Amado Margarida, Yan Qi, Comelli Elena M, Collins Brian E, Paulson James C
Departments of Molecular Biology and Molecular and Experimental Medicine, The Scripps Research Institute, 10550 Torrey Pines Road, La Jolla, CA 92037, USA.
J Biol Chem. 2004 Aug 27;279(35):36689-97. doi: 10.1074/jbc.M405629200. Epub 2004 Jun 21.
Following activation in the periphery, murine CD8+ T cells exhibit a characteristic increased binding of peanut agglutinin (PNA), reflecting an increased expression of hyposialylated O-linked glycans (Galbeta1-3GalNAcalpha-O-Thr/Ser) on the cell surface. In this report, we show that the majority of the PNA receptors expressed on activated CD8+ T cells are carried by CD45. Other glycoproteins (e.g. CD8) and the glycolipid asialo-GM1 also carry PNA receptors, although to a much lesser extent. Analysis of enzymes involved in the sialylation/de-sialylation pathways showed that generation of PNA receptors in activated CD8+ T cells is not due to up-regulation of endogenous sialidases. Instead, our results indicate that the PNA(high) phenotype results from de novo synthesis of CD45 carrying reduced sialylated core 1 O-glycans.
在外周被激活后，小鼠CD8⁺ T细胞表现出花生凝集素（PNA）结合能力的特征性增强，这反映了细胞表面低唾液酸化O-连接聚糖（Galβ1-3GalNAcα-O-Thr/Ser）表达的增加。在本报告中，我们表明活化的CD8⁺ T细胞上表达的大多数PNA受体由CD45携带。其他糖蛋白（如CD8）和糖脂脱唾液酸GM1也携带PNA受体，尽管程度要小得多。对参与唾液酸化/去唾液酸化途径的酶的分析表明，活化的CD8⁺ T细胞中PNA受体的产生并非由于内源性唾液酸酶的上调。相反，我们的结果表明，PNA（高）表型是由于携带减少的唾液酸化核心1 O-聚糖的CD45的从头合成所致。
