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1.
J Vet Sci ; 25(5): e70, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39363658

RESUMEN

IMPORTANCE: Infectious bursal disease (IBD) is an important viral poultry disease that vaccination can control. OBJECTIVE: This study examined the immune protection of immune-complex (Vaccine A) and attenuated live (Vaccine B) IBD vaccines in specific-pathogen-free (SPF) chickens against a novel Malaysian variant IBD virus (vaIBDV) challenge. METHODS: One-day-old (n =75) SPF chickens were divided randomly into the following three groups of 25 chicks each: Control, Vaccine A, and Vaccine B groups. The vaIBDV strain, UPM1432/2019, was used for the challenge at 21 and 28days post-vaccination (dpv). Five birds from unchallenged and challenged groups were sacrificed seven days post-challenge, and blood, bursa, spleen, and cloacal swabs were collected. The IBD antibodies (Abs), lymphoid lesions, and viral load were determined. RESULTS: The UPM1432/2019 virus induced bursal damage in vaccinated SPF chickens despite Ab titers. The mean Ab titers of the Vaccine A challenged group were significantly lower (p < 0.002) than in the unchallenged group at 28 dpv. The bursal indices of the vaccinated unchallenged groups did not differ significantly from those of the vaccinated challenged groups (p = 0.94). Microscopically, the bursae of the challenged groups showed significant atrophy. The bursal lesion score was higher (p < 0.05) in the control and Vaccine B challenged groups than the Vaccine A challenged group. The challenged group had a higher viral load than the vaccinated groups (p < 0.001). CONCLUSIONS AND RELEVANCE: Neither vaccine fully protected against a vaIBDV challenge, highlighting the limitations of current vaccines and the need for further research.


Asunto(s)
Infecciones por Birnaviridae , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Enfermedades de las Aves de Corral , Vacunas Virales , Animales , Virus de la Enfermedad Infecciosa de la Bolsa/inmunología , Pollos/inmunología , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/prevención & control , Infecciones por Birnaviridae/inmunología , Infecciones por Birnaviridae/virología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/inmunología , Vacunas Virales/inmunología , Organismos Libres de Patógenos Específicos , Vacunas Atenuadas/inmunología , Vacunación/veterinaria , Anticuerpos Antivirales/sangre
2.
Front Vet Sci ; 11: 1466099, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39268520

RESUMEN

Novel variant infectious bursal disease virus (nvIBDV) is an emerging genotype (A2dB1b) that can cause severe and prolonged immunosuppression in young chickens. Despite current commercial vaccines being proven to lack complete protection against nvIBDV, it remains unclear whether the oil emulsion inactivated vaccines (OEVs) of the homologous and heterologous virus or booster immunization can provide effective protection. In this study, OEVs with two types of nvIBDV isolates QZ191002 (A-nv/B-nv) and YL160304 (A-nv/B-HLJ0504-like) were prepared and evaluated the protective effects of OEVs plus the booster immunizations with different current commercial vaccines against the challenge of nvIBDVs. The results from vaccination-challenge experiments showed that nvIBDV could break through the protection provided by only one immunization dose of the commercial vaccines, with the protection rates ranging from 40% to 60%. Interestingly, even with booster immunization with different commercial vaccines, the protection rates could only be increased to 60%-80%. As expected, only the OEVs of the homologous virus could provide 100% protection against the homologous nvIBDV, which could induce high-level specific antibodies, ameliorate target organ damage, and significantly reduce the viral load of the bursal in the challenged chickens. Notably, YL160304-OEV performed better than QZ191002-OEV, providing 100% protection not only against the challenge of homologous strain but also against that of heterologous QZ191002 strain. Antibody levels of the immunized chickens gradually increased after a short decline and reached the highest level on the age of 28 days. Similarly, the percentages of lymphocytes CD4+, CD8+ T, and B in peripheral blood lymphocytes (PBLs) were significantly increased on 21 d and 28 d. Notably, despite the nvIBDV, OEVs initially induced a delayed responses in the early stages but ultimately reach higher levels of CD4+ and CD8+ T lymphocytes. The results of study suggest that even booster immunization with different commercial vaccines cannot provide complete protection against nvIBDV, while the OEVs made by the nvIBDVs can provide full protection. Moreover, YL160304-OEV exhibits a broader protective spectrum against different nvIBDV strains, making it a potential candidate for the development of new vaccine.

3.
Vet Microbiol ; 296: 110191, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39032445

RESUMEN

Infectious bursal disease virus (IBDV) is a highly contagious virus with a dsRNA genome, predominantly infecting chickens and causing significant economic losses due to high mortality rates. The emergence of recombinant, novel variant, and highly virulent strains that evade current vaccines has led to frequent epidemics and outbreaks in the poultry industry. The lack of targeted antivirals for IBDV underscores the pressing requirement to develop potent therapeutic options. Within this framework, our research investigated the effectiveness of picroside II, a naturally derived iridoid glycoside, against viruses in DF-1 cells. Our findings demonstrate that picroside II significantly inhibits viral replication, with its efficacy increasing proportionally to the dosage administered. Through time-addition and antiviral duration analysis, we determined that picroside II therapeutically blocks IBDV replication, with its effects persisting for over 72 hours. Further investigation revealed that picroside II specifically inhibits the cellular replication stage of IBDV's lifecycle. Additionally, our findings indicate that picroside II impairs VP1 polymerase activity by binding to the active pocket, which significantly disrupts the interaction between VP1 and VP3. Mutations at three critical binding sites on VP1 not only impair virus replication but also hinder polymerase function and disrupt VP1-VP3 interactions. Collectively, these results demonstrate that picroside II, by inhibiting viral polymerase activity, represents a promising antiviral agent against IBDV.


Asunto(s)
Antivirales , Pollos , Cinamatos , Virus de la Enfermedad Infecciosa de la Bolsa , Glucósidos Iridoides , Replicación Viral , Replicación Viral/efectos de los fármacos , Virus de la Enfermedad Infecciosa de la Bolsa/efectos de los fármacos , Virus de la Enfermedad Infecciosa de la Bolsa/fisiología , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Animales , Cinamatos/farmacología , Glucósidos Iridoides/farmacología , Antivirales/farmacología , Línea Celular , Proteínas Estructurales Virales/genética , Proteínas Estructurales Virales/metabolismo , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/tratamiento farmacológico
4.
Microb Pathog ; 194: 106802, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39032673

RESUMEN

Interferon-inducible transmembrane protein 3 (IFITM3), a member of the interferon-stimulating factor (ISG) family, has various antiviral functions. Infectious bursal disease virus (IBDV) mainly invades the bursa of Fabricius in chickens, causing a reduction in their immunity and resulting in death from secondary infections. Our previous study found that IBDV infection promotes the expression of chicken IFITM3. However, the role of chicken IFITM3 in IBDV infection remains unknown. To explore this role, the overexpression vector for IFITM3 was constructed and transfected into HD-11 and DF-1 cells. The results showed that the overexpression of IFITM3 significantly reduced IBDV proliferation. While the IBDV proliferation increased when IFITM3 was inhibited by using siRNA. To further explore the mechanism by which IFITM3 reduces IBDV proliferation, the effects of IFITM3 on interferon (IFN) were investigated. Transfecting the constructed IFITM3 vectors into HD-11 and DF-1 cells demonstrated that IFITM3 promoted the expression of IFN-α, IFN-ß, and IFN-γ. To investigate the mechanism by which IFITM3 regulates IFN expression, the effects of IFITM3 on IFN production were explored. The results showed that the IKB gene mainly affected the regulatory effects of IFITM3 on IFN. Taken together, IFITM3 may reduce viral proliferation by regulating changes in IFNs, and this process may involve a positive feedback effect of IFITM3 on IFN. IKB plays an important role in the regulation of IFN effects by IFITM3.


Asunto(s)
Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Interferones , Proteínas de la Membrana , Replicación Viral , Virus de la Enfermedad Infecciosa de la Bolsa/fisiología , Animales , Pollos/virología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Línea Celular , Interferones/metabolismo , Interferones/genética , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/virología , Infecciones por Birnaviridae/inmunología , Enfermedades de las Aves de Corral/virología , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , ARN Interferente Pequeño/genética , Regulación de la Expresión Génica , Bolsa de Fabricio/virología , Bolsa de Fabricio/metabolismo , Interferón beta/metabolismo , Interferón beta/genética
5.
Avian Pathol ; : 1-14, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38995197

RESUMEN

Infectious bursal disease virus (IBDV) can cause a highly contagious disease, resulting in severe damage to the immune system that causes immunosuppression in young chickens. Both spleen and thymus are important immune organs, which play a key role in eliciting protective immune responses. However, the effects of very virulent IBDV (vvIBDV) strain LJ-5 infection on chicken spleen and thymus are still unknown. In the present study, 3-week-old specific pathogen-free chickens were infected with vvIBDV for 1-5 days. The vvIBDV infection significantly increased the spleen index and decreased the thymus index. Microscopic analysis indicated necrosis, depletion of the lymphoid cells, and complete loss of structural integrity in spleen and thymus. Ultrastructural analysis displayed mitochondrial and nuclear damage, including mitochondrial cristae breaks, and deformation of nuclear membrane in vvIBDV-infected spleen and thymus tissues. Cytokine levels increased in the spleen and thymus after IBDV infection, promoting inflammation and causing an inflammatory imbalance. Moreover, the mRNA expression of apoptosis-related genes was significantly upregulated in the vvIBDV-infected group compared to the control group. Meanwhile, the mRNA expression of mitochondrial dynamics was altered in the spleen and thymus of vvIBDV-infected chickens. These results suggested that vvIBDV infection triggers an imbalance of inflammatory cytokines, and apoptosis in the spleen and thymus, resulting in immune injury in chickens. This study provides basic data for the further study of vvIBDV pathogenesis.

6.
Avian Dis ; 68(2): 99-111, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38885051

RESUMEN

The continued circulation of infectious bursal disease virus (IBDV) in Egypt, despite the use of various vaccines, is a serious problem that requires continuous detection of IBDV. In the current study, real-time reverse transcriptase polymerase chain reaction testing of 100 diseased chicken flocks during 2017-2021 revealed the presence of very virulent IBDV (vvIBDV) in 67% of the flocks, non-vvIBDV in 11%, and a mixture of both vvIBDV and non-vvIBDV in 4%. Twenty-nine IBDV isolates were submitted for partial sequencing of the viral protein 2 hypervariable region (VP2-HVR), and 27 isolates were confirmed to be genogroup A3 (vvIBDV) with 96.3%-98.5% similarity to the global A3 (vvIBDV) and 88.9%-97% similarity to genogroup A1 vaccine strains. The remaining two isolates were non-vvIBDV and showed 91.1% and 100% identity with classical genogroup A1 strains, respectively. Furthermore, the sequence and phylogenetic analysis of VP1 (amino acids 33-254) of two selected isolates of A3, 5/2017 and 98/2021, clustered them as B2, vvIBDV-like, strains with high similarity (99.5%) to four Egyptian, 99% to Chinese and European, and 97.7% to Chinese and Polish vvIBDV isolates. Experimental infection of commercial broiler chickens with two vvIBDV-A3B2 isolates (5/2017 and 98/2021) showed no mortality despite typical tissue lesions, clear histopathological changes, and strong ELISA antibody response. Isolate 98/2021 was more pathogenic, as confirmed by histopathology, whereas isolate 5/2017 induced a stronger serological response. In conclusion, vvIBDV (A3B2) strains with two amino acid (aa) substitutions in VP1 as V141I and V234I as well as VP2 as Y220F and G254S are still circulating in Egypt.


Análisis de las secuencias genéticas y de la patogenicidad del virus de la enfermedad infecciosa de la bolsa de pollos en Egipto durante los años 2017­2021. La circulación continua del virus de la enfermedad infecciosa de la bolsa (IBDV) en Egipto, a pesar del uso de varias vacunas, continua siendo un problema serio que requiere la detección continua de este virus. En el presente estudio, se realizó una prueba de transcripción reversa y reacción en cadena de la polimerasa en tiempo real de 100 parvadas enfermas de pollos durante los años 2017­2021 y reveló la presencia de virus muy virulentos (vvIBDV) en el 67% de las parvadas, otros tipos diferentes a los muy virulentos en el 11%, y una mezcla de virus muy virulentos y otros tiposen un 4% de las parvadas. Se enviaron veintinueve aislados del virus de la enfermedad infecciosa de la bolsa para la secuenciación parcial de la región hipervariable de la proteína viral 2 (VP2-HVR), y se confirmó que 27 aislados pertenecían al genogrupo A3 (vvIBDV) con una similitud del 96.3% al 98.5% con el genogrupo A3 global (vvIBDV) y de 88.9% a 97% de similitud con las cepas vacunales del genogrupo A1. Los dos aislamientos restantes no resultaron ser muy virulentos y mostraron un 91.1% y un 100% de identidad con las cepas clásicas del genogrupo A1, respectivamente. Además, la secuencia y el análisis filogenético de la proteina VP1 (aminoácidos 33-254) de dos aislados seleccionados de genogrupo A3, 5/2017 y 98/2021, los agruparon como cepas B2, similares a virus muy virulentos, con alta similitud (99.5%) con cuatro aislamientos de Egipto, con similitud de 99% con aislados chinos y europeos, y de 97.7% con aislados muy virulentos chinos y polacos. La infección experimental de pollos de engorde comerciales con dos aislados muy virulentos tipo A3B2 (5/2017 y 98/2021) no mostró mortalidad a pesar de las lesiones tisulares típicas, los cambios histopatológicos claros y la fuerte respuesta de anticuerpos por ELISA. El aislado 98/2021 fue más patógeno, según lo confirmado por histopatología, mientras que el aislado 5/2017 indujo una respuesta serológica más fuerte. En conclusión, las cepas muy virulentas (A3B2) con dos sustituciones de aminoácidos (aa) en la proteina VP1 como V141I y V234I, así como en VP2 tales como Y220F y G254S, todavía circulan en Egipto.


Asunto(s)
Infecciones por Birnaviridae , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Filogenia , Enfermedades de las Aves de Corral , Animales , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Virus de la Enfermedad Infecciosa de la Bolsa/patogenicidad , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/virología , Infecciones por Birnaviridae/epidemiología , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/epidemiología , Egipto/epidemiología , Virulencia
7.
Front Vet Sci ; 11: 1385958, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38812565

RESUMEN

Recently, herpesvirus of turkeys (HVT), which was initially employed as a vaccine against Marek's disease (MD), has been shown to be a highly effective viral vector for producing recombinant vaccines that can simultaneously express the protective antigens of multiple poultry diseases. Prior to the development of commercial HVT-vectored dual-insert vaccines, the majority of HVT-vectored vaccines in use only contained a single foreign gene and were often generated using time-consuming and inefficient traditional recombination methods. The development of multivalent HVT-vectored vaccines that induce simultaneous protection against several avian diseases is of great value. In particular, efficacy interference between individual recombinant HVT vaccines can be avoided. Herein, we demonstrated the use of CRISPR/Cas9 gene editing technology for the insertion of an IBDV (G2d) VP2 expression cassette into the UL45/46 region of the recombinant rHVT-HA viral genome to generate the dual insert rHVT-VP2-HA recombinant vaccine. The efficacy of this recombinant virus was also evaluated in specific pathogen-free (SPF) chickens. PCR and sequencing results showed that the recombinant virus rHVT-VP2-HA was successfully constructed. Vaccination with rHVT-VP2-HA produced high levels of specific antibodies against IBDV (G2d) and H9N2/Y280. rHVT-VP2-HA can provide 100% protection against challenges with IBDV (G2d) and H9N2/Y280. These results demonstrate that rHVT-VP2-HA is a safe and highly efficacious vaccine for the simultaneous control of IBDV (G2d) and H9N2/Y280.

8.
Res Vet Sci ; 174: 105293, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38754221

RESUMEN

Recently, several attempts have been made to replace egg-based with cell-based vaccines to prevent and control Infectious Bursal Disease Virus (IBDV). This study aimed to evaluate a new fish cell line (M99) for culturing and replicating IBDV. After observing complete cytopathic effects (CPE) on the M99 cell line, virus titers were determined using the TCID50 test, and the presence of the virus was confirmed using an RT-PCR test. Subsequently, 135 broiler chickens (14 days old) were randomly divided into three equal groups for immune response measurements: G1: immunized with a commercial vaccine, G2: immunized with an experimental vaccine, and G3: control. Antibody responses, bursal index, and histopathological evaluations were examined on different days after immunization. Based on the results, CPE of the virus was noticeable from the first passage, becoming complete by the third passage. The infectious titer of the virus was log106.9. Antibody titer measured 21 days after immunization in both vaccinated groups were significantly differed from the control group (p < 0.05). The results obtained from examining the bursal index and histopathological evaluations showed no significant difference between the studied groups at different times. Overall, this research is the first report on the successful cultivation of infectious bursal virus on a permanent cell line of fish origin, with the advantages of tolerance to a wide temperature range (26-40 degrees Celsius). Therefore, this cell line has potential for use to attenuate, cultivate, and adapt other pathogens to cold temperatures in future studies.


Asunto(s)
Infecciones por Birnaviridae , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Enfermedades de las Aves de Corral , Vacunas Virales , Replicación Viral , Virus de la Enfermedad Infecciosa de la Bolsa/inmunología , Animales , Vacunas Virales/inmunología , Pollos/virología , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/virología , Infecciones por Birnaviridae/prevención & control , Infecciones por Birnaviridae/inmunología , Línea Celular , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/inmunología , Peces/virología
9.
Avian Pathol ; 53(5): 419-429, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38784976

RESUMEN

Since the detection of antigenically atypical very virulent Infectious bursal disease viruses (vvIBDV) in Egypt in 1999, the country has been experiencing recurrent outbreaks with high mortality rates and typical gross lesions associated with typical vvIBDV. However, a significant change occurred in 2023, marked by a notable increase in reported subclinical IBDV cases. To evaluate the field situation, samples from 21 farms in 2023 and 18 farms from 2021 and 2022, all of which had experienced IBD outbreaks based on clinical diagnosis, were collected, and subjected to VP2-HVR sequencing. Phylogenetic analysis revealed that all samples collected in 2021 and 2022 clustered with classical virulent strains and vvIBDV. In 2023, one sample clustered with the Egyptian vvIBDV, another with classical virulent IBDV, and the rest with the novel variant IBDV (nVarIBDV) circulating in China. The alignment of deduced amino acid sequences for VP2 showed that all Egyptian classic virulent strains were identical to the Winterfield or Lukert strains, while vvIBDV strains exhibited two out of the three typical residues found in Egyptian vvIBDV, namely Y220F and G254S, but not A321T. Meanwhile, all Egyptian variant strains exhibited typical residues found in nVarIBDV. However, all Egyptian variants showed a mutation at position 321 (321V), which represents the most exposed part of the capsid and is known to have a massive impact on IBDV antigenicity, except for one sample that had 318G instead. This report highlights the emergence of a new variant IBDV in Egypt, clustered with the Chinese new variants, spreading subclinically in broiler farms across a wide geographic area.RESEARCH HIGHLIGHTS New variant IBDV which emerged in Egypt clustered with Chinese nVarIBDV.nVarIBDV spread subclinically across a wide geographic area.Mutation at 321 represents capsid's most exposed part, a defining feature.Antigenically modified vvIBDV still circulating in Egypt with typical lesions.


Asunto(s)
Infecciones por Birnaviridae , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Filogenia , Enfermedades de las Aves de Corral , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Virus de la Enfermedad Infecciosa de la Bolsa/patogenicidad , Virus de la Enfermedad Infecciosa de la Bolsa/aislamiento & purificación , Animales , Egipto/epidemiología , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/virología , Infecciones por Birnaviridae/epidemiología , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/epidemiología , Pollos/virología , Brotes de Enfermedades/veterinaria , Secuencia de Aminoácidos , Vacunas Virales/inmunología , Vacunación/veterinaria , Proteínas Estructurales Virales/genética , Virulencia , Variación Genética
10.
Poult Sci ; 103(7): 103797, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38713990

RESUMEN

Previous studies here have demonstrated that the rabbit sacculus rotundus-derived antimicrobial peptides (RSRP) could alter the intestinal mucosal immune responses in specific-pathogen-free (SPF) chickens, however, the protective effects of RSRP on chickens against infection remain questionable. In the present study, eighty SPF chickens were randomly divided into five groups and challenged with very virulent infectious bursal disease virus (vvIBDV) to determine the protective effects and its underlying mechanism of RSRP. Histopathology examination found that vvIBDV-infection caused severe damage in the bursa of Fabricius, especially the bursal lymphoid follicles underwent severe necrosis, depletion, hemorrhage, and edema. Unexpectedly, RSRP intervention significantly reduced the necrosis and depletion of lymphoid follicles in the vvIBDV-infected chickens. Moreover, RSRP treatment significantly decreased the expression of Bax (P < 0.01) as well as remarkably promoted the expression of Bcl-2 (P < 0.01), concomitantly alleviated the excessive apoptosis in the immune organs such as the bursa of Fabricius during vvIBDV infection. Notably, consistent with our previous reports that increased mast cell activation and degranulation in the bursa after vvIBDV infection, RSRP administration considerably reduced the mast cell density and the expression of tryptase, a marker for activated mast cells. Collectively, the present study indicates that rabbit sacculus rotundus-derived antimicrobial peptides could effectively protect the major immune organs including the bursa of Fabricius from the damage caused by vvIBDV infection, which provides the possibility and a promising perspective for the future application of antimicrobial peptides for poultry production.


Asunto(s)
Infecciones por Birnaviridae , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Enfermedades de las Aves de Corral , Animales , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/virología , Infecciones por Birnaviridae/prevención & control , Virus de la Enfermedad Infecciosa de la Bolsa/fisiología , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/inmunología , Conejos , Organismos Libres de Patógenos Específicos , Bolsa de Fabricio/efectos de los fármacos , Bolsa de Fabricio/virología , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/administración & dosificación , Distribución Aleatoria
11.
Virulence ; 15(1): 2333237, 2024 12.
Artículo en Inglés | MEDLINE | ID: mdl-38528779

RESUMEN

Infectious bursal disease virus (IBDV) causes immunosuppression and high mortality in young chickens. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are important regulators during viral infection. However, detailed the regulatory mechanisms of lncRNA-miRNA-mRNA have not yet been described in IBDV infection. Here, we analysed the role of lncRNA53557/gga-miR-3530-5p/STAT1 axis in very virulent IBDV (vvIBDV) infection. Evidently upregulated expression of lncRNA53557 was observed in bursa of Fabricius and DT40 cells. Meanwhile, overexpression of lncRNA53557 promoted STAT1 expression and inhibited vvIBDV replication and vice versa, indicating that the upregulation of lncRNA53557 was part of the host antiviral defence. The subcellular fractionation assay confirmed that lncRNA53557 can be localized in the cytoplasm. Further, dual-luciferase reporter, RNA pulldown, FISH and RT-qPCR assays revealed that lncRNA53557 were directly bound to gga-miR-3530-5p and had a negative regulatory relationship between them. Subsequent mechanistic analysis showed that lncRNA53557 acted as a competing endogenous RNA (ceRNA) of gga-miR-3530-5p to relieve the repressive effect of gga-miR-3530-5p on its target STAT1, as well as Mx1, OASL, and ISG15, thereby suppressing vvIBDV replication. The study reveals that a network of enriched lncRNAs and lncRNA-associated ceRNA is involved in the regulation of IBDV infection, offering new insight into the mechanisms underlying IBDV-host interaction.


Asunto(s)
MicroARNs , ARN Largo no Codificante , Animales , Pollos , ARN Largo no Codificante/genética , Línea Celular , MicroARNs/genética , MicroARNs/metabolismo
12.
Poult Sci ; 103(6): 103623, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38555757

RESUMEN

Infectious Bursal Disease is a highly contagious disease that affects young chickens and leads to significant economic losses. Its causal agent is a double-stranded RNA virus that, due to its high error rate during the replication process, gives rise to a constant generation of new virus variants. Until 2014, strains of Infectious Bursal Diseases Virus (IBDV) belonging to genogroup 4 predominated in Argentina, but there have been no reports since then regarding the circulating genogroups in poultry. In this study, 11 recent sequences of Argentine from the hypervariable region of VP2 protein (hvVP2) were analyzed to determine their genogroup, origin, evolution, and amino acid sequence. Samples from chickens showing signs of IBDV infection were collected, and the hvVP2 region was amplified using RT-PCR, followed by sequencing. The results indicated that the analyzed strains belong to genogroup 2, with an estimated evolutionary rate of 1.74 × 10-3 substitutions/site/year. It is speculated that the predominant group of sequences began to spread in Argentina around 2014 and had its origins in China. Another sample is related to strains from South Korea and is not closely linked to the main group. Furthermore, the predicted amino acid sequences show similarity to strains that can evade vaccine-induced immunity. These findings underscore the importance of active surveillance in poultry to mitigate losses caused by IBDV.


Asunto(s)
Infecciones por Birnaviridae , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa , Filogenia , Enfermedades de las Aves de Corral , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Animales , Infecciones por Birnaviridae/veterinaria , Infecciones por Birnaviridae/virología , Infecciones por Birnaviridae/epidemiología , Argentina/epidemiología , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/epidemiología , Proteínas Estructurales Virales/genética , Genotipo , Secuencia de Aminoácidos , Variación Genética
13.
Vaccines (Basel) ; 12(3)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38543860

RESUMEN

Infectious bursal disease (IBD), caused by IBD virus (IBDV), is an extremely contagious immunosuppressive disease that causes major losses for the poultry industry worldwide. Recently, the novel variant IBDV (G2d) has been highly prevalent in Korea, but the current vaccines against this very virulent IBDV have limited efficacy against this novel variant. To develop a vaccine against this variant IBDV, a recombinant virus designated rHVT-VP2 was constructed by inserting the IBDV (G2d) VP2 gene into herpesvirus of turkeys (HVT) using CRISPR/Cas9 gene-editing technology. The PCR and sequencing results obtained showed that the recombinant virus rHVT-VP2 was successfully constructed. Vaccination with rHVT-VP2 generated IBDV-specific antibodies in specific pathogen-free chickens starting from 2 weeks post-immunization. Seven days after the challenge, the autopsy results showed that the bursa atrophy rates of the rHVT-VP2, HVT, vaccine A, and positive control groups were 0%, 100%, 60%, and 100%, respectively, and the BBIX values were 1.07 ± 0.22, 0.27 ± 0.05, 0.64 ± 0.33, and 0.32 ± 0.06, respectively. These results indicate that rHVT-VP2 can provide 100% protection against a challenge with the IBDV (G2d), whereas vaccine A only provides partial protection. In conclusion, vaccination with the recombinant virus rHVT-VP2 can provide chickens with effective protection against variant IBDV (G2d).

14.
Vet Res Forum ; 15(1): 49-55, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38464605

RESUMEN

Purification is an important step in the production of viral vaccines that strongly affects product recovery and subsequent immune responses. The present study was carried out with the aim of improving the purification of infectious bursal disease virus (IBDV) by the tangential flow filtration (TFF) method. Then, the effect of the purified virus on the induction of immune responses against IBDV in specific pathogen free (SPF) chickens was investigated. The IBD07IR strain was propagated in embryonated SPF eggs. The virus was purified using a 100 kDa cassette. The quality of the recovered viruses was evaluated by titration. A total number of 60 SPF chickens were randomly divided into three groups (n = 20) and received the concentrated viral antigen, commercial live IBDV vaccine and phosphate-buffered saline at the age of 3 weeks by eye drop method. The bursa of Fabricius was examined histopathologically for possible changes. Sera were collected at 1-week intervals from day 0 until the end of 6 weeks after vaccination. The IBDV-specific antibody levels, induction of cell-mediated immunity and mRNA expression levels of cytokines were evaluated. The results showed that despite a relative raise in virus titer from 7.66 to 8.17 embryo infectious dose (EID)50 mL-1 following purification, both the purified IBDV and commercial vaccine are able to induce strong immune responses against the virus. Within a context of egg-based IBDV vaccine production, a single-step TFF can be applied for the relatively purification. This platform requires a further study in the selection of multiple membranes to optimize the operating conditions and final product.

15.
Front Vet Sci ; 11: 1334586, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38362295

RESUMEN

Infectious bursal disease virus (IBDV) infection causes highly contagious and immunosuppressive disease in poultry. The thymus, serving as the primary organ for T cell maturation and differentiation, plays an important role in the pathogenicity of IBDV in the infected chickens. However, there are no reports on the molecular pathogenesis of IBDV in the thymus currently. The aim of the study was to elucidate the molecular mechanisms underlying the pathogenicity of a field very virulent (vv) IBDV strain NN1172 in the thymus of SPF chickens using integrative transcriptomic and proteomic analyses. Our results showed that a total of 4,972 Differentially expressed genes (DEGs) in the thymus of NN1172-infected chickens by transcriptomic analysis, with 2,796 up-regulated and 2,176 down-regulated. Meanwhile, the proteomic analysis identified 726 differentially expressed proteins (DEPs) in the infected thymus, with 289 up-regulated and 437 down-regulated. Overall, a total of 359 genes exhibited differentially expression at both mRNA and protein levels, with 134 consistently up-regulated and 198 genes consistently down-regulated, as confirmed through a comparison of the RNA-seq and the proteomic datasets. The gene ontology (GO) analysis unveiled the involvement of both DEGs and DEPs in diverse categories encompassing cellular components, biological processes, and molecular functions in the pathological changes in IBDV-infected thymus. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the host mainly displayed severely disruption of cell survival/repair, proliferation and metabolism pathway, meanwhile, the infection triggers antiviral immune activation with a potential emphasis on the MDA5 pathway. Network inference analysis identified seven core hub genes, which include CDK1, TYMS, MCM5, KIF11, CCNB2, MAD2L1, and MCM4. These genes are all associated with cell-cycle regulating pathway and are likely key mediators in the pathogenesis induced by NN1172 infection in the thymus. This study discovered dominant pathways and genes which enhanced our understanding of the molecular mechanisms underlying IBDV pathogenesis in the thymus.

16.
Poult Sci ; 103(4): 103552, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38422756

RESUMEN

The novel variant IBDV (nVarIBDV, genotype A2dB1), characterized by bursal atrophy of fabricius and decreased lymphocytes, has been emerging on a large scale in Asia (including China) since late 2018. nVarIBDV is a new threat to the poultry industry, yet the currently licensed commercial vaccines, including the live viral vector vaccine, IBDV immune complex vaccine or VP2 subunit vaccine, are ineffective against nVarIBDV infection. In this study, specific-pathogen-free (SPF) chickens and broilers divided into 3 groups were vaccinated with the live viral vector vaccine, the VP2 subunit vaccine or the IBDV immune complex vaccine at 1 day-old, respectively. The SPF chickens received a secondary vaccination with the live B87 strain vaccine at 11-day-old. The bursa/body weight ratio, histopathology lesion of the bursa, and the differentiation between infected and vaccinated animals (DIVA) by qRT-PCR confirmed that the live viral vector vaccine or immune complex vaccine plus live B87 strain booster could provide at least 80% protection against the FJ2019-01 strain of nVarIBDV in SPF chickens. The broilers also received a secondary vaccination using a live W2512 G-61 strain vaccine at 14-day-old, and analyses showed that the VP2 subunit vaccine or immune complex vaccine plus the live W2512 G-61 strain booster also provided more than 80% protection against the FJ2019-01 strain of nVarIBDV. Unfortunately, the live viral vector vaccine plus live W2512 G-61 strain booster provided poor to moderate protection against FJ2019-01 in broilers. These findings suggest that combining commercial vaccines with rational booster immunization can effectively protect chickens against an nVarIBDV challenge.


Asunto(s)
Infecciones por Birnaviridae , Virus de la Enfermedad Infecciosa de la Bolsa , Enfermedades de las Aves de Corral , Vacunas Virales , Animales , Pollos , Inmunización Secundaria/veterinaria , Complejo Antígeno-Anticuerpo , Infecciones por Birnaviridae/prevención & control , Infecciones por Birnaviridae/veterinaria , Vacunas Atenuadas , Vacunas de Subunidad , Anticuerpos Antivirales , Bolsa de Fabricio/patología
17.
mBio ; 15(3): e0343323, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38289089

RESUMEN

Viruses have evolved intricate mechanisms to evade host antiviral responses and exploit cellular resources by manipulating the expression profile of host genes. During infection, viruses encode proteins with shutoff activity to globally inhibit host protein synthesis, which is an effective strategy for immune evasion. In this study, compelling evidence shows that infectious bursal disease virus (IBDV) infection triggers the suppression of host protein synthesis. Furthermore, using both in vitro and in vivo viral infection models, we have identified that IBDV specifically impedes the transcription of host genes via the shutoff activity of viral VP5, simultaneously conferring advantages to IBDV infection in these circumstances. The proposed mechanism suggests that VP5 competitively binds to RanBP1, disrupting the RanGDP/GTP gradient. This disruption interferes with cellular nucleocytoplasmic transport, impairing the nuclear import of proteins bearing nuclear localization signals. The nuclear transport of pivotal transcriptional regulatory factors, such as p65 and IFN regulatory factor 7, is also compromised, leading to the inhibition of pro-inflammatory cytokines and interferon expression. This newly discovered strategy employed by IBDV enables them to manipulate host gene expression, providing novel insights into how viruses evade host immune responses and establish infections.IMPORTANCEViruses manipulate host processes at various levels to regulate or evade both innate and adaptive immune responses, promoting self-survival and efficient transmission. The "host shutoff," a global suppression of host gene expression mediated by various viruses, is considered a critical mechanism for evading immunity. In this study, we have validated the presence of host shutoff during infectious bursal disease virus (IBDV) infection and additionally uncovered that the viral protein VP5 plays a pivotal role in inhibiting the overall synthesis of host proteins, including cytokines, through a transcription-dependent pathway. VP5 competitively binds with RanBP1, leading to disruption of the Ran protein cycle and consequently interfering with nucleocytoplasmic transport, which ultimately results in the suppression of host gene transcription. These findings unveil a novel strategy employed by IBDV to evade host innate immunity and rapidly establish infection. This study also suggests a novel supplement to understanding the pathway through which viruses inhibit host protein synthesis.


Asunto(s)
Virus de la Enfermedad Infecciosa de la Bolsa , Animales , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Replicación Viral , Inmunidad Innata , Evasión Inmune , Citocinas , Pollos
18.
Vet Anim Sci ; 23: 100326, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38162251

RESUMEN

A study conducted in the Faisalabad district sampled 50 cases across five IBD outbreaks, revealing an alarming 80 % infection rate among poultry. Our research focused on developing an immune complex (Antigen-antibody complex) with potential immunoprophylactic benefits to counter this formidable threat. Our study was based on producing egg yolk-derived polyclonal antibodies (IgY) targeting IBDV. Commercial layer birds were immunized with inactivated IBDV, yielding IgY antibodies extracted from their eggs exhibited substantially higher and more enduring antibody titers, with a geometric mean titer of 104. Further research involved the creation of an immune complex (ICx) where antigen was extracted from infected bursae tissues. The immunogenic response of ICx was assessed in poultry birds after a challenge with a virulent strain of IBD virus and compared to a conventional IBDV vaccine in poultry. Results revealed significantly higher and more enduring antibody titers induced by the ICx, offering enhanced protective immunity against the IBDV challenge, as evidenced by lower Bursa to bodyweight ratios in vaccinated birds.

19.
Avian Pathol ; 53(1): 56-67, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37823857

RESUMEN

RESEARCH HIGHLIGHTS: Different field IBDVs were found to circulate in the Near and Middle East.Multiple atypical genotypes (A3B1, A4B1, A6B1) were found to circulate extensively.Traditional very virulent IBDVs (A3B2) were a minority of the detected strains.Viral exchanges can be hypothesized between the region and different continents.


Asunto(s)
Infecciones por Birnaviridae , Virus de la Enfermedad Infecciosa de la Bolsa , Enfermedades de las Aves de Corral , Animales , Pollos/genética , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Epidemiología Molecular , Océano Índico , Infecciones por Birnaviridae/epidemiología , Infecciones por Birnaviridae/veterinaria , Filogenia , Medio Oriente/epidemiología , Proteínas Estructurales Virales/genética
20.
Front Microbiol ; 14: 1293072, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38075867

RESUMEN

Infectious bursal disease (IBD) classical virus strain (cIBDV) can cause morbidity and mortality in young chickens with severe long-term immunosuppression. However, since the emergence and widespread prevalence of very virulent strain (vvIBDV) in China from 1991, reports of cIBDV have become rare. A novel reassortant and recombinant strain GXYL211225 (genotype A1aB1a) with segment A originating from the classical strain (A1a) and segment B from the attenuated vaccine strain (B1a) was characterized in the study. Notably, segment A resulted from recombination between the cIBDV strains 150127-0.2 and Faragher52-70, expressing as a backbone from 150127-0.2, where a fragment located at the position of nucleotide (nt) 519-1 410 was replaced by the corresponding region of Faragher52-70. The infection of GXYL211225 caused mortality in SPF chicken embryos, despite lacking the critical amino acid (aa) residues 253H, 279 N and 284A associated with the cellular tropism, and induced significant cytopathic effect (CPE) on a wide range of cells, confirming its natural cell-adapted character. Furthermore, the challenge experiment of GXYL211225 was performed on the commercial Three-yellow chickens of 4-week-old, and with the vvIBDV HLJ-0504-like strain NN1172 and the novel variant (nv) IBDV strain QZ191002 as the comparison. All the challenged birds experienced reduced body-weight gain. QZ191002 infected birds showed no obvious clinical symptoms or mortality, while those of NN1172 and GXYL211225 showed typical IBD symptoms and resulted in 20% (2/10) and 10% (1/10) of mortality rates, respectively. At 7 days post-challenge (dpc), the damages of bursal of Fabricius (BF) varied among groups, with NN1172 causing the most severe lesions, followed by GXYL211225, and then QZ191002. It was also found that the pathogenicity was correlated positively with the viral load, aligning with the histopathological severity in BF. The study confirms the rapid and diverse evolution of the re-emerged classical strains in the field and emphasizes the need to monitor the changes of IBDV on both the genetic and pathogenic aspects for the effective control of the disease.

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