Approaches to identification of the stem cell in human esophageal epithelium

上皮的基底层通常被认为含有干细胞或祖细胞群。为了分析其生物学特性，我们尝试制备识别人食管上皮基底细胞的新型单克隆抗体。杂交瘤产生的ddY小鼠免疫与食管上皮细胞（EECs）在低钙浓度培养的脾细胞之间的融合。选择产生与人食管上皮基底细胞反应的单克隆抗体（moAb）的克隆NJ-E-H10，以观察其在上皮冰冻切片上的染色模式。NJ-E-H10免疫反应阳性细胞主要分布于上皮乳头间区的基底细胞胞浆中。在原代培养的内皮细胞中，免疫反应阳性细胞存在于生长集落的边缘区域，在那里内皮细胞延伸其细胞质并迁移出集落。免疫电镜观察显示，单克隆抗体NJ-E-H10在基底细胞的中间纤维周围有免疫反应性，但在纤维本身没有免疫反应性。在人皮肤中，在表皮的基底层中以及在毛囊中的外根鞘外层的角质形成细胞和汗腺中的肌上皮细胞中也观察到NJ-E-H10阳性细胞。由于NJ-E-H10免疫反应性的分布与迄今已知的抗体报道的分布不同，因此MoAb NJ-E-H10被认为是阐明复层上皮中基底细胞室的生物学特性的新标记物。

The basal layer of the epithelium is usually thought to contain stem or progenitor cell populations. In order to analyze its biological characteristics, we attempted to produce novel monoclonal antibodies recognizing basal cells of the human esophageal epithelium. Hybridomas were generated from fusions between spleen cells of ddY mice immunized with esophageal epithelial cells (EECs) cultured at low calcium concentrations. A clone, NJ-E-H10, producing a monoclonal antibody (moAb) reacting with basal cells of human esophageal epithelia, was selected for its staining pattern on frozen sections of the epithelia. The immunoreactivities of NJ-E-H10 were detected in the cytoplasm of basal cells predominantly located in the interpapillary zones of the epithelia. In the primary culture of EECs, immunoreactive cells were present at the marginal area of the growing colonies, where EECs extend their cytoplasm and migrate out of the colonies. Immunoelectron microscopy demonstrated the immunoreactivities of the moAb NJ-E-H10 around the intermediate filaments of basal cells, but not on the filaments themselves. In the human skin, NJ-E-H10 positive cells were also observed in the basal layer of the epidermis as well as in keratinocytes in the outer layer of the outer root sheath in hair follicles and myoepitheial cells in the sweat glands. Since the distribution of NJ-E-H10 immunoreactivities differs from that reported by hitherto-known antibodies, the MoAb NJ-E-H10 is considered a new marker for clarifing the biological properties of the basal cell compartment in stratified epithelia.