Gallego M, del Cacho E, Lopez-Bernad F, Bascuas J A
Department of Animal Pathology, Faculty of Veterinary Sciences, University of Zaragoza, Spain.
Anat Rec. 1997 Sep;249(1):81-5. doi: 10.1002/(SICI)1097-0185(199709)249:1<81::AID-AR10>3.0.CO;2-X.
In the chicken, circulating antigens enter the splenic white pulp via the Schweigger-Seidel sheaths (ellipsoids), where they are bound by cells, the ellipsoid associated cells (EAC), which are located on the periphery of the ellipsoid. There is an increasing body of evidence that these antigen-binding cells move through the PALS, to be finally located within the germinal centers, where these antigen-transporting EAC function as follicular dendritic cells (FDC). The aim of the current study was to further study the relationship between the EAC, the FDC, and the antigen-bearing EAC which migrate through the splenic white pulp.
In order to identify the splenic FDC and their presumed migrating EAC precursors in the chicken, we used a monoclonal antibody produced against chicken FDC and an antiserum anti-S-100 protein which identifies chicken dendritic cells in lymphoid organs.
Cells reacting with the 74.3 monoclonal antibody, which identifies FDC, were found within the germinal center, around the penicilliform capillary, in the periellipsoidal white pulp, and in the periarteriolar lymphatic sheaths (PALS). S-100+ cells were found in these same locations.
A comparison between the staining patterns obtained with both antibodies strongly suggested that the intrasplenic distribution of 74.3+ cells was identical with that of FDC, EAC, and antigen-binding EAC migrating in the PALS. Therefore, the 74.3 monoclonal antibody identified not only FDC but also the splenic precursor cells of FDC, in accordance with the hypothesis of the migration of the EAC through the white pulp. S-100+ cells were more numerous than 74.3+ cells, which is in accordance with the fact that S-100 protein antibody stains both FDC and interdigitating dendritic cells (ID). This has allowed us to suggest that 74.3- EAC may represent precursors of ID. The current findings reinforce previous investigations, which provided evidence supporting the migration of EAC through the PALS and further supported the hypothesis which considers EAC precursors of FDC.
在鸡体内，循环抗原通过施韦格 - 赛德尔鞘（椭球体）进入脾白髓，在那里它们被位于椭球体周边的细胞即椭球体相关细胞（EAC）所结合。越来越多的证据表明，这些抗原结合细胞穿过动脉周围淋巴鞘（PALS），最终定位于生发中心，在那里这些转运抗原的EAC发挥滤泡树突状细胞（FDC）的功能。本研究的目的是进一步研究EAC、FDC以及迁移穿过脾白髓的携带抗原的EAC之间的关系。
为了鉴定鸡脾中的FDC及其推测的迁移EAC前体，我们使用了一种针对鸡FDC产生的单克隆抗体和一种抗S - 100蛋白的抗血清，该抗血清可识别淋巴器官中的鸡树突状细胞。
在生发中心、笔形毛细血管周围、椭球体周围白髓以及动脉周围淋巴鞘（PALS）中发现了与识别FDC的74.3单克隆抗体发生反应的细胞。在这些相同位置也发现了S - 100 +细胞。
两种抗体获得的染色模式之间的比较强烈表明，74.3 +细胞在脾内的分布与FDC、EAC以及在PALS中迁移的抗原结合EAC的分布相同。因此，根据EAC穿过白髓迁移的假说，74.3单克隆抗体不仅识别FDC，还识别FDC的脾前体细胞。S - 100 +细胞比74.3 +细胞更多，这与S - 100蛋白抗体对FDC和交错突树突状细胞（ID）都染色的事实相符。这使我们推测74.3 - EAC可能代表ID的前体。目前的发现强化了先前的研究，先前研究提供了支持EAC通过PALS迁移的证据，并进一步支持了认为EAC是FDC前体的假说。
