Understanding the immunological basis of resistance to gastrointestinal nematode infections in livestock is important in order to develop novel methods of parasite control such as vaccination or genetic selection for parasite resistance. The present study aimed to investigate differences in immune response between parasite resistant Santa Ines and susceptible Ile de France sheep breeds to natural Haemonchus contortus infection. Parasitological parameters, humoral immunity, local and circulating cellular immune responses were evaluated in 19 Santa Ines and 19 Ile de France lambs undergoing different anthelmintic treatments regimens: suppressive treatments (SUP) or targeted selective treatments (TST) over a 5-month grazing period. Santa Ines lambs had significantly lower Haemonchus faecal egg count and worm burden compared to Ile de France regardless of treatment regime. In addition, circulating blood eosinophils count and parasite-specific IgG levels were significantly higher and more rapidly induced in Santa Ines lambs. Abomasal immune responses were generally greater in the resistant breed, which had significantly higher levels of parasite-specific IgA in mucus, and elevated number of globule leukocytes and CD3+ T cells within the abomasal mucosal. Furthermore, numbers of POU2F3+ epithelial cells, a tuft-cell specific transcription factor, were also elevated in the Santa Ines breed, suggesting that this breed is better able to initiate T-helper type 2 immune responses within the abomasum. In conclusion, the differential immunological responses detailed here are relevant to understanding resistance to gastrointestinal nematodes in other host breeds, as well as to resistance breeding as a sustainable control approach for parasitic infections.

中文翻译：

---

不同驱虫治疗方案下易感法兰西岛羊和耐药圣伊内斯羊对捻转血矛线虫感染免疫反应的差异


了解牲畜胃肠道线虫感染抗性的免疫学基础对于开发新的寄生虫控制方法（例如疫苗接种或寄生虫抗性遗传选择）非常重要。本研究旨在调查抗寄生虫的圣伊内斯绵羊和易感法兰西岛绵羊品种之间对天然捻转血矛线虫感染的免疫反应的差异。研究人员对 19 只圣伊内斯和 19 只法兰西岛羔羊进行了寄生虫学参数、体液免疫、局部和循环细胞免疫反应的评估，这些羔羊在 5 个月的放牧期内接受了不同的驱虫治疗方案：抑制治疗 (SUP) 或靶向选择性治疗 (TST)。无论治疗方案如何，与法兰西岛相比，圣伊内斯羔羊的粪便血矛线虫卵数量和蠕虫负担均显着降低。此外，圣伊内斯羔羊的循环血液嗜酸性粒细胞计数和寄生虫特异性 IgG 水平显着更高且诱导更快。抗性品种的真胃免疫反应通常更强，其粘液中寄生虫特异性 IgA 水平显着较高，并且真胃粘膜内的球状白细胞和 CD3+ T 细胞数量增加。此外，POU2F3+上皮细胞（一种簇细胞特异性转录因子）的数量在圣伊内斯品种中也有所增加，表明该品种能够更好地在皱胃内启动T辅助细胞2型免疫反应。总之，这里详述的差异免疫反应与了解其他宿主品种对胃肠道线虫的抗性以及抗性育种作为寄生虫感染的可持续控制方法有关。