Fukuda M
La Jolla Cancer Research Foundation, Cancer Research Center, CA 92037.
Glycobiology. 1991 Sep;1(4):347-56. doi: 10.1093/glycob/1.4.347.
Leukosialin, also called CD43 or sialophorin, is a major sialoglycoprotein expressed widely in various leukocytes (granulocytes, monocytes/macrophages and T-lymphocytes). Leukosialin is heavily glycosylated by O-linked oligosaccharides (70-80 oligosaccharides/molecule) and the structures of those O-glycans are characteristic to each cell lineage and differentiation stage. In particular, the branched hexasaccharide, NeuNAc alpha 2----3Gal beta 1----3(NeuNAc alpha 2----3Gal beta 1----4GlcNAc beta 1----6)GalNAc is specifically expressed in activated T-lymphocytes as well as in thymocytes and T-lymphocytes from patients with leukaemia, and immuno-deficiency syndromes. A portion of these O-glycans are attached to a domain with tandem repeats in the polypeptide of leukosialin. However, the entire translation product, including such tandem repeats, is coded by one exon and a short novel promoter sequence confers the expression of the leukosialin gene. Leukosialin is apparently involved in T-cell-B-cell interaction during immune reaction and binds to ligands on antigen-presenting B-cells. These results imply that leukosialin plays critical roles in immune cell interaction and differences in attached O-glycans most likely influence the interaction of leukosialin with ligands.
白细胞唾液酸蛋白，也称为CD43或唾液酸糖蛋白，是一种主要的唾液酸糖蛋白，广泛表达于各种白细胞（粒细胞、单核细胞/巨噬细胞和T淋巴细胞）中。白细胞唾液酸蛋白被O-连接寡糖大量糖基化（每个分子有70-80个寡糖），这些O-聚糖的结构对于每个细胞谱系和分化阶段都具有特征性。特别地，分支六糖NeuNAcα2----3Galβ1----3（NeuNAcα2----3Galβ1----4GlcNAcβ1----6）GalNAc在活化的T淋巴细胞以及白血病患者、免疫缺陷综合征患者的胸腺细胞和T淋巴细胞中特异性表达。这些O-聚糖的一部分连接到白细胞唾液酸蛋白多肽中具有串联重复的结构域上。然而，整个翻译产物，包括这样的串联重复序列，由一个外显子编码，并且一个短的新启动子序列赋予白细胞唾液酸蛋白基因的表达。白细胞唾液酸蛋白显然在免疫反应期间参与T细胞与B细胞的相互作用，并与抗原呈递B细胞上的配体结合。这些结果表明白细胞唾液酸蛋白在免疫细胞相互作用中起关键作用，并且所连接的O-聚糖的差异很可能影响白细胞唾液酸蛋白与配体的相互作用。
