Nagy N, Magyar A, Dávid C, Gumati M K, Oláh I
Department of Human Morphology and Developmental Biology, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
Anat Rec. 2001 Mar 1;262(3):279-92. doi: 10.1002/1097-0185(20010301)262:3<279::AID-AR1038>3.0.CO;2-I.
Two stromal elements, follicle-associated epithelium and secretory dendritic cells of the bursa of Fabricius were studied by light microscopy and two novel MAbs, that were produced against splenic cell suspensions of guinea fowls. Both antigens recognized by these MAbs, designated GIIF3 and NIC2, are localized in the cytoplasm of the stromal cells, and their molecular weights are 50 and 30 kD, respectively. During embryogenesis the GIIF3 and NIC2 cells emerge in the mesenchyme of the folds before follicle formation. The GIIF3 and the NIC2-positive cells accumulate under the surface epithelium of the plicae and migrate into the epithelium, that precedes the bud-formation. From the bud, the GIIF3-positive cells migrate up to the luminal surface, and they transform to distinct, highly polarized follicle-associated epithelial cells. Single GIIF3-positive cells are also present in the interfollicular epithelium. The NIC2 MAb recognized mesenchymal cells harbor in the lymphoepithelial compartment of the folliculus, and they elaborate cytoplasmic granules. Around Day 20 of embryogenesis large amount of NIC2-positive substance appear extracellularly in the medulla and around it. This period well correlates with the starting up of the bursal functions; clonal expansion of B cells, and generation of immune repertoire. After hatching the NIC2 stainability diminishes, and it is restricted to the medullary bursal secretory dendritic cells. The NIC2-positive, possibly elderly bursal secretory dendritic cells, are capable for migration into the follicle-associated epithelium. In eight-day old birds some cells of the follicle-associated epithelium reveals temporary NIC2 positivity, that may prove the transport of the follicle-associated epithelial cells into luminal direction. By 12 weeks of age the presence of NIC2-positive substance in the intercellular space of the FAE, rather than in the cells of FAE may indicate the termination of the transport of secretory substance. In conclusion, two types of mesenchymal cells enter the surface epithelium of the bursal folds. The GIIF3-positive cells appear on the luminal surface of the follicles and occupy the place of the follicle-associated epithelial cells. The NIC2-positive cells become secretory in nature and differentiate to bursal secretory dendritic cells. The follicle formation possibly, requires the joint presence of both GIIF3 and NIC2 cells in the epithelium.
利用光学显微镜以及两种针对珍珠鸡脾细胞悬液制备的新型单克隆抗体，对法氏囊的两种基质成分——滤泡相关上皮和分泌性树突状细胞进行了研究。这两种单克隆抗体（命名为GIIF3和NIC2）识别的两种抗原均定位于基质细胞的细胞质中，其分子量分别为50kD和30kD。在胚胎发育过程中，GIIF3和NIC2细胞在滤泡形成前出现在皱襞的间充质中。GIIF3和NIC2阳性细胞在皱襞表面上皮下聚集，并迁移到上皮中，这先于芽的形成。从芽开始，GIIF3阳性细胞向上迁移至管腔表面，并转变为独特的、高度极化的滤泡相关上皮细胞。单个GIIF3阳性细胞也存在于滤泡间上皮中。NIC2单克隆抗体识别位于滤泡淋巴上皮区室中的间充质细胞，这些细胞含有细胞质颗粒。在胚胎发育第20天左右，大量NIC2阳性物质出现在髓质及其周围的细胞外。这个时期与法氏囊功能的启动密切相关，即B细胞的克隆扩增和免疫库的产生。孵化后，NIC2的可染性降低，仅限于髓质法氏囊分泌性树突状细胞。NIC2阳性、可能较老的法氏囊分泌性树突状细胞能够迁移到滤泡相关上皮中。在8日龄的雏鸡中，滤泡相关上皮的一些细胞显示出暂时的NIC2阳性，这可能证明滤泡相关上皮细胞向管腔方向的转运。到12周龄时，FAE细胞间空间中存在NIC2阳性物质，而不是在FAE细胞中，这可能表明分泌物质转运的终止。总之，两种间充质细胞进入法氏囊皱襞的表面上皮。GIIF3阳性细胞出现在滤泡的管腔表面，并占据滤泡相关上皮细胞的位置。NIC2阳性细胞本质上变为分泌性细胞，并分化为法氏囊分泌性树突状细胞。滤泡的形成可能需要上皮中同时存在GIIF3和NIC2细胞。
