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1.
Viruses ; 12(2)2020 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-31991915

RESUMO

Ticks transmit a wide variety of pathogens including bacteria, parasites and viruses. Over the last decade, numerous novel viruses have been described in arthropods, including ticks, and their characterization has provided new insights into RNA virus diversity and evolution. However, little is known about their ability to infect vertebrates. As very few studies have described the diversity of viruses present in ticks from the Caribbean, we implemented an RNA-sequencing approach on Amblyomma variegatum and Rhipicephalus microplus ticks collected from cattle in Guadeloupe and Martinique. Among the viral communities infecting Caribbean ticks, we selected four viruses belonging to the Chuviridae, Phenuiviridae and Flaviviridae families for further characterization and designing antibody screening tests. While viral prevalence in individual tick samples revealed high infection rates, suggesting a high level of exposure of Caribbean cattle to these viruses, no seropositive animals were detected. These results suggest that the Chuviridae- and Phenuiviridae-related viruses identified in the present study are more likely tick endosymbionts, raising the question of the epidemiological significance of their occurrence in ticks, especially regarding their possible impact on tick biology and vector capacity. The characterization of these viruses might open the door to new ways of preventing and controlling tick-borne diseases.


Assuntos
Doenças dos Bovinos , Flaviviridae/isolamento & purificação , Ixodidae/virologia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , Rhipicephalus/virologia , Infestações por Carrapato/veterinária , Animais , Anticorpos Antivirais/sangue , Bovinos/imunologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Suscetibilidade a Doenças , Flaviviridae/genética , Flaviviridae/imunologia , Genoma Viral , Martinica , Filogenia , Vírus de RNA/genética , Vírus de RNA/imunologia , RNA Viral/análise , RNA Viral/genética , Estudos Soroepidemiológicos , Infestações por Carrapato/imunologia , Índias Ocidentais
2.
PLoS One ; 14(12): e0226300, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31887151

RESUMO

The liver flukes, Fasciola hepatica and F. gigantica, are common trematode parasites of livestock. F. hepatica is known to modulate the immune response, including altering the response to co-infecting pathogens. Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is a chronic disease which is difficult to control and is of both animal welfare and public health concern. Previous research has suggested that infection with liver fluke may affect the accuracy of the bTB skin test, but direction of the effect differs between studies. In a systematic review of the literature, all experimental and observational studies concerning co-infection with these two pathogens were sought. Data were extracted on the association between fluke infection and four measures of bTB diagnosis or pathology, namely, the bTB skin test, interferon γ test, lesion detection and culture/bacterial recovery. Of a large body of literature dating from 1950 to 2019, only thirteen studies met the inclusion criteria. These included studies of experimentally infected calves, case control studies on adult cows, cross sectional abattoir studies and a herd level study. All the studies had a medium or high risk of bias. The balance of evidence from the 13 studies included in the review suggests that liver fluke exposure was associated with either no effect or a decreased response to all of the four aspects of bTB diagnosis assessed: skin test, IFN γ, lesion detection and mycobacteria cultured or recovered. Most studies showed a small and/or non-significant effect so the clinical and practical importance of the observed effect is likely to be modest, although it could be more significant in particular groups of animals, such as dairy cattle.


Assuntos
Doenças dos Bovinos/imunologia , Coinfecção/veterinária , Fasciolíase/veterinária , Tuberculose Bovina/diagnóstico , Animais , Bovinos , Coinfecção/microbiologia , Coinfecção/parasitologia , Estudos Transversais , Fasciola hepatica/imunologia , Fasciolíase/complicações , Fasciolíase/imunologia , Testes de Liberação de Interferon-gama , Mycobacterium bovis/patogenicidade , Estudos Observacionais como Assunto , Sensibilidade e Especificidade , Teste Tuberculínico
3.
Infect Immun ; 88(1)2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31611273

RESUMO

Infection of the host with Mycobacterium avium subsp. paratuberculosis results in chronic and progressive enteritis that traverses both subclinical and clinical stages. The mechanism(s) for the shift from an asymptomatic subclinical disease state to advanced clinical disease is not fully understood. In the present study, naturally infected dairy cattle were divided into subclinical and clinical infection groups, along with noninfected control cows of similar parity, to study host immune responses in different stages of infection. Both infection groups had higher levels of secretion of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-2 (IL-2) than control cows, whereas only clinical cows had increased secretion of IL-10, IL-12, and IL-18 upon stimulation of peripheral blood mononuclear cells (PBMCs) with antigen. Conversely, secretion of IL-17Α was decreased for clinical cows compared to subclinical and control cows. Proinflammatory cytokine genes were upregulated only for subclinical cows, whereas increased IL-10 and IL-17 gene expression levels were observed for both infection groups. Increased CD4+, CD8+, and γδ T cell receptor-positive (TCR+) T cells were observed for subclinical cows compared to clinical cows. Although clinical cows expressed antigen-specific immune responses, the profile for subclinical cows was one of a dominant proinflammatory response to infection. We reason that a complex coordination of immune responses occurs during M. avium subsp. paratuberculosis infection, with these responses shifting as the host transitions through the different stages of infection and disease (subclinical to clinical). A further understanding of the series of events characterized by Th1/Th2/Th17 responses will provide mechanisms for disease progression and may direct insightful intervention strategies.


Assuntos
Antígenos de Bactérias/imunologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/patologia , Imunidade Celular , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/imunologia , Paratuberculose/patologia , Animais , Bovinos , Citocinas/metabolismo , Fatores Imunológicos/metabolismo , Mycobacterium avium subsp. paratuberculosis/crescimento & desenvolvimento , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia
4.
Vet Clin North Am Food Anim Pract ; 35(3): 405-429, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590895

RESUMO

Infectious diseases are the outcome of complex interactions between the host, pathogen, and environment. After exposure to a pathogen, the host immune system uses various mechanisms to remove the pathogen. However, environmental factors and characteristics of pathogens can compromise the host immune responses and subsequently alter the outcome of infection. In this article, genetic and epigenetic factors that shape the individual variation in mounting protective responses are reviewed. Different approaches that have been used by researchers to investigate the genetic regulation of immunity in ruminants and various sources of genetic information are discussed.


Assuntos
/veterinária , Ruminantes/genética , Ruminantes/imunologia , Animais , Animais Domésticos , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/imunologia , Resistência à Doença , Epigênese Genética , /imunologia
5.
Vet Clin North Am Food Anim Pract ; 35(3): 471-483, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590898

RESUMO

Host responses are often ineffective at clearing Mycoplasma bovis infection and may contribute to the pathogenesis of disease. M bovis possesses a surprisingly large repertoire of strategies to evade and modulate host responses. Unopsonized M bovis impairs phagocytosis and killing by neutrophils and macrophages. Apoptosis of neutrophils and lymphocytes is enhanced, whereas it is delayed in macrophages. Both proinflammatory and antiinflammatory cytokines are stimulated during M bovis infection depending on the cell type and location, and overall systemic responses tend to have a T-helper 2 bias. M bovis reduces proliferation of T cells and, in chronic infection, causes T-cell exhaustion.


Assuntos
Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma bovis/imunologia , Animais , Bovinos , Imunidade Celular , Imunidade Humoral , Infecções por Mycoplasma/imunologia
6.
Can J Vet Res ; 83(4): 313-316, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31571732

RESUMO

The objective of this study was to evaluate the effect of late-gestation vaccination of beef heifers with 2 doses of a killed-virus (KV) vaccine containing bovine herpesvirus 1 (BoHV-1), bovine viral diarrhea virus 1 (BVDV-1), and bovine viral diarrhea virus 2 (BVDV-2) on the serum concentrations of antibody against BoHV-1, BVDV-1, and BVDV-2 in heifers and their calves and on the IgG concentration in the calves. Of the 47 pregnant beef heifers selected, 26 received 2 doses of the vaccine at 6.5 to 8 mo of gestation (at pregnancy check), and 21 received 2 doses of saline. The mean log2 serum titers of neutralizing antibody against BoHV-1, BVDV-1, and BVDV-2 before vaccination did not differ significantly between the treatment groups; however, at calving all 3 mean titers were significantly greater (P < 0.05) in the vaccinated heifers than in the control heifers. At 24 h after birth the mean serum IgG levels in the calves did not differ significantly between the 2 groups, at 30.18 and 32.28 g/L, respectively (P < 0.05); however, the mean log2 serum titers of antibody to all 3 viruses were greater in the calves nursing colostrum from the vaccinated heifers than in the calves nursing colostrum from the nonvaccinated heifers and significantly so for BoHV-1 and BVDV-1 (P < 0.001 and P = 0.009, respectively). Thus, late-gestation vaccination of beef heifers could result in a greater and more consistent deposition of specific antibodies in colostrum, reducing the variability of initial titers in calves and increasing the duration of maternal immunity.


Assuntos
Anticorpos Antivirais/sangue , Doenças dos Bovinos/prevenção & controle , Vírus da Diarreia Viral Bovina/imunologia , Herpesvirus Bovino 1/imunologia , Imunoglobulina G/sangue , Vacinas Virais/imunologia , Animais , Especificidade de Anticorpos , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/imunologia , Feminino , Imunidade Materno-Adquirida , Gravidez , Vacinação/veterinária
7.
Vet Immunol Immunopathol ; 217: 109955, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31639586

RESUMO

The purpose of this work was to characterize the cellular phenotype in inflammatory infiltrates of fetal tissues from pregnant heifers immunized and experimentally challenged with Neospora caninum. Fetuses from 20 heifers separated into 5 groups were obtained. The experiment was designed as follow: Group A, heifers inoculated intravenously with live tachyzoites of Argentine strain NC-6 (n = 4); Group B heifers inoculated subcutaneously with soluble native antigen from the same strain formulated with immune stimulant complexes (ISCOMs) (n = 4); Group C heifers inoculated with recombinant proteins, rNcSAG1, rNcHSP20, rNcGRA7 formulated with ISCOMs (n = 4), Group D heifers inoculated subcutaneously with sterile phosphate buffered solution (n = 4) and Group E heifers inoculated subcutaneously with antigen-free ISCOMs (n = 4). Experimental challenge was performed at 70 days of gestation and all heifers were euthanized 34 days later. Fetal tissues were taken for histological studies. Inflammatory lesions were observed in brain and lung, and immunhistochemistry was used to identify CD3+, CD20+ and MHC II+ cells. The majority of the cells that infiltrate and circumscribe the lesions in the brain and lung tissue expressed MHC II antigen; varying between 70-90% of the total cellular infiltrate. CD3+ cells were also present within the lesions, contributing to up to 30% of the inflammatory cells. CD20+ cells appeared as a marginal group, in some cases, with a range between 10 and 25%. As expected, the immunolabeling of MHC II + and CD3 + cells in fetal tissues was associated with fetal infection with N. caninum. There were statistically significant differences in the distribution and population of the inflammatory infiltrate in relation to the immunogenic treatment and the type of tissue, with inflammatory cells being markedly less extensive fetuses from group A (dams previously exposed to N. caninum) and in brain tissue. This work showed that Neospora-infection induced MHC II+ and CD3+ cells in bovine fetuses from dams receiving experimental vaccines.


Assuntos
Coccidiose/imunologia , Feto/imunologia , Imunização/veterinária , Neospora/imunologia , Vacinas Protozoárias/imunologia , Animais , Encéfalo/citologia , Encéfalo/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Feminino , Feto/citologia , Imuno-Histoquímica , Pulmão/citologia , Pulmão/imunologia , Gravidez
8.
Vet Res ; 50(1): 72, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551079

RESUMO

Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 107 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.0001), and a second peak was detected at 3 dpi only in G-NcSpain7 (P < 0.0001). At 10 dpi, Nc-Spain7 was detected in placental samples from one animal related to focal necrosis, and Nc-Spain7 transmission was observed, although no foetal lesions were associated with this finding. The presence of Nc-Spain1H in the placenta or foetuses, as well as lesions, were not detected at 10 dpi. At 20 dpi, G-NcSpain7 animals showed almost 100% positive placental tissues and severe focal necrosis as well as 100% transmission. Remarkably, foetal mortality was detected in two G-NcSpain7 heifers. Only one animal from G-NcSpain1H presented positive placental samples. No foetal mortality was detected, and lesions and parasite transmission to the foetus were not observed in this group. Finally, 100% of G-NcSpain7 heifers at 20 dpi presented specific antibodies, while only 60% of G-NcSpain1H animals presented specific antibodies at 20 dpi. In addition, earlier seroconversion in G-Nc-Spain7 was observed. In conclusion, tachyzoites from Nc-Spain7 reached the placenta earlier and multiplied, leading to lesion development, transmission to the foetus and foetal mortality, whereas Nc-Spain1H showed delayed infection of the placenta and no lesional development or transmission during early infection.


Assuntos
Doenças dos Bovinos/imunologia , Coccidiose/veterinária , Feto/parasitologia , Neospora/patogenicidade , Placenta/parasitologia , Complicações Parasitárias na Gravidez/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Coccidiose/parasitologia , Feminino , Idade Gestacional , Neospora/fisiologia , Gravidez , Complicações Parasitárias na Gravidez/imunologia , Complicações Parasitárias na Gravidez/parasitologia , Vacinação/veterinária , Virulência/genética
9.
Lett Appl Microbiol ; 69(5): 366-372, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31508837

RESUMO

We evaluate the efficacy of recombinant DNA vaccine ABA392 against haemorrhagic septicaemia infection through intranasal administration route by targeting the mucosal immunity. The DNA vaccine was constructed and subjected to animal study using the Sprague Dawley (SD) rat. The study was divided into two major parts: (i) active and (ii) passive immunization studies, involving 30 animals for each part. Each group was then divided into five test groups: two test samples G1 and G2 with 50 and 100 µg ml-1 purified DNA vaccine; one positive control G5 with 106  CFU per ml formalin-killed PMB2; and two negative controls, G3 and G4 with normal saline and pVAX1 vector. Both studies were conducted for the determination of immunogenicity by total white blood cell count (TWBC), indirect ELISA and histopathological changes for the presence of the bronchus-associated lymphoid tissue (BALT). Our findings demonstrate that TWBC, IgA and IgG increased after each of the three vaccination regimes: groups G1, G2 and G5. Test samples G1 and G2 showed significant differences (P < 0·05) compared to the negative controls, G3 and G4, but no significant differences from the positive control G5. Groups G1, G2 and G5 showed more formation of BALT compared to the negative controls, G3 and G4. Our results show that intranasal inoculation of recombinant DNA vaccine ABA392 can provoke mucosal immunity which makes it a potential prophylactic against HS. SIGNIFICANCE AND IMPACT OF THE STUDY: New approach of combating haemorrhagic septicaemia disease among bovines by recombinant DNA vaccine is crucial to overcome the loss of edible products from the infected bovines. DNA vaccine can potentially serve as a better immunogen which would elicit both cellular and humoral immunity, and it is also stable for its molecular reproduction. This research report demonstrates an effective yet simple way of administering the DNA vaccine via the intranasal route in rats, to provoke the mucosal immunity through the development of immunoglobulins IgA, IgG and bronchus-associated lymphoid tissue which guard as the first-line defence at the host's mucosal lining.


Assuntos
Vacinas Bacterianas/administração & dosagem , Doenças dos Bovinos/prevenção & controle , Septicemia Hemorrágica/veterinária , Pasteurella multocida/imunologia , Vacinas de DNA/administração & dosagem , Administração Intranasal , Animais , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/genética , Vacinas Bacterianas/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , DNA Recombinante/administração & dosagem , DNA Recombinante/genética , DNA Recombinante/imunologia , Ensaio de Imunoadsorção Enzimática , Septicemia Hemorrágica/imunologia , Septicemia Hemorrágica/microbiologia , Septicemia Hemorrágica/prevenção & controle , Imunização Passiva , Masculino , Pasteurella multocida/genética , Ratos , Ratos Sprague-Dawley , Vacinas de DNA/genética , Vacinas de DNA/imunologia
10.
Exp Parasitol ; 206: 107758, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521628

RESUMO

The diagnostic performance of a cocktail formula consisting of two Babesia (B.) bovis recombinant proteins, including spherical body protein 1 (BbSBP-1) and spherical body protein 4 (BbSBP-4), was evaluated in the present study for the global detection of B. bovis infection in cattle and for the differentiation between B. bovis and B. bigemina infections. The efficacy and the practicality of the rBbSBP-1 and rBbSBP-4 cocktail formula for differentiation between the infection caused by both parasites were assessed using indirect enzyme-linked immunosorbent assay (iELISA) with serum samples collected from cattle experimentally infected by B. bovis (n = 33) or B. bigemina (n = 30). Cocktail antigen exhibited the highest optical density (OD) values with B. bovis-infected sera and the lowest OD values with normal bovine sera or B. bigemina-infected sera in comparison with the single antigen. A total of 581 field serum samples collected from four countries with known B. bovis endemicity: Ghana (n = 154), Egypt (n = 162), Thailand (n = 96), and South Africa (n = 169) were screened also in the current study using iELISA and the results were compared to those of indirect fluorescent antibody test (IFAT) as a reference. A cocktail formula (rBbSBP-1 and rBbSBP-4) exhibited the highest concordance rate (89.90%) and kappa value (0.73). The obtained results revealed the reliability of the rBbSBP-1 and rBbSBP-4 cocktail antigen for the detection of specific antibodies to B. bovis in cattle and demonstrated the usefulness of cocktail antigen for differentiation between B. bovis and B. bigemina infections compared with the single antigen in cattle, which will be useful for epidemiological surveys and control of bovine babesiosis.


Assuntos
Antígenos de Protozoários/imunologia , Babesia bovis/imunologia , Babesiose/parasitologia , Doenças dos Bovinos/parasitologia , Proteínas Recombinantes/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Babesiose/diagnóstico , Babesiose/imunologia , Western Blotting/veterinária , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/imunologia , DNA Complementar/biossíntese , DNA Complementar/imunologia , Egito , Ensaio de Imunoadsorção Enzimática/veterinária , Gana , Proteínas Recombinantes/genética , Sensibilidade e Especificidade , África do Sul , Tailândia
11.
Food Funct ; 10(10): 6543-6555, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31545328

RESUMO

Mastitis, a major disease affecting dairy cows, is most commonly caused by Staphylococcus aureus (S. aureus). Selenium (Se) can activate pivotal proteins in immune responses and regulate the immune system, and microRNA-155 (miR-155) is a key transcriptional regulator for inflammation-related diseases. We constructed the model of mouse mastitis in vivo and primary mouse mammary epithelial cells (MMECs) in vitro, which were induced by S. aureus. Se content of the mammary was estimated using an atomic fluorescence spectrophotometer. Histopathological analysis was performed via hematoxylin and eosin (H&E) staining. The mmu-miR-155-5p mimic was transfected in MMECs, and viability was determined through the MTT assay. Transfected efficiency was evaluated by qPCR and fluorescence staining. Cytokines including TNF-α, IL-1ß, IL-10 and TLRs were detected with qPCR. In addition, western blotting was used to evaluate the expression of the NF-κB and MAPKs signaling pathways. The results demonstrated that a Se-supplemented diet improved the content of Se in mammary tissues. Histopathological studies indicated that the mammary glands were protected in the Se-supplemented group after S. aureus infection. Se-supplementation suppressed the production of MPO, mmu-miR-155, TNF-α, IL-1ß, and TLR2 and significantly inhibited the phosphorylation of NF-κB and MAPKs in vivo and in vitro. All the data indicated that mmu-miR-155 played a pro-inflammatory role in our study, and Se-supplementation could suppress the expression of mmu-miR-155 to inhibit inflammation in S. aureus-induced mastitis in mice.


Assuntos
Doenças dos Bovinos/tratamento farmacológico , Mastite/tratamento farmacológico , MicroRNAs/genética , Selênio/administração & dosagem , Infecções Estafilocócicas/veterinária , Animais , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Citocinas/genética , Citocinas/imunologia , Feminino , Regulação da Expressão Gênica , Mastite/genética , Mastite/imunologia , Mastite/microbiologia , Camundongos , MicroRNAs/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Infecções Estafilocócicas/genética , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/fisiologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/imunologia
12.
Parasitol Res ; 118(10): 2945-2955, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31485864

RESUMO

The aim of the present study was to characterize the specific immune response in prepubertal female calves inoculated with Neospora caninum. Forty-eight N. caninum-seronegative 6-month-old Angus female calves were randomly allocated into two groups: group A calves were inoculated subcutaneously (sc) with 1 × 106 tachyzoites of the low virulence NC-Argentina LP1 isolate in sterile phosphate-buffered saline (PBS); group B calves were mock inoculated sc with sterile PBS. Calves from group A developed a specific immune response characterized by the production of IgG antibodies and the expression of IFN-γ and TNF-α cytokines. Animals did not present any febrile reaction or reactions at the site of inoculation. Although chronic N. caninum infection was developed in 50% of calves of group A after inoculation, according to the presence of antibodies against rNc-SAG4, antigen characteristic of bradyzoites, N. caninum antibodies dropped below the cut-off of ELISA from day 210 post-inoculation onwards. Future trials using the same group of inoculated animals will allow the characterization of the evolution of the immune response during pregnancy and to determine whether the immunization with the local isolate is able to prevent congenital transmission and to protect against heterologous challenges.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Doenças dos Bovinos/imunologia , Coccidiose/veterinária , Neospora/imunologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Coccidiose/parasitologia , Citocinas/metabolismo , Feminino , Imunização/veterinária , Neospora/patogenicidade , Distribuição Aleatória
13.
Vet Parasitol ; 273: 36-44, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31442891

RESUMO

Rhipicephalus (Boophilus) microplus ticks cause major constraints to public and livestock health, and serious economic losses. It is well known that the immune response to infestations with cattle ticks is influenced by the host genetic background leading to distinct immunological profiles between bovine hosts genetically susceptible and resistant. The influence of Bos indicus (Bi) and Bos taurus (Bt) maternal lineage ancestry of mitochondrial DNA in the profile of the immune response of Zebu cattle to ticks remains unknown. The present work evaluated the hematological parameters and the immune response profile in the peripheral blood of a Guzerat dairy herd, further categorized into two maternal lineage ancestry subgroups (Bi-mtDNA and Bt-mtDNA) after experimental infestation with larvae of R. microplus. Our data demonstrated that although hematological and erythrogram analysis showed a similar profile throughout, some cell populations present a distinct profile between the groups. Especially MON, CD335+ and CD8+ T-cells are predominant in Bi-mtDNA. Moreover, an overall picture of R. microplus infestation demonstrated that Bi-mtDNA presented a more efficient and earlier innate immune response. Bi-mtDNA showed a greater number of connections with R. microplus counts and also with the CD25+ activation marker of the immune response. Bi-mtDNA showed greater number of connections, with an important participation of the innate immune while Bt-mtDNA showed a delay in the immune response. Elucidating the mechanisms by which resistant animals prevent heavy tick infestation is a crucial step in the development of predictive biomarkers for tick resistance for use in selective breeding programs, and is also potentially useful for the development of anti-tick vaccines.


Assuntos
Doenças dos Bovinos/imunologia , Interações Hospedeiro-Parasita/imunologia , Imunidade Inata/imunologia , Rhipicephalus/imunologia , Infestações por Carrapato/veterinária , Animais , Cruzamento , Bovinos , DNA Mitocondrial/genética , Indústria de Laticínios , Feminino , Perfilação da Expressão Gênica , Linfócitos T/imunologia , Infestações por Carrapato/imunologia
14.
Res Vet Sci ; 126: 94-102, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31445399

RESUMO

Heat stress is well documented to have a negative influence on livestock productivity and these impacts may be exacerbated by climate change. Dairy cattle can be more vulnerable to the negative effects of heat stress as these adverse impacts may be more profound during pregnancy and lactation. New emerging diseases are usually linked to a positive relationship with climate change and the survival of microrganisms and/or their vectors. These diseases may exaggerate the immune suppression associated with the immune suppressive effect of heat stress that is mediated by the hypothalamic-pituitary-adrenal (HPA) and the sympathetic-adrenal-medullary (SAM) axes. It has been established that heat stress has a negative impact on the immune system via cell mediated and humoral immune responses. Heat stress activates the HPA axis and increases peripheral levels of glucocorticoids subsequently suppressing the synthesis and release of cytokines. Heat stress has been reported to induce increased blood cortisol concentrations which have been shown to inhibit the production of cytokines such as interleukin-4 (IL-4), IL-5, IL-6, IL-12, interferon γ (IFNγ), and tumor necrosis factor-α (TNF- α). The impact of heat stress on the immune responses of dairy cows could be mediated by developing appropriate amelioration strategies through nutritional interventions and cooling management. In addition, improving current animal selection methods and the development of climate resilient breeds may support the sustainability of livestock production systems into the future.


Assuntos
Doenças dos Bovinos/etiologia , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico/fisiologia , Animais , Bovinos , Doenças dos Bovinos/imunologia , Citocinas/metabolismo , Transtornos de Estresse por Calor/etiologia , Transtornos de Estresse por Calor/imunologia , Resposta ao Choque Térmico/imunologia , Sistema Hipotálamo-Hipofisário , Sistema Hipófise-Suprarrenal/fisiologia
15.
Ticks Tick Borne Dis ; 10(6): 101270, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31445874

RESUMO

Protection against the intraerythrocytic protozoan parasite Babesia bovis depends on both strong innate and adaptive immune response, this latter involving the presentation of parasite antigens to CD4+ T-lymphocytes by professional antigen-presenting cells. Secretion of Th1 cytokines by CD4+ T cell is also very important for isotype switching to IgG2, the best opsonising antibody isotype in cattle, to target extracellular parasites and parasite antigens displayed at the erythrocyte surface. In the field of vaccinology, heterologous prime-boost schemes combining protein-adjuvant formulations with a modified vaccinia Ankara vector expressing the same antigen have demonstrated the induction of both humoral and cellular immune responses. It has been previously demonstrated that MVA-infected dendritic cells can present antigens in the context of MHC II and activate CD4+ T cell. These results support the use of the MVA viral vector for a pathogen like Babesia bovis, which only resides within erythrocytes. In this study, 13-15-months-old Holstein-Friesian steers were immunised with a subunit vaccine as a prime and a modified vaccinia Ankara vector as a boost, both expressing a chimeric multi-antigen (rMABbo - rMVA). This antigen includes the immunodominant B and T cell epitopes of three B. bovis proteins: merozoite surface antigen - 2c (MSA - 2c), rhoptry associated protein 1 (RAP - 1) and heat shock protein 20 (HSP20). Responses were compared with the Babesia bovis live attenuated vaccine used in Argentina (R1A). Eleven weeks after the first immunisation, all bovines were challenged by the inoculation of a virulent B. bovis strain. All groups were monitored daily for hyperthermia and reduction of packed cell volume. Both the rMABbo - rMVA and R1A vaccinated animals developed high titters of total IgG antibodies and an antigen-specific Th1 cellular response before and after challenge. However, all rMABbo - rMVA steers showed clinical signs of disease upon challenge. Only the R1A live vaccine group developed an immune response associated with in vitro neutralising antibodies at a level that significantly inhibited the parasite invasion. The lack of protection observed with this recombinant formulation indicates the need to perform further basic and clinical studies in the bovine model in order to achieve the desired effectiveness. This is the first report in which a novel vaccine candidate against Babesia bovis was constructed based on a recombinant and rationally designed viral vector and evaluated in the biological model of the disease.


Assuntos
Babesia bovis/imunologia , Babesiose/prevenção & controle , Doenças dos Bovinos/prevenção & controle , Vacinas Protozoárias/imunologia , Vacinação/veterinária , Animais , Anticorpos Neutralizantes/imunologia , Babesiose/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Epitopos/imunologia , Imunidade Celular , Imunidade Humoral , Masculino , Proteínas Recombinantes/imunologia , Células Th1/imunologia , Vacinas Atenuadas/imunologia , Vírus Vaccinia/imunologia
16.
Vet Immunol Immunopathol ; 216: 109920, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31446205

RESUMO

Mycoplasma bovis causes chronic arthritis in calves. Mycoplasma arthritis shows severe inflammatory reactions in joints that is commonly treated with antibiotics and results in significant economic losses in the calf industry. A previous study showed that inflammatory cytokines and matrix metalloproteinases (MMPs) produced by synovial cells promote progression of the pathophysiology of bacterial arthritis. However, the mechanism underlying the pathogenesis of bovine Mycoplasma arthritis has not been fully clarified. In this study, we examined the immunologic response of bovine synovial tissue to M. bovis. We observed significant increases in expression of interleukin (IL)-1ß, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial tissue from Mycoplasma arthritis calves compared with tissues from normal calves. Expression of IL-6, IL-8, and MMP-1 mRNA was also induced in cultured synovial cells stimulated with M. bovis, but not expression of IL-1ß and MMP-3 mRNA. In contrast, the culture supernatant of peripheral blood mononuclear cells stimulated with M. bovis induced marked increases in the expression of IL-1ß, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial cells. Our results indicate that inflammatory cytokines and MMPs produced by synovial cells play a key role in the pathogenesis of Mycoplasma arthritis. We suggest that interactions between synovial cells and mononuclear cells in the presence of M. bovis induce expression of these cytokines and MMPs in synovial cells, resulting in severe inflammatory reactions in the joints.


Assuntos
Artrite Infecciosa/veterinária , Citocinas/metabolismo , Metaloproteases/metabolismo , Mycoplasma bovis , RNA Mensageiro/metabolismo , Membrana Sinovial/citologia , Animais , Apoptose/fisiologia , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Células Cultivadas , Citocinas/genética , Metaloproteases/genética , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/metabolismo , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/veterinária , RNA Mensageiro/genética
17.
Vet Immunol Immunopathol ; 216: 109919, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31446207

RESUMO

Mucosal surfaces such as the gastrointestinal tract, and skin are the front line of host defence and immunity against many pathogens. Gamma delta (γδ) T lymphocytes preferentially localize to the mucosal surfaces in several species including cattle, and are thought to play crucial roles in immunosurveillance and host defence, particularly against mycobacteria. Many γδ T cells are present in young calves, which is the period when calves are thought to be initially exposed to Mycobacterium avium subspecies paratuberculosis (Map). The role of mucosal γδ T cells in cattle, especially during host-pathogen interactions during early pre-clinical phases of infectious disease remains unclear. The purposes of this study were to investigate and characterize WC1+ and WC1neg γδ  T cell subsets in various segments of the gastrointestinal (GI) tract of young calves, and then to examine γδ  T cell subsets in the distal small intestine of calves after experimental intestinal Map infection by direct Peyer's patch inoculation. We show that in healthy calves, the relative proportion of γδ T cells is constant throughout the GI mucosa, though the ileum has significantly more γδ T cells. In the distal intestine, γδ T cells are mainly WC1neg and primarily located within the lamina propria of the jejunum and ileum. In Map-infected intestine, there are higher numbers of γδ T cells in the lamina propria and a greater proportion of WC1+ cells within the epithelial layer compared to control calves. While WC1neg γδ T cells preferentially localize to the distal small intestine of healthy calves, WC1+ γδ T cells are increased in the intestinal mucosa during Map infection, which is suggestive of effector cell function. Further, spectral microscopy and flow cytometry in tandem will lead to improved understanding of the functions of these cells during health and disease.


Assuntos
Doenças dos Bovinos/imunologia , Mucosa Intestinal/metabolismo , Glicoproteínas de Membrana/metabolismo , Mycobacterium avium subsp. paratuberculosis , Paratuberculose/imunologia , Subpopulações de Linfócitos T/metabolismo , Animais , Bovinos , Sobrevivência Celular , Células Cultivadas , Regulação da Expressão Gênica/imunologia , Mucosa Intestinal/patologia , Glicoproteínas de Membrana/genética , Paratuberculose/metabolismo
18.
Comp Immunol Microbiol Infect Dis ; 66: 101330, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31437690

RESUMO

The aim of this study was to evaluate the seroprevalence of Neospora caninum in dairy cows, as well as to verify the risk factors for N. caninum infection and inflammatory response in dairy cows. Using the indirect immunofluorescence reaction, the seroprevalence of neosporosis was determined to be 32.82%. Based on regression analysis, the presence of dogs at a farm increased the probability of a cow testing positive for N. caninum (OR = 20.01 [5.21-123.12]). These data suggest that N. caninum has a relevant prevalence in dairy cows of the Microregion of Rio do Sul (Brazil), with elevated frequencies of anti-N. caninum IgG. The data also suggest that the parasite is widely distributed in dairy herds of the micro-region, because 94.4% of properties screened had at least one seropositive animal. The principal risk factors for disease maintenance in herds may be considered the presence of dogs and absence of a diagnostic test when introducing new animals. Blood from these cows was used to measure variables related to the inflammatory response. Serum cholinesterase activity, as well as serum levels of globulins and C-reactive protein were higher in seropositive to N. caninum than in seronegative cows. Furthermore, the infection by parasite causes an intense inflammatory process, contributing to disease pathophysiology.


Assuntos
Doenças dos Bovinos/diagnóstico , Colinesterases/sangue , Colinesterases/imunologia , Coccidiose/veterinária , Neospora/patogenicidade , Animais , Anticorpos Antiprotozoários/sangue , Infecções Assintomáticas , Biomarcadores/sangue , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Fazendas , Feminino , Fatores de Risco , Estudos Soroepidemiológicos
19.
Vet Immunol Immunopathol ; 215: 109914, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31420065

RESUMO

This pilot study provides a preliminary assessment of the impact of genotype on acute innate immune pro-inflammatory, metabolic and endocrine responses to repeated lipopolysaccharide (LPS) administered to growing heifers. Heifers (n = 4/genotype) were from unselected (stable milk yield since 1964, UH) or contemporary (CH) Holstein cows that differed in milk yield (6200 vs 11,100 kg milk/305 d) or from contemporary Black Angus (CA) cows bred to contemporary Red Angus bulls. Heifers were challenged with iv administration of 0.5 µg LPS/kg body weight on day 1 (Challenge 1) and d 5 (Challenge 2) of study to assess endotoxin tolerance. Plasma was collected at -1, -0.5, 0, 1, 2, 3, 4, 6, 8, and 24 h relative to each LPS administration. Rectal body temperature (BT) was measured before each blood sampling and at 5 and 7 h. Data were analyzed by repeated measures with sampling time as the repeated effect. Each genotype had at least one pro-inflammatory response that indicated it might have a more robust response than the other genotypes. The CH heifers had a greater TNF-α response, UH heifers had greater IL-6 and XO responses and CA heifers had greater BT and SAA response to LPS than the other genotypes. There was a genotype by time by interaction as cortisol peaked earlier in CH and UH than in CA heifers. Glucose response was less in CA and insulin response was greater in CH heifers. Endotoxin tolerance to LPS was evident as pro-inflammatory, cortisol, glucose and insulin responses were less during Challenge 2 than during Challenge 1. Differences among genotypes during Challenge 1 were eliminated during Challenge 2 except for the greater SAA response in CA heifers and indicate the potential for differential impacts of genotype on the development of endotoxin tolerance. Specific reasons for these effects of genotype are not clear from these data but the results support the hypothesis for differential innate immune signaling among these bovine genotypes.


Assuntos
Bovinos/imunologia , Imunidade Inata/genética , Animais , Bovinos/genética , Doenças dos Bovinos/imunologia , Indústria de Laticínios , Feminino , Genótipo , Inflamação/imunologia , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/imunologia , Projetos Piloto
20.
J Dairy Sci ; 102(10): 9107-9116, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31400895

RESUMO

The dynamic interaction between the host and pathogens, along with environmental factors, influences the regulation of mammalian immune responses. Therefore, comprehensive in vivo immune-phenotyping during an active response to a pathogen can be complex and prone to confounding effects. Evaluating critical fundamental aspects of the immune system at a cellular level is an alternative approach to reduce this complexity. Therefore, the objective of the current study was to examine an in vitro model for functional phenotyping of bovine monocyte-derived macrophages (MDM), cells which play a crucial role at all phases of inflammation, as well influence downstream immune responses. As indicators of MDM function, phagocytosis and nitric oxide (NO-) production were tested in MDM of 16 cows in response to 2 common bacterial pathogens of dairy cows, Escherichia coli and Staphylococcus aureus. Notable functional variations were observed among the individuals (coefficient of variation: 33% for phagocytosis and 70% in the production of NO-). The rank correlation analysis revealed a significant, positive, and strong correlation (rho = 0.92) between NO- production in response to E. coli and S. aureus, and a positive but moderate correlation (rho = 0.58) between phagocytosis of E. coli and S. aureus. To gain further insight into this trait, another 58 cows were evaluated solely for NO- response against E. coli. The pedigree of the tested animals was added to the statistical model and the heritability was estimated to be 0.776. Overall, the finding of this study showed a strong effect of host genetics on the in vitro activities of MDM and the possibility of ranking Holstein cows based on the in vitro functional variation of MDM.


Assuntos
Doenças dos Bovinos/genética , Doenças dos Bovinos/imunologia , Infecções por Escherichia coli/veterinária , Macrófagos/imunologia , Infecções Estafilocócicas/veterinária , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Escherichia coli/imunologia , Infecções por Escherichia coli/imunologia , Feminino , Imunidade/genética , Macrófagos/efeitos dos fármacos , Óxido Nítrico/metabolismo , Linhagem , Fagocitose , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia
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