School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
Vet Parasitol. 2014 Mar 17;201(1-2):31-9. doi: 10.1016/j.vetpar.2014.01.013. Epub 2014 Jan 28.
Fasciola hepatica is a common parasite in cattle, and bovine fasciolosis causes significant production losses, as well as being a zoonotic disease of global importance. F. hepatica has been shown to have immunoregulatory effects and the aim of this research was to establish whether F. hepatica infection influences the response to vaccination against respiratory pathogens in calves. A total of 48 calves were randomly and equally allocated to two groups. The experimental group was infected with F. hepatica, while the other group was used as a control. At week 2 and 6 after infection calves from both groups were administered a vaccine containing inactivated PI-3, BRSV and Mannheimia haemolytica, pathogens commonly associated with bovine respiratory disease. Blood samples were taken weekly over 12 weeks to measure specific antibodies against all vaccine antigens and against F. hepatica, as well as IgG1 and IgG2 isotypes for PI-3 and BRSV specific antibodies. Faecal samples were examined for F. hepatica eggs and routine haematology and liver enzyme biochemistry were performed and cytokine production in vitro measured. Liver enzymes (GGT and GLDH) and eosinophils were significantly higher in the experimental group, whereas neutrophil numbers were higher in the control group. There was no significant difference between the groups in terms of vaccine-specific total responses to PI-3, BRSV and M. haemolytica. IgG1 levels were higher in comparison to IgG2 levels in both PI-3 and BRSV specific antibodies. IL-4 levels from stimulated and unstimulated PBMC were significantly higher in the control group. IFN-γ levels were significantly higher in PBMC from the control group when cultured in medium only. No significant differences were noted in the levels of other cytokines measured. In this work, no effect of early F. hepatica infection on the antibody responses to a range of respiratory vaccine antigens in calves was shown. However, differences in cytokine responsiveness of PBMC between control and infected groups were observed, indicating that further work in measuring the effect of F. hepatica infection response to challenge infection following vaccination would be warranted.
肝片吸虫是牛的一种常见寄生虫，牛片形吸虫病会导致严重的生产损失，并且是一种具有全球重要意义的人畜共患病。肝片吸虫已被证明具有免疫调节作用，本研究旨在确定肝片吸虫感染是否会影响小牛对呼吸道病原体疫苗的反应。总共 48 头小牛被随机平均分配到两组。实验组感染肝片吸虫，而另一组作为对照组。在感染后第 2 周和第 6 周，两组小牛均接种了一种含有灭活 PI-3、BRSV 和 Mannheimia haemolytica 的疫苗，这些病原体通常与牛呼吸道疾病有关。在 12 周内每周采集血液样本，以测量针对所有疫苗抗原和肝片吸虫的特异性抗体，以及针对 PI-3 和 BRSV 特异性抗体的 IgG1 和 IgG2 同种型。检查粪便样本中是否有肝片吸虫卵，并进行常规血液学和肝功能生化检查，并测量体外细胞因子的产生。实验组的肝酶（GGT 和 GLDH）和嗜酸性粒细胞显著升高，而对照组的中性粒细胞数量较高。两组在针对 PI-3、BRSV 和 M. haemolytica 的疫苗特异性总反应方面没有显著差异。PI-3 和 BRSV 特异性抗体中 IgG1 水平高于 IgG2 水平。与对照组相比，刺激和未刺激的 PBMC 中的 IL-4 水平显著升高。仅在培养基中培养时，对照组的 PBMC 中 IFN-γ 水平显著升高。未观察到测量的其他细胞因子水平的显著差异。在这项工作中，早期肝片吸虫感染对小牛一系列呼吸道疫苗抗原抗体反应没有影响。然而，观察到对照组和感染组之间 PBMC 细胞因子反应性的差异，表明需要进一步研究测量接种疫苗后肝片吸虫感染对挑战感染的反应。
