RESUMEN
Porcine reproductive and respiratory syndrome (PRRS) is endemic worldwide, seriously affecting the development of the pig industry, but vaccines have limited protective effects against PRRSV transmission. The aim of this study was to identify potential anti-PRRSV drugs. We examined the cytotoxicity of seven compounds formulated based on the mass ratio of glycyrrhizic acid to matrine and calculated their inhibition rates against PRRSV in vitro. The results showed that the seven compounds all had direct killing and therapeutic effects on PRRSV, and the compounds inhibited PRRSV replication in a time- and dose-dependent manner. The compound with the strongest anti-PRRSV effect was selected for subsequent in vivo experiments. Pigs were divided into a control group and a medication group for the in vivo evaluation. The results showed that pigs treated with the 4:1 compound had 100% morbidity after PRRSV challenge, and the mortality rate reached 75% on the 8th day of the virus challenge. These results suggest that this compound has no practical anti-PRRSV effect in vivo and can actually accelerate the death of infected pigs. Next, we further analyzed the pigs that exhibited semiprotective effects following vaccination with the compound to determine whether the compound can synergize with the vaccine in vivo. The results indicated that pigs treated with the compound had higher mortality rates and more severe clinical reactions after PRRSV infection (p < 0.05). The levels of proinflammatory cytokines (IL-6, IL-8, IL-1ß, IFN-γ, and TNF-α) were significantly greater in the compound-treated pigs than in the positive control-treated pigs (p < 0.05), and there was no synergistic enhancement with the live attenuated PRRSV vaccine (p < 0.05). The compound enhanced the inflammatory response, prompted the body to produce excessive levels of inflammatory cytokines and caused body damage, preventing a therapeutic effect. In conclusion, the present study revealed that the in vitro effectiveness of these agents does not indicate that they are effective in vivo or useful for developing anti-PRRSV drugs. Our findings also showed that, to identify effective anti-PRRSV drugs, comprehensive drug screening is needed, for compounds with solid anti-inflammatory effects both in vitro and in vivo. Our study may aid in the development of new anti-PRRSV drugs.
Asunto(s)
Alcaloides , Antivirales , Ácido Glicirrínico , Matrinas , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Quinolizinas , Replicación Viral , Animales , Virus del Síndrome Respiratorio y Reproductivo Porcino/efectos de los fármacos , Alcaloides/farmacología , Quinolizinas/farmacología , Quinolizinas/uso terapéutico , Porcinos , Antivirales/farmacología , Antivirales/uso terapéutico , Ácido Glicirrínico/farmacología , Ácido Glicirrínico/uso terapéutico , Síndrome Respiratorio y de la Reproducción Porcina/tratamiento farmacológico , Síndrome Respiratorio y de la Reproducción Porcina/virología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Replicación Viral/efectos de los fármacos , Citocinas/metabolismo , Análisis de SupervivenciaRESUMEN
BACKGROUND: This field evaluation was designed to evaluate the efficacy of a new porcine reproductive and respiratory syndrome virus-2 (PRRSV-2) modified live virus vaccine at three independent pig farms. METHODS: Three farms were selected for this study based on their respiratory disease status caused by PRRSV-2 infection in post-weaning and growing pigs. Each farm housed a total of 40, 18-day-old pigs that were randomly allocated to one of two treatment groups. Pigs were administered a 1.0 mL dose of the bivalent vaccine intramuscularly at 21 days of age in accordance with the manufacturer's recommendations, whereas unvaccinated pigs were administered a single dose of phosphate buffered saline at the same age. RESULTS: Vaccinated groups were measured and calculated significantly (p < 0.05) higher in body weight and average daily weight gain on all three farms compared with unvaccinated groups. Vaccinated groups elicited PRRS antibodies and PRRSV-2-specific interferon-γ secreting cells, which reduced the amount of PRRSV-2 genomic copies in the blood and reduced macroscopic and microscopic lung lesions severity when compared with unvaccinated groups. CONCLUSIONS: The field evaluation data demonstrated that a new PRRSV-2 modified live virus vaccine was efficacious in swine herds suffering from respiratory diseases caused by PRRSV-2 infection.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas Atenuadas , Vacunas Virales , Animales , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Porcinos , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/inmunología , Sus scrofa , Distribución AleatoriaRESUMEN
In this study, we investigated how Radix pseudostellariae polysaccharide (RPP) enhances the immune response of the inactivated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine through interactions with the microbiome and metabolome. We pretreated sows with 10 mg/kg body weight of RPP via drinking water for 7 days prior to intramuscular injection of the PRRSV vaccine. This significantly increased the concentrations of PRRSV GP5 protein antibody, interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-γ. Oral administration of RPP also significantly improved the abundance of beneficial bacteria in the stool, such as Parabacteroides distasonis, Prevotella_copri, Eubacterium_sp., and Clostridium_sp._CAG:226, and decreased the levels of potentially pathogenic bacteria, such as Paraeggerthella and [Clostridium] innocuum, compared to the vaccine alone. These bacterial changes were confirmed using quantitative real-time polymerase chain reaction (Q-PCR). Moreover, RPP treatment significantly increased the blood concentrations of L-theanine, taurodeoxycholic acid (TDCA), and N-arachidonoyl proline, and decreased the levels of L-glutamine, oclacitinib, lipoxin C4, and leukotriene C5 in sows after immunization (p< 0.05). The concentrations of various blood metabolites were validated using sandwich enzyme-linked immunosorbent assay (ELISA), confirming the accuracy of the metabolomics data. Intriguingly, the integration of microbiome and metabolome analyses highlighted the significance of Prevotella_copri and TDCA. We consequently developed a mouse immunity model using GP5 protein and discovered that oral administration of RPP significantly enhanced the levels of GP5 protein antibodies, IL-2, IL-4, IL-10, and IFN-γ in mouse serum. It also increased the number of CD3+ and CD3+CD4+ cells in the spleen. Additionally, Prevotella_copri was administered into the large intestine via the anus for 7 days prior to the intramuscular injection of the PRRSV GP5 protein. The results demonstrated a significant increase in TDCA and GP5 antibody concentration in the mouse serum, indicating that RPP modulates Prevotella_copri to elevate its metabolite TDCA, thereby enhancing the GP5 antibody level. In conclusion, oral administration of 10 mg/kg RPP optimizes gut flora diversity and blood metabolites, particularly Prevotella_copri and TDCA, thereby improving the immune response to the inactivated PRRSV vaccine.
Asunto(s)
Metaboloma , Polisacáridos , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas de Productos Inactivados , Vacunas Virales , Animales , Porcinos , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Vacunas Virales/inmunología , Femenino , Vacunas de Productos Inactivados/inmunología , Anticuerpos Antivirales/sangre , Citocinas/metabolismo , Microbiota/efectos de los fármacos , Microbiota/inmunología , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/inmunología , Adyuvantes InmunológicosRESUMEN
BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) is a prevalent swine pathogen, which has caused adverse impact on the global swine industry for almost 30 years. However, due to the immune suppression caused by the virus and the genetic diversity in PRRSV, no virus-targeting broad neutralizing strategy has been successfully developed yet. Antiviral peptide and nanobody have attracted extensive attention with the ease in production and the efficacy in practice. In this study, four new fusion proteins named nanobody peptide conjugates (NPCs) were developed by combining PRRSV specific non-neutralizing nanobodies with CD163-derived peptides targeting the receptor binding domain (RBD) of PRRSV proteins. RESULTS: Four NPCs were successfully constructed using two nanobodies against PRRSV N and nsp9 individually, recombining with two antiviral peptides 4H7 or 8H2 from porcine CD163 respectively. All four NPCs demonstrated specific capability of binding to PRRSV and broad inhibitory effect against various lineages of PRRSV in a dose-dependent manner. NPCs interfere with the binding of the RBD of PRRSV proteins to CD163 in the PRRSV pre-attachment stage by CD163 epitope peptides in the assistance of Nb components. NPCs also suppress viral replication during the stage of post-attachment, and the inhibitory effects depend on the antiviral functions of Nb parts in NPCs, including the interference in long viral RNA synthesis, NF-κB and IFN-ß activation. Moreover, an interaction was predicted between aa K31 and T32 sites of neutralizing domain 4H7 of NPC-N/nsp9-4H7 and the motif 171NLRLTG176 of PRRSV GP2a. The motif 28SSS30 of neutralizing domain 8H2 of NPC-N/nsp9-8H2 could also form hydrogens to bind with the motif 152NAFLP156 of PRRSV GP3. The study provides valuable insights into the structural characteristics and potential functional implications of the RBD of PRRSV proteins. Finally, as indicated in a mouse model, NPC intranasally inoculated in vivo for 12-24 h sustains the significant neutralizing activity against PRRSV. These findings inspire the potential of NPC as a preventive measure to reduce the transmission risk in the host population against respiratory infectious agents like PRRSV. CONCLUSION: The aim of the current study was to develop a peptide based bioactive compound to neutralize various PRRSV strains. The new antiviral NPC (nanobody peptide conjugate) consists of a specific nanobody targeting the viral protein and a neutralizing CD163 epitope peptide for virus blocking and provides significant antiviral activity. The study will greatly promote the antiviral drug R&D against PRRSV and enlighten a new strategy against other viral diseases.
Asunto(s)
Anticuerpos Neutralizantes , Antígenos CD , Antígenos de Diferenciación Mielomonocítica , Péptidos , Virus del Síndrome Respiratorio y Reproductivo Porcino , Receptores de Superficie Celular , Anticuerpos de Dominio Único , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Virus del Síndrome Respiratorio y Reproductivo Porcino/efectos de los fármacos , Animales , Anticuerpos de Dominio Único/inmunología , Anticuerpos de Dominio Único/farmacología , Anticuerpos de Dominio Único/química , Porcinos , Antígenos de Diferenciación Mielomonocítica/inmunología , Antígenos de Diferenciación Mielomonocítica/metabolismo , Receptores de Superficie Celular/inmunología , Antígenos CD/inmunología , Antígenos CD/metabolismo , Anticuerpos Neutralizantes/inmunología , Péptidos/química , Péptidos/farmacología , Péptidos/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Ratones , Replicación Viral/efectos de los fármacos , Línea CelularRESUMEN
Acute phase protein (APP) response to vaccine challenges is an attractive alternative to natural infection for identifying pigs with increased disease resilience and monitoring the productive performance. Currently, the methods used for APP quantification are diverse and often based on techniques that use antibodies that are not necessarily pig specific. The objective of this work is the development of a method based on a UPLC-SRM/MS system for simultaneous determination of haptoglobin, apolipoprotein A1, C-reactive protein, pig-major acute protein, and serum amyloid A and its application in pigs to monitor the effect of a vaccine administered against porcine reproductive and respiratory syndrome virus (PRRSV). With the aim of tracing the complete analytical process for each proteotypic peptide, a synthetic QconCat polypeptide construct was designed. It was possible to develop an SRM method including haptoglobin, apolipoprotein A1, pig-MAP, and serum amyloid A1. The PRRSV vaccine only affected haptoglobin. The pigs with positive viremia tended to show higher values than negative pigs, reaching significant differences in the three haptoglobin SRM-detected peptides but not with the data acquired by immunoenzymatic and spectrophotometric assays. These results open the door to the use of SRM to accurately monitor APP changes in experimental pigs.
Asunto(s)
Proteínas de Fase Aguda , Haptoglobinas , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Proteína Amiloide A Sérica , Vacunas Virales , Animales , Porcinos , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Síndrome Respiratorio y de la Reproducción Porcina/inmunología , Proteínas de Fase Aguda/análisis , Proteínas de Fase Aguda/inmunología , Proteínas de Fase Aguda/metabolismo , Haptoglobinas/análisis , Vacunas Virales/inmunología , Proteína Amiloide A Sérica/análisis , Apolipoproteína A-I/inmunología , Apolipoproteína A-I/análisis , Proteína C-Reactiva/análisis , Proteína C-Reactiva/inmunología , Vacunación , Espectrometría de Masas/métodos , Viremia/prevención & control , Viremia/inmunologíaRESUMEN
Porcine reproductive and respiratory syndrome virus (PRRSV) presents a significant threat to the global swine industry. The development of highly effective subunit nanovaccines is a promising strategy for preventing PRRSV variant infections. In this study, two different types of ferritin (Ft) nanovaccines targeting the major glycoprotein GP5, named GP5m-Ft and (Bp-IVp)3-Ft, were constructed and evaluated as vaccine candidates for PRRSV. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) demonstrated that both purified GP5m-Ft and (Bp-IVp)3-Ft proteins could self-assemble into nanospheres. A comparison of the immunogenicity of GP5m-Ft and (Bp-IVp)3-Ft with an inactivated PRRSV vaccine in BALB/c mice revealed that mice immunized with GP5m-Ft exhibited the highest ELISA antibody levels, neutralizing antibody titers, the lymphocyte proliferation index, and IFN-γ levels. Furthermore, vaccination with the GP5m-Ft nanoparticle effectively protected piglets against a highly pathogenic PRRSV challenge. These findings suggest that GP5m-Ft is a promising vaccine candidate for controlling PRRS.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Ferritinas , Ratones Endogámicos BALB C , Nanopartículas , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Proteínas del Envoltorio Viral , Vacunas Virales , Animales , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Ferritinas/inmunología , Porcinos , Ratones , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Nanopartículas/química , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Síndrome Respiratorio y de la Reproducción Porcina/inmunología , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Proteínas del Envoltorio Viral/inmunología , Proteínas del Envoltorio Viral/genética , Femenino , Interferón gamma/metabolismo , NanovacunasRESUMEN
OBJECTIVE: Porcine interferon-γ (poIFN-γ) and porcine granulocyte-macrophage colony-stimulating factor (poGM-CSF) are multifunctional cytokines that exhibit robust antiviral activity against porcine reproductive and respiratory syndrome virus (PRRSV). In this study, the immunoadjuvant effects of recombinant poIFN-γ-poGM-CSF fusion protein in inactivated PRRSV vaccine administered to piglets were assessed. ANIMALS: Twenty-eight 4-week-old specific pathogen-free piglets. METHODS: The experimental piglets were divided into control, highly pathologic PRRSV, PRRSV killed virus vaccine (KV), poIFN-γ-poGM-CSF, KV + 1.0 mg poIFN-γ-poGM-CSF, KV + 2.0 mg poIFN-γ-poGM-CSF, and KV + 4.0 mg poIFN-γ-poGM-CSF groups. A recombinant poIFN-γ-linker-poGM-CSF fusion gene was constructed via splicing by overlap extension PCR and prepared using an Escherichia coli expression system, after which its adjuvant activity in the context of PRRSV KV administration was assessed. RESULTS: This analysis revealed the successful construction of the poIFN-γ-linker-poGM-CSF fusion gene via splicing by overlap extension PCR, with recombinant poIFN-γ-linker-poGM-CSF successfully being prepared in E coli with a plasmid vector for expressing thioredoxin fusion proteins with an enterokinase site. Importantly, the coadministration of poIFN-γ-linker-poGM-CSF and PRRSV KV significantly increased neutralizing antibody titers, accelerated viral clearance, reduced clinical symptoms, and prevented highly pathogenic PRRSV infection. CLINICAL RELEVANCE: The recombinant poIFN-γ-poGM-CSF fusion protein is a promising candidate adjuvant for use in the context of swine immunization and viral challenge.
Asunto(s)
Factor Estimulante de Colonias de Granulocitos y Macrófagos , Interferón gamma , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas de Productos Inactivados , Vacunas Virales , Animales , Porcinos , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Síndrome Respiratorio y de la Reproducción Porcina/inmunología , Vacunas Virales/inmunología , Vacunas de Productos Inactivados/inmunología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Adyuvantes Inmunológicos/farmacología , Organismos Libres de Patógenos EspecíficosRESUMEN
PRRS is a viral disease that profoundly impacts the global swine industry, causing significant economic losses. The development of a novel and effective vaccine is crucial to halt the rapid transmission of this virus. There have been several vaccination attempts against PRRSV using both traditional and alternative vaccine design development approaches. Unfortunately, there is no currently available vaccine that can completely control this disease. Thus, our study aimed to develop an mRNA vaccine using the antigens expressed by single or fused PRRSV structural proteins. In this study, the nucleotide sequence of the immunogenic mRNA was determined by considering the antigenicity of structural proteins and the stability of spatial structure. Purified GP5 protein served as the detection antigen in the immunological evaluation. Furthermore, cellular mRNA expression was detected by immunofluorescence and western blotting. In a mice experiment, the Ab titer in serum and the activation of spleen lymphocytes triggered by the antigen were detected by ELISA and ICS, respectively. Our findings demonstrated that both mRNA vaccines can significantly stimulate cellular and humoral immune responses. More specifically, the GP5-mRNA exhibited an immunological response that was similar to that of the commercially available vaccine when administered in high doses. To conclude, our vaccine may show promising results against the wild-type virus in a natural host.
Asunto(s)
Anticuerpos Antivirales , Inmunidad Celular , Inmunidad Humoral , Ratones Endogámicos BALB C , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Proteínas del Envoltorio Viral , Vacunas Virales , Vacunas de ARNm , Animales , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Ratones , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Síndrome Respiratorio y de la Reproducción Porcina/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Vacunas Virales/genética , Porcinos , Femenino , Proteínas Estructurales Virales/inmunología , Proteínas Estructurales Virales/genética , ARN Mensajero/genéticaRESUMEN
BACKGROUND: At present, porcine reproductive and respiratory syndrome (PRRS) caused by the PRRS virus (PRRSV) is one of the most severe epidemics impacting pig farming globally. Despite the fact that a number of studies have been conducted on potential solutions to this problem, none have proven effective. The focus of problem solving is the use of natural ingredients such as plant extracts. Popular throughout Asia, Caesalpinia sappan (CS) is a therapeutic plant that inhibits PRRSV in vitro. Therefore, this study was performed to determine the efficacy of CS extract dietary supplementation on the productive performance, antibody levels, immunological indicators, and lung pathology of PRRSV-challenged weaned pigs. A total of 32 weaned piglets (28 days old) were randomized into 4 groups and kept separately for 14 days. The treatments were organized in a 2 × 2 factorial design involving two factors: PRRSV challenge and supplementation with 1 mg/kg CS extract. The pigs in the PRRSV-challenged groups were intranasally inoculated with 2 mL of PRRSV (VR2332) containing 104 TCID50/mL, while those in the groups not challenged with PRRSV were inoculated with 2 mL of normal saline. RESULTS: In the PRRSV-challenged group (CS + PRRSV), supplementation with CS extract led to an increase in white blood cells (WBCs) on Day 7 post infection (p < 0.05) and particularly in lymphocytes on Days 7 and 14. The antibody titer was significantly greater in the CS + PRRSV group than in the PRRSV-challenged group not administered CS (PRRSV group) on Day 14 postinfection (S/P = 1.19 vs. 0.78). In addition, CS extract administration decreased the prevalence of pulmonary lesions, which were more prevalent in the PRRSV-challenged pigs that did not receive the CS extract. CONCLUSION: The findings of this study suggest that supplementation with CS extract is beneficial for increasing WBC counts, especially lymphocytes, increasing the levels of antibodies and reducing the prevalence of lung lesions in PRRSV-infected pigs.
Asunto(s)
Caesalpinia , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Vacunas Virales , Animales , Anticuerpos Antivirales , Suplementos Dietéticos , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Síndrome Respiratorio y de la Reproducción Porcina/tratamiento farmacológico , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Porcinos , Enfermedades de los Porcinos/tratamiento farmacológico , Enfermedades de los Porcinos/prevención & controlRESUMEN
Georgina Mills reports on a bid from a UK-based company to have pigs that are bred to be resistant to porcine reproductive and respiratory syndrome approved for sale in the USA.
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Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Porcinos , Animales , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Supermercados , Enfermedades de los Porcinos/prevención & controlRESUMEN
Porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant threat to the global pork industry, resulting in substantial economic losses. Current control measures rely on modified live virus (MLV) vaccines with safety concerns. However, the lack of consensus on protective PRRSV antigens is impeding the development of effective and safety subunit vaccines. In this study, we conducted in vitro virus neutralization (VN) assays in MARC-145 and CRL-2843CD163/CD169 cell lines and primary porcine alveolar macrophages (PAMs) to systemically identify PRRSV structural proteins (SPs) recognized by virus-neutralizing antibodies in hyperimmune serum collected from piglets infected with highly pathogenic PRRSV (HP-PRRSV). Additionally, piglets immunized with different combinations of recombinant PRRSV-SPs were challenged with HP-PRRSV to evaluate their in vivo protection potential. Intriguingly, different in vitro VN activities of serum antibodies elicited by each PRRSV SP were observed depending on the cell type used in the VN assay. Notably, antibodies specific for GP3, GP4, and M exhibited highest in vitro VN activities in PAMs, correlating with complete protection (100% survival) against HP-PRRSV challenge in vivo after immunization of piglets with combination of GP3, GP4, M and N (GP3/GP4/M/N). Further analysis of lung pathology, weight gain, and viremia post-challenge revealed that the combination of GP3/GP4/M/N provided superior protective efficacy against severe infection. These findings underscore the potential of this SP combination to serve as an effective PRRSV subunit vaccine, marking a significant advancement in pork industry disease management.
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Guanidinas , Piperazinas , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Vacunas Virales , Animales , Porcinos , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Macrófagos Alveolares , Anticuerpos AntiviralesRESUMEN
Porcine reproductive and respiratory syndrome virus is one of the main pathogens threatening the global pig industry, and there is still a lack of effective therapeutic drugs. Sanggenon C is a flavanone Diels-Alder adduct compound extracted from the root bark of the mulberry genus, which has blood pressure-reducing, anti-atherosclerotic, anti-oxidative, and anti-inflammatory effects. In our previous study, Sanggenon C was confirmed to significantly inhibit PRRSV replication in vitro. However, its antiviral potential to inhibit PRRSV infection in vivo has not been evaluated in piglets. Here, the antiviral effect of Sanggenon C was evaluated in PRRSV-challenged piglets based on assessments of rectal temperature, viral load, pathological changes of lung tissue and secretion of inflammatory cytokines. The results showed that Sanggenon C treatment relieved the clinical symptoms, reduced the viral loads in the lungs and bloods, alleviated the pathological damage of lung tissue, decreased the secretion of inflammatory cytokines, and shorten the excretion time of virus from the oral and nasal secretions and feces of piglets after PRRSV infection. The results indicated that Sanggenon C is a promising anti-PRRSV drug, which provides a new strategy for the prevention and control of PRRS in clinical practice.
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Benzofuranos , Cromonas , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Animales , Porcinos , Síndrome Respiratorio y de la Reproducción Porcina/tratamiento farmacológico , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Citocinas , Antivirales/farmacología , Antivirales/uso terapéutico , Replicación Viral , Enfermedades de los Porcinos/patologíaRESUMEN
OBJECTIVE: Porcine reproductive and respiratory syndrome (PRRS) is a significant disease of swine. The purpose of this study was to determine whether application of a comprehensive, science-based approach to breeding herd biosecurity, known as next-generation biosecurity (NGB), could reduce PRRS incidence risk across a large commercial production company. ANIMALS: Pigs (381,404 sows across 76 breeding herds). METHODS: From 2009 to 2020, the annual incidence risk of PRRS in sow farms managed by the same company averaged 33%, ranging from 20% to 50%. To measure the effect of NGB on PRRS incidence risk, a retrospective cohort study was conducted from July 1, 2021, to June 30, 2023, across breeding herds managed by the same company. During the analysis, 2 groups of herds emerged: those that implemented protocols for all phases of NGB (NGB COMPLETE), and those that implemented all described protocols of biosecurity except for air filtration (NGB INCOMPLETE). RESULTS: During the 2-year assessment period, 56 breeding herds were classified as NGB COMPLETE, while 20 herds were NGB INCOMPLETE. The PRRS incidence risk in NGB COMPLETE herds was 8.9% as compared to 40.0% in NGB INCOMPLETE herds. From disease year 1 (July 1, 2021, to June 30, 2022) and disease year 2 (July 1, 2022, to June 30, 2023), system-wide PRRS incidence risk was 8.6% and 9.2%, respectively. The association between NGB status and PRRS incidence risk for the 2-year period was statistically significant at a P value of .006. CLINICAL RELEVANCE: Results of the present report provided evidence that improvements in biosecurity result in lower PRRS incidence risk under large-scale commercial swine production conditions.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Humanos , Porcinos , Animales , Femenino , Síndrome Respiratorio y de la Reproducción Porcina/epidemiología , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Estudios Retrospectivos , Incidencia , Bioaseguramiento , Medio Oeste de Estados Unidos/epidemiología , CruzamientoRESUMEN
BACKGROUND: Porcine reproductive and respiratory syndrome (PRRS) is a viral disease with worldwide distribution and an enormous economic impact. To control PRRS virus (PRRSV) infection, modified live vaccines (MLVs) are widely used in the field, mainly administered via an intramuscular (IM) route. Currently, some MLVs are authorized for intradermal (ID) administration, which has many practical and welfare advantages. The objectives of the study were to compare the immune responses (systemic in blood and mucosal in lungs) and vaccine efficacy in preventing challenge strain transmission after IM or needle-free ID immunization of piglets with an MLV against PRRSV-1 (MLV1). METHODS: Groups of sixteen 5-week-old specific pathogen-free piglets were vaccinated with Porcilis PRRS® (MSD) either by an IM (V+ IM) or ID route (V+ ID) using an IDAL®3G device or kept unvaccinated (V-). Four weeks after vaccination, in each group, 8 out of the 16 piglets were challenged intranasally with a PRRSV-1 field strain, and one day later, the inoculated pigs were mingled by direct contact with the remaining 8 sentinel noninoculated pigs to evaluate PRRSV transmission. Thus, after the challenge, each group (V+ IM, V+ ID or V-) included 8 inoculated and 8 contact piglets. During the postvaccination and postchallenge phases, PRRSV replication (RT-PCR), PRRSV-specific antibodies (ELISA IgG and IgA, virus neutralization tests) and cell-mediated immunity (ELISPOT Interferon gamma) were monitored in blood and bronchoalveolar lavages (BALs). RESULTS: Postvaccination, vaccine viremia was lower in V+ ID pigs than in V+ IM pigs, whereas the cell-mediated immune response was detected earlier in the V+ ID group at 2 weeks postvaccination. In the BAL fluid, a very low mucosal immune response (humoral and cellular) was detected. Postchallenge, the vaccine efficacy was similar in inoculated animals with partial control of PRRSV viremia in V+ ID and V+ IM animals. In vaccinated sentinel pigs, vaccination drastically reduced PRRSV transmission with similar estimated transmission rates and latency durations for the V+ IM and V+ ID groups. CONCLUSIONS: Our results show that the tested MLV1 induced a faster cell-mediated immune response after ID immunization two weeks after vaccination but was equally efficacious after IM or ID immunization towards a challenge four weeks later. Considering the practical and welfare benefits of ID vaccination, these data further support the use of this route for PRRS MLVs.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Vacunas Virales , Porcinos , Animales , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Viremia/veterinaria , Inmunidad Mucosa , Anticuerpos Antivirales , Vacunación/veterinaria , Vacunación/métodos , Vacunas AtenuadasRESUMEN
Normalization, the process of controlling for normal variation in sampling and testing, can be achieved in real-time PCR assays by converting sample quantification cycles (Cqs) to "efficiency standardized Cqs" (ECqs). We calculated ECqs as E-ΔCq, where E is amplification efficiency and ΔCq is the difference between sample and reference standard Cqs. To apply this approach to a commercial porcine reproductive and respiratory syndrome virus (PRRSV) RT-qPCR assay, we created reference standards by rehydrating and then diluting (1 × 10-4) a PRRSV modified-live vaccine (PRRS MLV; Ingelvac) with serum or oral fluid (OF) to match the sample matrix to be tested. Sample ECqs were calculated using the mean E and reference standard Cq calculated from the 4 reference standards on each plate. Serum (n = 132) and OF (n = 130) samples were collected from each of 12 pigs vaccinated with a PRRSV MLV from -7 to 42 d post-vaccination, tested, and sample Cqs converted to ECqs. Mean plate Es were 1.75-2.6 for serum and 1.7-2.3 for OF. Mean plate reference standard Cqs were 29.1-31.3 for serum and 29.2-31.5 for OFs. Receiver operating characteristic analysis calculated the area under the curve for serum and OF sample ECqs as 0.999 (95% CI: 0.997, 1.000) and 0.947 (0.890, 1.000), respectively. For serum, diagnostic sensitivity and specificity of the commercial PRRSV RT-qPCR assay were estimated as 97.9% and 100% at an ECq cutoff ≥ 0.20, and for OF, 82.6% and 100%, respectively, at an ECq cutoff ≥ 0.45.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Vacunas Virales , Porcinos , Animales , Síndrome Respiratorio y de la Reproducción Porcina/diagnóstico , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Anticuerpos Antivirales , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Vacunas Atenuadas , Enfermedades de los Porcinos/diagnósticoRESUMEN
Porcine reproductive and respiratory syndrome (PRRS) is a serious infectious disease and one of the major causes of death in the global pig industry. PRRS virus (PRRSV) strains have complex and diverse genetic characteristics and cross-protection between strains is low, which complicates vaccine selection; thus, the current vaccination strategy has been greatly compromised. Therefore, it is necessary to identify effective natural compounds for the clinical treatment of PRRS. A small molecule library composed of 720 natural compounds was screened in vitro, and we found that Sanggenon C (SC) was amongst the most effective natural compound inhibitors of PRRSV infection. Compared with ribavirin, SC more significantly inhibited PRRSV infection at both the gene and protein levels and reduced the viral titres and levels of protein expression and inflammatory cytokine secretion to more effectively protect cells from PRRSV infection and damage. Mechanistically, SC inhibits activation of the NF-κB signalling pathway by promoting TRAF2 expression, thereby reducing PRRSV replication. In conclusion, by screening natural compounds, we found that SC suppresses PRRSV infection by regulating the TRAF2/NF-κB signalling pathway. This study contributes to a deeper understanding of the therapeutic targets and pathogenesis of PRRSV infection. More importantly, our results demonstrate that SC has potential as a candidate for the treatment of PRRS.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Porcinos , Animales , FN-kappa B/metabolismo , Virus del Síndrome Respiratorio y Reproductivo Porcino/metabolismo , Síndrome Respiratorio y de la Reproducción Porcina/tratamiento farmacológico , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Factor 2 Asociado a Receptor de TNF/metabolismo , Línea Celular , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
In order to understand the prevalence and evolution of porcine reproductive and respiratory syndrome virus (PRRSV) in China and to develop subunit vaccine against the epidemic lineage, the genetic evolution analysis of PRRSV strains isolated in China from 2001 to 2021 was performed. The representative strains of the dominant epidemic lineage were selected to optimize the membrane protein GP5 and M nucleotide sequences, which were used, with the interferon and the Fc region of immunoglobulin, to construct the eukaryotic expression plasmids pCDNA3.4-IFNα-GP5-Fc and pCDNA3.4-IFNα-M-Fc. Subsequently, the recombinant proteins IFNα-GP5-Fc and IFNα-M-Fc were expressed by HEK293T eukaryotic expression system. The two recombinant proteins were mixed with ISA206VG adjuvant to immunize weaned piglets. The humoral immunity level was evaluated by ELISA and neutralization test, and the cellular immunity level was detected by ELISPOT test. The results showed that the NADC30-like lineage was the main epidemic lineage in China in recent years, and the combination of IFNα-GP5-Fc and IFNα-M-Fc could induce high levels of antibody and cellular immunity in piglets. This study may facilitate the preparation of a safer and more effective new PRRSV subunit vaccine.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas Virales , Humanos , Animales , Porcinos , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Células HEK293 , Proteínas del Envoltorio Viral/genética , Anticuerpos Antivirales , Vacunas Virales/genética , Proteínas Recombinantes , Vacunas de SubunidadRESUMEN
In this study, we developed and validated (1) singleplex real-time RT-PCR assays for specific detection of five PRRSV-2 MLV vaccine viruses (Ingelvac MLV, Ingelvac ATP, Fostera, Prime Pac, and Prevacent) and (2) a four-plex real-time RT-PCR assay (IngelvacMLV/Fostera/Prevacent/XIPC) including the internal positive control XIPC for detecting and distinguishing the three most commonly used vaccines in the USA (Prevacent, Ingelvac MLV, and Fostera). The singleplex and 4-plex vaccine-like PCRs and the reference PCR (VetMAXTM PRRSV NA&EU, Thermo Fisher Scientific, Waltham, MA, USA) did not cross-react with non-PRRSV swine viral and bacterial pathogens. The limits of detection of vaccine-like PCRs ranged from 25 to 50 genomic copies/reactions. The vaccine-like PCRs all had excellent intra-assay and inter-assay repeatability. Based on the testing of 531 clinical samples and in comparison to the reference PCR, the diagnostic sensitivity, specificity, and agreement were in the respective range of 94.67-100%, 100%, and 97.78-100% for singleplex PCRs and 94.94-100%, 100%, and 97.78-100% for the 4-plex PCR, with a CT cutoff of 37. In addition, 45 PRRSV-2 isolates representing different genetic lineages/sublineages were tested with the vaccine-like PCRs and the results were verified with sequencing. In summary, the vaccine-like PCRs specifically detect the respective vaccine-like viruses with comparable performances to the reference PCR, and the 4-plex PCR allows to simultaneously detect and differentiate the three most commonly used vaccine viruses in the same sample. PRRSV-2 vaccine-like PCRs provide an additional tool for detecting and characterizing PRRSV-2.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas Virales , Porcinos , Animales , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Síndrome Respiratorio y de la Reproducción Porcina/diagnóstico , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Reacción en Cadena en Tiempo Real de la Polimerasa , Vacunas Virales/genéticaRESUMEN
As an epizootic causative agent, the Getah virus (GETV) can cause moderate illness in horses, lethal disease in foxes, and reproductive disorders and fetal death in pigs. Due to the wide range of hosts and multiple routes of transmission, GETV has become a growing potential threat to the global livestock industry, and even to public health. More attention and research on GETV are urgently needed. In this study, we successfully isolated a novel GETV strain, named BJ0304, from a commercial live vaccine against porcine reproductive and respiratory syndrome virus (PRRSV) and determined its growth kinetics. Then, genetic and phylogenetic analyses were performed. The results revealed that BJ0304 was clustered into Group III, and it was most related to the GETV-V1 strain based on the complete genome sequence. Furthermore, the pathogenicity of the isolate was assessed and found to be a low virulent strain in mice relative to its closest homolog GETV-V1. Finally, mutation and glycosylation analysis showed that a unique mutation (171 T > I) at one amino acid of E2, which affected the glycosylation of E2, may be associated with viral pathogenicity. In summary, the general characteristic of a novel Group III-classified GETV-BJ0304 isolated from commercial live PRRSV vaccine was defined and then mutation/glycosylation-related potential virulence factor was discussed. This study highlights the complexity of GETV transmission routes in swine and the need for more surveillance on commercial animal vaccines, contributes to the understanding of genetic characterization of clinical isolates, provides possible virulence factors in favor of unveiling the viral pathogenesis, and eventually lays the foundation for the prevention and control of GETV.
Asunto(s)
Alphavirus , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas , Animales , Porcinos , Caballos , Ratones , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Alphavirus/genética , Filogenia , Síndrome Respiratorio y de la Reproducción Porcina/prevención & controlRESUMEN
BACKGROUND: Vertical transmission is key for the maintenance of porcine reproductive and respiratory syndrome virus (PRRSV) infection. In vaccinated farms, vertical transmission can still occur despite sows having some level of immunity because of repeated vaccination or contact with the wild-type virus. The present study aimed to correlate the age of sows and the amplitude of neutralizing antibodies (Nab) (heterologous neutralization) with PRRSV-1 vertical transmission (VT). For this purpose, umbilical cords of 1,554 newborns (corresponding to 250 litters) were tested for PRRSV by RT-PCR in two PRRSV-unstable vaccinated farms. In parallel, the sows were bled after farrowing and the levels of antibodies were determined by ELISA and by the viral neutralization test against the vaccine virus, the virus circulating in the farm, and other unrelated contemporary PRRSV-1 strains. The relationship between the parity and the probability of delivering infected piglets and the presence of broadly Nabs examined. RESULTS: The proportion of VT events in the two examined farms ranged from 18.9% to 23.0%. Young sows (parity 1-2) were 1.7 times more likely to have VT than older sows (p < 0.05). Despite higher ELISA S/P antibody ratios in younger sows (p < 0.05), NAb against the resident farm strain were at a similar level between sows delivering infected and healthy piglets regardless of age, mostly with low titers (2-3 log2). The titers of NAb against the vaccine virus were also low, and no correlations with VT were observed. When a panel of another 4 strains (1 isolated in the 1990s, and 3 contemporary strains) were used for the neutralization test, most sow sera were not capable of neutralizing the contemporary strains. CONCLUSIONS: Titers of NAb could not be correlated with the occurrence of PRRSV VT. The amplitude of NAb present in most vaccinated sows is limited with a considerable proportion unresponsive regarding NAb production.