Schroten H, Wolske A, Plogmann R, Hanisch F G, Hacker J, Uhlenbruck G, Wahn V
Universitäts-Kinderklinik, Düsseldorf.
Zentralbl Bakteriol. 1991 Jan;274(4):514-8. doi: 10.1016/s0934-8840(11)80089-7.
Investigations were carried out on the adhesion of cloned S-fimbriated E. coli, labelled with fluoresceinisothiocyanate (FITC) to human buccal epithelial cells. Fluorescence microscopic analysis revealed binding of bacteria to 75-95% of epithelial cells. Inhibition experiments with fetuin, alpha 1-acid glycoprotein and N-acetyl neuraminic acid confirmed the specificity of bacterial binding to sialoglycoproteins. Further studies using saliva as an inhibitor resulted in a 4-5 times stronger binding inhibition by newborn saliva in comparison to adult saliva coinciding with a 4-5 times higher content of total N-acetyl neuraminic acid in samples of newborn saliva. In Western blot analysis sialoglycoprotein bands with a molecular weight greater than 200 kD reacting with wheat germ agglutinin (WGA), were only identified in samples of newborn saliva. These bands are classified as mucins on account of molecular weight and staining. These data suggest that saliva mucins could represent a major defense mechanism against bacterial infections at a stage of ontogeny where the secretory IgA-system is not yet developed.
对用异硫氰酸荧光素（FITC）标记的克隆S-菌毛大肠杆菌与人颊上皮细胞的黏附情况进行了研究。荧光显微镜分析显示，75%至95%的上皮细胞有细菌黏附。用胎球蛋白、α1-酸性糖蛋白和N-乙酰神经氨酸进行的抑制实验证实了细菌与唾液酸糖蛋白结合的特异性。进一步使用唾液作为抑制剂的研究表明，与成人唾液相比，新生儿唾液对细菌结合的抑制作用强4至5倍，这与新生儿唾液样本中总N-乙酰神经氨酸含量高4至5倍相一致。在蛋白质免疫印迹分析中，仅在新生儿唾液样本中鉴定出与麦胚凝集素（WGA）反应的分子量大于200 kD的唾液酸糖蛋白条带。根据分子量和染色情况，这些条带被归类为黏蛋白。这些数据表明，在个体发育阶段，当分泌型IgA系统尚未发育时，唾液黏蛋白可能是抵御细菌感染的主要防御机制。
