Fas ligand expression is restricted to nonlymphoid thymic components in situ.
Fas ligand expression is restricted to nonlymphoid thymic components in situ.
复制标题
Fas 配体表达仅限于原位非淋巴胸腺成分。
作者：
L. French;A. Wilson;M. Hahne;I. Viard;J. Tschopp;H. Macdonald
细胞表面受体Fas（Apo-1/CD 95）及其配体（FasL）是细胞凋亡的介导者，其已被证明与成熟T细胞的活化诱导的死亡和溶细胞性T细胞介导的杀伤有关。然而，Fas通路在与胸腺选择事件相关的细胞凋亡中的作用是有争议的。尽管已知Fas和FasL在胸腺中表达，但FasL表达细胞的性质和体内定位尚未确定。使用最近开发的抗FasL抗体结合原位杂交的组织切片，我们在这项工作中表明，FasL表达细胞存在于胸腺，特别是在髓质。在胸腺基质细胞提取物中容易检测到FasL mRNA，但在分离的胸腺细胞中没有检测到。此外，免疫组化分析的系列组织切片与抗FasL的抗体染色结合上皮和树突状细胞标记物表明，胸腺上皮细胞和树突状细胞表达FasL原位。表达FasL的基质细胞和表达Fas的胸腺细胞的共存可能具有重要的意义，Fas途径的作用，与胸腺选择事件相关的细胞凋亡。
The cell surface receptor Fas (Apo-1/CD95) and its ligand (FasL) are mediators of apoptosis that have been shown to be implicated in activation-induced death of mature T cells and in killing mediated by cytolytic T cells. The role of the Fas pathway in apoptosis associated with thymic selection events is, however, controversial. Although Fas and FasL are known to be expressed in the thymus, the nature and in vivo localization of FasL-expressing cells have not been determined. Using recently developed anti-FasL Abs in combination with in situ hybridization on tissue sections, we show in this work that FasL-expressing cells are present in the thymus, particularly within the medulla. FasL mRNA was detected readily in thymic stromal cell extracts, but not in isolated thymocytes. Moreover, immunohistochemical analysis of serial tissue sections stained with Abs against FasL in conjunction with epithelial and dendritic cell markers indicated that both thymic epithelial and dendritic cells express FasL in situ. The coexistence of FasL-expressing stromal cells and Fas-expressing thymocytes may have important implications for the role of the Fas pathway in apoptosis associated with thymic selection events.