【摘要】 咽扁桃体(pharyngeal tonsil,Pha T)属于粘膜相关淋巴组织,在呼吸道的粘膜免疫中起重要作用,免疫球蛋白A(immunoglobulin A,IgA)和免疫球蛋白G(immunoglobulin G,IgG)是粘膜免疫的两个重要效应分子,具有广泛的免疫学功能。为了研究牦牛(Bos grunniens)咽扁桃体发育过程中组织学结构的变化,以及IgA与IgG抗体分泌细胞(antibody secreting cells,ASCs)在其内部的分布特征和变化规律,本研究采用组织学方法对新生与成年牦牛咽扁桃体的组织学结构进行观察比较;免疫组织化学法(immunohistochemistry,IHC)检测IgA和IgG在新生与成年牦牛咽扁桃体内的表达情况。组织学结果显示,牦牛咽扁桃体上皮由非网状上皮和网状上皮构成,实质由淋巴滤泡和弥散淋巴组织组成,弥散淋巴组织中分布有大量的高内皮静脉和淋巴管。新生牦牛咽扁桃体内仅观察到少数的初级淋巴滤泡,而成年牦牛咽扁桃内以次级淋巴滤泡为主,且成年组淋巴滤泡数量远高于新生组(P<0.01)。免疫组织化学结果显示,两个年龄段IgA和IgG ASCs在非网状上皮下区域、网状上皮区域、滤泡间区、淋巴滤泡和腺体间均有分布,且均在非网状上皮下区域分布最高;单位面积内,两个年龄段IgG ASCs的平均数目均高于IgA ASCs,且成年组两者之间差异极显著(P<0.01),而新生组两者差异不显著(P>0.05)。结果表明,牦牛咽扁桃体在新生阶段已形成初级淋巴滤泡;IgA和IgGASCs主要通过非网状上皮下区域到达粘膜外表面发挥免疫保护作用;两年龄段IgG ASCs在数量上均占优势,说明IgG可能在牦牛咽扁桃体免疫防御作用中处于主导地位。本研究为牛呼吸道粘膜免疫及相关疫病的发病机理提供了形态学和免疫学资料。更多还原

【Abstract】 Pharyngeal tonsil(Pha T) belongs to mucosal-associated lymphoid tissue and plays an important role in mucosal immunity of respiratory tract. IgA(immunoglobulin A) and IgG(immunoglobulin G), which are 2 important effector molecules of mucosal immunity, have extensive immunological function. This research aims to study the changes of histological structure characteristics of pharyngeal tonsils during the development of yak(Bos grunniens), and the distributive characteristics and changing regularities of IgA and IgG antibody secreting cells(ASCs) in pharyngeal tonsils. In this study, histology method was used to observe and compare the histological structure characteristics of pharyngeal tonsils between newborn and adult yak.The expression of IgA and IgG in pharyngeal tonsils of newborn and adult yak was detected by immunohistochemistry(IHC). Histological results showed that pharyngeal tonsilar epithelium was roughly divided into 2 types, namely non-reticular epithelium and reticular epithelium. Non-reticular epithelium referred to pseudostratified columnar epithelium with a large number of alcian blue-periodic acid schiff(ABPAS) positive goblet cells and non-keratinized stratified squamous epithelium. However, the reticular epithelium overlying the pharyngeal tonsil was the lymphoepithelium that was frequently infiltrated by lymphocyte. The lamina propria of yak pharyngeal tonsils was composed of lymphoid follicles and diffuse lymphoid tissue. A large number of high endothelial veins and lymphatic vessels could be found in the diffuse lymphoid tissue. After comparing with the pharyngeal tonsils of newborn and adult yak, only a several primary lymphoid follicles in the newborn yak’s pharyngeal tonsils was found. However, not only primary lymphoid follicles, but also secondary lymphoid follicles can be found in adult yak’s pharyngeal tonsils. In addition, the statistics of the number of lymphoid follicles showed that in the same unit field of view(100×),the number of lymphoid follicles was approximately(2 ± 0.6019) in newborn yak, while was approximately(13 ± 0.4079) in adult yak, which was much higher than that of the newborn(P<0.01). The immunohistochemical results showed that IgA and IgG ASCs were distributed in the subepithelial region of non-reticular epithelium, the reticular epithelium region, inter-follicles area, lymphoid follicles and glandular compartments in the 2 groups, and the distribution of IgA and IgG ASCs was the highest in the subepithelial region of non-reticular epithelium, respectively. In addition, the average number of IgG ASCs per unit area(0.023 mm2) were higher than that of IgA ASCs in both 2 groups, and there were significant difference in the adult group(P<0.01), but no difference in the newborn group(P>0.05). The results indicated that the primary lymphoid follicles of yak pharyngeal tonsils have been formed in the newborn stage; IgA and IgG ASCs played an important immunoprotective effect on the mucosal surface through the non-reticular epithelial; IgG may be dominant in the immune defense of yak pharyngeal tonsils due to there was a preponderance of IgG ASCs in 2 groups. This study provides morphological and immunological information for the mucosal immunity and the pathogenesis of related diseases.更多还原