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1.
Arch Virol ; 165(12): 2777-2788, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32964293

RESUMO

Besides the vaccine strains, the Malaysian variant (MV) and QX-like are the predominant IBVs detected on commercial poultry farms. These two virus strains are distinct based on genomic and pathogenicity studies. In this study, we determined the sequence of the S1 gene and compared the pathogenicity of serial passage 70 (P70) of Malaysian QX-like (QX/P70) and MV (MV/P70) strains with that of their respective wild-type viruses. The nucleotide and amino acid sequences of the complete S1 genes of QX/P70 and MV/P70 showed 1.4 to 1.6% and 3.0 to 3.3% variation, respectively, when compared to the wild-type virus. Most of the mutations were insertions and substitutions in the hypervariable regions (HVRs), primarily in HVR 3. Furthermore, selection pressure analysis showed that both viruses are under purifying selection. A pathogenicity study in specific-pathogen-free (SPF) chickens showed a reduction in respiratory and kidney lesions in chickens inoculated with MV/P70, but not with QX/P70, when compared to the respective wild-type viruses. However, MV/P70 is still pathogenic and can cause ciliary damage. In conclusion, the MV IBV strain is more responsive than the QX-like IBV strain following the attenuation process used for the development of a live attenuated IBV vaccine.


Assuntos
Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Animais , Galinhas , Infecções por Coronavirus/virologia , Vírus da Bronquite Infecciosa/patogenicidade , Doenças das Aves Domésticas/prevenção & controle , Análise de Sequência de Proteína , Inoculações Seriadas , Organismos Livres de Patógenos Específicos , Vacinas Atenuadas/imunologia
2.
Poult Sci ; 99(9): 4351-4359, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32867979

RESUMO

The vaccines currently available to control infectious bursal disease (IBD) include live-attenuated and inactivated vaccines, immune-complex vaccines, and vaccines consisting of viral constructs of herpesvirus of turkeys genetically engineered to express VP2 surface protein. To evaluate the impact of vaccines on the chicken immune system, 2 animal trials were performed in specific pathogen-free broiler chickens. In trial 1, birds were either vaccinated when they are one-day old with a dual recombinant herpes virus of turkey construct vaccine, expressing VP2 protein of (IBDV) and F protein of Newcastle disease virus, or an immune-complex IBDV vaccine or birds were not vaccinated. At 14, 28, and 35 D, the bursa of Fabricius was collected for bursa:body weight (B:BW) ratio calculation. In trial 2, birds were vaccinated when they were 1-day old according to the same protocol as trial 1, but at day 14, all groups also received a live infectious bronchitis (IB) vaccine. At 0, 7, 14, 21, and 28 days after IB vaccination, birds were tested by ELISA for IB serology and, soon after the last blood sampling, they were euthanized for collection of Harderian glands, trachea, and spleen and testing by flow cytometry for characterization of mononuclear cells. The immune-complex vaccine groups showed significantly lower B:BW ratio, lower IBV antibody titers, and higher mean percentage of CD8+ T cells in the spleen, trachea, and Harderian glands than those in the other experimental groups. The results of the in vivo trials coupled with a depth analysis of the repertoire of parameters involved in the immune response to IBD and IB vaccinations show one vaccine may influence the immune response of other vaccines included in the vaccination program.


Assuntos
Infecções por Birnaviridae/veterinária , Doenças das Aves Domésticas/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Birnaviridae/imunologia , Bolsa de Fabricius/patologia , Galinhas , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Vacinação/veterinária , Vacinas Atenuadas/imunologia
3.
Ann Hematol ; 99(10): 2329-2338, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32821971

RESUMO

Patients with the pre-leukemia bone marrow failure syndrome called severe congenital neutropenia (CN) have an approximately 15% risk of developing acute myeloid leukemia (AML; called here CN/AML). Most CN/AML patients co-acquire CSF3R and RUNX1 mutations, which play cooperative roles in the development of AML. To establish an in vitro model of leukemogenesis, we utilized bone marrow lin- cells from transgenic C57BL/6-d715 Csf3r mice expressing a CN patient-mimicking truncated CSF3R mutation. We transduced these cells with vectors encoding RUNX1 wild type (WT) or RUNX1 mutant proteins carrying the R139G or R174L mutations. Cells transduced with these RUNX1 mutants showed diminished in vitro myeloid differentiation and elevated replating capacity, compared with those expressing WT RUNX1. mRNA expression analysis showed that cells transduced with the RUNX1 mutants exhibited hyperactivation of inflammatory signaling and innate immunity pathways, including IL-6, TLR, NF-kappaB, IFN, and TREM1 signaling. These data suggest that the expression of mutated RUNX1 in a CSF3R-mutated background may activate the pro-inflammatory cell state and inhibit myeloid differentiation.


Assuntos
Síndrome Congênita de Insuficiência da Medula Óssea/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Células-Tronco Hematopoéticas/patologia , Células Mieloides/patologia , Mielopoese/genética , Neutropenia/congênito , Pré-Leucemia/genética , Receptores de Fator Estimulador de Colônias/genética , Animais , Divisão Celular , Ensaio de Unidades Formadoras de Colônias , Síndrome Congênita de Insuficiência da Medula Óssea/patologia , Subunidade alfa 2 de Fator de Ligação ao Core/fisiologia , Perfilação da Expressão Gênica , Imunidade Inata , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neutropenia/genética , Neutropenia/patologia , Pré-Leucemia/patologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores de Fator Estimulador de Colônias/fisiologia , Proteínas Recombinantes/genética , Organismos Livres de Patógenos Específicos
4.
Exp Parasitol ; 217: 107963, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32781092

RESUMO

This study analyzed the large-subunit (60S) ribosomal protein L12 of Eimeria tenella (Et60s-RPL12). A full-length cDNA was cloned, and the recombinant protein was expressed in E. coli BL21 and inoculated in rabbits to produce the polyclonal antibody. Quantitative real-time polymerase chain reaction and western blotting were used to analyze the transcription levels of Et60s-RPL12 and translation levels in different developmental stages of E. tenella. The results showed that the mRNA transcription level of Et60s-RPL12 was highest in second-generation merozoites, whereas the translation level was highest in unsporulated oocysts. Indirect immunofluorescence showed that Et60s-RPL12 was localized to the anterior region and surface of sporozoites, except for the two refractile bodies. As the invasion of DF-1 cells progressed, fluorescence intensity was increased, and Et60s-RPL12 was localized to the parasitophorous vacuole membrane (PVM). The secretion assay results using staurosporine indicated that this protein was secreted, but not from micronemes. The role of Et60s-RPL12 in invasion was evaluated in vitro. The results of the invasion assay showed that polyclonal antibody inhibited host cell invasion by the parasite, which reached about 12%. However, the rate of invasion was not correlated with the concentration of IgG.


Assuntos
Eimeria tenella/genética , Proteínas Ribossômicas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Ceco/parasitologia , Linhagem Celular , Embrião de Galinha , Galinhas , Biologia Computacional , DNA Complementar/genética , DNA Complementar/metabolismo , Eimeria tenella/química , Eletroforese em Gel de Poliacrilamida , Fezes/parasitologia , Fibroblastos , Técnica Indireta de Fluorescência para Anticorpo , Biossíntese de Proteínas , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Ribossômicas/química , Organismos Livres de Patógenos Específicos , Transcrição Genética
5.
Exp Parasitol ; 217: 107965, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32818513

RESUMO

Saturated salt floatation method is widely used for coccidian oocyst purification. However, the repeated procedures and inefficient oocysts recovery rate are a continuous challenge. This study aimed to investigate the best suitable floatation solution, along with optimal centrifugation speed and time for Eimeria tenella (E. tenella) oocyst and sporocyst purification. Different floatation solutions i-e, saturated salt, Sheather's sugar and sodium hypochlorite (NaClO) at 20-60% concentrations were used to purify oocyst. It was found that about 96.99% oocysts (8609×g for 10 min) were recovered under these conditions without any effect on the viability of sporocysts. The recovery rate of oocysts using 50% NaClO (V/V) was significantly higher than 35% saturated salt flotation solution (P < 0.05). The optimal method for purification of oocysts based our experimentation was centrifugation at 8609×g for 3 min using 50% NaClO floatation solution, and the optimized centrifugation conditions for improved recovery of sporocysts (about 99.3%) were at 2152×g for 5 min. The present study provided a better method for the coccidian oocyst purification, which could be successfully adopted as a better alternative to existing techniques commonly used for investigations/research pertaining to coccidia.


Assuntos
Centrifugação/normas , Eimeria tenella/isolamento & purificação , Análise de Variância , Animais , Galinhas , Eimeria tenella/crescimento & desenvolvimento , Fezes/parasitologia , Oocistos/isolamento & purificação , Oxidantes/administração & dosagem , Distribuição Aleatória , Hipoclorito de Sódio/administração & dosagem , Organismos Livres de Patógenos Específicos , Fatores de Tempo
6.
J Vis Exp ; (160)2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32628163

RESUMO

Studies of the gut microbiota contribution to the host physiology and immunocompetence are facilitated by the availability of germ-free animal models, which are considered the gold standard. Nesting birds are ideal models for the production of germ-free animals since there is no need to raise their relatives under sterile conditions. Germ-free chickens are mainly generated from specific-pathogen-free (SPF) experimental lines, which are poorly representative of commercial chicken lines. The method proposed here allowed the production of germ-free chickens from the fast growing broiler line Ross PM3, commonly used by the poultry industry. Eggs were quickly collected after laying at a broiler breeder farm. They underwent a strict decontamination process from the collection to the introduction in a sterile egg hatching isolator. The chicks have been hatched and kept in these sterile isolators during the period necessary to control their sterility. Originally developed for an experimental SPF white leghorn line, the present protocol has been adapted not only to the Ross PM3 broiler line but also to quails. It therefore represents a robust and readily adaptable procedure to other poultry species and nesting birds of economic, biological or ecological relevance.


Assuntos
Galinhas/crescimento & desenvolvimento , Galinhas/microbiologia , Microbiota , Organismos Livres de Patógenos Específicos , Animais , Óvulo/fisiologia
7.
PLoS One ; 15(7): e0234916, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614882

RESUMO

A great deal of attention has been focused on nanoparticles for cancer therapy, with the promise of tumor-selective delivery. However, despite intense work in the field over many years, the biggest obstacle to this vision remains extremely low delivery efficiency of nanoparticles into tumors. Due to the cost, time, and impact on the animals for in vivo studies, the nanoparticle field predominantly uses cellular uptake assays as a proxy to predict in vivo outcomes. Extensive research has focused on decreasing macrophage uptake in vitro as a proxy to delay nanoparticle accumulation in the mononuclear phagocytic system (MPS), mainly the liver and spleen, and thereby increase tumor accumulation. We have recently reported novel synthetic methods employing small molecule crosslinkers for the controlled assembly of small nanoparticles into larger aggregates and found that these nanoaggregates had remarkably high surface coverage and low cell uptake, even in macrophages. We further found that this extremely low cellular uptake could be recapitulated on solid gold nanoparticles by densely coating their surface with small molecules. Here we report our studies on the biodistribution and clearance of these materials in comparison to more conventional PEGylated gold nanoparticles. It was expected that the remarkably low macrophage uptake in vitro would translate to extended blood circulation time in vivo, but instead we found no correlation between either surface coverage or in vitro macrophage cell uptake and in vivo blood circulation. Gold nanoaggregates accumulate more rapidly and to a higher level in the liver compared to control gold nanoparticles. The lack of correlation between in vitro macrophage uptake and in vivo blood circulation suggests that the field must find other in vitro assays to use as a primary proxy for in vivo outcomes or use direct in vivo experimentation as a primary assay.


Assuntos
Materiais Revestidos Biocompatíveis/farmacocinética , Ouro/farmacocinética , Nanopartículas Metálicas , Polietilenoglicóis , Animais , Endocitose , Jejum/metabolismo , Feminino , Ouro/administração & dosagem , Ouro/sangue , Meia-Vida , Rim/metabolismo , Fígado/metabolismo , Macrófagos/fisiologia , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/classificação , Camundongos , Especificidade de Órgãos , Projetos Piloto , Células RAW 264.7 , Organismos Livres de Patógenos Específicos , Baço/metabolismo , Distribuição Tecidual
8.
Ann Hematol ; 99(10): 2315-2322, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32728937

RESUMO

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by lower platelet count resulting from immune cells-mediated platelet clearance. Tacrolimus is an immunosuppressive agent which selectively inhibits T cell activation. Whether tacrolimus plays a role in ITP remains unclear. This study aimed to investigate the effect of tacrolimus on ITP in mice. An ITP mouse model was established by injection of rat anti-mouse integrin GPIIb/CD41 immunoglobulin and treated with tacrolimus followed by isolation of peripheral blood mononuclear cells and plasma. The mRNA expression of T-bet, GATA3, and Foxp3 was measured by RT-PCR, and level of IFN-γ, IL-12p70, IL-4, IL-13, and TGF-ß in plasma was measured by ELISA. Tacrolimus inhibited antiplatelet antibody-mediated platelet clearance in ITP mouse model. Meanwhile, tacrolimus-treated ITP mice displayed a significant decrease in the mRNA expression of T-bet and plasma level of IFN-γ and IL-12p70 compared with ITP mice but without differences when compared with normal mice. Furthermore, the expression of GATA3, Foxp3, and plasma level of IL-4 and TGF-ß were upregulated in tacrolimus-treated ITP mice without significant differences to normal mice (except TGF-ß). Tacrolimus prevents antiplatelet antibody-mediated thrombocytopenia in ITP mice possibly through regulating T cell differentiations, suggesting it might be a novel approach for preventing ITP.


Assuntos
Imunossupressores/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Tacrolimo/uso terapêutico , Animais , Plaquetas/imunologia , Citocinas/biossíntese , Citocinas/genética , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Isoanticorpos/sangue , Camundongos , Camundongos Endogâmicos C57BL , Púrpura Trombocitopênica Idiopática/genética , Púrpura Trombocitopênica Idiopática/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Organismos Livres de Patógenos Específicos , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
9.
Cell ; 182(3): 734-743.e5, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32643603

RESUMO

COVID-19, caused by SARS-CoV-2, is a virulent pneumonia, with >4,000,000 confirmed cases worldwide and >290,000 deaths as of May 15, 2020. It is critical that vaccines and therapeutics be developed very rapidly. Mice, the ideal animal for assessing such interventions, are resistant to SARS-CoV-2. Here, we overcome this difficulty by exogenous delivery of human ACE2 with a replication-deficient adenovirus (Ad5-hACE2). Ad5-hACE2-sensitized mice developed pneumonia characterized by weight loss, severe pulmonary pathology, and high-titer virus replication in lungs. Type I interferon, T cells, and, most importantly, signal transducer and activator of transcription 1 (STAT1) are critical for virus clearance and disease resolution in these mice. Ad5-hACE2-transduced mice enabled rapid assessments of a vaccine candidate, of human convalescent plasma, and of two antiviral therapies (poly I:C and remdesivir). In summary, we describe a murine model of broad and immediate utility to investigate COVID-19 pathogenesis and to evaluate new therapies and vaccines.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/prevenção & controle , Modelos Animais de Doenças , Pandemias/prevenção & controle , Pneumonia Viral/patologia , Pneumonia Viral/prevenção & controle , Vacinação , Animais , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Humanos , Interferon gama/genética , Interferon gama/metabolismo , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Organismos Livres de Patógenos Específicos , Transdução Genética , Células Vero , Carga Viral , Replicação Viral
10.
Cell ; 182(3): 722-733.e11, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32645327

RESUMO

Vaccines are urgently needed to control the ongoing pandemic COVID-19 and previously emerging MERS/SARS caused by coronavirus (CoV) infections. The CoV spike receptor-binding domain (RBD) is an attractive vaccine target but is undermined by limited immunogenicity. We describe a dimeric form of MERS-CoV RBD that overcomes this limitation. The RBD-dimer significantly increased neutralizing antibody (NAb) titers compared to conventional monomeric form and protected mice against MERS-CoV infection. Crystal structure showed RBD-dimer fully exposed dual receptor-binding motifs, the major target for NAbs. Structure-guided design further yielded a stable version of RBD-dimer as a tandem repeat single-chain (RBD-sc-dimer) which retained the vaccine potency. We generalized this strategy to design vaccines against COVID-19 and SARS, achieving 10- to 100-fold enhancement of NAb titers. RBD-sc-dimers in pilot scale production yielded high yields, supporting their scalability for further clinical development. The framework of immunogen design can be universally applied to other beta-CoV vaccines to counter emerging threats.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vírus da SARS/imunologia , Design Universal , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/química , Linhagem Celular Tumoral , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas/imunologia , Receptores Virais/metabolismo , Vírus da SARS/química , Células Sf9 , Organismos Livres de Patógenos Específicos , Spodoptera , Transfecção , Vacinação/métodos , Células Vero , Vacinas Virais
11.
Avian Dis ; 64(2): 157-165, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32550616

RESUMO

The reemergence of infectious coryza (IC) caused by Avibacterium paragallinarum (AP) as an acute and occasionally chronic respiratory disease in domestic poultry has caused severe losses in several U.S. states. The disease is also associated with decreased egg production in layers and increased condemnations from air sac infections in broilers. A series of applied experiments were performed to elucidate the persistence of AP in infected broiler flocks, to genotype AP strains isolated from field cases, and to evaluate commercial and autogenous vaccine protection in commercial and specific-pathogen-free (SPF) chickens. Experimental evaluation of environmental persistence suggests that AP did not persist more than 12 hr in a hypothetically contaminated environment. Additionally, other detected potential pathogens such as Gallibacterium anatis and infectious bronchitis virus caused mild respiratory signs in the exposed birds. The HMTp210 and HagA genes of four IC field strains were sequenced and compared with published sequences of HMTp210 and HagA. The HMTp210 phylogeny showed a marginally imperfect clustering of the sequences in genogroups A, B, and C. Although not definitive, this phylogeny provided evidence that the four field strains aligned with previously characterized serovar C strains. Moreover, the base pair homology of the four strains was 100% identical to serovar C reference strains (H-18 and Modesto). HagA phylogeny was unclear, but interestingly, the IC field strains were 100% homologous to C-1 strains reported from Mexico and Ecuador. Finally, vaccine protection studies in commercial hens indicate that clinical signs are induced by a combination of IC and other concomitant pathogens infecting commercial birds. Additionally, vaccine protection experiments performed in SPF hens indicated that protection provided by the two commercial vaccines tested provided a reduction in clinical signs and bacterial shedding after two applications.


Assuntos
Vacinas Bacterianas/administração & dosagem , Galinhas , Genótipo , Infecções por Haemophilus/veterinária , Haemophilus paragallinarum/fisiologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Animais , Feminino , Infecções por Haemophilus/microbiologia , Infecções por Haemophilus/prevenção & controle , Haemophilus paragallinarum/imunologia , Doenças das Aves Domésticas/microbiologia , Organismos Livres de Patógenos Específicos
12.
Avian Dis ; 64(2): 183-196, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32550619

RESUMO

Nine infectious bronchitis virus (IBV) strains belonging to the GI-7 lineage were isolated between 2009 and 2017 in China. Phylogenetic analysis and comparisons of full-length sequences of the S1 gene suggested that the GI-7 lineage should be further classified as Taiwan (TW)-I and TW-II sublineages, which correspond to the previous TW-I and TW-II genotypes. The nine IBV strains were clustered in the TW-II sublineage. Further investigation revealed that viruses in the TW-I and TW-II were not only genetically but also antigenically different. Moreover, the TW-II sublineage contained various clades and recombinants. A recombinant was found to originate from recombination events between field strains (TW-II ck/CH/LJL/090608- and GI-19 ck/ CH/LDL/091022-like viruses) in which the recombination in the S1 subunit coding sequences had led to changes in antigenicity of the viruses. A more in-depth investigation demonstrated that TW-II viruses appear to have undergone a significant evolution following introduction in mainland China, which resulted in the viruses diverging into different clades. The viruses between the different clades in TW-II sublineage exhibited a significant change in genetic and antigenic characteristics. In addition, the five TW-II viruses selected on the basis of the results of S1 nucleotide sequence phylogenetic trees showed different pathogenicity to specific-pathogen-free chickens, although they could induce nephritis in the infected chickens and thus were identified as nephropathogenic strains.


Assuntos
Galinhas , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa , Doenças das Aves Domésticas/virologia , Glicoproteína da Espícula de Coronavírus/genética , Sequência de Aminoácidos , Animais , Antígenos Virais/genética , Antígenos Virais/metabolismo , China , Infecções por Coronavirus/virologia , Vírus da Bronquite Infecciosa/genética , Vírus da Bronquite Infecciosa/imunologia , Vírus da Bronquite Infecciosa/patogenicidade , Filogenia , Alinhamento de Sequência , Organismos Livres de Patógenos Específicos , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo
13.
J Vet Sci ; 21(3): e46, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32476320

RESUMO

BACKGROUND: High concentrations of particulate matter less than 2.5 µm in diameter (PM2.5) in poultry houses is an important cause of respiratory disease in animals and humans. Pseudomonas aeruginosa is an opportunistic pathogen that can induce severe respiratory disease in animals under stress or with abnormal immune functions. When excessively high concentrations of PM2.5 in poultry houses damage the respiratory system and impair host immunity, secondary infections with P. aeruginosa can occur and produce a more intense inflammatory response, resulting in more severe lung injury. OBJECTIVES: In this study, we focused on the synergistic induction of inflammatory injury in the respiratory system and the related molecular mechanisms induced by PM2.5 and P. aeruginosa in poultry houses. METHODS: High-throughput 16S rDNA sequence analysis was used for characterizing the bacterial diversity and relative abundance of the PM2.5 samples, and the effects of PM2.5 and P. aeruginosa stimulation on inflammation were detected by in vitro and in vivo. RESULTS: Sequencing results indicated that the PM2.5 in poultry houses contained a high abundance of potentially pathogenic genera, such as Pseudomonas (2.94%). The lung tissues of mice had more significant pathological damage when co-stimulated by PM2.5 and P. aeruginosa, and it can increase the expression levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-α through nuclear factor (NF)-κB pathway in vivo and in vitro. CONCLUSIONS: The results confirmed that poultry house PM2.5 in combination with P. aeruginosa could aggravate the inflammatory response and cause more severe respiratory system injuries through a process closely related to the activation of the NF-κB pathway.


Assuntos
Material Particulado/efeitos adversos , Pneumonia/etiologia , Infecções por Pseudomonas/fisiopatologia , Pseudomonas aeruginosa/fisiologia , Animais , Peso Corporal , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Subunidade p50 de NF-kappa B/metabolismo , Material Particulado/classificação , Pneumonia/induzido quimicamente , Pneumonia/microbiologia , Organismos Livres de Patógenos Específicos , Fator de Necrose Tumoral alfa/metabolismo
15.
Mol Immunol ; 124: 125-141, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32563081

RESUMO

Both mouse and human harbour memory phenotype CD8+ T cells specific for antigens in hosts that have not been previously exposed to these antigens. The origin and the nature of the stimuli responsible for generation of CD44hi CD8+ T cells in specific pathogen-free (SPF) mice remain controversial. It is known that microbiota plays a crucial role in the prevention and resolution of systemic infections by influencing myelopoiesis, regulating dendritic cells, inflammasome activation and promoting the production of type I and II interferons. By contrast, here we suggest that microbiota has a direct effect on generation of memory phenotype CD44hiGP33+CD8+ T cells. In SPF mice, it generates a novel GP33+CD44hiCD8+ T cell sub-population associating the properties of innate and genuine memory cells. These cells are highly enriched in the bone marrow, proliferate rapidly and express immediate effector functions. They dominate the response to LCMV and express particular TCRß chains. The sequence of these selected TCRß chains overlaps with that of GP33+CD8+ T cells directly selected by microbiota in the gut epithelium of SPF mice, demonstrating a common selection mechanism in gut and peripheral CD8+ T cell pool. Therefore microbiota has a direct role in priming T cell immunity in SPF mice and in the selection of TCRß repertoires during systemic infection. We identify a mechanism that primes T cell immunity in SPF mice and may have a major role in colonization resistance and protection from infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Microbiota/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Citotoxicidade Imunológica/imunologia , Memória Imunológica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Organismos Livres de Patógenos Específicos , Subpopulações de Linfócitos T/imunologia
16.
J Dairy Sci ; 103(7): 5816-5829, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32418689

RESUMO

Fermented milk is an effective carrier for probiotics, the consumption of which improves host health. The beneficial effects of probiotics, prebiotics, and synbiotics on gut dysbiosis have been reported previously. However, the way in which specific probiotics, prebiotics, and synbiotics regulate intestinal microbes remains unclear. Therefore, the probiotics Lactobacillus rhamnosus AS 1.2466 and Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 and the prebiotics xylooligosaccharide and red ginseng extracts were fed to mice to determine their effects on the intestinal microbiota. Then, mice were administered xylooligosaccharide and L. rhamnosus (synthesis) by gavage, and the number of L. rhamnosus was determined in the intestine at different times. The results show that probiotics and prebiotics can quickly reduce the Firmicutes/Bacteroidetes ratio, inhibit harmful bacteria (such as Klebsiella and Escherichia coli), and accelerate the recovery of beneficial intestinal microorganisms (such as Lactobacillus). In a complex intestinal microecology, different probiotics and prebiotics have different effects on specific intestinal microorganisms that cannot be recovered in the short term. In addition, after 20 d of intragastric xylooligosaccharide addition at 0.12 g/kg of body weight, L. rhamnosus colonization in the mouse ileum was 7.48 log cfu/mL, which was higher than in the low-dose group, prolonging colonization time and increasing the number of probiotics in the intestine. Therefore, this study demonstrated that probiotics and prebiotics can promote the balance of intestinal microbiota by regulating specific microbes in the intestine, and the effects of a suitable combination of synbiotics are beneficial, laying the foundation for the development of new dairy products rich in synbiotics.


Assuntos
Bactérias/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Prebióticos , Probióticos/farmacologia , Simbióticos , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Microbioma Gastrointestinal/fisiologia , Glucuronatos/administração & dosagem , Glucuronatos/farmacologia , Lactobacillus delbrueckii/química , Lactobacillus rhamnosus/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oligossacarídeos/administração & dosagem , Oligossacarídeos/farmacologia , Panax/química , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Prebióticos/administração & dosagem , Probióticos/administração & dosagem , Organismos Livres de Patógenos Específicos , Simbióticos/administração & dosagem
17.
Appl Environ Microbiol ; 86(14)2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32414800

RESUMO

Due to the complex microecology and microenvironment of dental plaque, novel caries prevention strategies require modulating the microbial communities ecologically and reducing the cariogenic properties effectively. Antimicrobial peptide GH12 reduced the lactic acid production and exopolysaccharide (EPS) synthesis of a Streptococcus mutans biofilm and a three-species biofilm in vitro in previous studies. However, the anticaries effects and microecological effects of GH12 remained to be investigated in a complex biofilm model in vitro and an animal caries model in vivo In the present study, GH12 at 64 mg/liter showed the most effective inhibition of lactic acid production, EPS synthesis, pH decline, and biofilm integrity of human dental plaque-derived multispecies biofilms in vitro, and GH12 at 64 mg/liter was therefore chosen for use in subsequent in vitro and in vivo assays. When treated with 64-mg/liter GH12, the dental plaque-derived multispecies biofilms sampled from healthy volunteers maintained its microbial diversity and showed a microbial community structure similar to that of the control group. In the rat caries model with a caries-promoting diet, 64-mg/liter GH12 regulated the microbiota of dental plaque, in which the abundance of caries-associated bacteria was decreased and the abundance of commensal bacteria was increased. In addition, 64-mg/liter GH12 significantly reduced the caries scores of sulcal and smooth surface caries in all locations. In conclusion, GH12 inhibited the cariogenic properties of dental plaque without perturbing the dental plaque microbiota of healthy individuals and GH12 regulated the dysbiotic microbial ecology and arrested caries development under cariogenic conditions.IMPORTANCE The anticaries effects and microecological regulation effects of the antimicrobial peptide GH12 were evaluated systematically in vitro and in vivo GH12 inhibited the cariogenic virulence of dental plaque without overintervening in the microbial ecology of healthy individuals in vitro GH12 regulated the microbial ecology of dental plaque to a certain extent in vivo under cariogenic conditions, increased the proportion of commensal bacteria, and decreased the abundance of caries-associated bacteria. GH12 significantly suppressed the incidence and severity of dental caries in vivo This study thus describes an alternative antimicrobial therapy for dental caries.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Cárie Dentária/prevenção & controle , Placa Dentária/microbiologia , Microbiota/efeitos dos fármacos , Adulto , Animais , Biofilmes/crescimento & desenvolvimento , Cárie Dentária/genética , Feminino , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Organismos Livres de Patógenos Específicos , Adulto Jovem
18.
Exp Parasitol ; 215: 107917, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32446699

RESUMO

Cystic echinococcosis (CE) is a worldwide hazardous zoonotic parasitosis caused by Echinococcus granulosus. CE development involves complex immunological mechanisms, including participation of multiple immune cells and effector molecules. Myeloid-derived suppressor cells (MDSCs) are known to be involved in chronic and acute inflammatory conditions. In this study, we aimed to characterize the immune function of MDSCs in CE to improve the understanding, prevention and treatment of CE. Our results indicated that MDSCs overexpressing Ly6C and Ly6G inhibit the formation and activity of T helper 2 cells in a NO-dependent manner during E. granulosus infection.


Assuntos
Equinococose/imunologia , Echinococcus granulosus/imunologia , Células Supressoras Mieloides/imunologia , Células Th2/imunologia , Análise de Variância , Animais , Anticorpos Monoclonais , Arginase/análise , Medula Óssea/efeitos dos fármacos , Medula Óssea/imunologia , Citocinas/análise , Feminino , Citometria de Fluxo , Humanos , Ceratolíticos/farmacologia , Camundongos , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/enzimologia , Óxido Nítrico/análise , Espécies Reativas de Oxigênio/análise , Organismos Livres de Patógenos Específicos , Baço/citologia , Baço/efeitos dos fármacos , Baço/imunologia , Tretinoína/farmacologia
19.
J Infect Dis ; 222(4): 551-555, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32444876

RESUMO

We simulated 3 transmission modes, including close-contact, respiratory droplets and aerosol routes, in the laboratory. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be highly transmitted among naive human angiotensin-converting enzyme 2 (hACE2) mice via close contact because 7 of 13 naive hACE2 mice were SARS-CoV-2 antibody seropositive 14 days after being introduced into the same cage with 3 infected-hACE2 mice. For respiratory droplets, SARS-CoV-2 antibodies from 3 of 10 naive hACE2 mice showed seropositivity 14 days after introduction into the same cage with 3 infected-hACE2 mice, separated by grids. In addition, hACE2 mice cannot be experimentally infected via aerosol inoculation until continued up to 25 minutes with high viral concentrations.


Assuntos
Betacoronavirus , Infecções por Coronavirus/transmissão , Pneumonia Viral/transmissão , Aerossóis , Canal Anal/virologia , Animais , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Chlorocebus aethiops , Feminino , Humanos , Imunoglobulina G/sangue , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Transgênicos , Pandemias , Peptidil Dipeptidase A/genética , Faringe/virologia , RNA Viral/isolamento & purificação , Sistema Respiratório/virologia , Risco , Organismos Livres de Patógenos Específicos , Fatores de Tempo , Células Vero , Carga Viral , Perda de Peso
20.
Virus Res ; 285: 198002, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32380209

RESUMO

In the present study, an IBV strain I0305/19 was isolated from a diseased commercial broiler flock in 2019 in China with high morbidity and mortality. The isolate I0305/19 was clustered together with viruses in sublineage D of GI-19 lineage on the basis of the complete S1 sequence analysis. Isolate I0305/19 and other GI-19 viruses isolated in China have the amino acid sequence MIA at positions 110-112 in the S protein. Further analysis based on the complete genomic sequence showed that the isolate emerged through at least four recombination events between GI-19 ck/CH/LJS/120848- and GI-13 4/91-like strains, in which the S gene was found to be similar to that of the GI-19 ck/CH/LJS/120848-like strain. Pathological assessment showed the isolate was a nephropathogenic IBV strain that caused high morbidity of 100 % and mortality of 80 % in 1-day-old specific-pathogen-free (SPF) chicks. The isolate I0305/19 exhibited broader tropisms in different tissues, including tracheas, lungs, bursa of Fabricius, spleen, liver, kidneys, proventriculus, small intestines, large intestines, cecum, and cecal tonsils. Furthermore, subpopulations of the virus were found in tissues of infected chickens; this finding is important in understanding how the virulent IBV strains can potentially replicate and evolve to cause disease. This information is also valuable for understanding the mechanisms of replication and evolution of other coronaviruses such as the newly emerged SARS-CoV-2.


Assuntos
Galinhas/virologia , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/genética , Vírus da Bronquite Infecciosa/patogenicidade , Doenças das Aves Domésticas/virologia , Recombinação Genética , Tropismo Viral , Animais , China , Infecções por Coronavirus/virologia , Genoma Viral , Vírus da Bronquite Infecciosa/classificação , Vírus da Bronquite Infecciosa/fisiologia , Filogenia , Organismos Livres de Patógenos Específicos , Glicoproteína da Espícula de Coronavírus/genética , Replicação Viral
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