Sun Juan, Xu Yuanfang, Cui Yan, Liu Penggang, Yu Sijiu, He Junfeng, Zhang Qian, Huang Yufeng, Yang Xue
Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China.
Gansu Province Livestock Embryo Engineering Research Center, Department of Clinical Veterinary Medicine, Faculty of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China.
Histol Histopathol. 2018 Jun;33(6):577-588. doi: 10.14670/HH-11-954. Epub 2017 Dec 14.
This study aimed to describe the age-related morphological changes and the distribution of IgA and IgG antibody-secreting cells (ASCs) in yaks. The palatine tonsils of twenty clinically healthy yaks, viz. newborn juvenile, adult and aged, were studied using histology, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA). The results showed that the palatine tonsils found in two tonsillar sinus were elongated kidney-shaped structures. Some external crypts and internal crypts were present. The palatine tonsils were partially enclosed by a connective tissue capsule and had trabeculae extending into the organ. Within these encapsulated organs, mucous glands were seen very obviously. Each crypt was highly branched and lined with stratified squamous non-keratinized epithelium. Several nonepithelial cells infiltrated between the epithelial cells, forming patches of reticular epithelium or lymphoepithelium. In newborn yaks, the lymphoid follicles were not observed. In other groups, the lymphoid follicles consisted of primary lymphoid follicles and secondary lymphoid follicles. Both IgA and IgG ASCs were distributed in the interfollicular areas, lymphoid follicles, the subepithelial areas of the non-reticular crypt epithelium, and the reticular crypt epithelium, with a few positive cells aggregated around the gland. The density of the two ASCs and the expression of the two proteins gradually increased from newborn to adult and reached a peak at adult age; they then decreased with age. However, the density of the IgG ASCs and the expression of IgG protein was significantly higher than that of IgA in all groups (P<0.01). The results indicated that the palatine tonsils were not only lymphoepithelial structures but also typical secondary lymphoid organs. IgG could be a significant component of mucosal immune responses in the palatine tonsils of yaks.
本研究旨在描述牦牛与年龄相关的形态变化以及IgA和IgG抗体分泌细胞（ASC）的分布情况。使用组织学、免疫组织化学和酶联免疫吸附测定（ELISA）对20头临床健康牦牛（即新生幼崽、成年和老年牦牛）的腭扁桃体进行了研究。结果表明，在两个扁桃体窦中发现的腭扁桃体为细长的肾形结构。存在一些外隐窝和内隐窝。腭扁桃体部分被结缔组织囊包围，并有小梁延伸至器官内部。在这些被膜包裹的器官内，黏液腺非常明显。每个隐窝高度分支，内衬复层鳞状非角化上皮。上皮细胞之间有几种非上皮细胞浸润，形成网状上皮或淋巴上皮斑。在新生牦牛中未观察到淋巴滤泡。在其他组中，淋巴滤泡由初级淋巴滤泡和次级淋巴滤泡组成。IgA和IgG ASC均分布于滤泡间区、淋巴滤泡、非网状隐窝上皮的上皮下区域和网状隐窝上皮，少数阳性细胞聚集在腺体周围。两种ASC的密度和两种蛋白的表达从新生到成年逐渐增加，并在成年时达到峰值；随后随年龄增长而下降。然而，在所有组中，IgG ASC的密度和IgG蛋白的表达均显著高于IgA（P<0.01）。结果表明，腭扁桃体不仅是淋巴上皮结构，也是典型的次级淋巴器官。IgG可能是牦牛腭扁桃体黏膜免疫反应的重要组成部分。
