia , Afinidade de Anticorpos/fisiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/sangue , Proteínas não Estruturais Virais/metabolismo , Vacinas Virais/imunologia , Zika virus/imunologia , Infecção por Zika virus/diagnóstico
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