Bruijntjes J P, Kuper C F, Robinson J E, Schuurman H J
TNO Toxicology and Nutrition Institute, Zeist, The Netherlands.
Dev Immunol. 1993;3(2):113-22. doi: 10.1155/1993/90759.
The histology of epithelium-free areas in the subcapsular region of the thymus was studied in Wistar rats. Lymphocytes in these areas were CD4/CD8 double-positive, TCR alpha/beta positive in low intensity, and in CD5 labeling either negative or positive in low intensity. There was a high proliferative activity as assessed by bromodeoxyuridine incorporation in vivo and detected by immunohistochemistry. Various macrophage types were observed. They were either large and round to slightly dendritic, or small and dendritic. Most large cells were positive for MHC Class II, and labeled by the antimacrophage antibodies ED1 and ED2. A few cells were strongly positive for Sudan black, Oil red O, nonspecific esterase, and acid phosphatase; they resembled the large rounded macrophages in the corticomedullary zone, although their MHC Class II and ED2 staining was more intense. A few cells showed features of tangible body macrophages, as they contained cellular debris. Serial sections showed that epithelium-free areas run from the subcapsular area to deep in the cortex, and often border the medulla. This opens the opportunity for immature lymphocytes to move into the medulla and corticomedullary zone without contacting and potential selection with cortical stromal elements other than macrophages in the epithelium-free areas. In this case, the epithelium-free areas may offer a separate intrathymic pathway for T lymphocytes.
在Wistar大鼠中研究了胸腺被膜下区域无上皮区域的组织学。这些区域的淋巴细胞为CD4/CD8双阳性，TCRα/β呈低强度阳性，CD5标记呈阴性或低强度阳性。通过体内溴脱氧尿苷掺入评估并通过免疫组织化学检测，发现有较高的增殖活性。观察到了各种类型的巨噬细胞。它们要么大且呈圆形至稍具树突状，要么小且具树突状。大多数大细胞MHC II类呈阳性，并被抗巨噬细胞抗体ED1和ED2标记。少数细胞苏丹黑、油红O、非特异性酯酶和酸性磷酸酶呈强阳性；它们类似于皮质髓质区的大圆形巨噬细胞，尽管其MHC II类和ED2染色更强。少数细胞表现出含铁血黄素巨噬细胞的特征，因为它们含有细胞碎片。连续切片显示无上皮区域从被膜下区域延伸至皮质深部，且常与髓质相邻。这为未成熟淋巴细胞提供了机会，使其能够在不与无上皮区域中除巨噬细胞外的皮质基质成分接触和进行潜在选择的情况下进入髓质和皮质髓质区。在这种情况下，无上皮区域可能为T淋巴细胞提供一条独立的胸腺内途径。
