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1.
Arch Virol ; 165(1): 87-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707455

RESUMO

In May 2017, high mortality of chickens and Muscovy ducks due to the H5N8 highly pathogenic avian influenza virus (HPAIV) was reported in the Democratic Republic of Congo (DR Congo). In this study, we assessed the molecular, antigenic, and pathogenic features in poultry of the H5N8 HPAIV from the 2017 Congolese outbreaks. Phylogenetic analysis of the eight viral gene segments revealed that all 12 DR Congo isolates clustered in clade 2.3.4.4B together with other H5N8 HPAIVs isolated in Africa and Eurasia, suggesting a possible common origin of these viruses. Antigenically, a slight difference was observed between the Congolese isolates and a representative virus from group C in the same clade. After intranasal inoculation with a representative DR Congo virus, high pathogenicity was observed in chickens and Muscovy ducks but not in Pekin ducks. Viral replication was higher in chickens than in Muscovy duck and Pekin duck organs; however, neurotropism was pronounced in Muscovy ducks. Our data confirmed the high pathogenicity of the DR Congo virus in chickens and Muscovy ducks, as observed in the field. National awareness and strengthening surveillance in the region are needed to better control HPAIVs.


Assuntos
Antígenos Virais/metabolismo , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/imunologia , Doenças das Aves Domésticas/virologia , África , Animais , Ásia , Galinhas , República Democrática do Congo , Patos/classificação , Patos/virologia , Europa (Continente) , Sequenciamento de Nucleotídeos em Larga Escala , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Filogenia , Filogeografia , Doenças das Aves Domésticas/imunologia , Especificidade da Espécie , Replicação Viral
2.
Int J Nanomedicine ; 14: 7533-7548, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571862

RESUMO

Background: The influenza A virus (IAV) is known for its high variability and poses a huge threat to the health of humans and animals. Pigs play a central role in the cross-species reassortment of IAV. Ectodomain of matrix protein 2 (M2e) is the most conserved protective antigen in IAV and can be used to develop nanovaccines through nanoparticles displaying to increase its immunogenicity. However, the high immunogenicity of nanoparticles can cause the risk of off-target immune response, and excess unwanted antibodies may interfere with the protective efficacy of M2e-specific antibodies. Therefore, it is necessary to select reasonable nanoparticles to make full use of antibodies against nanoparticles while increasing the level of M2e-specific antibodies. Porcine circovirus type 2 (PCV2) is the most susceptible virus in pigs and can promote IAV infection. It is meaningful to develop a vaccine that can simultaneously control swine influenza virus (SIV) and PCV2. Methods: In the present study, M2e of different copy numbers were inserted into the capsid (Cap) protein of PCV2 and expressed in Escherichia coli to form self-assembled chimeric virus-like particles (VLPs) nanovaccine. BALB/c mice and pigs were immunized with these nanovaccines to explore optimal anti-IAV and anti-PCV2 immunity. Results: Cap is capable of carrying at least 81 amino acid residues (three copies of M2e) at its C-terminal without impairing VLPs formation. Cap-3M2e VLPs induced the highest levels of M2e-specific immune responses, conferring protection against lethal challenge of IAVs from different species and induced specific immune responses consistent with PCV2 commercial vaccines in mice. In addition, Cap-3M2e VLPs induced high levels of M2e-specific antibodies and PCV2-specific neutralizing antibodies in pigs. Conclusion: Cap-3M2e VLP is an economical and promising bivalent nanovaccine, which provides dual protection against IAV and PCV2.


Assuntos
Circovirus/imunologia , Vírus da Influenza A/imunologia , Nanopartículas/uso terapêutico , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Especificidade de Anticorpos/imunologia , Aves/virologia , Proteínas do Capsídeo/química , Proliferação de Células , Citocinas/metabolismo , Cães , Feminino , Humanos , Imunidade Humoral , Influenza Aviária/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/virologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Linfócitos/citologia , Células Madin Darby de Rim Canino , Camundongos Endogâmicos BALB C , Testes de Neutralização , Proteínas Recombinantes/isolamento & purificação , Suínos , Vírion/imunologia , Vírion/ultraestrutura
3.
Mol Immunol ; 114: 497-512, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31518854

RESUMO

Compounding with the problem of frequent antigenic shift and occasional drift of the segmented genome of Avian Influenza Virus (AIV), vaccines based on major surface glycoproteins such as haemagglutinin (HA) to counter heterosubtypic AIV infection in chickens remain unsuccessful. In contrast, neuraminidase (NA), the second most abundant surface glycoprotein present in viral capsid is less mutable and, in some instances, successful in eliciting inter-species cross-reactive antibody responses. However, without selective activation of B-cells and T-cells, the ability of NA to induce strong cell mediated immune responses is limited, thus NA based vaccines cannot singularly address the risk of virus escape from host defence. To this end, the highly conserved ectodomain of influenza matrix protein-2 (M2e) has emerged as an attractive cross-protective vaccine target. The present study describes the potential of recombinant Lactococcus lactis (rL. lactis) in expressing functional influenza NA or M2e proteins and conferring effective mucosal and systemic immune responses in the intestine as well as in the upper respiratory airways (trachea) of chickens. In addition, lavages collected from trachea and intestine of birds administered with rL. lactis expressing influenza NA or M2e protein were found to protect MDCK cells against avian influenza type A/PR/8/34 (H1N1) virus challenge. Although minor, the differences in the expression of pro-inflammatory cytokines gene transcripts targeted in this study among the birds administered with either empty or rL. lactis could be attributed to the activation of innate response by L. lactis.


Assuntos
Galinhas/imunologia , Imunidade nas Mucosas/imunologia , Influenza Aviária/imunologia , Lactococcus lactis/imunologia , Neuraminidase/imunologia , Proteínas da Matriz Viral/imunologia , Animais , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Galinhas/virologia , Reações Cruzadas/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Linfócitos T/imunologia , Vacinação/métodos
4.
Protein Pept Lett ; 26(12): 940-948, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31362650

RESUMO

BACKGROUND: Bursa of Fabricius plays the vital functions on B cell development and antibody production in poultry. The bursal-derived peptide plays the essential roles on avian immature B cell development. OBJECTIVES: Here we explored the functions of the recently reported bursal nonapeptide (BP9) on the antibody production and the molecular basis of BP9 on avian immature B cell. METHODS: Chicken were twice immunized with Avian Influenza Virus (AIV) inactivated vaccine plus with BP9 at three dosages, respectively. On two weeks after the second immunization, sera samples were collected from all experimental groups to measure AIV-specific Agglutination Inhibition (HI) antibody titers. Also, on 7th day after the second immunization, spleen lymphocytes were isolated from the immunized chicken to detect the lymphocyte viabilities. DT40 cells were treated with BP9 from 0.02 to 2 µg/mL for 4 and 20h to detect sIgM mRNA levels, and total RNAs from BP9-treated DT40 cells were collected to investigate the gene expression profiles of DT40 cells, and to analyze the enriched pathways and functional biological processes. Finally, nine gene expressions were validated with quantitative PCR (qPCR). RESULTS: Our investigation proved the strong regulatory roles of BP9 on AIV-specific HI antibody titers and lymphocyte viabilities. BP9 promoted sIgM mRNA levels in DT40 cells, and upregulated 598 gene expressions and downregulated 395 gene expressions in DT40 cells with 0.2µg/mL BP9 treatment. Moreover, our findings verified the significantly enriched six pathways and various the biological functional processes of BP9 on avian immature B cell. Also, we found eight signaling pathways in the enriched biological processes of BP9-treated DT40 cells, and the expressions of nine selected genes with qPCR were identical to that of microarray data. CONCLUSION: BP9 promoted the antibody production in the 21-old-day chicken immunization, and stimulated the sIgM expression in DT40 cells. Furthermore, we analyzed the gene expression profile and immune-related biological processes of DT40 cells treated with BP9, which provided some new insights into the mechanism on immature B cell development, and provided important references for adjuvant development on vaccine improvement and clinical application.


Assuntos
Bolsa de Fabricius/química , Vacinas contra Influenza/imunologia , Influenza Aviária/prevenção & controle , Oligopeptídeos/imunologia , Células Precursoras de Linfócitos B/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Formação de Anticorpos , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Galinhas , Humanos , Imunização , Imunoglobulina M/metabolismo , Influenza Aviária/imunologia , Influenza Aviária/virologia , Oligopeptídeos/química , Células Precursoras de Linfócitos B/citologia , Células Precursoras de Linfócitos B/efeitos dos fármacos , Vacinas de Produtos Inativados/imunologia
5.
Virology ; 534: 132-142, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31255797

RESUMO

The chicken upper respiratory tract is the portal of entry for respiratory pathogens including avian influenza virus (AIV). There is a paucity of information about the role of airway epithelial cells in the induction of antiviral responses in the chicken trachea. A better understanding of the role of these cells in the initiation of innate responses may improve prophylactic or therapeutic strategies for control of viral infections. The present study aimed to characterize antiviral innate responses in chicken tracheal epithelial cells (cTECs) induced by TLR ligands. The results demonstrated that stimulation of cTECs with TLR ligands induced antiviral responses, and subsequently reduced the replication of AIV in cTECs. Additionally, stimulated cTECs were able to influence the function of other cells such as macrophages. Overall, these results provided evidence that cTECs mount antiviral responses after stimulation with TLR ligands through IRF7 and NF-κB signaling pathways, leading to activation of other cells, such as macrophages.


Assuntos
Células Epiteliais/imunologia , Vírus da Influenza A/fisiologia , Influenza Aviária/imunologia , Macrófagos/imunologia , Doenças das Aves Domésticas/imunologia , Traqueia/virologia , Animais , Proteínas Aviárias/genética , Proteínas Aviárias/imunologia , Galinhas , Células Epiteliais/virologia , Imunidade Inata , Vírus da Influenza A/genética , Influenza Aviária/genética , Influenza Aviária/virologia , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-8/genética , Interleucina-8/imunologia , Ligantes , Macrófagos/virologia , Poli I-C/imunologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/virologia , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Traqueia/citologia , Traqueia/imunologia
6.
Vet Microbiol ; 234: 77-82, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213275

RESUMO

Control of currently circulating re-assorted low-pathogenicity avian influenza (LPAI) H9N2 is a major concern for both animal and human health. Thus, an improved LPAI H9N2 vaccination strategy is needed to induce complete immunity in chickens against LPAI H9N2 virus strains. Cytokines play a crucial role in mounting both the type and extent of an immune response generated following infection with a pathogen or after vaccination. To improve the efficacy of inactivated LPAI H9N2 vaccine, prokaryotic expression recombination chicken interferon-α (rchIFN-α) was used as vaccine adjuvant.In this study chIFN-α was used as adjuvant in inactivated AI H9N2 vaccine, modulated the immune response of chickens against the vaccine antigen through enhanced humoral and Th1-biased cell-mediated immunity, compared to chickens that received single AI H9N2 vaccine. To further test the protective efficacy of this improved vaccination regimen, immunized chickens were challenged with a high dose of LPAI H9N2 virus. Combined administration rchIFN-α showed markedly enhanced protection compared to single administration of the vaccine, as determined by mortality, clinical severity, and feed and water intake. This enhancement of protective immunity was further confirmed by reduced rectal shedding and replication of AIV H9N2 in challenged chickens. Our results indicate the value of combined administration of rchIFN-α to generate an effective immunization strategy in chickens against LPAI H9N2.


Assuntos
Imunogenicidade da Vacina , Vacinas contra Influenza/imunologia , Influenza Aviária/prevenção & controle , Interferon-alfa/genética , Adjuvantes Imunológicos , Animais , Anticorpos Antivirais/sangue , Galinhas , Imunidade Celular , Imunidade Humoral , Vírus da Influenza A Subtipo H9N2/imunologia , Vacinas contra Influenza/genética , Influenza Aviária/imunologia , Interferon-alfa/imunologia , Organismos Livres de Patógenos Específicos , Vacinas de Produtos Inativados/genética , Vacinas de Produtos Inativados/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Eliminação de Partículas Virais
7.
Microb Pathog ; 135: 103613, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31254602

RESUMO

Avian influenza viruses (AIVs) in wild birds pose a pandemic threat to humans and to the poultry industry. To assess AIV and AIV antibody prevalence in wild birds in China, a systematic review and meta-analysis were conducted. We searched PubMed, Google Scholar, Cochrane Library, Clinical Trial, VIP, CNKI, and WANFANG for published papers related to the prevalence of AIVs and their associated antibodies in wild birds in China from Mar. 10, 2005 to Sept. 20, 2018. Repeat studies, reviews, and other host studies were excluded, as well as those with inconsistent data, incomplete information, or only prevalence data or data from outside of mainland China. In total, data from 28 publications were compiled and analyzed. Based on out meta-analysis, the pooled prevalence of AIVs in wild birds in China was found to be 2.5% (571/23,024), and the pooled prevalence of AIV antibodies was 26.5% (1,210/4,566). The pooled prevalence of AIVs was significantly higher in wild birds from Central China (5.5%, 271/4, 955) compared to all other regions and the pooled prevalence of AIV antibodies was significantly in wild birds from South China (56.8%, 92/162) in comparison to all other regions. The prevalence of both AIVs and AIV antibodies in Anseriformes were higher compared to non-Anseriformes. In addition, the largest number of studies found in this review were on the HA subtypes of AIVs (H5, H7, and H9) and their associated antibodies. In summary, our findings suggest that the prevalence of AIVs and their antibodies in wild birds vary among regions and species of wild bird. Thus, further monitoring of the prevalence of AIVs and their antibodies in wild birds in China is necessary and should be used for guiding powerful and effective regulatory measures that will prevent the spread of AIVs across species.


Assuntos
Animais Selvagens/virologia , Anticorpos/sangue , Aves/virologia , Vírus da Influenza A , Influenza Aviária/epidemiologia , Influenza Aviária/imunologia , Animais , China/epidemiologia , Bases de Dados Factuais , Pandemias , Prevalência
8.
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
9.
Vet Microbiol ; 231: 24-32, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955817

RESUMO

Avian influenza virus (AIV) H9N2 infection causes economic losses on poultry farms, and immunostimulants are essential for improving chicken immunity. This study evaluated the immunological and pathological effects of vitamin E with Fetomune Plus® (a commercial product based on a yeast extract and vitamins) on chickens experimentally infected with AIV H9N2. Three groups of white Hy-Line chicks were included. The G1 group was kept as an uninfected untreated control, the G2 group was intranasally infected with the AIV H9N2 strain (0.5 ml of 106 50% egg infectious dose (EID50)), and the G3 group was infected and treated with vitamin E (200 mg/kg of diet) and Fetomune Plus® (1 ml/liter of drinking water) for four weeks. The gene expression of interferon-gamma (IFN-γ), interleukin (IL)-6, and IL-2 was determined at 3, 5 and 7 days post-infection (PI). Virus shedding titers and rates and haemagglutination inhibition (HI) antibody titers were detected. Clinical signs, mortalities and post-mortem lesions were recorded. The birds were weighed, and relative organ weights were calculated. Tissue specimens were taken for histopathological examination and immunohistochemistry (IHC). The expression of IFN-γ in the duodenum revealed a significant increase in G2 compared to G3 at 3 days PI, while the duodenal and splenic expression of IL-6 was significantly increased in G2 compared to G3 at 5 days PI. IL-2 was overexpressed in the duodenum in G3 compared to G2 at 3 and 5 days PI. A significant decrease (P ≤ 0.05) in the virus shedding titer and an increase in the HI titers were detected in G3 compared to G2. The clinical signs and the mortality rate were clearly appeared in G2 than in G3. By IHC, lower H9N2 staining intensity was observed in the examined organs from G3 than in those from G2. In conclusion, as a first report, vitamin E with Fetomune Plus® supplementation for four weeks could improve the immunological and pathological effects of H9N2 infection on chickens.


Assuntos
Suplementos Nutricionais , Influenza Aviária/terapia , Doenças das Aves Domésticas/terapia , Vitamina E/imunologia , Ração Animal , Animais , Anticorpos Antivirais/sangue , Galinhas , Citocinas/imunologia , Testes de Inibição da Hemaglutinação , Imuno-Histoquímica , Vírus da Influenza A Subtipo H9N2 , Influenza Aviária/imunologia , Interferon gama/imunologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Eliminação de Partículas Virais/efeitos dos fármacos , Vitamina E/administração & dosagem
10.
Poult Sci ; 98(9): 3488-3495, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30941436

RESUMO

H9N2 avian influenza has been prevalent in chicken flocks of China for years. In the first half year of 2018, clinical cases of suspected H9N2 infection were collected from chicken flocks in Shandong province. Nine strains of H9N2 influenza virus were isolated. The pathological changes of the dead chickens were mainly respiratory inflammation, renal swelling, and secondary infection. The microscopic lesions were consistent with the pathogenic characteristics of H9N2 influenza virus. From November 2017 to June 2018, a total of 3,380 serum samples were randomly collected from commercial laying hens in Shandong Province. The H9 antibody levels were tested with the isolated strain (CK/SD/231/17) as the antigen. It showed that the average of antibody titers of H9 avian influenza was 9.24 1og2. Hemagglutination inhibition experiments were conducted on chicken serum with the vaccine virus and the isolated virus (CK/SD/231/17) as the antigens. It was found that the antibody titer measured with the vaccine virus was 1 or 2 titers higher than the isolated strain. It indicated that the antigenicity of H9N2 circulating strain was different from that of vaccine strain. The nucleotide sequences of HA gene of these recent H9N2 avian influenza virus isolates shared homologies from 93.8 to 99.9%. Phylogenetic analysis revealed that the eight gene segments of the viruses were in the same clades with G57 gene reference strain. The amino acid site analysis of influenza resistance showed that the virus was sensitive to neuraminidase inhibitors and resistant to amantadine. Highlights: The protection rate of the H9N2 AIV vaccine almost reached 100% before 2016, but the antibody level of serum samples showed high diversity in this study, which means the poultry were infected. The antigenicity of isolated H9N2 strains was different from that of vaccine strain. Current available vaccines may provide only limited protection.


Assuntos
Galinhas , Genótipo , Vírus da Influenza A Subtipo H9N2/fisiologia , Vacinas contra Influenza/imunologia , Influenza Aviária/imunologia , Doenças das Aves Domésticas/imunologia , Animais , China , Evolução Molecular , Feminino , Imunogenicidade da Vacina/imunologia , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/patologia , Doenças das Aves Domésticas/patologia
11.
Virol J ; 16(1): 46, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975159

RESUMO

BACKGROUND: Compared with chickens, ducks are normally resistant to avian influenza virus without clinical signs while they habor almost all subtypes of influenza A viruses. To date, however the mechanism for duck anti-influenza has not been completely understood. The H9N2 avian influenza virus (AIV) is the most prevalent subtype of influenza A virus that infects chickens and ducks in China. However, H9N2 AIV replication and the host immune response in these domestic birds has not been systematically investigated. METHODS: In the present study, we compared the kinetics and magnitudes of antibody responses in chickens and ducks after infection with H9N2 AIV by the intranasal route or intravenous route. Furthermore, we determined the viral replication and distribution in chickens and ducks after infection with H9N2 AIV by the intravenous route. RESULTS: Our results revealed that the antibody response was rapid and robust in ducks than in chickens at early time (2-3dpi) after intravenous infection with H9N2 AIVs, while delayed and lower antibody detected in ducks than in chickens after intranasal infection with H9N2 AIVs. The virus was detected in multiple organs tissues in chickens but not in ducks infected by the intravenous route. CONCLUSIONS: Our results provide the evidence that humoral immune response could play a critical role in duck resistance for influenza, which expands our knowledge on duck anti-influenza characteristics.


Assuntos
Anticorpos Antivirais/sangue , Galinhas/imunologia , Patos/imunologia , Imunidade Humoral , Influenza Aviária/imunologia , Administração Intravenosa , Animais , Galinhas/virologia , Resistência à Doença , Patos/virologia , Vírus da Influenza A Subtipo H9N2/fisiologia , Carga Viral , Replicação Viral
12.
Vet Ital ; 55(1): 95-101, 2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30951187

RESUMO

The aim of this study was to compare pathological lesions and viral antigen expression in the organs of mute swans (Cygnus olor) naturally infected with highly pathogenic avian influenza virus subtypes H5N1 and H5N8. The examination was conducted on the carcasses of 22 mute swans which died during the avian influenza outbreaks in Serbia in 2006 and 2016-2017. Avian influenza virus subtype H5N8 isolated from mute swans in 2016-2017 was clustered within the 2.3.4.4 clade group B. After necropsy, lung, liver, spleen, pancreas, kidney and brain tissues were sampled for histopathology and immunohistochemical examination. Avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most significant gross lesions were necrosis and haemorrhages in the pancreas. Major histological lesions were multifocal necroses in the pancreas, spleen and liver, non-purulent encephalitis, lung congestion and oedema. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas and brain was strongly consistent with histological lesions in both infected groups. Our findings showed that pancreas was the most affected organ in all examined mute swans. In addition to increased mortality rate, similar pathological findings were detected in mute swans naturally infected with highly pathogenic avian influenza viruses H5N1 and H5N8.


Assuntos
Anseriformes , Surtos de Doenças/veterinária , Virus da Influenza A Subtipo H5N1/fisiologia , Vírus da Influenza A Subtipo H5N8/fisiologia , Influenza Aviária , Animais , Influenza Aviária/epidemiologia , Influenza Aviária/imunologia , Influenza Aviária/patologia , Sérvia/epidemiologia
13.
Vet Res ; 50(1): 18, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30823888

RESUMO

The G1-H9N2 avian influenza virus (AIV) has caused significant economic losses in the commercial poultry industry due to reduced egg production and increased mortality. The field observations have shown that H9N2 viruses circulate and naturally mix with other pathogens and these simultaneous infections can exacerbate disease. To avoid an incorrect virus characterization, due to co-infection, isolates were purified by in vitro plaque assays. Two plaque purified G1-H9N2 clones, selected on different cell types, named MDCK-and CEF-clone in regards to the cell culture used, were studied in vivo, revealing two different virulence phenotypes. Subsequently, the underlying mechanisms were studied. Specifically, the phenotypical outcome of SPF bird infection by the two clones resulted in completely different clinical outcomes. These differences in clinical outcome were used to study the factors behind this output in more detail. Further studies demonstrated that the more severe disease outcome associated with the MDCK-clone involves a strong induction of pro-inflammatory cytokines and a lack of type I interferon production, whereas the mild disease outcome associated with the CEF-clone is related to a greater antiviral cytokine response. The immunosuppressive effect of the MDCK-clone on splenocytes was further demonstrated via ChIFN-γ lack production after ex vivo mitogenic stimulation. Genome sequencing of the two clones identified only four amino acid differences including three in the HA sequence (HA-E198A, HA-R234L, HA-E502D-H9 numbering) and one in the NA sequence (NA-V33M). In the present study, valuable insights on the mechanisms responsible for AI pathogenicity and molecular mechanisms of H9N2 infections in chicken were obtained while highlighting the impact of the cells viruses are grown on their virulence.


Assuntos
Vírus da Influenza A Subtipo H9N2/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Galinhas/imunologia , Galinhas/virologia , Regulação da Expressão Gênica , Genoma Viral/genética , Testes de Inibição da Hemaglutinação/veterinária , Imunidade Inata , Técnicas In Vitro , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Influenza Aviária/imunologia , Influenza Aviária/patologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/patologia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA/veterinária , Ensaio de Placa Viral/veterinária , Virulência , Eliminação de Partículas Virais
14.
Emerg Microbes Infect ; 8(1): 186-196, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30866772

RESUMO

From May 2016 to March 2017, 22 poultry outbreaks of avian influenza A(H5N1) were reported in Cameroon, mainly in poultry farms and live bird markets. No human cases were reported. In this study, we sought to describe the 2016 A(H5N1) outbreak strain and to investigate the risk of infection in exposed individuals. We find that highly pathogenic influenza subtype A(H5N1), clade 2.3.2.1c from Cameroon is closely related phylogenetically and antigenically to strains isolated in central and western Africa at the time. No molecular markers of increased human transmissibility were noted; however, seroconversion was detected in two poultry workers (1.5% of total screened). Therefore, the continued outbreaks of avian influenza in poultry and the risk of zoonotic human infection highlight the crucial need for continued and vigilant influenza surveillance and research in Africa, especially in areas of high poultry trade, such as Cameroon.


Assuntos
Surtos de Doenças/veterinária , Virus da Influenza A Subtipo H5N1/imunologia , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Adolescente , Adulto , África Central/epidemiologia , África Ocidental/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Animais , Camarões/epidemiologia , Fazendeiros , Feminino , Humanos , Virus da Influenza A Subtipo H5N1/classificação , Influenza Aviária/imunologia , Influenza Aviária/virologia , Influenza Humana/imunologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Filogenia , Filogeografia , Aves Domésticas , Soroconversão , Adulto Jovem , Zoonoses/virologia
15.
Vet Microbiol ; 230: 123-129, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30827377

RESUMO

Immunosuppressive viral diseases have a great economic importance in the poultry industry due to the increased susceptibility to secondary infections. Chicken anaemia virus (CAV) is one of the major immunosuppressive diseases in chickens. In addition, low pathogenic avian influenza (LPAI) of subtype H9N2 and infectious bronchitis (IB) viruses are among the most frequently reported respiratory viral diseases in poultry worldwide. In the present study, specific pathogen free chickens were used to understand the impact of CAV on secondary infection with LPAI-H9N2 or IB viruses. Clinical outcomes, viral shedding dynamics, and cytokine levels wereassessed. The results exhibit that chickens previously infected with CAV produceconsiderablyhigher titresof LPAI-H9N2 or IB viruses in the oropharyngeal swabs (P < 0.05), tracheas and kidneys. In addition, the immunologic effect of CAV provokedthe development of clinical signs of LPAI-H9N2 and IB virus infections. Moreover, results suggested that pre-infection with CAV directly correlated with elevated levels of IL-6 and IFNγ. These findings underline the importance of CAV pre-infection on LPAI-H9N2 or IB infection in chickens, and indicate that co-circulation of CAV can contribute to the spread and evolution of LPAI H9N2 and IB viruses.


Assuntos
Infecções por Circoviridae/veterinária , Coinfecção/veterinária , Infecções por Coronavirus/veterinária , Influenza Aviária/imunologia , Doenças das Aves Domésticas/virologia , Animais , Vírus da Anemia da Galinha/imunologia , Galinhas/virologia , Infecções por Circoviridae/imunologia , Coinfecção/imunologia , Coinfecção/virologia , Infecções por Coronavirus/imunologia , Citocinas/sangue , Vírus da Bronquite Infecciosa/imunologia , Vírus da Influenza A Subtipo H9N2 , Doenças das Aves Domésticas/imunologia , Organismos Livres de Patógenos Específicos , Eliminação de Partículas Virais
16.
PLoS Pathog ; 15(2): e1007531, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30731004

RESUMO

Virus ecology and evolution play a central role in disease emergence. However, their relative roles will vary depending on the viruses and ecosystems involved. We combined field studies, phylogenetics and experimental infections to document with unprecedented detail the stages that precede initial outbreaks during viral emergence in nature. Using serological surveys we showed that in the absence of large-scale outbreaks, horses in Mongolia are routinely exposed to and infected by avian influenza viruses (AIVs) circulating among wild birds. Some of those AIVs are genetically related to an avian-origin virus that caused an epizootic in horses in 1989. Experimental infections showed that most AIVs replicate in the equine respiratory tract without causing lesions, explaining the absence of outbreaks of disease. Our results show that AIVs infect horses but do not spread, or they infect and spread but do not cause disease. Thus, the failure of AIVs to evolve greater transmissibility and to cause disease in horses is in this case the main barrier preventing disease emergence.


Assuntos
Cavalos/imunologia , Influenza Aviária/genética , Animais , Animais Selvagens , Ásia , Evolução Biológica , Aves , Surtos de Doenças , Transmissão de Doença Infecciosa/veterinária , Evolução Molecular , Cavalos/genética , Humanos , Influenza Aviária/imunologia , Influenza Humana , Infecções por Orthomyxoviridae/veterinária , Filogenia
17.
BMC Genomics ; 20(1): 36, 2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-30634898

RESUMO

BACKGROUND: Long non-coding RNAs (lncRNAs) are important component of mammalian genomes, where their numbers are even larger than that of protein-coding genes. For example, human (Homo sapiens) (96,308 vs. 20,376) and mouse (Mus musculus) (87,774 vs. 22,630) have more lncRNA genes than protein-coding genes in the NONCODEv5 database. Recently, mammalian lncRNAs were reported to play critical roles in immune response to influenza A virus infections. Such observation inspired us to identify lncRNAs related to immune response to influenza A virus in duck, which is the most important natural host of influenza A viruses. RESULTS: We explored features of 62,447 lncRNAs from human, mouse, chicken, zebrafish and elegans, and developed a pipeline to identify lncRNAs using the identified features with transcriptomic data. We then collected 151,970 assembled transcripts from RNA-Seq data of 21 individuals from three tissues and annotated 4094 duck lncRNAs. Comparing to duck protein-coding transcripts, we found that 4094 lncRNAs had smaller number of exons (2.4 vs. 10.2) and longer length of transcripts (1903.0 bp vs. 1686.9 bp) on average. Among them, 3586 (87.6%) lncRNAs located in intergenic regions and 619 lncRNAs showed differential expression in ducks infected by H5N1 virus when compared to control individuals. 58 lncRNAs were involved into two co-expressional modules related to anti-influenza A virus immune response. Moreover, we confirmed that eight lncRNAs showed remarkably differential expression both in vivo (duck individuals) and in vitro (duck embryo fibroblast cells, DEF cells) after infected with H5N1 viruses, implying they might play important roles in response to influenza A virus infection. CONCLUSIONS: This study presented an example to annotate lncRNA in new species based on model species using transcriptome data. These data and analysis provide information for duck lncRNAs' function in immune response to influenza A virus.


Assuntos
Patos/imunologia , Patos/virologia , Virus da Influenza A Subtipo H5N1 , Influenza Aviária/genética , Influenza Aviária/imunologia , RNA Longo não Codificante/imunologia , Animais , Caenorhabditis elegans/genética , Galinhas/genética , Galinhas/imunologia , Patos/genética , Humanos , Camundongos , Peixe-Zebra/genética
18.
J Gen Virol ; 100(3): 414-430, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30672726

RESUMO

The accessory protein, PB1-F2, of influenza A virus (IAV) functions in a chicken host to prolong infectious virus shedding and thus the transmission window. Here we show that this delay in virus clearance by PB1-F2 in chickens is accompanied by reduced transcript levels of type 1 interferon (IFN)-induced genes and NFκB-activated pro-inflammation cytokines. In vitro, two avian influenza isolate-derived PB1-F2 proteins, H9N2 UDL01 and H5N1 5092, exhibited the same antagonism of the IFN and pro-inflammation induction pathways seen in vivo, but to different extents. The two PB1-F2 proteins had different cellular localization in chicken cells, with H5N1 5092 being predominantly mitochondrial-associated and H9N2 UDL being cytoplasmic but not mitochondrial-localized. We hypothesized that PB1-F2 localization might influence the functionality of the protein during infection and that the protein sequence could alter cellular localization. We demonstrated that the sequence of the C-terminus of PB1-F2 determined cytoplasmic localization in chicken cells and this was linked with protein instability. Mitochondrial localization of PB1-F2 resulted in reduced antagonism of an NFκB-dependent promoter. In parallel, mitochondrial localization of PB1-F2 increased the potency of chicken IFN 2 induction antagonism. We suggest that mitochondrial localization of PB1-F2 restricts interaction with cytoplasmic-located IKKß, reducing NFκB-responsive promoter antagonism, but enhances antagonism of the IFN2 promoter through interaction with the mitochondrial adaptor MAVS. Our study highlights the differential mechanisms by which IAV PB1-F2 protein can dampen the avian host innate signalling response.


Assuntos
Virus da Influenza A Subtipo H5N1/metabolismo , Vírus da Influenza A Subtipo H9N2/metabolismo , Influenza Aviária/imunologia , Interferon beta/genética , NF-kappa B/genética , Doenças das Aves Domésticas/genética , Proteínas Virais/metabolismo , Animais , Galinhas , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/genética , Influenza Aviária/virologia , Interferon beta/imunologia , NF-kappa B/imunologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Regiões Promotoras Genéticas , Proteínas Virais/genética
19.
J Immunol ; 202(2): 382-391, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30617120

RESUMO

Avian influenza A viruses (IAVs) naturally infect different avian species, and aquatic birds are their natural reservoir. Sporadically, avian IAVs can be transmitted to humans, and some, such as H5N1 and H7N9 viruses, cause severe disease in humans. Antigenically novel avian influenza viruses that infect and cause disease in humans pose a potential pandemic threat if they are able to spread efficiently from person to person. The immune response of the host is crucial in determining disease pathogenesis and is the basis for the development of control strategies. In this review, we examine the innate and adaptive immune responses to avian influenza viruses and their role in disease and recovery. Furthermore, we discuss the progress in developing vaccines against avian IAVs and summarize obstacles in designing universal and pandemic influenza vaccines.


Assuntos
Vacinas contra Influenza/imunologia , Influenza Aviária/imunologia , Influenza Humana/imunologia , Orthomyxoviridae/fisiologia , Imunidade Adaptativa , Animais , Aves , Reservatórios de Doenças , Humanos , Imunidade Inata , Pandemias
20.
Arch Virol ; 164(3): 807-817, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30671655

RESUMO

The emergent highly pathogenic avian influenza A (H7N9) (HPAI) virus is a major public concern in China. Therefore, it is crucially important to develop an effective vaccine against this virus. In this study, we constructed a baculovirus vaccine expressing the hemagglutinin (HA) of H7N9 strain A/Chicken/Jiaxing/148/2014 (JX148). The recombinant baculovirus (rBac-JX148HA) generated in this study showed good growth in insect cells and good safety, and it stably expressed the HA protein. We compared the immunogenicity and efficacy of the inactivated whole-virus vaccine JX148 and rBac-JX148HA. One chicken in the JX148-treated group died on day 4 post-challenge, and three chickens had typical clinical symptoms (survival rate, 90%; morbidity, 40%). However, no chickens immunized with rBac-JX148HA showed clinical signs during the 14-day observation period. An analysis of viral shedding and viral replication demonstrated that rBac-JX148HA more efficiently inhibited viral shedding and viral replication than the inactivated whole-virus vaccine. Taken together, these results indicate that the inactivated recombinant baculovirus vaccine induces a high hemagglutination inhibition antibody titer, provides complete protection against challenge with the highly pathogenic H7N9 virus, and effectively inhibits viral shedding. Therefore, the candidate vaccine has potential utility in the prevention and control of H7N9 avian influenza and is also appropriate for veterinary vaccines using cell suspension culture technology.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Subtipo H7N9 do Vírus da Influenza A/imunologia , Influenza Aviária/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Animais , Anticorpos Antivirais/imunologia , Baculoviridae/genética , Baculoviridae/metabolismo , Galinhas , China , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Subtipo H7N9 do Vírus da Influenza A/fisiologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Influenza Aviária/imunologia , Influenza Aviária/virologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Vacinação , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Virulência , Eliminação de Partículas Virais
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