Webb Oscar, Kelly Filberto, Benitez Javier, Li Juncheng, Parker Maisha, Martinez Marcia, Samms Michael, Blake Andrew, Pezzano Mark, Guyden Jerry C
Department of Biology, The City College of New York, 138th St. at Convent Avenue, New York, NY, USA.
Cell Immunol. 2004 Apr;228(2):119-29. doi: 10.1016/j.cellimm.2004.04.008.
Much debate has been generated about the existence of thymic nurse cells within the thymus. Until now, the authenticity of an epithelial cell capable of internalizing developing thymocytes within the thymic cortex has been in question. Here, we use the thymic nurse cell-specific monoclonal antibody, ph91, to define the in vivo location of thymic nurse cells. For the first time, thymic nurse cells enclosing several thymocytes were detected in the subcapsular region of the thymic cortex in a "honeycomb-like" configuration. In vitro studies show the internalization process using digitalized time-lapse microscopy. Internalized thymocytes have also been reported to interact with macrophages within the TNC complex. The cytoplasmic interaction between thymocytes and macrophages was detected using time-lapse microscopy. Using fluorescence microscopy, we show polymerization of actin within macrophages at the contact point with thymocytes, which is indicative of an immunological synapse. Microfilaments and microtubules within TNCs were shown to be associated with thymocyte binding and internalization, but neither interacted with macrophages. Also, we provide data to show that thymocytes are actively involved in the internalization process. These experiments show for the first time the existence of thymic nurse cells within the thymic microenvironment. They provide a visual documentation of thymocyte uptake by thymic nurse cells, and define an interaction between thymocytes and macrophages within the TNC complex.
关于胸腺内是否存在胸腺哺育细胞已经引发了诸多争论。到目前为止，能够在胸腺皮质内内化发育中的胸腺细胞的上皮细胞的真实性一直存在疑问。在这里，我们使用胸腺哺育细胞特异性单克隆抗体ph91来确定胸腺哺育细胞在体内的位置。首次在胸腺皮质的被膜下区域以“蜂窝状”结构检测到包裹着多个胸腺细胞的胸腺哺育细胞。体外研究使用数字化延时显微镜展示了内化过程。据报道，内化的胸腺细胞也会在胸腺哺育细胞复合体中与巨噬细胞相互作用。使用延时显微镜检测到了胸腺细胞与巨噬细胞之间的细胞质相互作用。利用荧光显微镜，我们展示了巨噬细胞内肌动蛋白在与胸腺细胞接触点处的聚合，这表明存在免疫突触。胸腺哺育细胞内的微丝和微管被证明与胸腺细胞的结合和内化有关，但均未与巨噬细胞相互作用。此外，我们提供的数据表明胸腺细胞积极参与内化过程。这些实验首次证明了胸腺微环境中存在胸腺哺育细胞。它们提供了胸腺哺育细胞摄取胸腺细胞的直观记录，并确定了胸腺哺育细胞复合体中胸腺细胞与巨噬细胞之间的相互作用。
