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1.
J Immunol ; 212(9): 1479-1492, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38477617

RESUMO

During avian influenza virus (AIV) infection, host defensive proteins promote antiviral innate immunity or antagonize viral components to limit viral replication. UFM1-specific ligase 1 (UFL1) is involved in regulating innate immunity and DNA virus replication in mammals, but the molecular mechanism by which chicken (ch)UFL1 regulates AIV replication is unclear. In this study, we first identified chUFL1 as a negative regulator of AIV replication by enhancing innate immunity and disrupting the assembly of the viral polymerase complex. Mechanistically, chUFL1 interacted with chicken stimulator of IFN genes (chSTING) and contributed to chSTING dimerization and the formation of the STING-TBK1-IRF7 complex. We further demonstrated that chUFL1 promoted K63-linked polyubiquitination of chSTING at K308 to facilitate chSTING-mediated type I IFN production independent of UFMylation. Additionally, chUFL1 expression was upregulated in response to AIV infection. Importantly, chUFL1 also interacted with the AIV PA protein to inhibit viral polymerase activity. Furthermore, chUFL1 impeded the nuclear import of the AIV PA protein and the assembly of the viral polymerase complex to suppress AIV replication. Collectively, these findings demonstrate that chUFL1 restricts AIV replication by disrupting the viral polymerase complex and facilitating type I IFN production, which provides new insights into the regulation of AIV replication in chickens.


Assuntos
Vírus da Influenza A , Influenza Aviária , Interferon Tipo I , Ubiquitina-Proteína Ligases , Replicação Viral , Animais , Galinhas/genética , Imunidade Inata , Vírus da Influenza A/metabolismo , Vírus da Influenza A/fisiologia , Influenza Aviária/metabolismo , Nucleotidiltransferases , Replicação Viral/genética , Ubiquitina-Proteína Ligases/metabolismo
2.
J Immunol ; 213(2): 187-203, 2024 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-38829131

RESUMO

The RING finger (RNF) family, a group of E3 ubiquitin ligases, plays multiple essential roles in the regulation of innate immunity and resistance to viral infection in mammals. However, it is still unclear whether RNF proteins affect the production of IFN-I and the replication of avian influenza virus (AIV) in ducks. In this article, we found that duck RNF216 (duRNF216) inhibited the duRIG-I signaling pathway. Conversely, duRNF216 deficiency enhanced innate immune responses in duck embryonic fibroblasts. duRNF216 did not interacted with duRIG-I, duMDA5, duMAVS, duSTING, duTBK1, or duIRF7 in the duck RIG-I pathway. However, duRNF216 targeted duTRAF3 and inhibited duMAVS in the recruitment of duTRAF3 in a dose-dependent manner. duRNF216 catalyzed K48-linked polyubiquitination of duck TRAF3, which was degraded by the proteasome pathway. Additionally, AIV PB1 protein competed with duTRAF3 for binding to duRNF216 to reduce degradation of TRAF3 by proteasomes in the cytoplasm, thereby slightly weakening duRNF216-mediated downregulation of IFN-I. Moreover, although duRNF216 downregulated the IFN-ß expression during virus infection, the expression level of IFN-ß in AIV-infected duck embryonic fibroblasts overexpressing duRNF216 was still higher than that in uninfected cells, which would hinder the viral replication. During AIV infection, duRNF216 protein targeted the core protein PB1 of viral polymerase to hinder viral polymerase activity and viral RNA synthesis in the nucleus, ultimately strongly restricting viral replication. Thus, our study reveals a new mechanism by which duRNF216 downregulates innate immunity and inhibits AIV replication in ducks. These findings broaden our understanding of the mechanisms by which the duRNF216 protein affects AIV replication in ducks.


Assuntos
Patos , Imunidade Inata , Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Transdução de Sinais , Ubiquitina-Proteína Ligases , Replicação Viral , Animais , Patos/imunologia , Patos/virologia , Replicação Viral/imunologia , Transdução de Sinais/imunologia , Influenza Aviária/imunologia , Influenza Aviária/virologia , Virus da Influenza A Subtipo H5N1/imunologia , Virus da Influenza A Subtipo H5N1/fisiologia , Imunidade Inata/imunologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/imunologia , Fibroblastos/imunologia , Fibroblastos/virologia , Proteínas Aviárias/imunologia , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Ubiquitinação , Proteína DEAD-box 58/metabolismo , Proteína DEAD-box 58/imunologia
3.
J Immunol ; 210(6): 786-794, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36715497

RESUMO

Mitochondrial antiviral signaling protein (MAVS) is a key adaptor in cellular innate immunity. Ubiquitination plays an important role in regulating MAVS-mediated innate immune responses; however, the molecular mechanisms underlying ubiquitination of MAVS have not been fully elucidated. In this study, we first identified the mitochondria-resident E3 ligase duck membrane-associated RING-CH 8 (duMARCH8) in ducks as a negative regulator of duck MAVS (duMAVS). Overexpression of duMARCH8 impaired the duMAVS-mediated signaling pathway, whereas knockdown of duMARCH8 resulted in the opposite effects. The suppression was due to duMARCH8 interacting with duMAVS and degrading it in a proteasome-dependent manner. We further found that duMARCH8 interacted with the 176-619 regions of duMAVS. Moreover, duMARCH8 catalyzed the K29-linked polyubiquitination of duMAVS at Lys 398 to inhibit the MAVS-mediated signaling pathway. Collectively, our findings reveal a new strategy involving MARCH8 that targets the retinoic acid-inducible gene-I-like receptor signaling pathway to regulate innate immune responses in ducks.


Assuntos
Patos , Transdução de Sinais , Animais , Proteínas de Transporte/metabolismo , Transdução de Sinais/fisiologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Proteínas Mitocondriais/metabolismo
4.
Emerg Infect Dis ; 23(12): 2100-2102, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29148388
5.
Virol J ; 11: 147, 2014 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-25117968

RESUMO

BACKGROUND: Newcastle disease (ND) is an OIE listed disease caused by virulent avian paramyxovirus type 1 (APMV-1) strains, which is enzootic and causes large economic losses in the poultry sector. Genotype VII and genotype IX NDV viruses were the predominant circulating genotype in China, which may possibly be responsible for disease outbreaks in chicken flocks in recent years. While ducks and geese usually have exhibited inapparent infections. METHODS: In the present study, we investigate the complete genome sequence, the clinicopathological characterization and transmission of two virulent Newcastle disease viruses, SS-10 and NH-10, isolated from domestic ducks in Southern China in 2010. RESULTS: F, and the complete gene sequences based on phylogenetic analysis demonstrated that SS-10 (genotype VII) and NH-10 (genotype IX) belongs to class II. The deduced amino acid sequence was (112)R-R-Q-K/R-R-F(117) at the fusion protein cleavage site. Animal experiment results showed that the SS-10 virus isolated from ducks was highly pathogenic for chickens and geese, but low pathogenic for ducks. It could be detected from spleen, lung, kidney, trachea, small intestine, bursa of fabricius, thymus, pancreas and cecal tonsils, oropharyngeal and cloacal swabs, and could transmit to the naive contact birds. Moreover, it could transmit to chickens, ducks and geese by naive contact. However, the NH-10 virus isolated from ducks could infect some chickens, ducks and geese, but only caused chickens to die. Additionally, it could transmit to the naive contact chickens, ducks, and geese. CONCLUSION: The two NDV isolates exhibited different biological properties with respect to pathogenicity and transmission in chickens, ducks and geese. Therefore, no species-preference exists for chicken, duck or goose viruses and more attention should be paid to the trans-species transmission of VII NDVs between ducks, geese and chickens for the control and eradication of ND.


Assuntos
Patos/virologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/classificação , Vírus da Doença de Newcastle/genética , Doenças das Aves Domésticas/virologia , Animais , Galinhas , China , Surtos de Doenças , Gansos , Genoma Viral , Dados de Sequência Molecular , Doença de Newcastle/transmissão , Vírus da Doença de Newcastle/patogenicidade , Fases de Leitura Aberta , Doenças das Aves Domésticas/transmissão , RNA Viral , Análise de Sequência de DNA , Virulência/genética
6.
Vet Res ; 45: 66, 2014 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-24939427

RESUMO

Melanoma differentiation-associated gene 5 (MDA5) is an important intracellular receptor that recognizes long molecules of viral double-stranded RNA in innate immunity. To understand the mechanism of duck MDA5-mediated innate immunity, we cloned the MDA5 cDNA from the Muscovy duck (Cairina moschata). Quantitative real-time PCR analysis indicates that duck MDA5 mRNA was constitutively expressed in all sampled tissues. A significant increase of MDA5 mRNA was detected in the brain, spleen and lungs of ducks after infection with an H5N1 highly pathogenic avian influenza virus (HPAIV). We investigated the role of the predicted functional domains of MDA5. The results indicate the caspase activation and recruitment domain (CARD) of duck MDA5 had a signal transmission function through IRF-7-dependent signaling pathway. Overexpression of the CARD strongly activated the chicken IFN-ß promoter and upregulated the mRNA expression of antiviral molecules (such as OAS, PKR and Mx), proinflammatory cytokines (such as IL-2, IL-6, IFN-α and IFN-γ, but not IL-1ß and IL-8) and retinoic acid-inducible gene I (RIG-I)-like receptors (RLR) (RIG-I and LGP2) without exogenous stimulation. We also demonstrate the NS1 of the H5N1 HPAIV inhibited the duck MDA5-mediated signaling pathway in vitro. These results suggest that duck MDA5 is an important receptor for inducing antiviral activity in the host immune response of ducks.


Assuntos
Proteínas Aviárias/genética , Patos , Virus da Influenza A Subtipo H5N1/imunologia , Influenza Aviária/imunologia , Doenças das Aves Domésticas/imunologia , Transdução de Sinais , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , Animais , Proteínas Aviárias/química , Proteínas Aviárias/metabolismo , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Fibroblastos/fisiologia , Fibroblastos/virologia , Imunidade Inata , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/genética , Influenza Aviária/virologia , Dados de Sequência Molecular , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/virologia , Alinhamento de Sequência/veterinária , Proteínas não Estruturais Virais/metabolismo
7.
J Virol ; 86(14): 7724-5, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22733886

RESUMO

We report here the complete genomic sequence of an H7N3 avian influenza virus (AIV) isolate, which was obtained from duck in 1996. This is the first report of this subtype of AIV being isolated from duck in Guangdong of Southern China. Genomic sequence and phylogenetic analyses showed that it was highly homologous with the wild bird virus A/ruddy turnstone/Delaware Bay/135/1996 (H7N3) and that all eight genes of this virus belonged to the North America gene pool. The availability of genome sequences is helpful to further investigations of epidemiology and evolution of AIV between waterfowl and wild birds.


Assuntos
Patos/virologia , Genoma Viral , Vírus da Influenza A Subtipo H7N3/genética , Influenza Aviária/virologia , Animais , Sequência de Bases , China , Vírus da Influenza A Subtipo H7N3/isolamento & purificação , Dados de Sequência Molecular , Filogenia , Análise de Sequência de RNA
8.
J Virol ; 86(14): 7722-3, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22733885

RESUMO

In this study, we report the first genomic information on an H5N1 avian influenza virus (AIV) isolated from a condor in Guangdong Province in southern China in 2003. Full genome sequencing and phylogenetic analyses show that it is a recombinant virus containing genome segments derived from the Eurasia and North America gene pools. This will be useful for analyses of the evolution of H5N1 AIV in southern China.


Assuntos
Falconiformes/virologia , Genoma Viral , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Animais , Sequência de Bases , China , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Dados de Sequência Molecular , Neuraminidase/genética , Filogenia , Análise de Sequência de RNA
9.
J Virol ; 86(16): 8894-5, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22843856

RESUMO

An H5N1 avian influenza virus (AIV) designated A/Parrot/Guangdong/C99/2005 (H5N1) was first isolated from a sick parrot in Guangdong in southern China in 2005. The complete genome of this strain was analyzed. Genome sequence analysis showed that all 8 gene segments of the virus nucleotide had 99.0% homology to A/chicken/Henan/12/2004 (H5N1). Phylogenetic analysis demonstrated that all 8 gene segments of the virus were derived from the Eurasian lineage. The availability of genome sequences is useful to investigate the host range and genetic evolution of the H5N1 avian influenza virus in Southern China.


Assuntos
Genoma Viral , Virus da Influenza A Subtipo H5N1/genética , RNA Viral/genética , Análise de Sequência de DNA , Animais , China , Análise por Conglomerados , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/virologia , Dados de Sequência Molecular , Papagaios , Filogenia , Homologia de Sequência do Ácido Nucleico
10.
J Virol ; 86(14): 7716, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22733881

RESUMO

An H10N8 avian influenza virus (AIV), designated A/Duck/Guangdong/E1/2012 (H10N8), was isolated from a duck in January 2012. This is first report that this subtype of AIV was isolated from a live bird market (LBM) in Guangdong Province in southern China. Furthermore, the complete genome of this strain was analyzed. The availability of genome sequences is helpful to further investigations of epidemiology and molecular characteristics of AIV in southern China.


Assuntos
Patos/virologia , Genoma Viral , Vírus da Influenza A/genética , Animais , Sequência de Bases , China , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Dados de Sequência Molecular , Neuraminidase/genética , Fases de Leitura Aberta/genética , Análise de Sequência de RNA
11.
J Virol ; 86(14): 7717-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22733882

RESUMO

Here, we reported the complete genome sequence of a novel H6N2 avian influenza virus (AIV) isolated from chicken in Guangdong, Southern China, in 2011 which was a natural recombinant virus between the H6N2 and H5N1 subtypes. It will help to understand the epidemiology and molecular characteristics of H6N2 influenza virus in Southern China.


Assuntos
Galinhas/virologia , Genoma Viral , Vírus da Influenza A/genética , Animais , Sequência de Bases , China , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Influenza Aviária/virologia , Dados de Sequência Molecular , Neuraminidase/classificação , Neuraminidase/genética , Filogenia , Recombinação Genética , Análise de Sequência de RNA
12.
J Virol ; 86(16): 8890-1, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22843854

RESUMO

We report the complete genome sequence of an H5N2 avian influenza virus (AIV) that was first isolated from a parrot in Guangdong in southern China in 2004. Genomic sequence and phylogenetic analyses showed that it was highly homologous with the North American H5N2 viruses and all eight genes of this virus belonged to the North American gene lineage. These data will help in the investigation of the epidemiology and host range of AIVs in southern China.


Assuntos
Genoma Viral , Vírus da Influenza A Subtipo H5N2/genética , RNA Viral/genética , Análise de Sequência de DNA , Animais , China , Análise por Conglomerados , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Influenza Aviária/virologia , Epidemiologia Molecular , Dados de Sequência Molecular , Papagaios , Filogenia
13.
Poult Sci ; 102(10): 102969, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37566967

RESUMO

Since 2005, novel duck reoviruses have been outbreaks in duck breeding areas such as central China and South China. In recent years, the incidence rate of this disease is still increasing, bringing serious economic losses to waterfowl breeding industry. This study isolated 3 novel duck reoviruses (NDRV-SDLS, NDRV-SDWF, and NDRV-SDYC) from sick ducks in 3 local duck farms in Shandong Province. The study aimed to investigate the characteristics of these viruses. The virus is inoculated into duck embryo fibroblasts, where the virus replicates to produce syncytium and dies within 3 to 5 d. The viruses were also isolated from infected ducks, and RT-PCR amplified the whole genomes after passage purification in duck embryos. The resulting whole genome was analyzed for genetic evolution. The total length of the gene sequencing was 23,418 bp, divided into 10 fragments. Gene sequence comparison showed that the 3 strains had high similarity with novel duck reoviruses (NDRV) but low similarity with chicken-origin reovirus (chicken ARV) and Muscovy duck reovirus (MDRV), especially in the σC segment. Phylogenetic analysis of the 10 fragments showed that the 3 isolates constituted the same evolutionary clade as other DRV reference strains and were far related to ARV and MDRV in different evolutionary clades. The results of all 10 segments indicate that the isolates are in the evolutionary branch of NDRV, suggesting that the novel waterfowl reovirus is the dominant circulating strain in Shandong. This study complements the gene bank information of NDRV and provides references for vaccine research and disease prediction of NDRV in Shandong.


Assuntos
Orthoreovirus Aviário , Doenças das Aves Domésticas , Infecções por Reoviridae , Animais , Orthoreovirus Aviário/genética , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/veterinária , Filogenia , Galinhas , China/epidemiologia , Doenças das Aves Domésticas/epidemiologia
14.
Poult Sci ; 102(10): 102920, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37473522

RESUMO

In recent years, with the expansion of duck breeding industry in China, the infection rate of duck circovirus (DuCV) in duck and the mixed infection rate of DuCV with other diseases increased significantly, which seriously endanger the development of duck breeding industry. To study the epidemic status of duck circovirus in China, analyze the virus's genetics and evolution, and establish a foundation for scientific prevention and control of duck circovirus, our laboratory collected 4 disease materials preliminarily diagnosed as duck circovirus infections. Conventional PCR was used to amplify 4 strains of duck circovirus with a full length of 1993bp, and their sequences were compared and analyzed. The analysis showed that the 4 DuCVs had typical circovirus characteristics, including 3 major ORFs: ORFV1 (Rep protein), ORFC1 (Cap protein), ORFC2 (apoptosis-related protein), and a stem ring structure. The 4 strains were compared with 22 other reference strains, and the results revealed that all 4 strains belonged to the DuCV-I type represented by the German strain AY228555. Furthermore, the homology between the 4 DuCVs and the reference strains was up to 98.6%, which help us to understand the genotype and genetic variation of DuCV in these regions and provide a reference for the prevention and control of DuCV.


Assuntos
Infecções por Circoviridae , Circovirus , Doenças das Aves Domésticas , Animais , Circovirus/genética , Doenças das Aves Domésticas/epidemiologia , Galinhas/genética , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/veterinária , Evolução Molecular , Clonagem Molecular , Filogenia
15.
Front Microbiol ; 14: 1211355, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37405154

RESUMO

Waterfowl, such as ducks, are natural hosts for avian influenza viruses (AIVs) and act as a bridge for transmitting the virus to humans or susceptible chickens. Since 2013, chickens and ducks have been threatened by waterfowl-origin H5N6 subtype AIVs in China. Therefore, it is necessary to investigate the genetic evolution, transmission, and pathogenicity of these viruses. In this study, we determined the genetic characteristics, transmission, and pathogenicity of waterfowl-origin H5N6 viruses in southern China. The hemagglutinin (HA) genes of H5N6 viruses were classified into the MIX-like branch of clade 2.3.4.4h. The neuraminidase (NA) genes belonged to the Eurasian lineage. The PB1 genes were classified into MIX-like and VN 2014-like branches. The remaining five genes were clustered into the MIX-like branch. Therefore, these viruses belonged to different genotypes. The cleavage site of the HA proteins of these viruses was RERRRKR/G, a molecular characteristic of the H5 highly pathogenic AIV. The NA stalk of all H5N6 viruses contained 11 amino acid deletions at residues 58-68. All viruses contained 627E and 701D in the PB2 proteins, which were molecular characteristics of typical bird AIVs. Furthermore, this study showed that Q135 and S23 viruses could replicate systematically in chickens and ducks. They did not cause death in ducks but induced mild clinical signs in them. All the infected chickens showed severe clinical signs and died. These viruses were shed from the digestive and respiratory tracts and transmitted horizontally in chickens and ducks. Our results provide valuable information for preventing H5N6 avian influenza outbreaks.

16.
Front Microbiol ; 14: 1105529, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36960283

RESUMO

Since 2017, the new H7N9 highly pathogenic avian influenza viruses (HPAIVs) have been responsible for more than 200,000 cases of chicken infection and more than 120,000 chicken deaths in China. Our previous study found that the Q26 was chicken-origin H7N9 HPAIV. In this study, we analyzed the genetic characterization of Q24, Q65, Q66, Q85, and Q102 H7N9 avian influenza viruses isolated from Guangdong, China in 2017. Our results showed that these viruses were highly pathogenic and belonged to two different genotypes, which suggested they occurred genetic reassortant. To investigate the pathogenicity, transmission, and host immune responses of H7N9 virus in chickens, we selected Q24 and Q26 viruses to inoculate chickens. The Q24 and Q26 viruses killed all inoculated chickens within 3 days and replicated effectively in all tested tissues. They were efficiently transmitted to contact chickens and killed them within 4 days through direct contact. Furthermore, we found that the expressions of several immune-related genes (e.g., TLR3, TLR7, MDA5, MAVS, IFN-ß, IL-6, IL-8, OAS, Mx1, MHC I, and MHC II) were upregulated obviously in the lungs and spleen of chickens inoculated with the two H7N9 viruses at 24 h post-inoculation (HPI). Among these, IL-6 and IFN-ß in lungs were the most upregulated (by 341.02-381.48-fold and 472.50-500.56-fold, respectively). These results suggest that the new H7N9 viruses isolated in 2017, can replicate and transmit effectively and trigger strong immune responses in chickens, which helps us understand the genetic and pathogenic variations of H7N9 HPAIVs in China.

17.
Front Microbiol ; 14: 1301653, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38098674

RESUMO

Duck Tembusu virus (DTMUV) is an emerging pathogen that poses a serious threat to the duck industry in China. Currently, polymerase chain reaction (PCR), quantitative PCR (qPCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP) are commonly used for DTMUV detection. However, these methods require complex steps and special equipment and easily cause false-positive results. Therefore, we urgently need to establish a simple, sensitive and specific method for the clinical field detection of DTMUV. In this study, we developed an RT-LAMP-based CRISPR-Cas12a assay targeting the C gene to detect DTMUV with a limited detection of 3 copies/µL. This assay was specific for DTMUV without cross-reaction with other common avian viruses and only required some simple pieces of equipment, such as a thermostat water bath and blue/UV light transilluminator. Furthermore, this assay showed 100% positive predictive agreement (PPA) and negative predictive agreement (NPA) relative to SYBR Green qPCR for DTMUV detection in 32 cloacal swabs and 22 tissue samples, supporting its application for clinical field detection.

18.
Acta Vet Hung ; 60(1): 157-64, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22366140

RESUMO

To understand the genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV) in South China, we collected 231 clinical samples from pigs with suspected PRRSV infection in Guangdong between 2007 and 2009. We found that 74 of 231 samples were positive by RT-PCR. The PCR products of the ORF5 gene of 35 isolates from different farms were sequenced and their DNA sequences were compared to 23 other PRRSV isolates in the GenBank. We found that the nucleotide similarity among all South China isolates ranged from 87.6% to 100%, and all belonged to the North American genotype. Most of them were classified into subgenotype I, but the rest mapped to subgenotypes III, V or VI. Those in subgenotypes I and III were found to be highly variable in the primary neutralising epitope (PNE) with a specific amino acid mutation (F39/L39→I39), and a few isolates in subgenotypes I and III isolates also had a mutation at L41 (L41→S41). PRRSV isolates in subgenotypes III, V and VI had less potential glycosylation sites than those in subgenotype I. Our data contribute to the understanding of molecular variation of PRRSV in South China.


Assuntos
Variação Genética , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , China/epidemiologia , Regulação Viral da Expressão Gênica , Dados de Sequência Molecular , Filogenia , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Suínos , Proteínas do Envelope Viral
19.
Front Immunol ; 13: 1016214, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36685538

RESUMO

The innate immune response is a host defense mechanism that induces type I interferon and proinflammatory cytokines. Tripartite motif (TRIM) family proteins have recently emerged as pivotal regulators of type I interferon production in mammals. Here, we first identified duck TRIM29, which encodes 571 amino acids and shows high sequence homology with other bird TRIM29 proteins. DuTRIM29 inhibited IFN-ß and IRF7 promoter activation in a dose-dependent manner and downregulated the mRNA expression of IFN-ß, IRF7, Mx and IL-6 mediated by duRIG-I. Moreover, duTRIM29 interacted and colocalized with duMAVS in the cytoplasm. DuTRIM29 interacted with duMAVS via its C-terminal domains. In addition, duTRIM29 inhibited IFN-ß and IRF7 promoter activation and significantly downregulated IFN-ß and immune-related gene expression mediated by duMAVS in ducks. Furthermore, duTRIM29 induced K29-linked polyubiquitination and degradation of duMAVS to suppress the expression of IFN-ß. Overall, our results demonstrate that duTRIM29 negatively regulates type I IFN production by targeting duMAVS in ducks. This study will contribute to a better understanding of the molecular mechanism regulating the innate immune response by TRIM proteins in ducks.


Assuntos
Patos , Interferon Tipo I , Animais , Interferon beta/metabolismo , Imunidade Inata , Expressão Gênica , Mamíferos/metabolismo
20.
Virol J ; 8: 144, 2011 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-21447173

RESUMO

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) has been acknowledged as one of the most important agents affecting swine. The scavenger receptor CD163 is one of the important entry mediators for PRRSV. RESULTS: The tD4 and tD5 CD163 genes were amplified, and the PCR products were cloned into pET-28a(+) (designated pET-28a-tD4 and pET-28a-tD5, respectively). The plasmids pET-28a-tD4 and pET-28a-tD5 were then transformed into the E. coli BL21 (DE3) strain and expressed by adding 1 mmol/L of isopropyl-beta-D-thiogalactopyranoside. The proteins were highly expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with a binding buffer containing the following compounds: ß-mercaptoethanol, urea, Tween 20, glycerol, and SDS, while they were rarely expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with binding buffer without the compounds. The tD4 and tD5 proteins were purified, and BALB/c mice were immunized with the purified proteins. Western blotting analysis showed that the tD4 and tD5 proteins were capable of reacting with tD5 antibodies; the titer of both the tD4 and tD5 antiserums was 1:160 against the tD5 protein, as shown by ELISA. CONCLUSIONS: These studies provide a new way for the purification of proteins expressed in inclusion bodies and the preparation of the corresponding antibodies.


Assuntos
Anticorpos/isolamento & purificação , Antígenos CD/química , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/química , Antígenos de Diferenciação Mielomonocítica/imunologia , Receptores de Superfície Celular/química , Receptores de Superfície Celular/imunologia , Suínos/imunologia , Animais , Anticorpos/imunologia , Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Terciária de Proteína , Receptores de Superfície Celular/genética , Suínos/genética
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