Angiotensin converting enzyme 2 alleviates infectious bronchitis virus-induced cellular inflammation by suppressing IL-6/JAK2/STAT3 signaling pathway / 生物工程学报

The goal of this study was to investigate the regulatory effect of angiotensin converting enzyme 2 (ACE2) on cellular inflammation caused by avian infectious bronchitis virus (IBV) and the underlying mechanism of such effect. Vero and DF-1 cells were used as test target to be exposed to recombinant IBV virus (IBV-3ab-Luc). Four different groups were tested: the control group, the infection group[IBV-3ab-Luc, MOI (multiplicity of infection)=1], the ACE2 overexpression group[IBV-3ab Luc+pcDNA3.1(+)-ACE2], and the ACE2-depleted group (IBV-3ab-Luc+siRNA-ACE2). After the cells in the infection group started to show cytopathic indicators, the overall protein and RNA in cell of each group were extracted. real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA expression level of the IBV nucleoprotein (IBV-N), glycoprotein 130 (gp130) and cellular interleukin-6 (IL-6). Enzyme linked immunosorbent assay (ELISA) was used to determine the level of IL-6 in cell supernatant. Western blotting was performed to determine the level of ACE2 phosphorylation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). We found that ACE2 was successfully overexpressed and depleted in both Vero and DF-1 cells. Secondly, cytopathic indicators were observed in infected Vero cells including rounding, detaching, clumping, and formation of syncytia. These indicators were alleviated in ACE2 overexpression group but exacerbated when ACE2 was depleted. Thirdly, in the infection group, capering with the control group, the expression level of IBV-N, gp130, IL-6 mRNA and increased significantly (P < 0.05), the IL-6 level was significant or extremely significant elevated in cell supernatant (P < 0.05 or P < 0.01); the expression of ACE2 decreased significantly (P < 0.05); protein phosphorylation level of JAK2 and STAT3 increased significantly (P < 0.05). Fourthly, comparing with the infected group, the level of IBV-N mRNA expression in the ACE2 overexpression group had no notable change (P > 0.05), but the expression of gp130 mRNA, IL-6 level and expression of mRNA were elevated (P < 0.05) and the protein phosphorylation level of JAK2 and STAT3 decreased significantly (P < 0.05). In the ACE2-depleted group, there was no notable change in IBV-N (P > 0.05), but the IL-6 level and expression of mRNA increased significantly (P < 0.05) and the phosphorylation level of JAK2 and STAT3 protein decreased slightly (P > 0.05). The results demonstrated for the first time that ACE2 did not affect the replication of IBV in DF-1 cell, but it did contribute to the prevention of the activation of the IL-6/JAK2/STAT3 signaling pathway, resulting in an alleviation of IBV-induced cellular inflammation in Vero and DF-1 cells.

The potential inhibitory impact of curcumin, epigallocatechin gallate and their combinations on infectious bronchitis virus in vivo

Aims@#Infectious bronchitis virus (IBV) is a highly contagious, acute viral respiratory disease that mostly affects chickens. The poultry sector has suffered enormous losses as a result of IBV. Currently, live attenuated vaccines are routinely used to prevent and control IBV. However, due to the enormous genetic variety, vaccinations are becoming ineffective, with low cross-protection effects among vaccine serotypes. The present study aimed at investigating the possible antiviral effects of curcumin, epigallocatechin gallate (EGCG) and their mixtures against IBV in vivo.@*Methodology and results@#Curcumin, EGCG and their combinations were administered to infected and uninfected chicken groups and viral load titers were determined by real-time PCR. The clinical symptoms of both the negative and positive control groups were also compared. Finally, the trachea tissues of each group were examined histopathologically. According to our findings, the viral titer and the clinical signs dropped significantly during the pretreatment infection procedure. Curcumin, EGCG and their combinations also show significant antiviral activities.@*Conclusion, significance and impact of study@#This study clearly shown that natural compounds and their combinations, such as curcumin or/and ECGC can reduce viral pathogenicity in vivo, suggesting that they might have therapeutic implications in the poultry sector.

Cross-species surveillance and risk factors associated with Avian Coronavirus in North-Central and South West Regions of Nigeria

@#Infectious bronchitis viral (IBV) (Avian coronavirus) diseases is among the major reproductive diseases affecting the avian production in Africa. There is scanty information on its current status and vaccination compliance among captive wild birds (CWB) and indigenous chickens (LC) in Nigeria. This study aimed to assess the exposure and the risk factors associated with IBV in CWB and LC from North-central and South west regions of Nigeria. Sera samples from 218 LC and 43 CWB were examined for IBV IgG using enzyme linked immunosorbent assay. Also, owners of LC and managers of CWB were interviewed using a pre-tested structured checklist. An overall IBV prevalence of 42.9% (112/261) was obtained. Captive wild birds and indigenous chickens had 11.6% (5/43) and 49.1% (107/218) prevalence respectively with a significant difference (p< 0.0001, OR= 7.3, 95% CI= 2.8-19.3). Also, geo-location indicated significant difference in IBV exposure among birds (p<0.034). Furthermore, the study showed that there had never been laboratory screening on all acquired wild birds for exposure to infectious agents in the study location while none of these birds (LB/CWB) had history of vaccination. Since IBV is endemic in Nigeria, the use of vaccine for prophylactic measure should be advocated among LC and CWB owners in order to avoid unnecessary losses. Also, the essence of screening for infectious agents in newly acquired wild birds should be considered crucial for health sustenance and public safety.

Construction and characterization of a recombinant vaccine encoding the nucleocapsid protein gene of avian infectious bronchitis virus / Construção e caracterização de uma vacina recombinante codificando o gene da proteina do nucleocapsideo do virus da bronquite infecciosa das galinhas

A vacinação é a forma mais utilizada para prevenir a bronquite infecciosa causada pelo vírus da bronquite infecciosa das galinhas (IBV). Contudo, as vacinas convencionais são incapazes de diferenciar aves infectadas de vacinadas. No presente trabalho foi construído, caracterizado, e avaliado como candidato vacinal, um adenovírus recombinante expressando o gene N do IBV. O gene N foi clonado em um adenovírus humano tipo 5 defectivo e transfectado para as células HEK-293A para gerar rAd5_N. Após o vetor ser obtido como esperado e a confirmação da expressão da proteína N em HEK-293ª, foi realizada inoculação pela via oculo-nasal na dose de 10 7 TCID 50 /0,1mL para imunização de galinhas livres de patógenos específicos (SPF). A resposta imunológica do Ad5_N e a proteção contra o desafio ao IBV foram avaliadas e comparadas com uma vacina viva comercial. Não foram detectados anticorpos anti-IBV em aves vacinadas com o Ad5_N. A vacina comercial induziu anticorpos detectáveis a partir do 7º dia pós-vacinal. Em aves vacinadas com o Ad5_N não houve aumento na expressão de IFNγ. Neste estudo, o rAd5_N obtido não conferiu proteção contra desafio com IBV-M41. Os resultados indicam a necessidade de avaliar adenovírus recombinantes expressando outros genes do IBV.(AU)

Genomic characteristics of natural recombinant infectious bronchitis viruses isolated in Korea / 대한수의학회지

Two infectious bronchitis virus (IBV) K046-12 and K047-12 strains were isolated and the nearly complete genomes of them were sequenced. Sequence comparisons showed that the K046-12 genome was most similar to Korean IBV strains, and the K047-12 genome was most similar to QX-like IBV strains. Phylogenetic analysis showed that nearly all K046-12 and most K046-12 genes were placed in the same cluster as Korean IBV isolates, but the S1 region was placed in the same cluster as Mass-type IBVs. For K047-12, nearly all K047-12 and most K047-12 genes were located in the same cluster as QX-like IBVs, but the M region was located in the same cluster as Korean IBV isolates with K047-12. Recombination analysis confirmed that K046-12 is a recombinant strain with the primary parental sequence derived from Korean IBVs and minor parental sequence derived from Mass-type IBV, and K047-12 is a recombinant strain with the major parental sequence derived from QX-IBV and minor parental sequence derived from Korean IBVs. This study showed that new IBV recombinants are constantly generated among various IBVs, including those used for vaccination. Therefore, genetic analysis of new virus isolates should be performed for effective infectious bronchitis control and appropriate vaccine development.

Increased expression of interleukin-6 related to nephritis in chickens challenged with an avian infectious bronchitis virus variant / Aumento da expressão de interleucina-6 relacionada com nefrite in galinhas desafiadas com uma variante do vírus da bronquite infecciosa

A Brazilian field isolate (IBV/Brazil/PR05) of avian infectious bronchitis virus (IBV), associated with development of nephritis in chickens, was previously genotyped as IBV variant after S1 gene sequencing. The aim of this study was to evaluate the levels of IL-6 in kidneys and trachea of birds vaccinated and challenged with IBV/Brazil/PR05 strain, correlating these results with scores of microscopic lesions, specific IBV antigen detection and viral load. The up-regulation of IL-6 and the increased levels of viral load on renal and tracheal samples were significantly correlated with scores of microscopic lesions. Reduced levels of viral load were detected in kidneys of birds previously vaccinated and challenged, compared to non-vaccinated challenged group, although markedly microscopic lesions were observed for both groups. The expression of IL-6, present both in the kidney and in the tracheas, was dependent on the load of the virus present in the tissue, and the development of lesions was related with IL-6 present in the tissues. These data suggest that variant IBV/Brazil/PR05 can induce the expression of proinflammatory cytokines in a manner correlated with viral load and increased IL-6 is involved in the tissue with the influx of inflammatory cells and subsequent nephritis. This may contribute with a model to the development of immunosuppressive agents of IL-6 to prevent acute inflammatory processes against infection with IBV and perhaps other coronaviruses, as well as contribute to the understanding of the immunopathogenesis of IBV nephropatogenic strains.

Uma estirpe variante do vírus da bronquite infecciosa (VBI) associada com o desenvolvimento de nefrite em galinhas, foi isolado e identificado como variante por análise do gene S1. A estirpe IBV/Brazil/PR05 foi testada quanto à sua capacidade de induzir a expressão de interleucina-6 (IL-6) nos tecidos renais e traqueais. Galinhas vacinadas com a estirpe Massachusetts H120 e não vacinadas foram desafiadas com a estirpe IBV/Brazil/PR05. Cinco dias após a infecção, traquéias e rins foram coletados para análise por RT-qPCR, imunohistoquímica e histopatologia. Foi determinada a expressão relativa de IL-6 e da carga viral. A expressão de IL-6 e carga viral foram correlacionadas com o desenvolvimento de nefrite e lesão traqueal. A expressão de IL-6 foi maior quando houve aumento da carga viral na traqueia e nos rins. A carga viral presente nos rins foi inferior quando as aves foram vacinadas, entretanto foi observada nefrite acentuada. Houve alta correlação entre o desenvolvimento de nefrite e o nível de expressão de IL-6, bem como a expressão de IL-6 e a carga viral. A expressão de IL-6, presente tanto nos rins e nas traqueias, foi relacionada a carga viral presente nestes tecidos, e o desenvolvimento das lesões foi relacionado com a expressão de IL-6. Estes dados sugerem que a variante IBV/Brazil/PR05 pode induzir a expressão de citocinas pró-inflamatórias de forma correlacionada com a carga viral, e o aumento de IL-6 está envolvido com o influxo de células inflamatórias no tecido, o que evolui para o desenvolvimento de nefrite. Isto pode contribuir como um modelo para o desenvolvimento de agentes imunossupressores da IL-6 para evitar processos inflamatórios agudos contra infecção com o VBI e talvez outros coronavírus, bem como contribuir para o entendimento da imunopatogênese das estirpes nefropatogênicas deste vírus.

Elevated level of renal xanthine oxidase mRNA transcription after nephropathogenic infectious bronchitis virus infection in growing layers

To assess relationships between xanthine oxidase (XOD) and nephropathogenic infectious bronchitis virus (NIBV) infection, 240 growing layers (35 days old) were randomly divided into two groups (infected and control) of 120 chickens each. Each chicken in the control and infected group was intranasally inoculated with 0.2 mL sterile physiological saline and virus, respectively, after which serum antioxidant parameters and renal XOD mRNA expression in growing layers were evaluated at 8, 15 and 22 days post-inoculation (dpi). The results showed that serum glutathione peroxidase and superoxide dismutase activities in the infected group were significantly lower than in the control group at 8 and 15 dpi (p < 0.01), while serum malondialdehyde concentrations were significantly higher (p < 0.01). The serum uric acid was significantly higher than that of the control group at 15 dpi (p < 0.01). In addition, the kidney mRNA transcript level and serum activity of XOD in the infected group was significantly higher than that of the control group at 8, 15 and 22 dpi (p < 0.05). The results indicated that NIBV infection could cause the increases of renal XOD gene transcription and serum XOD activity, leading to hyperuricemia and reduction of antioxidants in the body.

Production and immunogenicity of chimeric virus-like particles containing the spike glycoprotein of infectious bronchitis virus

Infectious bronchitis virus (IBV) poses a severe threat to the poultry industry and causes heavy economic losses worldwide. Vaccination is the most effective method of preventing infection and controlling the spread of IBV, but currently available inactivated and attenuated virus vaccines have some disadvantages. We developed a chimeric virus-like particle (VLP)-based candidate vaccine for IBV protection. The chimeric VLP was composed of matrix 1 protein from avian influenza H5N1 virus and a fusion protein neuraminidase (NA)/spike 1 (S1) that was generated by fusing IBV S1 protein to the cytoplasmic and transmembrane domains of NA protein of avian influenza H5N1 virus. The chimeric VLPs elicited significantly higher S1-specific antibody responses in intramuscularly immunized mice and chickens than inactivated IBV viruses. Furthermore, the chimeric VLPs induced significantly higher neutralization antibody levels than inactivated H120 virus in SPF chickens. Finally, the chimeric VLPs induced significantly higher IL-4 production in mice. These results demonstrate that chimeric VLPs have the potential for use in vaccines against IBV infection.

Construção de uma biblioteca de fragmentos de anticorpos monoclonais de galinhas com cadeia única (scFv) por phage display com reatividade cruzada para estirpes heterólogas do vírus da bronquite infecciosa aviária / Construction of an avian single chain monoclonal antibodies (scFv) library by phage display that cross-reacted with heterologous avian infectious bronchitis virus strains

Anticorpos monoclonais constituem a base de vários testes usados na detecção e na identificação de antígenos. Nesse contexto, tais imuno-reagentes têm sido extensivamente empregados na identificação de estirpes virais envolvidas na etiologia de surtos de bronquite infecciosa a campo, permitindo o aperfeiçoamento das técnicas de detecção e caracterização antigênica do vírus da bronquite infecciosa das galinhas (VBI). No presente estudo, uma biblioteca de fragmentos de anticorpos de galinha originalmente preparada por phage display contra a estirpe vacinal (H120) do VBI foi usada para a seleção de fragmentos de anticorpos recombinantes com reatividade cruzada para as estirpes heterólogas IBVPR01 e IBVPR05, isoladas de surtos a campo no Brasil e a estirpe SE-17, isolada nos Estados Unidos. Após três ciclos de panning, foi identificado, pelo ELISA, um conjunto de 15 anticorpos scFv expressos em fagos e com reatividade cruzada para essas mesmas estirpes do VBI. A análise por Western-blotting revelou que dois desses clones apresentavam fagos expressando fragmentos de anticorpos monoclonais com reatividade cruzada para a nucleoproteína N das três estirpes do VBI e também para a forma recombinante dessa nucleoproteína derivada da estirpe M41. Concluindo, os fragmentos de anticorpos monoclonais recombinantes scFv-N produzidos em fagos interagem com um epítopo mais conservado da proteína N do VBI e apresentam um grande potencial para utilização na detecção e no diagnóstico direto desse vírus.

Monoclonal antibodies are the basis of various techniques used for antigen detection or characterization, and their use is specially recommended for the identification of viral strains involved in the etiology of infectious bronchitis outbreaks. These antibodies are homogeneous, highly specific and fully characterizable, allowing the improvement of immunological techniques detection and antigenic characterization of avian infectious bronchitis virus strains (IBV). A phage display library was used, which was prepared previously against the IBV vaccine strain (H120) for the selection of new scFv antibody fragments specific for heterologous IBV strains isolated from outbreaks in Brazil (IBVPR01, IBVPR05) and USA (SE-17). After three cycles of panning, a set of 15 scFv antibodies were expressed in phages and cross-reacted in ELISA with these three viral strains. Western-blotting analysis showed that two of the clones were expressing scFv specific for the nucleoprotein of these IBV strains, as well as to the recombinant form of this protein derived from M41. In conclusion, the recombinant fragments of monoclonal antibodies expressed in phage have a great potential for future use in immunodiagnostic techniques and to study the evolution of infectious bronchitis virus.

Clonagem, expressão e caracterização da nucleoproteína recombinante do vírus da bronquite infecciosa em Escherichia coli e em Pichia pastoris / Cloning, expression, and characterization of the nucleocapsid protein of infectious bronchitis virus in Escherichia coli and Pichia pastoris

O gene da proteína de nucleocapsídeo (1.230 pb) da estirpe M41 do vírus da bronquite infecciosa (VBI) foi amplificado pelas reações de transcrição reversa e em cadeia da polimerase (RT-PCR) e clonado, em seguida, em dois sistemas; pET28a - Escherichia coli e pFLD -Pichia pastoris. Os produtos recombinantes construídos para expressão (pET28a-N ou pFLD-N) foram identificados por análises de PCR e de sequenciamento de nucleotídeos. Os clones transformantes da linhagem BL21 de E. coli e da linhagem GS115 de P. pastoris foram submetidos aos protocolos apropriados de indução. A expressão da proteína N de fusão com etiqueta de poli-histidina e com massa molecular de 54 kDa foi determinada pelas técnicas de SDS-PAGE e de Western blotting, confirmando-se que ambas proteínas N recombinantes apresentaram tamanhos e antigenicidade compatíveis com a proteína N nativa do próprio VBI. O sistema E. coli expressou uma quantidade relevante da proteína N recombinante, enquanto que o sistema P. pastoris produziu uma baixa recuperação dessa proteína recombinante. A proteína N recombinante gerada pelo sistema bacteriano foi purificada em resina de níquel-sepharose. O conjunto de resultados indica que o sistema de expressão constituído por pET28a ­ E. coli é mais efetivo para produzir a proteína N recombinante do VBI destinada ao uso como antígeno para detectar anticorpos anti-virais específicos em ensaios de imunodiagnóstico para essa infecção viral.

The nucleocapsid protein (N) gene (1,230 bp) of the M41 strain of infectious bronchitis virus (IBV) was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR), and cloned in two systems; pET28a Escherichia coli and pFLD Pichia pastoris. The recombinant expression constructs (pET28a-N or pFLD-N) were identified by PCR and sequencing analysis. The transformant clones of BL21 strain of E. coli or GS115 of P. pastoris were submitted to appropriate inducting protocols. Expression of histidine-tagged fusion N proteins with a molecular mass of 54 kDa was determined by SDS-PAGE and Western blotting analysis, confirming that both recombinant N proteins were comparable in size and antigenicity to native IBV N protein. The E. coli system overexpressed the recombinant N protein, while the P. pastoris system produced a low yield of this recombinant protein. The bacteria expressed N protein was purified by chromatography on nickel-sepharose resin. These results indicated that the pET28a E. coli expression system is more effective to generate N recombinant protein for using as an antigen to detect anti-IBV antibodies in immuno-assays for this viral infection.

Isolation and biological properties of avian infectious bronchitis virus isolated from Shanxi province / 中国兽医学报

Five field strains of infectious bronchitis virus (IBV) were isolated from suspected flocks from different time and different regions of Shanxi province,respectively,and characterized by a series of systematic identification assays,such as morphological observation by electron-microscope,interfering with the propagation of NDV,virus pathological role to chicken embryo,virus pathological role to SPF chickens,hemagglutination activity,physiscochemical,and reverse transcription polymerase chain reaction(RT-PCR).The results showed:The typical coronavirus which the spherical virions 60-120 nm in diameter and surface covered with spike like corona were observed under electron-microscope)The propagation of NDV strain was seriously interfered by the 5 isolates respectively;The embryonated chicken egg passages of the 5 isolates could dwarf with chicken embryos;The five isolates had no hemagglutination activity,but after treatment with 1% trypsin,it can agglutinate chicken red blood cell.The strains are sensitive to chloroform and ethyl ether.The SPF chickens which inoculated with the 5 isolates showed clinical sign and result in respiratory and kidney diseases,flower-steak,and swollen with severe urate deposition.The specific fragments of N gene of the 5 isolates were amplified by RT-PCR,respectiveiy.On the basis of all above mentioned results,the 5 isolates were classified as IBV.The study got a good preparedness for further study on molecular epidemioogy of the 5 IBV isolates.

Influence of compound Chinese traditional medicine on immunity of chicken inoculated by infectious bronchitis virus / 中国兽医学报

A model of infectious bronchit was developed in SPF chickens by repeated intranasal infectious routes,and then the influence of compound Chinese traditional medicine on cellular immunity and humoral immunity during preventing and curing infectious bronchitis was studied by MTT,flow cytometry and serum neutralization test in tracheal organ culture.The results showed that compared with the infected group,the compound Chinese traditional medicine group could significantly increase the weight gain of chickens(P<0.05),promote the growth of immunity apparatus,enhance the T lymphocytes proliferate response of chickens and increase serum neutralization antibody titers of chickens significantly(P<0.05),and the ratio of CD4+/CD8+T lymphocytes was improved significantly(P<0.01).The aforementioned results indicated that the compound Chinese traditional medicine could reinforce immune function via preventing both cellular and humoral immunity from depression in the chickens with IBV.

Detection and molecular characterization of infectious bronchitis virus isolated from recent outbreaks in broiler flocks in Thailand

Thirteen field isolates of infectious bronchitis virus (IBV) were isolated from broiler flocks in Thailand between January and June 2008. The 878-bp of the S1 gene covering a hypervariable region was amplified and sequenced. Phylogenetic analysis based on that region revealed that these viruses were separated into two groups (I and II). IBV isolates in group I were not related to other IBV strains published in the GenBank database. Group 1 nucleotide sequence identities were less than 85% and amino acid sequence identities less than 84% in common with IBVs published in the GenBank database. This group likely represents the strains indigenous to Thailand. The isolates in group II showed a close relationship with Chinese IBVs. They had nucleotide sequence identities of 97-98% and amino acid sequence identities 96-98% in common with Chinese IBVs (strain A2, SH and QXIBV). This finding indicated that the recent Thai IBVs evolved separately and at least two groups of viruses are circulating in Thailand.

Genetic grouping of avian infectious bronchitis virus isolated in Brazil based on RT-PCR/RFLP analysis of the S1 gene / Agrupamento genético de isolados do vírus da bronquite infecciosa das aves no Brasil com base na análise do gene S1 por RT-PCR-RFLP

Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.

Doze isolados de campo do Brasil e uma estirpe de referência vacinal do vírus da bronquite infecciosa das aves (VBI) foram propagadas em ovos embrionados SPF. O gene S1 dessas amostras foi analisado por RT-PCR seguido de RFLP, empregando-se as enzimas de restrição HaeIII, XcmI e BstyI. Observou-se a existência de cinco genotipos diferentes: M (Massachusetts), A , B, C e D. Cinco dos doze isolados de campo do VBI foram classificados no genótipo Massachusetts e os sete vírus restantes foram classificados em quatro genotipos diferentes; A (2), B (2), C (2) ou D (1). Os resultados desta genotipagem concordam com os dados obtidos na análise imunológica previamente realizada para a maior parte destes vírus, destacando a ocorrência de uma variabilidade marcante entre os isolados do VBI que estão circulando nas granjas avícolas comerciais do Brasil.

Sequence analysis of the S1 glycoprotein gene of infectious bronchitis viruses: identification of a novel phylogenetic group in Korea

Twelve Korean infectious bronchitis viruses (IBVs) were isolated in the field from chickens suspected of being carriers of infectious bronchitis between 2001 and 2003. The S1 glycoprotein genes of these IBV isolates were amplified by reverse transcriptase-polymerase chain reaction (RTPCR) and analyzed by restriction fragment length polymorphism (RFLP) analysis. These Korean IBV isolates were classified into three groups according to their RFLP patterns obtained using the restriction enzyme HaeIII. Half of the twelve isolates were similar to the KM91 RFLP pattern, which is a common pattern in Korea. Three more isolates were related to the Arkansas strain pattern, but with some unique variations. The other three viruses showed variant RFLP patterns. For a comparison with the published sequences for non-Korean IBV strains, amplified PCR products from the twelve isolates were cloned and sequenced. The Korean IBV field isolates had 71.2-99.7% nucleotide sequence homology with each other and 45.9-80.7% nucleotide sequence homology with non-Korean IBV strains. With respect to the deduced amino acid sequence, the Korean IBV isolates had 71.5-99.3% similarity with each other and 44.9-80.3% similarity with non-Korean IBV strains. Phylogenetic tree analysis revealed that some of the IBV isolates appear to belong to a new group, different from the non-Korean IBV strains or from previously isolated Korean IBV strains. Specifically, the new Korean IBV isolates K10217-03, K3-3 and K1255-03 represented a separate group. These findings suggest that the Korean IBVs appear to be continuously evolving.

Effects of Kangliyin on N Gene Relative Expression in the Infectious Bronchitis Virus Infected Model / 中药新药与临床药理

Objective To observe the therapeutic effect of Kangliyin(KLY,the compound Chinese herbal formulation with the functions of clearing heat and damp elimination,regulating stomach and dissipate phlegm) on the models with infection of infectious bronchitis virus(IBV),and to evaluate its effect on the IBV N gene relative expression by using real-time florescent quantitative polymerase chain reaction(PCR).Methods Seven-day-old chicks were inoculated with IBV by the nasal and ocular administration.The chicks were divided into 6 groups by stratified random sampling according to the body weight.The 6 groups were blank control group,model group,three KLY treatment groups(receiving KLY at the dosage of 10 g/kg? d-1,20 g/kg? d-1 or 40 g/kg? d-1,respectively),and positive control group(ganciclovir at the dosage of 0.004 g/kg? d-1).The chicks in the model group and blank control group received normal saline,and the medication groups received the corresponding medicine according to the experimental design from the next day of inoculation,and the treatment lasted 5 days.The relative quantity of IBV N gene expression in the lung and bronchial tissues were assayed by real-time florescent quantitative PCR,and the clinical manifestations and the pathological changes of all groups were also examined.Results Compared with the model group,KLY could significantly inhibit the IBV N gene expression,improve the general clinical symptoms and respiratory symptoms,and improve the pathological changes in the bronchus and lung of the IBV infected model.Conclusion KLY could effectively inhibit the viral replication,repair the pathological damage in the bronchus and lung,and improve the general clinical symptoms in the IBV infected model,which is beneficial to the recovery of the chicks from IBV infection.

Effects of Kangliyin on the levels of serum antibody in the chick model of respiratory coronavirus infection / 中国病理生理杂志

AIM:To study the effects of Kangliyin compound (KLY,the compound formulation of a Chinese herbal medicine has 15 kinds of ingredients,including artemisia apiacea,baical skullcap root,tangerine peel,pinellia tuber,frutus aurantii immaturus,caulis bambusae in taeniis,tuckahoe,the larva of silkworm with botrytis,turmeric,agastache,rhubarb,cicada ecdysis,and so on.) treatment on the infectious bronchitis virus (IBV) infection models and to evaluate its effects on the levels of IBV antibody in the serum. METHODS:Seven-day-old chicks were inoculated with the respiration type of IBV M41 strain. All the chicks were bred in a low temperature and highly moisturized controlled environment. The model group and normal control group were fed with sterile normal saline,while the three treatment groups were administrated with KLY compound. Positive control group was irrigated with ganciclovir. These feeds were lasted for 5 d. The clinical symptoms and the pathological changes of all groups' bronchus and lung tissues were examined. The levels of IBV antibody in the serum in each group were also checked by using ELISA method at the end of the study. RESULTS:Compared with the model group,KLY compound significantly increased the serum titer of IBV antibody in the three treatment groups (P