Pos O, Oostendorp R A, van der Stelt M E, Scheper R J, Van Dijk W
Department of Medical Chemistry, Faculty of Medicine, Free University Amsterdam, The Netherlands.
Inflammation. 1990 Apr;14(2):133-41. doi: 10.1007/BF00917452.
Human alpha 1-acid glycoprotein (AGP) has been shown to modulate various cellular and humoral immune reactions in vitro. Using glycosidase-modified derivatives of AGP, the importance of its carbohydrate moiety with regard to these effects has been noted. In normal serum, three molecular AGP forms interacting differently with concanavalin A (Con A) are present. The ratio of these forms is often changed during various physiopathological conditions. In this study, we could show that differences exist between the three AGP forms with regard to their immunomodulatory effectiveness. At physiological concentrations, the Con A-nonreactive variant AGP-A induced a stronger inhibition of the anti-CD3 stimulated lymphocyte proliferation than the other forms. Interestingly, AGP-A was also found to be responsible for the stimulation of lymphocyte proliferation induced by low AGP concentrations in vitro. Both immunomodulatory effects of AGP were abrogated by desialylation of the glycoprotein. These results support an immunomodulatory role of AGP in conditions characterized by a changed ratio of the differently glycosylated AGP forms.
人α1-酸性糖蛋白（AGP）已被证明在体外可调节多种细胞免疫和体液免疫反应。利用AGP的糖苷酶修饰衍生物，已注意到其碳水化合物部分在这些效应方面的重要性。在正常血清中，存在三种与伴刀豆球蛋白A（Con A）相互作用方式不同的分子AGP形式。在各种生理病理条件下，这些形式的比例经常发生变化。在本研究中，我们可以证明三种AGP形式在免疫调节有效性方面存在差异。在生理浓度下，Con A无反应性变体AGP-A比其他形式对抗CD3刺激的淋巴细胞增殖具有更强的抑制作用。有趣的是，还发现AGP-A负责体外低AGP浓度诱导的淋巴细胞增殖刺激。AGP的两种免疫调节作用都因糖蛋白的去唾液酸化而消除。这些结果支持了AGP在以不同糖基化AGP形式比例改变为特征的条件下的免疫调节作用。
