Human T-lymphocyte activation is associated with changes in O-glycan biosynthesis.
Human T-lymphocyte activation is associated with changes in O-glycan biosynthesis.
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DOI：
10.1016/s0021-9258(18)68157-8
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发表时间：
1988-10
期刊：
影响因子：
--
通讯作者：
F. Piller;V. Piller;R. Fox;Minoru Fukuda
中科院分区：
文献类型：
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作者：
F. Piller;V. Piller;R. Fox;Minoru Fukuda
人T淋巴细胞被抗CD3抗体和白介素2激活，导致主要细胞表面唾液酸糖蛋白的表观分子量显著增加。两种唾液酸糖蛋白都被单特异性抗血清鉴定为白唾液素，分子量的差异被发现是由于碳水化合物结构的变化。我们的结果表明，静息T淋巴细胞在白唾液中表达二唾液酸四糖NeuNAcα2-3Gal-β1-3(NeuNAcα2--6)Gal-NAC-Ser/Thr，而激活的人T细胞只表达更复杂的结构NeuNAcα2-3Galβ1-3(NeuNAcα2-3Galβ1-4GlcNAc Beta 1-6)GalNAc-Ser/Thr。与静息细胞相比，活化T淋巴细胞中O-糖链生物合成途径的根本性转变显然是由于α2-6唾液酸基转移酶活性的降低和β1-6GlcNAc转移酶的平行戏剧性刺激。由于这两种酶竞争相同的前体底物，它们活性的协调变化很可能是在人T淋巴细胞激活过程中白唾液酸糖结构完全改变的原因。
The activation of human T-lymphocytes by anti-CD3 antibodies and interleukin-2 results in a marked increase in apparent molecular weight of the major cell-surface sialoglycoprotein. Both forms of the sialoglycoprotein were identified as leukosialin by a monospecific antiserum, and the differences in molecular weight were found to be due to changes in the carbohydrate structures. Our results suggest that resting T-lymphocytes express on leukosialin the disialotetrasaccharides NeuNAc alpha 2—-3Gal beta 1—-3(NeuNAc alpha 2—-6)Gal-NAc-Ser/Thr, whereas activated human T-cells carry on leukosialin exclusively the more complex structures NeuNAc alpha 2—-3Gal beta 1—-3(NeuNAc alpha 2—-3Gal beta 1—-4GlcNAc beta 1—-6)GalNAc-Ser/Thr. The radical shift in the biosynthetic pathway of O-glycans in activated T-lymphocytes compared to resting cells is apparently caused by a decrease of alpha 2—-6 sialyltransferase activity and by the parallel dramatic stimulation of the beta 1—-6GlcNAc-transferase. Since both enzymes compete for the same precursor substrate, the coordinate changes in their activities are most likely responsible for the complete change of the carbohydrate structures on leukosialin during the activation of human T-lymphocytes.