Davidson N J, Boyd R L
Department of Pathology and Immunology, Monash University Medical School, Prahran, Australia.
Dev Immunol. 1993;3(2):147-58. doi: 10.1155/1993/51718.
The chicken thymic microenvironment, as it developed in an embryonic thymus organ culture system, was phenotypically mapped using a panel of mAb defining both epithelial and nonepithelial stromal cell antigens. We have previously reported that thymocyte proliferation and differentiation with proceed for up to 6-8 days in thymus organ culture, hence demonstrating the functional integrity of the thymic microenvironment in vitro. During this time, the stromal component reflected that of the normal embryo with cortical and medullary epithelial areas readily identifiable by both morphology and surface-antigen expression. An abundance of subcapsular and cortical epithelial antigens was detected in the cultured thymus, particularly those normally expressed by the epithelium lining the capsule, trabeculae, and vascular regions (type I epithelium) in the adult and embryonic thymus. Medullary epithelial antigens developed in organ culture, although were present in lower frequency than observed in the age-matched embryonic thymus. MHC class II expression by both epithelial and nonepithelial cells was maintained at high levels throughout the culture period. With increasing time in culture, the ratio of epithelial to nonepithelial cells decreased, concurrent with a decrease in thymocyte frequency and suggestive of a bidirectional interaction between these two cell types. Thus, a functionally intact thymic microenvironment appears to be maintained in embryonic thymus organ culture, a model that is currently being exploited to assess the role of stromal antigens, as defined by our mAb, in the process of thymopoiesis.
在胚胎胸腺器官培养系统中发育的鸡胸腺微环境，使用一组定义上皮和非上皮基质细胞抗原的单克隆抗体进行了表型定位。我们之前报道过，胸腺细胞在胸腺器官培养中增殖和分化可持续6 - 8天，从而证明了体外胸腺微环境的功能完整性。在此期间，基质成分反映了正常胚胎的情况，皮质和髓质上皮区域通过形态学和表面抗原表达都很容易识别。在培养的胸腺中检测到大量被膜下和皮质上皮抗原，特别是那些在成年和胚胎胸腺中通常由被膜、小梁和血管区域内衬上皮（I型上皮）表达的抗原。髓质上皮抗原在器官培养中发育，尽管其出现频率低于在年龄匹配的胚胎胸腺中观察到的频率。上皮细胞和非上皮细胞的MHC II类表达在整个培养期间都维持在高水平。随着培养时间的增加，上皮细胞与非上皮细胞的比例下降，同时胸腺细胞频率也下降，这表明这两种细胞类型之间存在双向相互作用。因此，在胚胎胸腺器官培养中似乎维持了功能完整的胸腺微环境，目前正在利用这个模型来评估我们的单克隆抗体所定义的基质抗原在胸腺生成过程中的作用。
