Le Bivic A, Hirn M, Reggio H
Laboratoire de Différenciation Cellulaire, Faculté des Sciences, Marseille, France.
Proc Natl Acad Sci U S A. 1988 Jan;85(1):136-40. doi: 10.1073/pnas.85.1.136.
A monoclonal antibody that recognizes a membrane glycoprotein specific for the apical membrane of human colonic epithelial cells has been used to follow the differentiation and polarization of a cell line, HT-29, derived from a human colon adenocarcinoma. When these cells formed a polarized epithelium, the antigen was concentrated at the apical plasma membrane. It was also found intracellularly in vesicles and vacuoles. When HT-29 cells were undifferentiated and unpolarized, the antigen was not expressed significantly at the plasma membrane but was found concentrated in the membranes of intracellular vacuoles. Cells not yet organized into an epithelium may thus synthesize a membrane protein specific for their future apical membranes and store it intracellularly until the polarization process takes place. Intermediary stages of differentiation were occasionally recognized. They are characterized by a small number of cells surrounding an intercellular lumen. These lumina displayed apical membrane features (the presence of the apical antigen, of some microvilli, and of junctional complexes), although the cells were not fully differentiated. The differentiation process in HT-29 cells is apparently similar to that observed during embryonic development of the intestine. Therefore, HT-29 cells represent a useful model system to study epithelial differentiation in vitro.
一种单克隆抗体可识别对人结肠上皮细胞顶端膜具有特异性的膜糖蛋白，该抗体已被用于追踪源自人结肠腺癌的细胞系HT - 29的分化和极化过程。当这些细胞形成极化上皮时，抗原集中在顶端质膜。在细胞内的囊泡和液泡中也能发现该抗原。当HT - 29细胞未分化且未极化时，抗原在质膜上未显著表达，但集中在细胞内液泡的膜中。因此，尚未组织成上皮的细胞可能会合成一种对其未来顶端膜具有特异性的膜蛋白，并将其储存在细胞内，直到极化过程发生。偶尔能识别出分化的中间阶段。其特征是少数细胞围绕着一个细胞间腔。尽管这些细胞未完全分化，但这些腔显示出顶端膜的特征（存在顶端抗原、一些微绒毛和连接复合体）。HT - 29细胞的分化过程显然与在肠道胚胎发育过程中观察到的过程相似。因此，HT - 29细胞是体外研究上皮分化的有用模型系统。
