Palmer Mitchell V, Thacker Tyler C, Waters W Ray
Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA 50010, USA.
Vet Immunol Immunopathol. 2009 Feb 15;127(3-4):277-85. doi: 10.1016/j.vetimm.2008.10.336. Epub 2008 Nov 7.
The paired palatine tonsils, located at the junction of the nasopharynx and oropharynx, are ideally positioned to sample antigens entering through the nasal cavity or oral cavity. Entering antigens will first contact tonsilar epithelium. To better understand the cellular composition of this important epithelial layer, palatine tonsils were collected from six, 7-month-old calves and examined by light microscopy, immunohistochemistry and electron microscopy. Morphometric analysis showed that epithelium overlying lymphoid follicles (reticular epithelium) contained more B-cells, CD4+, CD8+, CD11c+, CD172a+ and gamma/delta TCR+ cells than non-reticular epithelium, with B-cells, CD4+ cells and CD11c+ cells being most numerous. Scanning and transmission electron microscopy of reticular epithelium identified an interrupted basement membrane and vascular elements within the epithelium, as well as cells with characteristics morphologically consistent with cells identified as M-cells in other species. Bovine palatine tonsilar reticular epithelium contains key immune cells, as well as potential M-cell-like cells; elements essential for antigen uptake, antigen processing and initiation of immune responses.
成对的腭扁桃体位于鼻咽和口咽的交界处，处于理想位置，能够对通过鼻腔或口腔进入的抗原进行取样。进入的抗原首先会接触扁桃体上皮。为了更好地了解这一重要上皮层的细胞组成，从6头7月龄犊牛身上采集腭扁桃体，并通过光学显微镜、免疫组织化学和电子显微镜进行检查。形态计量学分析表明，覆盖淋巴滤泡的上皮（网状上皮）比非网状上皮含有更多的B细胞、CD4 +、CD8 +、CD11c +、CD172a +和γ/δTCR +细胞，其中B细胞、CD4 +细胞和CD11c +细胞数量最多。网状上皮的扫描电镜和透射电镜检查发现上皮内有中断的基底膜和血管成分，以及形态特征与其他物种中鉴定为M细胞的细胞一致的细胞。牛腭扁桃体网状上皮含有关键免疫细胞以及潜在的M细胞样细胞；这些是抗原摄取、抗原加工和免疫反应启动所必需的成分。
