Gipson I K, Yankauckas M, Spurr-Michaud S J, Tisdale A S, Rinehart W
Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114.
Invest Ophthalmol Vis Sci. 1992 Jan;33(1):218-27.
A monoclonal antibody has been produced that binds to the apical squames (flattened cells) of the rat ocular surface epithelium and to the goblet cells of the conjunctiva. Immunoelectron microscopic localization of the antigen indicates that in apical cells it is present along the apical-microplical membrane in the region of the glycocalyx. In subapical squames, the antigen is in cytoplasmic vesicles. In some goblet cells, the antigen is in the Golgi network, and in others, it is located primarily in the membrane of the mucous granules. SDS-PAGE and immunoblot analysis demonstrate that the molecular weight of the antigen is greater than 205 kD, and the electrophoretic band stains with Alcian blue followed by silver stain. Periodate oxidation of immunoblots and cryostat sections removes antibody binding. Neuraminidase treatment of cryostat sections does not remove antibody binding, whereas N-glycanase does. Taken together, these data indicate that the antigen recognized by the monoclonal antibody is a carbohydrate epitope on a high-molecular-weight, highly glycosylated glycoprotein in the glycocalyx of the ocular surface epithelium and goblet cell mucin granule membrane. The antigen appears to be stored within cytoplasmic vesicles and reaches the glycocalyx when cells differentiate to the apical-most position where the glycocalyx interfaces with the mucin layer of the tear film.
已制备出一种单克隆抗体，它能与大鼠眼表上皮的顶端鳞状细胞（扁平细胞）以及结膜的杯状细胞结合。抗原的免疫电子显微镜定位表明，在顶端细胞中，它沿糖萼区域的顶端微绒毛膜存在。在顶端下方的鳞状细胞中，抗原存在于细胞质小泡中。在一些杯状细胞中，抗原存在于高尔基体网络中，而在另一些杯状细胞中，它主要位于黏液颗粒的膜上。SDS-PAGE和免疫印迹分析表明，抗原的分子量大于205 kD，电泳带经阿尔辛蓝染色后再经银染。免疫印迹和冷冻切片的高碘酸盐氧化可消除抗体结合。冷冻切片经神经氨酸酶处理不能消除抗体结合，而经N-糖苷酶处理则可以。综上所述，这些数据表明，单克隆抗体识别的抗原是眼表上皮糖萼和杯状细胞黏蛋白颗粒膜中一种高分子量、高度糖基化糖蛋白上的碳水化合物表位。该抗原似乎存储在细胞质小泡中，当细胞分化到最顶端位置（此时糖萼与泪膜的黏蛋白层相接触）时，抗原到达糖萼。
