Genotype VIId Newcastle Disease Virus Research Articles

Experimental trials to assess the immune modulatory influence of thyme and ginseng oil on NDV-vaccinated broiler chickens.

The use of traditional medicine against viral diseases in animal production has been practiced worldwide. Herbal extracts possess organic substances that would improve chicken body performance. The current study was designed to evaluate the effect of either thyme or ginseng oil in regard to their immune-modulatory, antiviral, and growth promoter properties. Two hundred and forty-one-day-old broiler chicks were allocated into eight equal groups as the following: group 1; nonvaccinated and nontreated and group 2; Newcastle disease virus (NDV) vaccinated and nontreated. Birds of groups 3 and 4 were treated with thyme oil (200 mg/l of drinking water for 12 hours/day) without or with NDV vaccination. Birds of groups 5 and 6 were treated with ginseng oil (200 mg/l of drinking water for 12 hours/day) without or with NDV vaccination. Birds of groups 7 and 8 were treated with a combination of ginseng oil (100 mg/l of drinking water) and thyme oil (100 mg/l of drinking water) for 12 hours/day. On the 35th day of life, birds in all the experimental groups were given 0.1 ml of a virulent genotype VIId NDV strain suspension containing 106.3 EID50/ml intramuscularly. Administration of ginseng and thyme oils each alone or simultaneously to birds either vaccinated or nonvaccinated elicited a significant improvement in body performance parameters. Administration of thyme and ginseng each alone or concurrently to vaccinated birds (Gp 4, 6, and 8) induced a higher hemagglutination inhibition (HI) titer of 6, 7.3, and 6.3 log2 at 21 days of age, 6.7, 7.6, and 7 log2, at 28 days of age and 7, 8, and 6.8 log2 at 35 days of age, respectively. Challenge with vNDV genotype VII led to an increase in the NDV-specific HI-Ab titers 10 days post challenge in all the experimental groups. In addition, thyme, ginseng oils, or a combination of them improved the protection from mortality in vaccinated birds; by 100%, 100%, and 90%, respectively, compared with 80% protection from mortality in vaccinated-only birds post-NDV challenge. Moreover, NDV-vaccinated birds treated either with thyme; ginseng or their combination showed negative detection of the virus in both tracheal and cloacal swabs and nonvaccinated groups that received oils showed improvement in vNDV shedding in tracheal and cloacal swabs. It could be concluded that the administration of thyme and ginseng essential oils to broilers can improve productive performance parameters, stimulate humoral immunity against, and protect from vNDV infection.

Different kinetics of chicken interferon-alpha signalling transduction responses following immunization of broiler chickens with different Newcastle disease virus vaccines and infection with virulent genotype VIId strain

ABSTRACT Newcastle disease virus (NDV) is a highly contagious and notifiable avian disease leading to grave economic losses in the poultry industry. Although the immune responses against NDV have been widely investigated, little is known regarding the virus interaction with the host innate immune responses. In this study, we tested the effect of different commercially applied Newcastle disease vaccines as well as virulent NDV genotype VIId on the expression pattern of the upstream regulator and downstream effector genes related to chicken interferon-alpha (chIFNα) signalling transduction pathway. Using quantitative real-time PCR analysis, mild transient induction of chIFNα-inducible genes was detected in bird spleen 72 h post-vaccination (hpv) with either live LaSota (respiratory) or VG/GA (enteric) strains. Vaccination with the enteric VG/GA strain led to stimulation of the investigated pathway as early as 24 hpv which continued up to 7 days in bird caecal tonsils. Subcutaneous injection with inactivated LaSota oil adjuvant-based vaccine led to continual stimulation of the investigated pathway up to 7 days post-vaccination (dpv). The recombinant herpesvirus of turkey (rHVT) - NDV vaccine led to remarkable stimulation of all the tested cytokines up to 17 dpv in comparison with LaSota and VG/GA NDV vaccines. Stronger but transient activation of all the tested cytokines was detected in spleens during the first 24 h post-challenge with virulent NDV (vNDV) which reduced gradually and diminished later due to the virus-induced lymphocytic depletion. This study will aid in the discovery of new approaches to control NDV.

Susceptibility of Japanese Quail and Chickens to Infection with Newcastle disease Virus Genotype VIId

Susceptibility of Japanese Quail and Chickens to Infection with Newcastle disease Virus Genotype VIId

Surveillance and Molecular Characterization of Newcastle Disease Virus From Chickens in North Egypt During 2015-2017

In the present study, fifty broiler chickens flocks suspected to be infected with Newcastle disease virus (NDv) in 5 Egyptian provinces Gharbia (7/50), El Behera(21/50), Kafr EL sheikh (8/50) and Matrouh(7/50) and Alexendaria(7/50) during the period (from september 2015 to February 2017) were investigated for clinical and postmortem examination as well as virus isolation and molecular identification. The results of virus isolation on embryonated chicken SPF eggs (ECE) revealed that 16/50 samples were haemagglutinatig agents by slide haemagglutination test.These haemagglutinating agents were confirmed as NDv by real time PCR .The deduced amino acid sequences of the fusion protein of selected 8 positive isolates revealed that (7/8) isolates possessed the motif 112RRQKRI117at the cleavage site,indicating that these isolates are velogenic ,whereas the other (1/8) isolates carries the motif 112GRQGRL117indicating that is lentogenic . Phylogenetic analysis demonstrated that the 7 strains belong to the NDv genotype VIId, and the other strain was of genotype II.These isolates were detected even in vaccinated flocks that indicate the possible causes of those outbreaks may be not only useless of vaccines ,but also immunesuppression,use of heterogenous vaccines ,improper application of biosecurity ,moreover,may be arole in spreading of velogenic strain of NDv in Egypt .

Molecular characterization of full fusion protein (F) of Newcastle disease virus genotype VIId isolated from Egypt during 2012-2016.

Aim:The aim of this work was to study the full F gene sequence of Newcastle disease virus (NDV) in regard to pathotyping and genotyping and to study the evolution of this NDV in Egypt.Materials and Methods:The present study was conducted using samples from seven suspected NDV flocks of vaccinated chickens during 2012-2016 from six governorates in Egypt. The NDV was successfully isolated from pathological specimens through inoculation in specific pathogen-free embryonated chicken eggs.Results:Pathogenicity of the NDV isolates has been estimated through intracerebral pathogenicity index and ranged from 1.66 to 1.73 which indicates the velogenic type of NDV isolates. Pathotyping and genotyping of these isolates were done through sequencing of full-length F gene. Results indicated that the seven NDV isolates showed characteristic cleavage site motif (112RRQKRF117) for the velogenic strains of NDV. Phylogenetic analysis of the F gene clustered these isolates within Group I of genotype VIId within Israeli strains NDV/IS/2015, NDV-Ch/SD883, and most of the Middle East strains. Six of seven sequenced isolates have six potential N-linked glycosylation sites. The neutralization epitope on the five antigenic sites of fusion is conserved in all Egyptian strains of this study except NDV-KFR-B7-2012 which has a substitution at D 170 N in epitope A4. In all our strains, 10 cysteine residues are recorded, except one loss of cysteine at residue 370 in both NDV-EG-35-2014 and NDV-GHB-328F-2016.Conclusion:All viruses in this study have 52 amino acid substitutions within fusion gene in compared with Lasota strain that reveals importance for its antigenic and structural function. The present work highlights the important need to sequence F gene of NDV genotype VIId to investigate the evolution of this NDV in Egypt.

Evolutionary insights into the fusion protein of Newcastle disease virus isolated from vaccinated chickens in 2016 in Egypt

Newcastle disease virus (NDV) infections are one of the most devastating causes of economic losses in the poultry industry and despite extensive vaccination, outbreaks are being reported around the globe especially from developing and tropical countries. Analysis of NDV field strains from vaccinated flocks would highlight essential areas of consideration not only to design effective immunization strategies but also to devise vaccines that provide sterile immunity. For this purpose, 91 NDV suspected outbreaks were investigated and screened for NDV genetic material. A total of 16 NDV-positive isolates were examined using biological, genetics and bioinformatics analysis to assess the epidemiological association and to identify motifs that are under vaccine-induced immune pressures. In line with the clinical outcomes, all isolates showed the 112RRQKR|F117 cleavage motif and phylogenetic analysis revealed grouping of isolates into the genotype VII, and specifically sub-genotype VIId. Further analysis of the putative fusion protein sequence showed a number of substitutions (n=10) in functionally important domains and based on these differences, the studied isolates could be categorized into four distinct groups (A-D). Importantly, two residues (N30 and K71) were conserved in the commercial live vaccine and Egyptian field strains that are present in class II, genotype II. Collectively, these data enhance our knowledge of the evolution of genotype VIId NDV under the vaccine-induced immune pressures. In addition, our findings suggest that the use of genotype II-type vaccines in Egypt may be implicated in the emergence of new variants rather than providing benefits against NDV infections.

Genetic, antigenic, and pathogenic characteristics of Newcastle disease viruses isolated from geese in China.

Four Newcastle disease virus (NDV) strains were isolated from domestic, commercial geese that showed clinical signs that were believed to be the result of NDV infections. The genetic, antigenic, and pathogenic characteristics of the 4 NDVs were compared with those of NDV strains that were isolated from chickens. The complete genomes of 2 of the NDV strains contained 15,186 nucleotides (nt); the other 2 contained 15,192 nt, and exhibited the typical genomic organization of genotype II NDV and molecular characteristics of VIId NDVs. Phylogenetic analysis confirmed that the genotype II and VIId NDVs that were isolated from geese belonged to the same clusters as the corresponding genotypes of the chicken isolates. A serologic assay demonstrated that the antigenic relatedness among the NDVs was associated with their genotypes, rather than their hosts, and that amino acid substitutions in the F and/or HN proteins may contribute to the antigenic differences among these NDV genotypes. Geese infected with genotype VIId NDVs that were isolated from geese and chickens showed similar pathologic characteristics. NDVs that were isolated from geese did not differ in genetic, serologic, and pathogenic characteristics from those isolated from chickens, indicating that these NDVs were derived from chicken NDVs. Given the significance of geese in NDV epidemiology, effective biosecurity measures should be adopted to prevent the interspecies transmission of NDVs.

Deterioration of eggshell quality is related to calbindin in laying hens infected with velogenic genotype VIId Newcastle disease virus

The aim of this study was to determine the mechanism by which Newcastle disease virus (NDV) affects eggshell quality. Thirty-week-old specific pathogen free (SPF) egg-laying hens were inoculated with the velogenic genotype VIId NDV strain (infected group) or with inoculating media without virus (control group) by combined intraocular and intranasal routes. The levels of CaBP-D28k mRNA expression in the uterus, a gene related to eggshell quality, were examined by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The quality of eggshells was analyzed by scanning electron microscopy (SEM). The infected group showed a marked decline in egg production when compared to the control group. The NDV antigen was found more abundantly in the glandular epithelium of the infected hens' uteri from 1 to 15 d post-inoculation (dpi). The levels of CaBP-D28k mRNA expression in the uteri of infected hens were significantly lower than in the control hens from 3 to 15 dpi (P < 0.05). The changes in the Ca concentrations in the eggshells were consistent with the expression of CaBP-D28k mRNA in the infected hens. Ultrastructural examination of eggshells showed significantly reduced shell thickness in the infected hens from 1 to 15 dpi (P < 0.05). Furthermore, obvious changes in the structure of the external shell surface and shell membrane were detected in the infected hens compared with the control hens. In conclusion, the current study confirmed that velogenic genotype VIId NDV infection is associated with the deterioration of the eggshell quality of the laying hens.

Strong inflammatory responses and apoptosis in the oviducts of egg-laying hens caused by genotype VIId Newcastle disease virus.

BackgroundNewcastle disease virus (NDV) can cause serious damage to the reproductive tracts of egg-laying hens and leads to egg production and quality reduction. However, the mechanism of severe pathological damage in the oviducts of egg-laying hens after NDV infection has not been fully elucidated. In this study, the correlation between the primary pathological lesions and viral load in the oviducts of egg-laying hens infected with the velogenic genotype VIId NDV strain was evaluated by pathological observation and virus detection. Subsequently, apoptosis, the expression of immune-related genes and lymphocyte infiltration into the infected oviducts were determined to explore the potential causes of the pathological changes.ResultsA higher viral load and severe tissue lesions and apoptotic bodies were observed in the oviduct of NDV-infected hens compared with the control. Immune-related genes, including TLR3/7/21, MDA5, IL-2/6/1β, IFN-β, CXCLi1/2, and CCR5, were significantly upregulated in the magnum and uterus. IL-2 presented the highest mRNA level change (137-fold) at 5 days post infection (dpi) in the magnum. Infection led to CD3+CD4+ and CD3+CD8α+ lymphocyte infiltration into the magnum of the oviduct. A higher viral load was found to be associated with pathological changes and the elevated expression of proinflammatory cytokines in the NDV-infected hens.ConclusionsOur results indicate that the severe lesions and apoptosis in the oviducts of egg-laying hens caused by genotype VIId NDV strains are associated with the excessive release of inflammatory cytokines, chemokines and lymphocyte infiltration, which contribute to the dysfunction of the oviducts and the decrease of egg production in hens.

Infection of Goose with Genotype VIId Newcastle Disease Virus of Goose Origin Elicits Strong Immune Responses at Early Stage.

Newcastle disease (ND), caused by virulent strains of Newcastle disease virus (NDV), is a highly contagious disease of birds that is responsible for heavy economic losses for the poultry industry worldwide. However, little is known about host-virus interactions in waterfowl, goose. In this study, we aim to characterize the host immune response in goose, based on the previous reports on the host response to NDV in chickens. Here, we evaluated viral replication and mRNA expression of 27 immune-related genes in 10 tissues of geese challenged with a genotype VIId NDV strain of goose origin (go/CH/LHLJ/1/06). The virus showed early replication, especially in digestive and immune tissues. The expression profiles showed up-regulation of Toll-like receptor (TLR)1–3, 5, 7, and 15, avian β-defensin (AvBD) 5–7, 10, 12, and 16, cytokines [interleukin (IL)-8, IL-18, IL-1β, and interferon-γ], inducible NO synthase (iNOS), and MHC class I in some tissues of geese in response to NDV. In contrast, NDV infection suppressed expression of AvBD1 in cecal tonsil of geese. Moreover, we observed a highly positive correlation between viral replication and host mRNA expressions of TLR1-5 and 7, AvBD4-6, 10, and 12, all the cytokines measured, MHC class I, FAS ligand, and iNOS, mainly at 72 h post-infection. Taken together, these results demonstrated that NDV infection induces strong innate immune responses and intense inflammatory responses at early stage in goose which may associate with the viral pathogenesis.

PHYLOGENETIC AND HISTOPATHOLOGICAL CHARACTERIZATION OF NEWCASTLE DISEASE VIRUSES REVEALS HIGH PREVALENCE OF VERY VIRULENT STRAINS OF GENOTYPE VIID IN EGYPT

Newcastle disease virus (NDV) is a highly contagious disease in poultry, also considered as a major challenge for the commercial and traditional poultry industry in Egypt. In this study clinicopathological and immunohistochemistry examination of fourteen flocks from different provinces in Egypt during 2013 and 2014 revealed velogenic ND features and positive staining for ND virus (NDV) antigen in pantropic organs of all strains which also revealed positive NDV by RRT-PCR, as it is alreadyconvinced that the fusion protein cleavage site has been deemed as responsible for the pathogenicity of NDV and selected as a target to identify and type lentogenic and velogenic strains, viral Genomic RNAs were extracted from representing swabs and organs of examined flocks, and partially amplifiedfor fusion gene of NDV using RT-PCR, then forwarded to gene sequencing. Four chosen samples amplified for full fusion gene sequence using specific sets of newly designed primers from the available sequence data of NDV strains in Gen Bank, The resulted sequence showed motif 112RRQKRF117 which is indicative of velogenic character NDV strains, and indicate presence of 2 mutations E74D and D170N in two strains. Phylogenetic analysis revealed that Egyptian strains are closely related to NDV genotype VIId strains of south East Asian countries based on the high nucleotide and amino acid similarity.

SEQUENCE AND PHYLOGENETIC ANALYSIS OF NEWCASTLE DISEASE VIRUS GENOTYPE VII ISOLATED IN MALAYSIA DURING 1999-2012

Newcastle disease virus (NDV) is a contagious viral disease of many avian species particularly domestic poultry, and is responsible for causing significant economic losses to the poultry industry in Southeast Asia including Malaysia. Here we report the sequence and phylogenetic analysis of NDV that has been circulating in Malaysia. A total of 151 NDV isolates were selected during 1999-2012 throughout Malaysia and were characterized phylogenetically. The partial region of matrix (M) and fusion (F) protein of NDV was amplified by reverse transcriptase PCR, directly sequenced and compared genetically to the published sequences obtained from GenBank. The deduced amino acid sequence of the F protein cleavage site revealed the presence of three different motifs; 112RRRKRF117, 112RRQKRF117 typical for velogenic strains while 112GKQGRL117 indicates it is from avirulent strain or lentogenic strain. The phylogenetic analysis revealed that 13 isolates belonged to genotype I, 2 to genotype III, 6 to genotype VI, 1 to genotype VIII and 129 to genotype VII. Isolates belonging to genotype VII were further divided into five subgenotypes; VIIa, VIIb, VIId, VIIe and VIIh. Based on the phylogenetic tree and geographical data, it is found that NDV genotype VIIb and VIIe were isolated in 1999 while in year 2000 to 2009, most of the NDV isolates were NDV genotype VIId originated from China. No subgenotype VIId viruses were recovered after 2009 in Malaysia. In 2010-2012, NDV outbreaks were caused by subgenotypes VIIa and VIIh in Peninsular Malaysia. Interestingly, these subgenotypes have been isolated in East Malaysia since 2002 but did not cause major outbreak. These information points to the existence of multiple genotypes of NDV in Malaysia especially genotype VII and these findings emphasize the importance of continuous surveillance of NDV in Malaysia.

Characterization and Sequencing of a Genotype VIId Newcastle Disease Virus Isolated from Laying Ducks in Jiangsu, China.

We report here the complete genome sequence and biological characterization of a virulent Newcastle disease virus (NDV) strain, NDV/duck/Jiangsu/JSD0812/2008, isolated from laying ducks in Jiangsu Province, China. The genome is 15,192 nucleotides in length and is classified in subgenotype VIId of genotype VII, class II.

The M, F and HN genes of genotype VIId Newcastle disease virus are associated with the severe pathological changes in the spleen of chickens.

BackgroundThe strains of the genotype VIId Newcastle disease virus (NDV) induce more severe tissue damage in lymphoid organs than other virulent strains. The underlying molecular mechanisms are poorly understood.MethodsGenotype IV NDV Herts/33 and genotype VIId NDV JS5/05 have a distinctive pathological profile in the spleen. These two strains of viruses were selected as parental viruses to generate a panel of chimeric viruses by replacing the M, F and HN genes of Herts/33 individually or in combination with the corresponding genes of JS5/05 using reverse genetic. Virulence and in vitro characteristics of the recombinant viruses were assessed. In addition, pathological changes, virus load, and transcriptional cytokine response in the spleen of chickens infected with these recombinant viruses were also analyzed.ResultsPathogenicity test showed that all chimeric viruses are virulent. In vitro characterization revealed that gene replacement did not change growth kinetics and HN expression on cell surface of the recombinant viruses. However, replacement of the M, F and HN genes resulted in apparent changes in the fusion activity. Moreover, pathological studies revealed that only inclusion of the homologous M, F and HN genes of JS5/05 in Herts/33 backbone resulted in severe pathological changes characterized by extensive necrosis in the spleen, similar to that induced by JS5/05. In addition, this gene replacement significantly increased virus replication and the levels of transcriptional cytokine response, compared to Herts/33. Conversely, inclusion of the M, F and HN genes of Herts/33 into JS5/05 backbone resulted in Herts/33-specific pathological changes and significantly decreased virus load and the expression levels of cytokine genes, compared to JS5/05.ConclusionsThe M, F and HN genes are related to the severe pathological changes in the spleen of chickens infected with genotype VIId NDV.

Identification of a Genotype VIId Newcastle Disease Virus Isolated from Sansui Sheldrake Ducks in Guizhou Province, China

In this study, we report the complete genome sequence of a novel Newcastle disease virus (NDV) strain, Sheldrake duck/China/Guizhou/SS1/2014, isolated from Sansui Sheldrake duck flocks in Guizhou Province, southwestern China. The genome of this isolate is 15,192 nucleotides in length, which belongs to NDV genotype VIId in class II. This discovery will help us further study the epidemiology characteristics and molecular pathogenesis of genotype VIId NDV in Sansui Sheldrake ducks.

Molecular characterization of chicken-derived genotype VIId Newcastle disease virus isolates in China during 2005–2012 reveals a new length in hemagglutinin–neuraminidase

Newcastle disease (ND) is one of the most important diseases of poultry, and causes severe economic losses in the global poultry industry. Although all Newcastle disease virus (NDV) isolates belong to a single serotype, significant genetic diversity has been described between different NDV isolates. Here, we report the molecular characterization of 23 virulent genotype VIId NDV isolates of class II circulating in China. Phylogenetic construction and analysis revealed the existence of distinctly genomic and amino acid differences that clearly distinguished these isolates from other typical NDV genotypes and vaccine strains. We also report a new 582-amino-acid hemagglutinin–neuraminidase in genotype VII NDV strains. This is believed to be the first study to investigate systematically the most predominant NDV strains, and provides more information on the genetic nature of genotype VIId NDV of class II circulating in China.

Complete Genome Sequences of Newcastle Disease Virus Strains Isolated from Three Different Poultry Species in China

In 2000, three Newcastle disease virus (NDV) strains were isolated from outbreaks of infection in layers, ducklings, and geese in the same region of China during the same time period. Here, we report their complete genome sequences, which belong to the NDV genotype VIId. This discovery might provide clues as to the evolution of the NDVs of different avian origins.

Complete Genome Sequence of a Newly Emerging Newcastle Disease Virus

The complete genome sequence of a newly emerging Newcastle disease virus, isolated in China, was determined. A phylogenetic analysis based on the F gene revealed that the isolate is phylogenetically related to Newcastle disease virus genotype VIId. Sequence analysis indicated that amino acid residue substitutions occur at neutralizing epitopes on the hemagglutinin-neuraminidase (HN) protein.

Genomic characterisation of a lentogenic Newcastle disease virus strain HX01 isolated from sick pigs in China

This paper describes the complete genome sequence of HX01, an isolate of the Newcastle disease virus (NDV) collected from a swine disease outbreak. The genome is 15,186 nt long and consists of six genes in the order of 3'-NP-P-M-F-HN-L-5'. This genome has the same length as the old NDV genotypes (I-IV), whereas the new NDV genotypes (V-IX) are 15,192 nt long. Compared with the genomic sequences of the reference NDV strains, the HX01 genome is highly similar to the genome of other NDV strains. However, some unique features of the HN gene were found in HX01. HX01 possesses the motif (112)G-R-Q-G-R-L(117) at the fusion protein cleavage site, which is typical of lentogenic strains. Pathogenicity tests based on the mean death time and the intracerebral pathogenicity index also revealed the isolate's lentogenic character. Phylogenetic analysis based on the variable region of the F gene (nt 47-420) revealed that HX01 was clustered to genotype II within class II NDV. Genetically, HX01 has a high similarity with the La Sota vaccine strain based on the single gene or complete genomic but is far different from the prevalent genotype VIId NDV which circulates in fowls and waterfowls in mainland China.

Strong innate immune response and cell death in chicken splenocytes infected with genotype VIId Newcastle disease virus

BackgroundGenotype VIId Newcastle disease virus (NDV) isolates induce more severe damage to lymphoid tissues, especially to the spleen, when compared to virulent viruses of other genotypes. However, the biological basis of the unusual pathological changes remains largely unknown.MethodsVirus replication, cytokine gene expression profile and cell death response in chicken splenocytes infected with two genotype VIId NDV strains (JS5/05 and JS3/05), genotype IX NDV strain F48E8 and genotype IV NDV strain Herts/33 were evaluated. Statistical significance of differences between experimental groups was determined using the Independent-Samples T test.ResultsJS5/05 and JS3/05 caused hyperinduction of type I interferons (IFNs) (IFN-α and -β) during detection period compared to F48E8 and Herts/33. JS5/05 increased expression level of IFN-γ gene at 6 h post-inoculation (pi) and JS3/05 initiated sustained activation of IFN-γ within 24 h pi, whereas transcriptional levels of IFN-γ remained unchanged at any of the time points during infection of F48E8 and Herts/33. In addition, compared to F48E8 and Herts/33, JS3/05 and JS5/05 significantly increased the amount of free nucleosomal DNA in splenocytes at 6 and 24 h pi respectively. Annexin-V and Proidium iodid (PI) double staining of infected cells showed that cell death induced by JS3/05 and JS5/05 was characterized by marked necrosis compared to F48E8 and Herts/33 at 24 h pi. These results indicate that genotype VIId NDV strains JS3/05 and JS5/05 elicited stronger innate immune and cell death responses in chicken splenocytes than F48E8 and Herts/33. JS5/05 replicated at a significantly higher efficiency in splenocytes than F48E8 and Herts/33. Early excessive cell death induced by JS3/05 infection partially impaired virus replication.ConclusionsViral dysregulaiton of host response may be relevant to the severe pathological manifestation in the spleen following genotype VIId NDV infection.