Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.085
Filtrar
1.
Emerg Microbes Infect ; 9(1): 2278-2288, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33003988

RESUMO

The emergence of SARS-CoV-2 has resulted in an ongoing global pandemic with significant morbidity, mortality, and economic consequences. The susceptibility of different animal species to SARS-CoV-2 is of concern due to the potential for interspecies transmission, and the requirement for pre-clinical animal models to develop effective countermeasures. In the current study, we determined the ability of SARS-CoV-2 to (i) replicate in porcine cell lines, (ii) establish infection in domestic pigs via experimental oral/intranasal/intratracheal inoculation, and (iii) transmit to co-housed naïve sentinel pigs. SARS-CoV-2 was able to replicate in two different porcine cell lines with cytopathic effects. Interestingly, none of the SARS-CoV-2-inoculated pigs showed evidence of clinical signs, viral replication or SARS-CoV-2-specific antibody responses. Moreover, none of the sentinel pigs displayed markers of SARS-CoV-2 infection. These data indicate that although different porcine cell lines are permissive to SARS-CoV-2, five-week old pigs are not susceptible to infection via oral/intranasal/intratracheal challenge. Pigs are therefore unlikely to be significant carriers of SARS-CoV-2 and are not a suitable pre-clinical animal model to study SARS-CoV-2 pathogenesis or efficacy of respective vaccines or therapeutics.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/veterinária , Pandemias/veterinária , Pneumonia Viral/veterinária , Doenças dos Suínos/virologia , Animais , Betacoronavirus/genética , Betacoronavirus/imunologia , Linhagem Celular , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/transmissão , Modelos Animais de Doenças , Reservatórios de Doenças , Suscetibilidade a Doenças , Feminino , Masculino , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Pneumonia Viral/transmissão , RNA Viral/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/patologia , Doenças dos Suínos/transmissão , Cultura de Vírus , Replicação Viral , Sequenciamento Completo do Exoma
2.
J Vet Sci ; 21(5): e74, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016020

RESUMO

BACKGROUND: The quality of a vaccine depends strongly on the effects of the adjuvants applied simultaneously with the antigen in the vaccine. The adjuvants enhance the protective effect of the vaccine against a viral challenge. Conversely, oil-type adjuvants leave oil residue inside the bodies of the injected animals that can produce a local reaction in the muscle. The long-term immunogenicity of mice after vaccination was examined. ISA206 or ISA15 oil adjuvants maintained the best immunity, protective capability, and safety among the oil adjuvants in the experimental group. OBJECTIVES: This study screened the adjuvant composites aimed at enhancing foot-and-mouth disease (FMD) immunity. The C-type lectin or toll-like receptor (TLR) agonist showed the most improved protection rate. METHODS: Experimental vaccines were fabricated by mixing various known oil adjuvants and composites that can act as immunogenic adjuvants (gel, saponin, and other components) and examined the enhancement effect on the vaccine. RESULTS: The water in oil (W/O) and water in oil in water (W/O/W) adjuvants showed better immune effects than the oil in water (O/W) adjuvants, which have a small volume of oil component. The W/O type left the largest amount of oil residue, followed by W/O/W and O/W types. In the mouse model, intramuscular inoculation showed a better protection rate than subcutaneous inoculation. Moreover, the protective effect was particularly weak in the case of inoculation in fatty tissue. The initial immune reaction and persistence of long-term immunity were also confirmed in an immune reaction on pigs. CONCLUSIONS: The new experimental vaccine with immunostimulants produces improved immune responses and safety in pigs than general oil-adjuvanted vaccines.


Assuntos
Adjuvantes Imunológicos/farmacologia , Vírus da Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Vacinas Virais/farmacologia , Animais , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Febre Aftosa/imunologia , Febre Aftosa/virologia , Camundongos , Camundongos Endogâmicos C57BL , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas Virais/imunologia
3.
Exp Parasitol ; 218: 107997, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32946882

RESUMO

Toxocara cati is one of the causative agents of human toxocariasis. Serological methods are used for diagnosis in paratenic hosts like humans but the humoral immune response triggered by this parasite is unknown. We characterized the humoral immune response to T. cati excretory-secretory antigens (TES) in pigs as animal model during the acute and chronic stages of infection. ELISA and Western Blot techniques were used to determine antibody response. Pigs were experimentally inoculated with 100,000 infective Toxocara cati eggs. Blood was collected at 7, 14, 21 and 28 days post-inoculation (d.p.i.) to assess the acute stage of infection and 90, 120 and 180 d. p.i. for chronic stage analysis. ELISA showed values higher than the cut-off of specific IgM and IgG at 7 d. p.i. with significant differences at 0 and 7 d. p.i. for IgM and at 14, 21 and 28 d. p.i. for IgG in the acute stage. Higher and stable levels were detected in the chronic stage. Western Blot showed bands from 102 to 38 kDa detected by specific IgM and IgG. More immunogenic bands were identified by specific IgG. In the chronic stage of infection a band near 31 kDa was the only band detected by IgM until 150 d. p.i. Specific IgG recognized bands between 102 and 31 kDa. This study demonstrates how the humoral immune response evolves in the acute and chronic stages of infection and provides evidence on the role of the pig as a paratenic host of T. cati.


Assuntos
Anticorpos Anti-Helmínticos/biossíntese , Imunidade Humoral , Doenças dos Suínos/imunologia , Toxocara/imunologia , Toxocaríase/imunologia , Análise de Variância , Animais , Anticorpos Anti-Helmínticos/sangue , Área Sob a Curva , Western Blotting , Gatos , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Imunoglobulina G/biossíntese , Imunoglobulina G/sangue , Imunoglobulina M/biossíntese , Imunoglobulina M/sangue , Masculino , Curva ROC , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/parasitologia , Toxocaríase/parasitologia
4.
PLoS Negl Trop Dis ; 14(9): e0008601, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32886659

RESUMO

Scabies is a neglected tropical disease of global significance. Our understanding of host-parasite interactions has been limited, particularly in crusted scabies (CS), a severe clinical manifestation involving hyper-infestation of Sarcoptes scabiei mites. Susceptibility to CS may be associated with immunosuppressive conditions but CS has also been seen in cases with no identifiable risk factor or immune deficit. Due to ethical and logistical difficulties with undertaking research on clinical patients with CS, we adopted a porcine model which parallels human clinical manifestations. Transcriptomic analysis using microarrays was used to explore scabies pathogenesis, and to identify early events differentiating pigs with ordinary (OS) and crusted scabies. Pigs with OS (n = 4), CS (n = 4) and non-infested controls (n = 4) were compared at pre-infestation, weeks 1, 2, 4 and 8 post-infestation. In CS relative to OS, there were numerous differentially expressed genes including pro-inflammatory cytokines (IL17A, IL8, IL19, IL20 and OSM) and chemokines involved in immune cell activation and recruitment (CCL20, CCL27 and CXCL6). The influence of genes associated with immune regulation (CD274/PD-L1 and IL27), immune signalling (TLR2, TLR8) and antigen presentation (RFX5, HLA-5 and HLA-DOB) were highlighted in the early host response to CS. We observed similarities with gene expression profiles associated with psoriasis and atopic dermatitis and confirmed previous observations of Th2/17 pronounced responses in CS. This is the first comprehensive study describing transcriptional changes associated with the development of CS and significantly, the distinction between OS and CS. This provides a basis for clinical follow-up studies, potentially identifying new control strategies for this severely debilitating disease.


Assuntos
Interações Hospedeiro-Parasita/imunologia , Sarcoptes scabiei/imunologia , Escabiose/veterinária , Sus scrofa/imunologia , Sus scrofa/parasitologia , Animais , Citocinas/genética , Citocinas/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Imunomodulação/imunologia , Escabiose/imunologia , Escabiose/patologia , Pele/imunologia , Pele/parasitologia , Pele/patologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/parasitologia , Células Th17/imunologia , Células Th2/imunologia , Transcriptoma/genética
5.
Vet Microbiol ; 247: 108785, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32768229

RESUMO

Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes watery diarrhea, vomiting and mortality in nursing piglets. Type III interferons (IFN-λs) are the major antiviral cytokines in intestinal epithelial cells, the target cells in vivo for PDCoV. In this study, we found that PDCoV infection remarkably inhibited Sendai virus-induced IFN-λ1 production by suppressing transcription factors IRF and NF-κB in IPI-2I cells, a line of porcine intestinal mucosal epithelial cells. We also confirmed that PDCoV infection impeded the activation of IFN-λ1 promoter stimulated by RIG-I, MDA5 and MAVS, but not by TBK1 and IRF1. Although the expression levels of IRF1 and MAVS were not changed, PDCoV infection resulted in reduction of the number of peroxisomes, the platform for MAVS to activate IRF1, and subsequent type III IFN production. Taken together, our study demonstrates that PDCoV suppresses type III IFN responses to circumvent the host's antiviral immunity.


Assuntos
Infecções por Coronavirus/veterinária , Células Epiteliais/imunologia , Células Epiteliais/virologia , Interações Hospedeiro-Patógeno/imunologia , Interferons/antagonistas & inibidores , Animais , Linhagem Celular , Coronavirus , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Fator Regulador 1 de Interferon/antagonistas & inibidores , Fator Regulador 1 de Interferon/imunologia , Interferons/imunologia , Intestinos/citologia , Intestinos/virologia , Rim/citologia , Rim/virologia , NF-kappa B/antagonistas & inibidores , NF-kappa B/imunologia , Vírus Sendai/imunologia , Transdução de Sinais/imunologia , Suínos/virologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia
6.
Arch Virol ; 165(10): 2301-2309, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757056

RESUMO

Porcine circovirus type 2 (PCV2) is a major pathogen associated with swine diseases. It is the smallest single-stranded DNA virus, and its genome contains four major open reading frames (ORFs). ORF2 encodes the major structural protein Cap, which can self-assemble into virus-like particles (VLPs) in vitro and contains the primary antigenic determinants. In this study, we developed a high-efficiency method for obtaining VLPs and optimized the purification conditions. In this method, we expressed the protein Cap with a 6× His tag using baculovirus-infected silkworm larvae as well as the E. coli BL21(DE3) prokaryotic expression system. The PCV2 Cap proteins produced by the silkworm larvae and E. coli BL21(DE3) were purified. Cap proteins purified from silkworm larvae self-assembled into VLPs in vitro, while the Cap proteins purified from bacteria were unable to self-assemble. Transmission electron microscopy confirmed the self-assembly of VLPs. The immunogenicity of the VLPs produced using the baculovirus system was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Furthermore, the purification process was optimized. The results demonstrated that the expression system using baculovirus-infected silkworm larvae is a good choice for obtaining VLPs of PCV2 and has potential for the development of a low-cost and efficient vaccine.


Assuntos
Anticorpos Antivirais/biossíntese , Baculoviridae/genética , Bombyx/virologia , Proteínas do Capsídeo/imunologia , Circovirus/imunologia , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas Virais/biossíntese , Animais , Antígenos Virais/química , Antígenos Virais/imunologia , Baculoviridae/imunologia , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Circovirus/genética , Epitopos/química , Epitopos/imunologia , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Histidina/genética , Histidina/imunologia , Soros Imunes/química , Imunogenicidade da Vacina , Larva/virologia , Camundongos , Oligopeptídeos/genética , Oligopeptídeos/imunologia , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Vacinas Virais/isolamento & purificação
7.
J Med Microbiol ; 69(9): 1183-1196, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32812860

RESUMO

Introduction. PCV2 is a DNA virus that exists widely in pigs and has caused great economic losses to the pig industry worldwide. In the existing commercial PCV2 enzyme-linked immunosorbent assay (ELISA) kits both natural infection with PCV2 and vaccine immunization produce results that are positive for PCV2 Cap antibodies and therefore they cannot diagnose PCV2 infection in immunized pig farms.Aim. To establish a PCV2 non-structural protein antibody detection method that distinguishes between antibodies resulting from natural prior exposure (infection) and those induced by subunit vaccine immunization.Methodology. Based on the non-structural Rep' protein, we established an indirect ELISA (iELISA) using sera from guinea pigs and piglets.Results. The results for iELISA for guinea pig serum showed that animals vaccinated with a whole-virus inactivated PCV2 vaccine had 100 % (10/10) Cap antibody positivity and 100 % (10/10) Rep' antibody positivity. Guinea pigs vaccinated with a recombinant subunit PCV2 vaccine had 100 % (10/10) Cap antibody positivity, while no (0/10) guinea pigs were Rep' antibody-positive. The combined detection results for the Rep' iELISA and a PCV2 Antibody Test kit (Commercial) showed that pigs vaccinated with a whole-virus inactivated PCV2 vaccine or PCV2 SD/2017 had 100 % (5/5) Cap antibody positivity and 100 % (5/5) Rep' antibody positivity. Pigs vaccinated with a recombinant subunit PCV2 vaccine had 100 % (5/5) Cap antibody positivity, while no (0/10) pigs were Rep' antibody-positive.Conclusion. This paper describes an effective iELISA method that can distinguish natural infection with PCV2 (Cap and Rep positive) or inoculation with a whole-virus inactivated vaccine (Cap and Rep positive) from subunit vaccine immunization (Cap-positive, Rep-negative). These comparative assays could be very useful in the control of PCV2 in pig herds.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Circoviridae/sangue , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Doenças dos Suínos/sangue , Proteínas Virais/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/análise , Infecções por Circoviridae/imunologia , Circovirus/genética , Imunização , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Proteínas Virais/administração & dosagem , Proteínas Virais/genética , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
8.
Viruses ; 12(6)2020 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-32486349

RESUMO

Porcine epidemic diarrhea virus (PEDV) causes a porcine disease associated with swine epidemic diarrhea. The type I interferon (IFN-I or IFN α/ß) is a key mediator of innate antiviral response during virus infection. Different antagonistic strategies have been identified and determined as to how PEDV infection inhibits the host's IFN responses to escape the host innate immune pathway, but the pathogenic mechanisms of PEDV infection are not fully elucidated. Our preliminary results revealed that endogenous TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), the key components in the IFN signaling pathway were downregulated in PEDV infected IPEC-J2 cells by iTRAQ analysis. In this study, we screened nsp15 as the most important viral encoded protein involved in TBK1 and IRF3 reduction. Endoribonuclease (EndoU) activity has been well determined for coronavirus nsp15. Three residues (H226, H241, and K282) of PEDV nsp15 were identified as critical amino acids for PEDV EndoU but not D265, which was not well correlated with published results of other coronaviruses, such as severe acute respiratory syndrome virus (SARS-CoV). Moreover, PEDV nsp15 can directly degrade the RNA levels of TBK1 and IRF3 dependent on its EndoU activity to suppress IFN production and constrain the induction of IFN stimulated genes (ISGs), by which PEDV antagonizes the host innate response to facilitate its replication. Collectively, these results have confirmed that PEDV nsp15 was capable of subverting the IFN response by the RNA degradation of TBK1 and IRF3.


Assuntos
Endorribonucleases/imunologia , Fator Regulador 3 de Interferon/metabolismo , Interferon Tipo I/imunologia , Vírus da Diarreia Epidêmica Suína/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas não Estruturais Virais/imunologia , Animais , Linhagem Celular , Chlorocebus aethiops , Infecções por Coronavirus/patologia , Infecções por Coronavirus/veterinária , Regulação para Baixo , Células HEK293 , Humanos , Fator Regulador 3 de Interferon/genética , Interferon Tipo I/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Estabilidade de RNA/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/patologia , Células Vero
9.
Arch Virol ; 165(7): 1653-1658, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: covidwho-245259

RESUMO

Although porcine deltacoronavirus (PDCoV) is a significant pandemic threat in the swine population and has caused significant economic losses, information regarding the immune response in conventionally weaned pigs infected with PDCoV is scarce. Hence, the immune response in conventionally weaned pigs infected with PDCoV was assessed after challenge and rechallenge. After the first challenge, obvious diarrhea and viral shedding developed successively in all pigs in the four inoculation dose groups from 3 to 14 days postinfection (dpi), and all pigs recovered (no clinical symptoms or viral shedding) by 21 dpi. All pigs in the four groups exhibited significantly increased PDCoV-specific IgG, IgA and virus-neutralizing (VN) antibody (Ab) titers and IFN-γ levels in the serum after the first challenge. All pigs were completely protected against rechallenge at 21 dpi. The serum levels of PDCoV-specific IgG, IgA, and VN Abs increased further after rechallenge. Notably, the IFN-γ level declined continuously after 7 dpi. In addition, the levels of PDCoV-specific IgG, IgA and VN Abs in saliva increased significantly after rechallenge and correlated well with the serum Ab titers. Furthermore, the appearance of clinical symptoms of PDCoV infection in conventionally weaned pigs was delayed with reduced inoculation doses. In summary, the data presented here offer important reference information for future PDCoV animal infection and vaccine-induced immunoprotection experiments.


Assuntos
Infecções por Coronavirus/veterinária , Coronavirus/fisiologia , Doenças dos Suínos/imunologia , Animais , Anticorpos Antivirais/imunologia , Coronavirus/genética , Coronavirus/isolamento & purificação , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Diarreia/imunologia , Diarreia/virologia , Interferon gama/imunologia , Suínos , Doenças dos Suínos/virologia , Eliminação de Partículas Virais
10.
PLoS One ; 15(5): e0232782, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32369529

RESUMO

The efficacy of foot-and-mouth disease virus (FMDV) inactivated vaccines is mainly dependent on the integrity of the whole (146S) viral particles. If the intact capsids disassemble to 12S subunits, antibodies against internal-not protective epitopes, may be induced. Serological correlates with protection may be hampered if antibodies against internal epitopes are measured. Here we compared the performance of different ELISAs with the virus-neutralization test (VNT) that measures antibodies against exposed epitopes. Sera from pigs immunized with one dose of an expired commercial FMDV vaccine were used. This vaccine contained about 50% of O1/Campos and over 90% of A24/Cruzeiro strains total antigen as whole 146S particles. Specific-total antibodies were measured with the standard liquid-phase blocking ELISA (LPBE). We also developed an indirect ELISA (IE) using sucrose gradient purified 146S particles as capture antigen to titrate total antibodies, IgM, IgG1 and IgG2. A good correlation was found between VNT titers and IgG-ELISAs for A24/Cruzeiro, with the lowest correlation coefficient estimated for IgG2 titers. For O1/Campos, however, the presence of antibodies against epitopes different from those of the whole capsid, elicited by the presence of 12S particles in the vaccine, hampered the correlation between LPBE and VNT, which was improved by using purified O1/Campos 146S-particles for the liquid-phase of the LPBE. Interestingly, 146S particles but not 12S were efficiently bound to the ELISA plates, confirming the efficiency of the IE to detect antibodies against exposed epitopes. Our results indicate that any serological test assessing total antibodies or IgG1 against epitopes exposed in intact 146S-particles correlate with the levels of serum neutralizing antibodies in vaccinated pigs, and might potentially replace the VNT, upon validation. We recommend that antigen used for serological assays aimed to measure protective antibodies against FMDV should be controlled to ensure the preservation of 146S viral particles.


Assuntos
Vírus da Febre Aftosa/imunologia , Febre Aftosa/terapia , Doenças dos Suínos/terapia , Suínos/virologia , Vacinas Virais/uso terapêutico , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Febre Aftosa/imunologia , Testes de Neutralização , Suínos/imunologia , Doenças dos Suínos/imunologia , Vacinas Virais/imunologia
11.
Parasite Immunol ; 42(7): e12728, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32394439

RESUMO

Helminth infection represents a major health problem causing approximately 5 million disability-adjusted life years worldwide. Concerns that repeated anti-helminthic treatment may lead to drug resistance render it important that vaccines are developed but will require increased understanding of the immune-mediated cellular and antibody responses to helminth infection. IL-4 or antibody-activated murine macrophages are known to immobilize parasitic nematode larvae, but few studies have addressed whether this is translatable to human macrophages. In the current study, we investigated the capacity of human macrophages to recognize and attack larval stages of Ascaris suum, a natural porcine parasite that is genetically similar to the human helminth Ascaris lumbricoides. Human macrophages were able to adhere to and trap A suum larvae in the presence of either human or pig serum containing Ascaris-specific antibodies and other factors. Gene expression analysis of serum-activated macrophages revealed that CCL24, a potent eosinophil attractant, was the most upregulated gene following culture with A suum larvae in vitro, and human eosinophils displayed even greater ability to adhere to, and trap, A suum larvae. These data suggest that immune serum-activated macrophages can recruit eosinophils to the site of infection, where they act in concert to immobilize tissue-migrating Ascaris larvae.


Assuntos
Ascaríase/imunologia , Ascaris suum/imunologia , Quimiocina CCL24/metabolismo , Eosinófilos/imunologia , Macrófagos/imunologia , Animais , Anticorpos Anti-Helmínticos/sangue , Formação de Anticorpos , Ascaris lumbricoides/imunologia , Humanos , Soros Imunes/farmacologia , Larva/imunologia , Contagem de Leucócitos , Camundongos , Suínos , Doenças dos Suínos/imunologia , Vacinas/imunologia
12.
Vet Q ; 40(1): 183-189, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32448096

RESUMO

Background: Outbreaks of porcine epidemic diarrhea virus (PEDV) infection have re-emerged and spread rapidly worldwide, resulting in significant economic losses. Vaccination is the best way to prevent PEDV infection in young piglets.Objective: To enhance the efficacy of an inactivated vaccine against PEDV, we evaluated the adjuvant properties of Fc domain of IgG.Methods: Fifteen crossbred gilts (180 ∼ 210 days old) were used. Five pigs in group 1 were intramuscularly vaccinated twice at 4 weeks and 2 weeks prior to farrowing with 106 TCID50 of inactivated PEDV. Five pigs in group 2 were intramuscularly vaccinated twice at 4 weeks and 2 weeks prior to farrowing with 106 TCID50 of inactivated PEDV-sFc. Five pigs in group 3 were not vaccinated and served as negative controls. Serum samples were collected at farrowing and subjected to ELISA, a serum neutralizing (SN) test, and a cytokine assay. Statistical analysis was performed by a two-tailed unpaired t-test.Results: Vero cells expressing swine IgG Fc on its surface was established. When PEDV was propagated in the cells expressing the swine Fc, PEDV virion incorporated the Fc. Immunization of pigs with inactivated PEDV harbouring Fc induced significantly higher antibody production against PEDV, comparing to the immunization with normal inactivated PEDV. In addition, we observed significantly increased IFN-γ levels in sera.Conclusion: Our results indicate that Fc molecule facilitate immune responses and PEDV harbouring Fc molecule could be a possible vaccine candidate. However, a challenge experiment would be needed to investigate the protective efficacy of PEDV harbouring Fc.


Assuntos
Infecções por Coronavirus/veterinária , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/imunologia , Vírus da Diarreia Epidêmica Suína/imunologia , Doenças dos Suínos/imunologia , Adjuvantes Imunológicos , Animais , Chlorocebus aethiops , Infecções por Coronavirus/imunologia , Feminino , Imunização , Testes de Neutralização , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas de Produtos Inativados/imunologia , Células Vero , Vacinas Virais/imunologia
13.
Arch Virol ; 165(7): 1653-1658, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32399787

RESUMO

Although porcine deltacoronavirus (PDCoV) is a significant pandemic threat in the swine population and has caused significant economic losses, information regarding the immune response in conventionally weaned pigs infected with PDCoV is scarce. Hence, the immune response in conventionally weaned pigs infected with PDCoV was assessed after challenge and rechallenge. After the first challenge, obvious diarrhea and viral shedding developed successively in all pigs in the four inoculation dose groups from 3 to 14 days postinfection (dpi), and all pigs recovered (no clinical symptoms or viral shedding) by 21 dpi. All pigs in the four groups exhibited significantly increased PDCoV-specific IgG, IgA and virus-neutralizing (VN) antibody (Ab) titers and IFN-γ levels in the serum after the first challenge. All pigs were completely protected against rechallenge at 21 dpi. The serum levels of PDCoV-specific IgG, IgA, and VN Abs increased further after rechallenge. Notably, the IFN-γ level declined continuously after 7 dpi. In addition, the levels of PDCoV-specific IgG, IgA and VN Abs in saliva increased significantly after rechallenge and correlated well with the serum Ab titers. Furthermore, the appearance of clinical symptoms of PDCoV infection in conventionally weaned pigs was delayed with reduced inoculation doses. In summary, the data presented here offer important reference information for future PDCoV animal infection and vaccine-induced immunoprotection experiments.


Assuntos
Infecções por Coronavirus/veterinária , Coronavirus/fisiologia , Doenças dos Suínos/imunologia , Animais , Anticorpos Antivirais/imunologia , Coronavirus/genética , Coronavirus/isolamento & purificação , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Diarreia/imunologia , Diarreia/virologia , Interferon gama/imunologia , Suínos , Doenças dos Suínos/virologia , Eliminação de Partículas Virais
14.
Vet Immunol Immunopathol ; 223: 110034, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32278900

RESUMO

Porcine circovirus type 2 (PCV2) has one of the highest evolutionary rates among DNA viruses. Traditionally, PCV2 vaccines have been based on the 2a genotype as this was the first genotype discovered. Today, eight genotypes of PCV2 viruses have been identified, and, taken together with the rapid evolutionary rate, propensity to recombine, and high rate of vaccination, further variation in PCV2 is expected. For these reasons, there is a growing genetic gap between available vaccines and field strains. When selecting vaccines, it is important to consider vaccines that contain T cell epitopes that are well-matched to the circulating strains. To quantify the relatedness between PCV2 vaccines and field strains, we predicted and compared their T cell epitope content and calculated Epitope Content Comparison (EpiCC) scores using established in silico tools. T cell epitopes predicted to bind common class I and class II swine leukocyte antigen (SLA) alleles were identified from two major structural proteins, the capsid (encoded by ORF2) and the replicase (encoded by ORF1). The T cell epitope content of three commercial PCV2a-based vaccines (a baculovirus expressed PCV2a ORF2 [VacAlt], a PCV1-PCV2a chimeric virus vaccine [VacA] and a combination cPCV2a-cPCV2b chimeric virus vaccine [VacAB]) and an experimental PCV2b ORF2-based chimeric virus vaccine [VacB] (Table 1), were compared to that of 161 PCV2 field strains (representing genotypes a-f). The T cell epitope content and conservation between vaccine and field strains varied. While all vaccine strains provided broad coverage of the field strains including heterologous genotypes, none of the vaccines covered all the putative T cell epitopes identified in the field strains. PCV2a-based vaccine strains generally scored higher in terms of conserved epitope content against PCV2a field isolates but were not identical. The PCV2b-based vaccine strain had higher scores against PCV2b and PCV2d field strains. The combination PCV2a-PCV2b vaccine (VacAB) had, on average, the highest EpiCC score. PCV2 continues to evolve and EpiCC analysis provides a new tool to assess the possible impact of virus genetic divergence on T cell epitope coverage of vaccine strains. Given that multiple genotypes are currently found and may co-exist on farms, this analysis suggests that a combination of PCV2a and PCV2b vaccine strains may be required to provide optimal coverage of current and future field isolates.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/imunologia , Epitopos de Linfócito T/genética , Vacinas Virais/genética , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/genética , Simulação por Computador , Epitopos de Linfócito T/imunologia , Genótipo , Imunidade Celular , Suínos , Doenças dos Suínos/imunologia
15.
PLoS One ; 15(4): e0231942, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32339193

RESUMO

Salmonella enterica serovar Typhimurium is an animal welfare and public health concern due to its ability to parasite livestock and potentially contaminate pork products. To reduce Salmonella shedding and the risk of pork contamination, antibiotic therapy is used and can contribute to antimicrobial resistance. Here we hypothesized that immune system education by the microbiota can play a role in intestinal resilience to infection. We used amoxicillin (15mg/Kg) to modulate the intestinal microbiome of 10 piglets, paired with same age pigs that received a placebo (n = 10) from 0 to 14 days of age. Animals were euthanized at 4-weeks old. Each pig donated colon sections for ex vivo culture (n = 20 explants/pig). Explants were inoculated with S. Typhimurium, PBS or LPS (n = 6 explants/pig/group, plus technical controls). The gut bacteriome was characterized by sequencing of the 16S rRNA at 7, 21 days of age, and upon in vitro culture. Explants response to infection was profiled through high-throughput mRNA sequencing. In vivo antibiotic treatment led to ß-diversity differences between groups at all times (P<0.05), while α-diversity did not differ between amoxicillin and placebo groups on day 21 and at euthanasia (P<0.03 on day 7). Explant microbiomes were not different from in vivo. In vitro challenge with S. Typhimurium led to lower necrosis scores in explants from amoxicillin-treated pigs, when compared to explants placebo-treated pigs (P<0.05). This was coupled with the activation of immune-related pathways in explants from amoxicillin-treated pigs (IL-2 production, NO production, BCR activation), when compared to placebo-treated pigs. In addition, several DNA repair and intestinal wound healing pathways were also only activated in explants from amoxicillin-treated pigs. Taken together, these findings suggest that immune education by the amoxicillin-disturbed microbiota may have contributed to mitigate intestinal lesions following pathogen exposure.


Assuntos
Antibacterianos/farmacologia , Epigênese Genética/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Salmonella typhimurium/patogenicidade , Amoxicilina/farmacologia , Animais , Animais Recém-Nascidos , Bactérias/genética , Bactérias/isolamento & purificação , Colo/citologia , Colo/microbiologia , Colo/patologia , Regulação para Baixo/efeitos dos fármacos , Fezes/microbiologia , Análise de Componente Principal , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo , Salmonelose Animal/imunologia , Suínos , Doenças dos Suínos/imunologia , Regulação para Cima/efeitos dos fármacos
16.
J Anim Sci ; 98(5)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32300795

RESUMO

The objective of this experiment was to investigate the impact of an F18 enterotoxigenic Escherichia coli (ETEC) challenge on growth performance, aspects of intestinal function, and selected immune responses of piglets, as well as to evaluate potential protective effects of direct-fed microbial (DFM) blends. Seventy-two weaned piglets (6.4 ± 0.2 kg body weight [BW]; ~21 d of age) were assigned to one of four treatments: 1) NC: Nonchallenged (n = 10), 2) positive challenged control (PC): F18 ETEC-challenged (n = 10), 3) PC + DFM1 (n = 8; three strains of Bacillus amyloliquefaciens; 7.5 × 105 colony-forming units [cfu]/g), or 4) PC + DFM2 (n=8; 2 strains of B. amyloliquefaciens and one strain of Bacillus subtilis; 1.5 × 105 cfu/g). Feed intake and BW were recorded on day 0, 7, and 17. Pigs were sham-infected either with 6 mL phosphate-buffered saline or inoculated with 6 mL F18 ETEC (~1.9 × 109 cfu/mL) on day 7 (0 d postinoculation [dpi]). All ETEC-challenged pigs were confirmed to be genetically susceptible to F18. Pigs had ad libitum access to feed and water throughout the 17-d trial. Fecal scores were visually ranked and rectal temperatures were recorded daily. To evaluate ETEC shedding, fecal swabs were collected on dpi 0, 1, 2, 3, 5, 7, and 10. Blood samples were collected on dpi 0, 1, 2, 4, 7, and 10. Ileal tissues were collected at necropsy on dpi 10. All challenged treatments had lower final BW, decreased average daily gain (ADG), and average daily feed intake (ADFI) during the 10-d postchallenge period (P < 0.01). The DFM2 treatment increased E. coli shedding on dpi 2 and decreased iton dpi 7 (P < 0.05) compared with the PC. Rectal temperature decreased across all challenged treatments (P < 0.01). Ileal mRNA abundance of occludin (OCLN) and zonula occludens-1 (ZO-1) decreased in PC and DFM1 compared with NC (P < 0.05). Pigs fed DFM2 had intermediate ileal mRNA abundance of OCLN and increased ZO-1 mRNA compared with pigs in PC (P < 0.05). Interleukin 8 (IL-8) increased in the plasma of PC and DFM2 on dpi 2 compared with NC (P < 0.05). Mucosal IL-8 increased in PC compared with NC (P < 0.05). All challenged treatments tended to have elevated tumor necrosis factor-α (TNF-α) mRNA abundance compared with NC (P < 0.10). Challenged pigs had reduced secretory immunoglobulin A and villus height compared with NC pigs (P < 0.05). The impact of an ETEC challenge on intestinal function and the immune system has been revealed, information critical to developing improved treatment regimes.


Assuntos
Bacillus amyloliquefaciens/fisiologia , Bacillus subtilis/fisiologia , Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/veterinária , Imunidade Inata , Probióticos/análise , Doenças dos Suínos/prevenção & controle , Animais , Derrame de Bactérias , Dieta/veterinária , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Fezes/microbiologia , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Masculino , Distribuição Aleatória , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Desmame
17.
Virus Res ; 282: 197955, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32247757

RESUMO

Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes acute diarrhea, vomiting, dehydration and mortality in neonatal piglets, resulting in significant economic losses to the pig industry. However, there is currently little information on vaccine studies and commercially available vaccines for PDCoV. Hence, herein, a PDCoV strain, CH/XJYN/2016, was successfully isolated and serially propagated in vitro, and its biological characteristics were determined. Compared to that of previously reported and recently isolated PDCoV strains from China and the United States, the S gene of the CH/XJYN/2016 strain contains novel mutations. Infection studies revealed that CH/XJYN/2016 is pathogenic to suckling piglets and conventional weaned pigs. In addition, the median pig diarrhea dose (PDD50) of PDCoV in conventional weaned pigs was determined (2.0 log10PDD50/3 mL). Furthermore, an inactivated cell-adapted CH/XJYN/2016-based vaccine candidate was developed with different adjuvants. Compared with nonvaccinated pigs, conventional weaned pigs given the inactivated vaccine developed a potent humoral immune response and showed no clinical signs or viral shedding after challenge, indicating a potent protective effect of the vaccine against PDCoV infection. Therefore, the PDCoV vaccine developed in this study is a promising vaccine candidate that can be used for the control of PDCoV infection in pigs.


Assuntos
Infecções por Coronavirus/veterinária , Coronavirus/imunologia , Coronavirus/patogenicidade , Doenças dos Suínos/virologia , Vacinas Virais/imunologia , Animais , Linhagem Celular , Coronavirus/classificação , Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Genoma Viral/genética , Imunogenicidade da Vacina , Mutação , Filogenia , Inoculações Seriadas , Glicoproteína da Espícula de Coronavírus/genética , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Vacinas de Produtos Inativados/imunologia
18.
Sci Rep ; 10(1): 4510, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32161289

RESUMO

Novel H1N2 influenza A viruses (IAVs) in swine have been identified in Chile co-circulating with pandemic H1N1 2009-like (A(H1N1)pdm09-like) viruses. The objective of this study was to characterize antigenically the swine H1 IAVs circulating in Chile. Genetic analysis based on the HA1 domain and antigenic analysis by hemagglutination inhibition assay were carried out. Three antigenic clusters were identified, named Chilean H1 A (ChH1A), Chilean H1 B (ChH1B), and A(H1N1)pdm09-like. The antigenic sites of ChH1A and ChH1B strains were 10-60% distant from those of commercial vaccine strains at the amino acid sequence level. Antigenic variants were identified within the clusters ChH1A and A(H1N1)pdm09-like. Substitutions in the main antigenic sites (E153G in Sa, Q193H in Sb, D168N in Ca1, P137S in Ca2, and F71L in Cb) were detected in variants from the ChH1A cluster, whereas only a single substitution in antigenic site Sa (G155E) was detected in variants from A(H1N1)pdm09-like cluster, which confirms the importance to carrying out antigenic analyses in addition to genetic analyses to evaluate control measures such as vaccination. These results highlight the need to update vaccines for swine in Chile and the importance of continued surveillance to determine the onward transmission of antigenic variants in Chilean pig populations.


Assuntos
Antígenos Virais/imunologia , Interações Hospedeiro-Patógeno/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Sequência de Aminoácidos , Animais , Variação Antigênica , Antígenos Virais/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Filogenia , Análise de Sequência de DNA , Suínos
19.
Epidemiol Infect ; 148: e73, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32167441

RESUMO

Since the incursion of influenza A(H1N1)pdm09 virus in 2009, serosurveillance every year of the Norwegian pig population revealed the herd prevalence for influenza A(H1N1)pdm09 (HIN1pdm09) has stabilised between 40% and 50%. Between 30 September 2009 and 14 September 2017, the Norwegian Veterinary Institute and Norwegian Food Safety Authority screened 35,551 pigs for antibodies to influenza A viruses (IAVs) from 8,636 herds and found 26% or 8,819 pigs' sera ELISA positive (titre ≥40). Subtyping these IAV antibodies from 8,214 pigs in 3,629 herds, by a routine haemagglutination inhibition test (HAIT) against four standard antigens produced 13,771 positive results (HAIT titre ≥40) of binding antibodies. The four antigen subtypes eliciting positive HAIT titre in descending frequencies were immunogen H1N1pdm09 (n = 8,200 or 99.8%), swine influenza A virus (SIVs) subtypes swH1N1 (n = 5,164 or 62%), swH1N2 (n = 395 or 5%) and swH3N2 (n = 12 or 0.1%). Of these 8,214 pig pigs sera, 3,039 produced homologous HAIT subtyping, almost exclusively immunogen H1N1pdm09 (n = 3,026 or 99.6%). Using HAIT titre of pig and herd geometric mean titre (GMT) as two continuous outcome variables, and with the data already structured hierarchically, we used mixed effects linear regression analysis to investigate the impact of predictors of interests had on the outcomes. For the full data, the predictors in the regression model include categorical predictors antigen subtype (H1N1pdm09, swH1N1, swH1N2 & swH3N2), and production type (sow herd or fattening herd), ordinal predictors year (longitudinally from 2009 to 2017) and number of antigens in heterologous reactions (1, 2, 3, 4) in the same pig serum. The last predictor, the proportion of HAIT positive (antigen specific) in tested pigs within the herd, was a continuous predictor, which served as a proxy for days post-infection (dpi) or humoral response time in the pig or herd. Regression analysis on individual pig HAIT titres showed that antigen as a predictor, the coefficient for immunogen H1N1pdm09 was at least fourfold higher (P < 0.001) than the three SIVs antigen subtypes, whose much lower coefficients were statistically no different between the three SIVs antigen subtypes. Correspondingly, for herd GMT, immunogen H1N1pdm09 was 28-40-fold higher than the three SIVs antigen subtypes. Excluding the HAIT data of the three SIVs antigen subtypes, regression analysis focusing only on immunogen H1N1pdm09 increased greatly the coefficients of the predictors in the models. Homologous reactions (99.6% H1N1pdm09) have lower HAIT titres while the likelihood of the number of antigens involved in HAIT heterologous reactions in a single pig serum increased with higher HAIT titres of immunogen H1N1pdm09. For predictor 'production', sows and sow herds had higher HAIT titres and GMT compared to fattening pigs and fattening herds respectively. Herds with 'higher proportion of pigs tested positive' also had higher HAIT titre in the pig and herd GMT.


Assuntos
Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Infecções por Orthomyxoviridae , Doenças dos Suínos , Animais , Anticorpos Antivirais/sangue , Vírus da Influenza A/imunologia , Modelos Lineares , Noruega/epidemiologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Estudos Retrospectivos , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia
20.
Vet Microbiol ; 242: 108588, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122592

RESUMO

Coinfection with porcine circovirus type 2 (PCV2) and Mycoplasma hyorhinis (Mhr) can induce more-severe disease than a single infection with either. We evaluated the efficacy of a new vaccine combining inactivated PCV2 and Mhr, in a model of PCV2 and Mhr infection. Twenty-five 35-day-old PCV2- and Mhr-free pigs were randomly divided into five groups, with five pigs in each group. The pigs in groups 1 and 2 were vaccinated with the combined vaccine and then challenged with Mhr or PCV2, respectively. The pigs in groups 3 and 4 were not vaccinated and then challenged with PCV2 or Mhr, respectively, and group 5 was used as the unvaccinated unchallenged control. Two weeks after booster immunization via the intramuscular route, all the pigs except those in control group 5 were challenged with PCV2 or Mhr. All the pigs were euthanized 28 days after challenge. The pigs in vaccinated groups 1 and 2 showed a significant increase in weight after challenge with PCV2 or Mhr (P < 0.001), with an average daily gain (ADG) of 0.315 kg compared with unvaccinated groups 3 and 4 (0.279 kg). Mhr was isolated from the unvaccinated pig lungs after Mhr challenge, whereas it was not isolated from the vaccinated pigs. No PCV2 or Mhr was detected with PCR or histochemical staining in vaccinated groups 1 and 2. A statistical analysis showed that the PCV2 and Mhr combined vaccine providing protected against PCV2 infection causing viremia and inguinal lymphadenopathy (5 pigs protected out 5) or against Mhr infection causing fiber inflammation (4 pigs out 5). Thus, we have developed an effective combined vaccine for the prevention and control of PCV2 or Mhr infections in swine herds, this will help reduce prevalence of PCV2 and Mhr coinfections.


Assuntos
Vacinas Bacterianas/imunologia , Infecções por Circoviridae/veterinária , Infecções por Mycoplasma/veterinária , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Vacinas Bacterianas/administração & dosagem , Infecções por Circoviridae/prevenção & controle , Circovirus/classificação , Circovirus/imunologia , Coinfecção/microbiologia , Coinfecção/veterinária , Coinfecção/virologia , Imunização Secundária , Injeções Intramusculares , Infecções por Mycoplasma/prevenção & controle , Mycoplasma hyorhinis/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Virais/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA