Zapico David, Espinosa José, Muñoz María, Reyes Luis Ernesto, Benavides Julio, Marín Juan Francisco García, Fernández Miguel
Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, C/ Profesor Pedro Cármenes s/n, E-24071 León, Spain.
Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), E-24346 Grulleros, Spain.
Animals (Basel). 2025 Jun 22;15(13):1841. doi: 10.3390/ani15131841.
Vaccination remains the most cost-effective way to control clinical paratuberculosis in dairy herds, but its effect on the immune response at the intestine have been poorly characterized. The aim of this study was to evaluate the expression of toll-like receptor (TLR)-1, TLR2, TLR4, TLR9, interferon (IFN)-γ, inducible nitric oxide synthase (iNOS) and cluster of differentiation (CD)-204 in calves vaccinated with Silirum and then experimentally infected with paratuberculosis, using immunohistochemical techniques. Samples of the injection-site granuloma, scapular lymph node, intestine and mesenteric lymph nodes were studied. Lesions were classified as focal, multifocal and diffuse paucibacillary (lymphocytic). The immunolabeling for TLR1, TLR2, TLR4 and IFN-γ was assessed according to the number of immunolabeled cells, while TLR9, iNOS and CD204 immunolabeling in the lesions was evaluated using a histological score (H-score). Vaccinated calves with focal forms showed a significant increase in the number of macrophages immunolabeled TLR2 at the intestine and in the H-score values for iNOS in the granulomas. A greater immunolabeling of TLR2 and IFN-γ was detected at the injection-site granuloma. Animals with multifocal lesions, regardless of the vaccination status, showed lower numbers of TLR2+ macrophages and higher H-score values for CD204 in the granulomas. Thus, the protection conferred by the Silirum vaccine is associated with an enhanced immunological response in the intestine.
疫苗接种仍然是控制奶牛群临床副结核病最具成本效益的方法，但其对肠道免疫反应的影响尚未得到充分描述。本研究的目的是使用免疫组织化学技术，评估接种Silirum疫苗后再经实验性感染副结核病的犊牛中Toll样受体（TLR）-1、TLR2、TLR4、TLR9、干扰素（IFN）-γ、诱导型一氧化氮合酶（iNOS）和分化簇（CD）-204的表达。研究了注射部位肉芽肿、肩胛淋巴结、肠道和肠系膜淋巴结的样本。病变分为局灶性、多灶性和弥漫性少菌型（淋巴细胞性）。根据免疫标记细胞的数量评估TLR1、TLR2、TLR4和IFN-γ的免疫标记，而使用组织学评分（H评分）评估病变中TLR9、iNOS和CD204的免疫标记。患有局灶性病变的接种犊牛在肠道中免疫标记TLR2的巨噬细胞数量显著增加，肉芽肿中iNOS的H评分值也显著增加。在注射部位肉芽肿中检测到TLR2和IFN-γ的免疫标记更强。患有多灶性病变的动物，无论疫苗接种状态如何，肉芽肿中TLR2+巨噬细胞数量较少，CD204的H评分值较高。因此，Silirum疫苗提供的保护与肠道中增强的免疫反应相关。
