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1.
Trop Anim Health Prod ; 53(1): 65, 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33392825

RESUMO

This is the first study investigating the changes in some gene expressions related to the TLR pathway in vivo in sheep. Lipopolysaccharide (LPS) and lipoteichoic acid (LTA) molecules were administrated separately and in combination to the Akkaraman lambs via intranasal route. For this purpose, 28 lambs were distributed into four groups (LPS, LTA, LPS + LTA, and control, n = 7). Blood samples were collected to isolate the peripheral blood mononuclear cells (PBMCs) at 24 h and on day 7. Expression levels of TLR2, TLR4, MyD88, TRAF6, TNF-α, IL-1ß, IL-6, IL-10, NF-κß, and IFN-γ genes were determined by qRT-PCR. Increases were determined in the expression data of TLR2 [LPS (P < 0.05) and LTA + LPS (P < 0.01)], TLR4 [LTA + LPS (P < 0.05)], TNF-α, IL-10 [LTA + LPS (P < 0.05)], and IFN-γ genes in all groups in the mRNA expression analysis of PBMCs isolated at 24 h whereas decreases were determined in the expression levels of these genes on day 7. The combination of LPS + LTA stimulated lamb PBMCs more effectively than separate administration of LPS and LTA at 24 h. Therefore, this article may contribute to the understanding the host-pathogen interaction of respiratory-transmitted bacterial diseases concerning PBMCs at 24 h and on day 7. Also this study may contribute to the dose adjustment for bacterial vaccine studies in sheep. Experimental application doses will be helpful for in vivo and in vitro drug and vaccine development studies in the fields of pharmacology and microbiology.


Assuntos
Interações Hospedeiro-Patógeno , Leucócitos Mononucleares/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Ovinos/imunologia , Administração Intranasal , Animais , Citocinas/metabolismo , Expressão Gênica , Lipopolissacarídeos , Masculino , Ácidos Teicoicos , Fator de Necrose Tumoral alfa/metabolismo
2.
PLoS One ; 15(9): e0238781, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32911525

RESUMO

Maedi-visna (MV) is a complex lentiviral disease syndrome characterised by long immunological and clinical latencies and chronic progressive inflammatory pathology. Incurable at the individual level, it is widespread in most sheep-keeping countries, and is a cause of lost production and poor animal welfare. Culling seropositive animals is the main means of control, but it might be possible to manage virus transmission effectively if its epidemiology was better quantified. We derive a mathematical epidemiological model of the temporal distributions of seroconversion probabilities and estimate susceptibility, transmission rate and latencies in three serological datasets. We demonstrate the existence of epidemiological latency, which has not explicitly been recognised in the SRLV literaure. This time delay between infection and infectiousness apparently exceeds the delay between infection and seroconversion. Poor body condition was associated with more rapid seroconversion, but not with a higher probability of infection. We estimate transmission rates amongst housed sheep to be at about 1,000 times faster than when sheep were at grass, when transmission was negligible. Maternal transmission has only a small role in transmission, because lambs from infected ewes have a low probability of being infected directly by them, and only a small proportion of lambs need be retained to maintain flock size. Our results show that MV is overwhelmingly a disease of housing, where sheep are kept in close proximity. Prevalence of MV is likely to double each year from an initial low incidence in housed flocks penned in typically-sized groups of sheep (c. 50) for even a few days per year. Ewes kept entirely at grass are unlikely to experience transmission frequently enough for MV to persist, and pre-existing infection should die out as older ewes are replaced, thereby essentially curing the flock.


Assuntos
Pneumonia Intersticial Progressiva dos Ovinos/transmissão , Vírus Visna-Maedi/patogenicidade , Animais , Monitoramento Epidemiológico/veterinária , Incidência , Modelos Teóricos , Pneumonia Intersticial Progressiva dos Ovinos/imunologia , Pneumonia Intersticial Progressiva dos Ovinos/virologia , Prevalência , Soroconversão , Ovinos/imunologia , Ovinos/virologia , Doenças dos Ovinos/epidemiologia , Vírus Visna-Maedi/imunologia
3.
Anim Sci J ; 91(1): e13378, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32329195

RESUMO

Interferon-tau (IFNT) regulates maternal recognition during early pregnancy in ruminants. The liver can serve as a hematopoietic organ, and it has immune functions. This study hypothesized whether mRNA and proteins of interferon-stimulated genes (ISGs) induced by early pregnancy are upregulated in maternal liver. Therefore, we determined the expression of interferon-stimulated gene 15-kDa protein (ISG15), 2',5'-oligoadenylate synthetase 1 (OAS1), myxovirus resistance protein 1 (MX1), interferon-gamma-inducible protein 10 (IP-10), and signal transducer and activator of transcription 1 (STAT1) in maternal livers during early pregnancy in sheep. Ovine livers were sampled on day 16 of the estrous cycle, and days 13, 16, and 25 of pregnancy, and expression of ISGs was detected by quantitative real-time PCR, Western blot, and immunohistochemistry analysis. Our results showed that there were increases in expression of the mRNA and proteins of ISG15, OAS1, IP-10, STAT1, and MX1 during early pregnancy. STAT1 protein was limited to the hepatocytes, and endothelial cells of proper hepatic arteries and hepatic portal veins. In conclusion, the upregulation of ISG15, OAS1, IP-10, STAT1, and MX1 proteins may be implicated in maternal hepatic immune adjustment and other functions during early pregnancy in sheep.


Assuntos
2',5'-Oligoadenilato Sintetase/genética , 2',5'-Oligoadenilato Sintetase/metabolismo , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Citocinas/genética , Citocinas/metabolismo , Expressão Gênica , Fígado/metabolismo , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Prenhez/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Ovinos/genética , Ovinos/fisiologia , Ubiquitinas/genética , Ubiquitinas/metabolismo , Animais , Ciclo Estral/genética , Ciclo Estral/metabolismo , Feminino , Fígado/imunologia , Gravidez , Prenhez/imunologia , Ovinos/imunologia , Regulação para Cima
4.
J Dairy Sci ; 103(6): 5501-5508, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32307170

RESUMO

Breeding stress-resilient livestock is a potential strategy to help mitigate the negative effect of environmental and pathogenic stressors. The hypothalamic-pituitary-adrenal axis and immune system are activated during stress events and release mediators into the circulation that help restore physiological homeostasis. The purpose of this study was to assess a comprehensive set of circulatory mediators released in response to an acute immune stress challenge to identify candidate biomarkers that can be used for the selection of stress-resilient animals. Fifteen female lambs were stress challenged with an intravenous bolus of lipopolysaccharide (LPS; 400 ng/kg), and blood was collected from the jugular vein at 0, 2, 4, and 6 h after LPS challenge to identify and monitor candidate stress biomarkers; temperature was also recorded over time. Biomarker responses were evaluated with a repeated-measures model to compare time points with baseline values. As expected, all sheep had a monophasic febrile response to LPS challenge, and cortisol increased and returned to baseline by 6 h. The cytokines tumor necrosis factor-α, IL-6, IFN-γ (proinflammatory), and IL-10 (anti-inflammatory) increased, but only tumor necrosis factor-α returned to baseline during the monitoring period. The cytokines IL-1α, IL-1ß, IL-17α (proinflammatory), and IL-4 (anti-inflammatory) did not respond to LPS challenge. All chemokines (CCL2, CCL3, CCL4, CXCL10, and IL-8) responded to LPS challenge; however, only CCL2, CCL3, CCL4, and CXCL10 increased over time, and only CCL3, CCL4, and CXCL10 returned to baseline during the monitoring period. MicroRNA (miR-145, miR-233, and miR-1246) also increased and remained elevated during the study. In summary, the LPS challenge induced a strong stress response in Rideau-Dorset sheep that could be monitored with a distinct profile of circulatory biomarkers.


Assuntos
Biomarcadores/sangue , Citocinas/sangue , Endotoxemia/sangue , Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Ovinos/fisiologia , Animais , Cruzamento , Citocinas/genética , Endotoxemia/imunologia , Feminino , Hidrocortisona/sangue , Lipopolissacarídeos/efeitos adversos , MicroRNAs/genética , Ovinos/sangue , Ovinos/genética , Ovinos/imunologia , Estresse Fisiológico
5.
J Dairy Sci ; 103(7): 6583-6587, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32331871

RESUMO

Finding a rapid and simple method of serum IgG determination in lambs is essential for monitoring failure of passive transfer of immunity. The aim of this study was to assess the ability of capillary electrophoresis (CE), an instrument mainly used in blood serum protein analysis, to estimate IgG content in serum of newborn lambs through determination of only total Ig percentage by comparing the results with those obtained with radial immunodiffusion (RID), the reference method for serum IgG quantification. Serum samples were collected at 24 h after birth from 40 Sarda lambs. The IgG concentration measured by RID and serum total Ig concentration measured by CE were (mean ± standard deviation) 29.8 ± 16.1 g/L and 37.8 ± 15.0%, respectively. Data provided by RID and CE analysis showed a polynomial trend (RID = 0.02CE2 - 0.04CE + 4.13; coefficient of determination, R2 = 0.96), displaying a strong relationship between these 2 methods. Applying the polynomial equation, the IgG values were predicted. Predicted IgG values were highly correlated (r = 0.98) and related (R2 = 0.96) to IgG values obtained by RID assay. These data were subjected to Bland-Altman analysis, revealing a high level of agreement between CE and RID methods with a bias that was not different from 0 (-0.04 g/L) and agreement limits of -6.38 g/L (low) and +6.30 g/L (high). In addition, the linear regression analysis between differences (dependent variable) and average of IgG concentration by CE and RID (independent variable) did not show proportional bias (R2 = 0.01). In conclusion, CE is a reliable instrument for a lamb health monitoring program, where Bland-Altman analysis also confirmed that the CE method can be a suitable alternative to RID.


Assuntos
Eletroforese Capilar/veterinária , Imunoglobulina G/sangue , Ovinos/sangue , Animais , Animais Recém-Nascidos , Feminino , Imunodifusão/veterinária , Modelos Estatísticos , Análise de Regressão , Ovinos/imunologia
6.
Parasit Vectors ; 13(1): 185, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32268924

RESUMO

BACKGROUND: Tick distribution in Sweden has increased in recent years, with the prevalence of ticks predicted to spread towards the northern parts of the country, thus increasing the risk of tick-borne zoonoses in new regions. Tick-borne encephalitis (TBE) is the most significant viral tick-borne zoonotic disease in Europe. The disease is caused by TBE virus (TBEV) infection which often leads to severe encephalitis and myelitis in humans. TBEV is usually transmitted to humans via tick bites; however, the virus can also be excreted in the milk of goats, sheep and cattle and infection may then occur via consumption of unpasteurised dairy products. Virus prevalence in questing ticks is an unreliable indicator of TBE infection risk as viral RNA is rarely detected even in large sample sizes collected at TBE-endemic areas. Hence, there is a need for robust surveillance techniques to identify emerging TBEV risk areas at early stages. METHODS: Milk and colostrum samples were collected from sheep and goats in Örebro County, Sweden. The milk samples were analysed for the presence of TBEV antibodies by ELISA and validated by western blot in which milk samples were used to detect over-expressed TBEV E-protein in crude cell extracts. Neutralising titers were determined by focus reduction neutralisation test (FRNT). The stability of TBEV in milk and colostrum was studied at different temperatures. RESULTS: In this study we have developed a novel strategy to identify new TBEV foci. By monitoring TBEV antibodies in milk, we have identified three previously unknown foci in Örebro County which also overlap with areas of TBE infection reported during 2009-2018. In addition, our data indicates that keeping unpasteurised milk at 4 °C will preserve the infectivity of TBEV for several days. CONCLUSIONS: Altogether, we report a non-invasive surveillance technique for revealing risk areas for TBE in Sweden, by detecting TBEV antibodies in sheep milk. This approach is robust and reliable and can accordingly be used to map TBEV "hotspots". TBEV infectivity in refrigerated milk was preserved, emphasising the importance of pasteurisation (i.e. 72 °C for 15 s) prior to consumption.


Assuntos
Anticorpos Antivirais/análise , Encefalite Transmitida por Carrapatos/imunologia , Encefalite Transmitida por Carrapatos/veterinária , Monitoramento Epidemiológico/veterinária , Leite/imunologia , Animais , Colostro/imunologia , Vírus da Encefalite Transmitidos por Carrapatos , Feminino , Cabras/imunologia , Humanos , Testes de Neutralização , RNA Viral/genética , Ovinos/imunologia , Suécia/epidemiologia , Zoonoses/parasitologia , Zoonoses/transmissão
7.
Immunology ; 160(1): 52-63, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32052861

RESUMO

As a pineal gland hormone, melatonin acts through its receptors to modulate the immune system. The immune system is composed of primary and secondary organs, and immune organs are adapted to the presence of the fetal alloantigen during pregnancy. However, it is unclear whether melatonin affects maternal immune organs during early pregnancy in sheep. In this study, the ovine thymus, lymph node, spleen and liver were sampled at day 16 of the oestrous cycle, and at days 13, 16 and 25 of pregnancy. The expression of melatonin receptor 1A (MT1), melatonin receptor 1B (MT2) and cluster of differentiation 4 (CD4) was detected by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry experiments. Our results showed that during early pregnancy there was an upregulation of MT1 mRNA and protein in the thymus, lymph node and liver, and there was a downregulation in the spleen. The expression of MT2 mRNA and protein was increased in the thymus but decreased in the spleen and liver, and there was no significant change in the lymph node during early pregnancy. CD4 protein was upregulated in the thymus, lymph node and liver, but there were no significant changes in the spleen during early pregnancy. In conclusion, early pregnancy induces tissue-specific expression of MT1, MT2 and CD4, which may be due to the different functions of the thymus, lymph node, spleen and liver. Further, melatonin is involved in immune regulation of the maternal thymus, lymph node, spleen and liver during early pregnancy in sheep.


Assuntos
Antígenos CD4/metabolismo , Histocompatibilidade Materno-Fetal , Melatonina/metabolismo , Prenhez/imunologia , Receptores de Melatonina/metabolismo , Ovinos/imunologia , Animais , Feminino , Perfilação da Expressão Gênica , Tolerância Imunológica , Fígado/imunologia , Fígado/metabolismo , Linfonodos/imunologia , Linfonodos/metabolismo , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/imunologia , Baço/imunologia , Baço/metabolismo , Timo/imunologia , Timo/metabolismo , Regulação para Cima/imunologia
8.
Benef Microbes ; 11(2): 175-181, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-31990221

RESUMO

Studies aiming at the development and evaluation of alternative methods to minimise losses caused by the gastrointestinal nematode Haemonchus contortus are extremely important. Such research is essential, given the high morbidity rates among sheep and the significant mortality rates of lambs, allied to the low efficacy of commercial products for the control of this parasite. The purpose of this study was to evaluate the effect of the Saccharomyces cerevisiae (YT001 - YEASTECH) on the control of H. contortus and its modulation of the immune response in experimentally infected sheep. Eighteen sheep were divided into two groups. Group 1, the control group, comprised animals infected with H. contortus and supplemented with distilled water, while Group 2, the treated group, consisted of animals infected and supplemented with S. cerevisiae (400 million cfu/day of suspension for 49 days). The following parasitological parameters were evaluated: number of eggs per gram of faeces, number of infective larvae (L3) recovered per faecal culture, and parasitic load of the abomasum. The following immunological parameters were quantified: immunoglobulin (Ig)A in the mucous secretions and serum IgG; cytokines interleukin (IL)-4, IL-5 and IL-10; number of eosinophils in the abomasal mucosa and groups of cells positive for the markers: MHCII, CD4+CD25+, CD5+CD8+, WC4, CD5+CD4+, CD8+CD11b+ and CD5+WC1 by whole blood flow cytometry. The results revealed a significant decrease (P<0.05) in the number of larvae and significantly higher serum IgG levels (P<0.05) in the group supplemented with S. cerevisiae. The supplemented animals showed significantly larger numbers of eosinophils (P<0.05), as well as more cells positive for MHCII, CD4+CD25+, CD5+CD8+ than the control animals. This study confirmed the beneficial action of S. cerevisiae on the host immune response to H. contortus, as evidenced mainly by the smaller number of L3 recovered from the faeces of sheep supplemented with S. cerevisiae.


Assuntos
Suplementos Nutricionais/microbiologia , Hemoncose/veterinária , Probióticos/administração & dosagem , Saccharomyces cerevisiae/imunologia , Doenças dos Ovinos/terapia , Ovinos/imunologia , Administração Oral , Animais , Anticorpos Anti-Helmínticos/sangue , Citocinas/imunologia , Eosinófilos/imunologia , Fezes/parasitologia , Hemoncose/imunologia , Hemoncose/terapia , Haemonchus , Interações entre Hospedeiro e Microrganismos/imunologia , Imunoglobulina A/análise , Imunoglobulina G/sangue , Contagem de Leucócitos , Masculino , Contagem de Ovos de Parasitas , Ovinos/parasitologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia
9.
J Immunol Methods ; 478: 112722, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31816281

RESUMO

In 2012, the FORS system was accepted by the International Society of Blood Transfusion as the 31st blood group system. Forssman (Fs) antigen (Ag) expression is most commonly found on sheep red blood cells (RBC) but rare in human RBC. Anti-Fs antibodies (Ab) are naturally occurring in human sera and are predominantly IgM but they can also be IgG. To this day, the global prevalence of the FORS system is unknown. Currently, there is a lack of natural FORS1-positive RBC available to use for anti-Fs screening in large populations. This study was designed to produce FORS1-positive cells viable for 40 days use in the anti-Fs screening. Three to 5% FORS1-positive cells were produced using sheep's blood and CellStab stabilizer solution. The quality of the FORS1-positive cells was investigated in more than three independent experiments of ABO titration, osmotic fragility test and supernatant haemolysis. For each batch of FORS1-positive cells produced, an extended antibody panel was performed. To demonstrate that the FORS1-positive cells can be used for up to 40 days, anti-Fs screening and classification were carried out in a patient and donor population. Antigenic expression and membrane integrity of FORS1-positive cells remained stable for 40 days. Good FORS1 Ag preservation was established, and minimal haemolysis was observed. In conclusion, a novel and easy-to-produce reagent has been developed and submitted to a patent with stable FORS1 Ag expression. With this FORS1-positive cell suspension, it is now possible to screen and classify anti-Fs Ab in large populations.


Assuntos
Antígenos de Grupos Sanguíneos/isolamento & purificação , Tipagem e Reações Cruzadas Sanguíneas/métodos , Eritrócitos/metabolismo , Antígeno de Forssman/isolamento & purificação , Cultura Primária de Células/métodos , Animais , Antígenos de Grupos Sanguíneos/imunologia , Linhagem Celular , Sobrevivência Celular , Eritrócitos/imunologia , Antígeno de Forssman/imunologia , Antígeno de Forssman/metabolismo , Humanos , Ovinos/sangue , Ovinos/imunologia , Fatores de Tempo
10.
J Anim Sci ; 98(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31768520

RESUMO

AbstractThis study evaluated the effect of early weaning (EW) of artificially reared lambs using a restricted milk replacer (MR) feeding and step-down weaning system on the short- and long-term effects on growth, feed intake, selected blood metabolites and hormones, body composition, and small intestine development. Mixed-sex twin-born 2 to 5 d old lambs were randomly allocated to individual pens and fed MR at 20% of initial individual BW in week 1 and 15% in week 2 followed by weaning off MR by the end of week 4 (EW; n = 16) or week 6 (Control; Ctrl, n = 16) using a step-down procedure. Concentrate starter and fiber diets were offered ad libitum to week 9, then gradually removed over a 10-d period. All lambs were managed as a single group on pasture from weeks 6 to 16 of the trial. Feed intake was recorded daily in the first 6 wk, and BWs recorded weekly. At weeks 2, 4, 6, and 8, and pre- and postclostridial vaccination at week 8, blood samples were collected for analysis of selected blood metabolites, IGF-1, and immune function. Body composition was evaluated in eight animals per group at weeks 4 and 16 after euthanasia, and duodenal samples collected for histomorphometric evaluation. Early weaned lambs had lower DM, ME, CP, and NDF intake than Ctrl lambs at 21, 15, 21, and 36 d of rearing, respectively (P < 0.001), driven by lower intakes of MR from day 15 (P < 0.001) as per the experimental design, and lower total DMI of fiber (P = 0.001) from 21 to 42 d of rearing. Lamb BW tended (P = 0.097) to be lower in EW than Ctrl lambs from 5 to 10 wk of rearing, with lower ADG in EW lambs from weeks 3 to 6 (P = 0.041). Early weaning had negligible effects on duodenal morphology, organ, and carcass weights at weeks 4 and 16. Plasma metabolites (urea nitrogen, triglycerides, NEFA, glucose, and total protein) were similar between groups, while ß-hydroxybutyrate was greater in EW than Ctrl lambs at weeks 4 and 6 (P = 0.018) but not week 8 indicative of early rumen development. Serum IGF-1 tended to be lower in EW than Ctrl lambs from weeks 2 to 6 only (P = 0.065). All lambs developed antibody responses postvaccination and there was no effect of treatment (P = 0.528). The results of this study illustrate that artificially reared lambs can be weaned off MR by 4 or 6 wk of rearing without compromising growth, small intestine morphology, major organ development, and body composition, nor immune function at either 4 (preweaning) or 16 (postweaning) wk of age.


Assuntos
Ingestão de Alimentos , Ovinos/fisiologia , Ácido 3-Hidroxibutírico/sangue , Animais , Nitrogênio da Ureia Sanguínea , Composição Corporal , Sistema Endócrino/crescimento & desenvolvimento , Feminino , Intestino Delgado/crescimento & desenvolvimento , Masculino , Distribuição Aleatória , Rúmen/crescimento & desenvolvimento , Ovinos/crescimento & desenvolvimento , Ovinos/imunologia , Desmame
11.
Rev. argent. microbiol ; 51(4): 316-323, dic. 2019. graf
Artigo em Inglês | LILACS | ID: biblio-1057395

RESUMO

Abstract Bovine leukemia virus (BLV) is an important cattle pathogen that causes major economic losses worldwide, especially in dairy farms. The use of animal models provides valuable insight into the pathogenesis of viral infections. Experimental infections of sheep have been conducted using blood from BLV-infected cattle, infectious BLV molecular clones or tumor-derived cells. The Fetal Lamb Kidney cell line, persistently infected with BLV (FLK-BLV), is one of the most commonly used long-term culture available for the permanent production of virus. FLK-BLV cells or the viral particles obtained from the cell-free culture supernatant could be used as a source of provirus or virus to experimentally infect sheep. In this report, we aimed to determine the minimum amount of FLK-BLV cells or cell-free supernatant containing BLV needed to produce infection in sheep. We also evaluated the amount of antibodies obtained from a naturally-infected cow required to neutralize this infection. We observed that both sheep experimentally inoculated with 5000 FLK-BLV cells became infected, as well as one of the sheep receiving 500 FLK-BLV cells. None of the animals inoculated with 50 FLK-BLV cells showed evidence of infection. The cell-free FLK-BLV supernatant proved to be infective in sheep up to a 1:1000 dilution. Specific BLV antibodies showed neutralizing activity as none of the sheep became infected. Conversely, the animals receiving a BLV-negative serum showed signs of BLV infection. These results contribute to the optimization of a sheep bioassay which could be useful to further characterize BLV infection.


Resumen El virus de la leucosis bovina (bovine leukemia virus [BLV]) es un importante agente patógeno del ganado que causa importantes pérdidas económicas en todo el mundo, especialmente en los rodeos lecheros. El uso de modelos animales proporciona información valiosa sobre la patogénesis de las infecciones virales. Se realizaron infecciones experimentales en ovejas usando sangre de bovinos infectados con BLV, clones moleculares de BLV infecciosos o células derivadas de tumores. La línea celular Fetal Lamb Kidney, persistentemente infectada con el BLV (FLK-BLV), es uno de los cultivos a largo plazo más utilizados para la producción permanente de virus. Las células FLK-BLV o las partículas virales obtenidas del sobrenadante del cultivo libre de células podrían usarse como fuente de provirus o de virus para infectar experimentalmente ovejas. En este trabajo, nuestro objetivo fue determinar la cantidad mínima de células FLK-BLV o de sobrenadante libre de células que contiene BLV necesaria para producir infección en ovejas. También evaluamos la cantidad de anticuerpos bovinos anti-BLV necesaria para neutralizar la infección. Observamos que las dos ovejas inoculadas experimentalmente con 5000 células FLK-BLV se infectaron, y que una de las dos ovejas que recibieron 500 células FLK-BLV se infectó. Ninguno de los animales inoculados con 50 células FLK-BLV mostró evidencia de infección. El sobrenadante FLK-BLV libre de células demostró ser infectivo en ovejas hasta la dilución 1:1000. Los anticuerpos BLV específicos mostraron actividad neutralizante, ya que ninguna de las ovejas se infectó. Por el contrario, los animales que recibieron un suero BLV negativo mostraron signos de infección por BLV. Estos resultados contribuyen a la optimización de un bioensayo en ovejas útil para caracterizar la infección por BLV.


Assuntos
Animais , Bioensaio/veterinária , Ovinos/imunologia , Leucose Enzoótica Bovina/prevenção & controle , Vírus da Leucemia Bovina/patogenicidade , Infecções por Deltaretrovirus/imunologia , Modelos Animais
12.
BMC Genomics ; 20(1): 816, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699027

RESUMO

BACKGROUND: The Djallonke sheep is well adapted to harsh environmental conditions, and is relatively resistant to Haemonchosis and resilient to animal trypanosomiasis. The larger Sahelian sheep, which cohabit the same region, is less well adapted to these disease challenges. Haemonchosis and Trypanosomiasis collectively cost the worldwide animal industry billions of dollars in production losses annually. RESULTS: Here, we separately sequenced and then pooled according to breed the genomes from five unrelated individuals from each of the Djallonke and Sahelian sheep breeds (sourced from Ghana), at greater than 22-fold combined coverage for each breed. A total of approximately 404 million (97%) and 343 million (97%) sequence reads from the Djallonke and Sahelian breeds respectively, were successfully mapped to the sheep reference genome Oar v3.1. We identified approximately 11.1 million and 10.9 million single nucleotide polymorphisms (SNPs) in the Djallonke and Sahelian breeds, with approximately 15 and 16% respectively of these not previously reported in sheep. Multiple regions of reduced heterozygosity were also found; 70 co-localised within genomic regions harbouring genes that mediate disease resistance, immune response and adaptation in sheep or cattle. Thirty- three of the regions of reduced heterozygosity co-localised with previously reported genes for resistance to haemonchosis and trypanosomiasis. CONCLUSIONS: Our analyses suggest that these regions of reduced heterozygosity may be signatures of selection for these economically important diseases.


Assuntos
Adaptação Fisiológica/genética , Resistência à Doença/genética , Genômica , Heterozigoto , Ovinos/genética , Ovinos/fisiologia , Clima Tropical , Animais , Cruzamento , Cromossomos de Mamíferos/genética , Feminino , Masculino , Polimorfismo de Nucleotídeo Único , Ovinos/imunologia , Ovinos/microbiologia , Tripanossomíase/imunologia
13.
PLoS Genet ; 15(11): e1008461, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31697674

RESUMO

Much of our knowledge of the drivers of immune variation, and how these responses vary over time, comes from humans, domesticated livestock or laboratory organisms. While the genetic basis of variation in immune responses have been investigated in these systems, there is a poor understanding of how genetic variation influences immunity in natural, untreated populations living in complex environments. Here, we examine the genetic architecture of variation in immune traits in the Soay sheep of St Kilda, an unmanaged population of sheep infected with strongyle gastrointestinal nematodes. We assayed IgA, IgE and IgG antibodies against the prevalent nematode Teladorsagia circumcincta in the blood plasma of > 3,000 sheep collected over 26 years. Antibody levels were significantly heritable (h2 = 0.21 to 0.57) and highly stable over an individual's lifespan. IgA levels were strongly associated with a region on chromosome 24 explaining 21.1% and 24.5% of heritable variation in lambs and adults, respectively. This region was adjacent to two candidate loci, Class II Major Histocompatibility Complex Transactivator (CIITA) and C-Type Lectin Domain Containing 16A (CLEC16A). Lamb IgA levels were also associated with the immunoglobulin heavy constant loci (IGH) complex, and adult IgE levels and lamb IgA and IgG levels were associated with the major histocompatibility complex (MHC). This study provides evidence of high heritability of a complex immunological trait under natural conditions and provides the first evidence from a genome-wide study that large effect genes located outside the MHC region exist for immune traits in the wild.


Assuntos
Animais Selvagens/imunologia , Imunidade Inata , Ovinos/imunologia , Infecções por Strongylida/imunologia , Animais , Animais Selvagens/sangue , Anticorpos/sangue , Anticorpos/imunologia , Helmintos/imunologia , Helmintos/patogenicidade , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Ovinos/sangue , Infecções por Strongylida/sangue
14.
PLoS One ; 14(10): e0223978, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618247

RESUMO

Guertu virus (GTV) is a tick-borne phleboviruses (TBPVs) which belongs to the genus Banyangvirus in the family of Phenuiviridae. In vitro and in vivo studies of GTV demonstrated that it was able to infect animal and human cell lines and could cause pathological lesions in mice. Glycoproteins (GP, including Gn and Gc) on the surface of Guertu virus (GTV) could bind to receptors on host cells and induce protective immunity in the host, but knowledge is now lacking on the information of B cell epitopes (BCEs) present on GTV-GP protein. The aim of this study was to identify all BCEs on Gn of the GTV DXM strain using rabbit pAbs against GTV-Gn. Seven fine BCEs and two antigenic peptides (APs) from nine reactive 16mer-peptides were identified, which are EGn1 (2PIICEGLTHS11), EGn2 (135CSQDSGT141), EGn3 (165IP EDVF170), EGn4 (169VFQEL K174), EGn5 (187IDGILFN193), EGn6 (223QTKWIQ228), EGn7 (237CHKDGIGPC245), AP-8 (299GVRVRPKCYGFSRMMA314) and AP-9 (355CASH FCSSAESGKKNT370), of which six of mapped BCEs were recognized by the IgG-positive sheep serum obtained from sheep GTV-infected naturally. Multiple sequence alignments (MSA) based on each mapped BCE motif identified that the most of identified BCEs and APs are highly conserved among 10 SFTSV strains from different countries and lineages that share relatively close evolutionary relationships with GTV. The fine epitope mapping of the GTV-Gn would provide basic data with which to explore the GTV-Gn antigen structure and pathogenic mechanisms, and it could lay the foundation for the design and development of a GTV multi-epitope peptide vaccine and detection antigen.


Assuntos
Mapeamento de Epitopos/métodos , Glicoproteínas/química , Peptídeos/metabolismo , Phlebovirus/metabolismo , Sequência de Aminoácidos , Animais , Modelos Moleculares , Conformação Proteica , Coelhos , Alinhamento de Sequência , Ovinos/imunologia , Proteínas do Envelope Viral/química
15.
Science ; 365(6459): 1296-1298, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31604239

RESUMO

Our understanding of the deterioration in immune function in old age-immunosenescence-derives principally from studies of modern human populations and laboratory animals. The generality and significance of this process for systems experiencing complex, natural infections and environmental challenges are unknown. Here, we show that late-life declines in an important immune marker of resistance to helminth parasites in wild Soay sheep predict overwinter mortality. We found senescence in circulating antibody levels against a highly prevalent nematode worm, which was associated with reduced adult survival probability, independent of changes in body weight. These findings establish a role for immunosenescence in the ecology and evolution of natural populations.


Assuntos
Envelhecimento/imunologia , Resistência à Doença/imunologia , Helmintíase Animal/imunologia , Imunossenescência , Ovinos/imunologia , Ovinos/parasitologia , Animais , Anticorpos Anti-Helmínticos/sangue , Peso Corporal , Feminino , Imunoglobulina G/sangue , Modelos Lineares , Masculino , Contagem de Ovos de Parasitas , Carga Parasitária , Escócia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Análise de Sobrevida
16.
Vaccine ; 37(41): 6068-6075, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31471154

RESUMO

Bluetongue (BT) is a hemorrhagic non-contagious, biting midge-transmitted disease of wild and domestic ruminants that is caused by bluetongue virus (BTV). Annual vaccination plays a pivotal role in BT disease control in endemic regions. Due to safety concerns of the current BTV multivalent live attenuated vaccine (LAV), a safe efficacious new generation subunit vaccine such as a plant-produced BT virus-like particle (VLP) vaccine is imperative. Previously, homogenous BTV serotype 8 (BTV-8) VLPs were successfully produced in Nicotiana benthamiana plants and provided protective immunity in sheep. In this study, combinations of BTV capsid proteins from more than one serotype were expressed and assembled to form chimaeric BTV-3 and BTV-4 VLPs in N. benthamiana plants. The assembled homogenous BTV-8, as well as chimaeric BTV-3 and chimaeric BTV-4 VLP serotypes, were confirmed by SDS-PAGE, Transmission Electron microscopy (TEM) and protein confirmation using liquid chromatography-mass spectrometry (LC-MS/MS) based peptide sequencing. As VP2 is the major determinant eliciting protective immunity, the percentage coverage and number of unique VP2 peptides detected in assembled chimaeric BT VLPs were used as a guide to assemble the most appropriate chimaeric combinations. Both plant-produced chimaeric BTV-3 and BTV-4 VLPs were able to induce long-lasting serotype-specific neutralizing antibodies equivalent to the monovalent LAV controls. Antibody levels remained high to the end of the trial. Combinations of homogenous and chimaeric BT VLPs have great potential as a safe, effective multivalent vaccine with the ability to distinguish between vaccinated and infected individuals (DIVA) due to the absence of non-structural proteins.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vírus Bluetongue/imunologia , Bluetongue/prevenção & controle , Ovinos/imunologia , Vacinação/veterinária , Animais , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Tabaco/virologia , Vacinas Atenuadas/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/imunologia
17.
J Anim Sci ; 97(11): 4496-4502, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31504598

RESUMO

Hazel leaves (Corylus avellana) fed to sheep resulted in decreased methane emissions without negatively affecting feed intake and were found to have antioxidant properties in vitro. The objective of this study was to evaluate effects of hazel leaves, rich in tannins, on blood antioxidant activity, cellular immune response, and heart beat parameters in sheep. Four experimental pellets were produced by mixing alfalfa and hazel leaves in different proportions, including alfalfa alone as a control, 30% and 60% of hazel leaves, the latter also with 3.8% polyethylene glycol (PEG). Six adult, nonpregnant, nonlactating female sheep (71 ± 5.7 kg of body weight) were allocated to 4 treatments in a 6 × 4 crossover design with four 18-d periods. The diet consisted of experimental pellets and ryegrass-dominated hay (ratio 80% to 20% in dry matter), resulting in hazel leaf proportions of approximately 0%, 25%, and 50% in the total diet. Blood samples were collected at the end of each period to determine plasma total phenol concentration and markers of oxidative status as well as peripheral blood mononuclear cells (PBMC) activation and proliferation response in vitro. Heart rate (HR) and HR variability parameters were measured for 2 consecutive days in each period, during different activities (i.e., eating pellets or hay, or lying). Treatments were compared with multiple comparisons and contrast analysis was used to test for linear and quadratic relations. Compared with control, feeding a high dosage of hazel leaves enhanced (P = 0.006) the plasma total antioxidant capacity, which linearly (P = 0.016) increased with increasing level of hazel leaves in the diet. The total phenol concentration and activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione reductase in the plasma were not different (P ≥ 0.23) among the treatments; however, the latter slightly increased linearly (P = 0.047) with increasing hazel leaves proportion. No differences were observed in the activation and proliferation of PBMC among treatments. The HR decreased linearly (P ≤ 0.009) during pellet eating and lying and the root mean square of successive differences of interbeat intervals (RMSSD) increased linearly (P = 0.037) when lying with increasing level of hazel leaves in the diet. In conclusion, our findings indicate that hazel leaves are a promising supplement to improve oxidative status with no effect on cellular immune response and cardiac stress level of sheep.


Assuntos
Antioxidantes/metabolismo , Corylus/química , Suplementos Nutricionais/análise , Imunidade Celular/efeitos dos fármacos , Ovinos/fisiologia , Ração Animal/análise , Animais , Proliferação de Células , Dieta/veterinária , Feminino , Frequência Cardíaca/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Lolium , Medicago sativa , Metano/metabolismo , Folhas de Planta/química , Ovinos/sangue , Ovinos/imunologia , Taninos/metabolismo
18.
Parasite Immunol ; 41(12): e12674, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31557338

RESUMO

Cystic echinococcosis (CE) can be diagnosed by means of several serological approaches, but their results vary among laboratories due to the molecular characteristics of the reference antigens used. Thus, this study aimed to address both the relevance of an EGPE cell line previously obtained from Echinococcus granulosus protoscoleces G1 and the complexity of the immune response by using two different in vitro growth stages as separate sources of parasite antigens. The serum reactivity was investigated by western blotting (WB) in 21 CE patients from an endemic area in a matched case-control design and also in seven experimentally infected sheep and five healthy control sheep. EGPE-antigen-human serum sensitivity by WB was higher than that of hydatid fluid (HF) WB, ELISA and DD5 (P < .05, Chi-square test). EGPE protein extract was immunogenic in mice and hyperimmune plasma reacted with HF proteins, and AgB2 expression was detected by molecular analysis. Proteins of 37 to 60 kDa were recognized by 95.24% of the CE patients' sera but, with poor specificity. Statistically significant differences were found between serum protein extract recognition at 7 and 20 days of cell growth. The EGPE cell line is a laboratory source of antigens for improvement of CE serological diagnosis.


Assuntos
Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Equinococose/veterinária , Echinococcus granulosus/imunologia , Ovinos/parasitologia , Animais , Western Blotting , Estudos de Casos e Controles , Linhagem Celular , Equinococose/diagnóstico , Equinococose/parasitologia , Echinococcus granulosus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Extratos Vegetais , Ovinos/imunologia
19.
Front Immunol ; 10: 1492, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31379805

RESUMO

The ability of lymphocytes to recirculate between blood and secondary lymphoid tissues such as lymph nodes (LNs) and spleen is well established. Sheep have been used as an experimental system to study lymphocyte recirculation for decades and multiple studies document accumulation and loss of intravenously (i.v.) transferred lymphocytes in efferent lymph of various ovine LNs. Yet, surprisingly little work has been done to accurately quantify the dynamics of lymphocyte exit from the LNs and to estimate the average residence times of lymphocytes in ovine LNs. In this work we developed a series of mathematical models based on fundamental principles of lymphocyte recirculation in the body under non-inflammatory (resting) conditions. Our analysis suggested that in sheep, recirculating lymphocytes spend on average 3 h in the spleen and 20 h in skin or gut-draining LNs with a distribution of residence times in LNs following a skewed gamma (lognormal-like) distribution. Our mathematical models also suggested an explanation for a puzzling observation of the long-term persistence of i.v. transferred lymphocytes in the efferent lymph of the prescapular LN (pLN); the model predicted that this is a natural consequence of long-term persistence of the transferred lymphocytes in circulation. We also found that lymphocytes isolated from the skin-draining pLN have a 2-fold increased entry rate into the pLN as opposed to the mesenteric (gut-draining) LN (mLN). Likewise, lymphocytes from mLN had a 3-fold increased entry rate into the mLN as opposed to entry rate into pLN. In contrast, these cannulation data could not be explained by preferential retention of cells in LNs of their origin. Taken together, our work illustrates the power of mathematical modeling in describing the kinetics of lymphocyte migration in sheep and provides quantitative estimates of lymphocyte residence times in ovine LNs.


Assuntos
Linfonodos/imunologia , Linfócitos/imunologia , Ovinos/imunologia , Animais , Movimento Celular/imunologia , Contagem de Leucócitos/métodos , Mesentério/imunologia , Baço/imunologia
20.
Vaccine ; 37(39): 5844-5853, 2019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31431410

RESUMO

Eight different vaccination schemes using four commercially available inactivated Bluetongue vaccines against serotypes 4 and 8 in three different combinations (setting 1-3) were tested under field conditions for their ability to generate a measurable immune response in sheep. Animals of setting 1 (groups A-D) were simultaneously vaccinated using either individual injections at different locations (groups A & D) or double injection by a twin-syringe (groups B & C). For both application methods, a one-shot vaccination (groups C & D) was compared to a boosted vaccination (groups A & B). Sheep of setting 2 (groups E-G) were vaccinated in an alternating, boosted pattern at fortnightly intervals starting with serotype 4 (groups E & F) or vice versa (group G). Group H of setting 3 was vaccinated simultaneously and vaccines were injected individually as a one-shot application. Each group consisted of 30 sheep. The immunogenic response was tested in all sheep (n = 240) by ELISA (IDScreen®Bluetongue Competition), while serum neutralisation tests were performed in five to six sheep from each group (n = 45). All vaccine combinations were well tolerated by all sheep. Of all vaccines and schemes described, the simultaneous double injected boosted vaccination of setting 1 (group B) yielded the highest median serotype-specific titres 26 weeks after the first vaccination (afv) and 100% seropositive animals (ELISA) one year afv. In setting 1, there were no relevant significant differences in the immunogenic response between simultaneously applied vaccines at different sites or at the same injection site. Importantly, a one-shot vaccination induced comparable immunogenicity to a boosted injection half a year afv. Low serotype-specific neutralising antibody levels were detected in settings 2 and 3 and are attributed to diverse factors which may have influenced the measured immunogenicity.


Assuntos
Vírus Bluetongue/imunologia , Bluetongue/imunologia , Bluetongue/prevenção & controle , Ovinos/imunologia , Vacinas Combinadas/imunologia , Vacinas de Produtos Inativados/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Imunização Secundária/métodos , Sorogrupo , Vacinação/métodos , Vacinas Virais/imunologia
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