RAT AND HUMAN COLONIC MUCINS BIND TO AND INHIBIT ADHERENCE LECTIN OF ENTAMOEBA-HISTOLYTICA
RAT AND HUMAN COLONIC MUCINS BIND TO AND INHIBIT ADHERENCE LECTIN OF ENTAMOEBA-HISTOLYTICA
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DOI：
10.1172/jci113199
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发表时间：
1987-11-01
影响因子：
15.9
通讯作者：
RAVDIN, JI
中科院分区：
文献类型：
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作者：
CHADEE, K;PETRI, WA;RAVDIN, JI
溶组织内阿米巴粘附的建立由170-kD Gal/GalNAc可降解凝集素介导，并且是哺乳动物靶细胞的细胞溶解和吞噬作用所必需的。我们研究了大鼠和人结肠粘蛋白与无菌大肠杆菌在体外相互作用的生化机制。溶组织滋养体粗粘液阻止阿米巴粘附中国仓鼠卵巢（CHO）细胞高达70%。通过Sepharose 4 B层析、核酸酶消化和氯化铯梯度离心纯化结肠粘蛋白导致抑制性粘蛋白的1,000倍富集。纯化的大鼠粘蛋白抑制阿米巴对同种大鼠结肠上皮细胞的粘附和细胞溶解。氧化和酶促裂解的大鼠粘蛋白半乳糖和GalNAc残基完全废除阿米巴粘附粘蛋白抑制。大鼠125 I-粘蛋白与阿梅利翁的结合是半乳糖特异性的、可饱和的、可逆的和pH依赖性的。特异于170-kD阿米巴Gal/GalNAc凝集素的单克隆抗体完全抑制大鼠125 I-粘蛋白的结合。大鼠粘蛋白结合到Affigel亲和纯化条件培养基中的阿米巴凝集素。结肠粘蛋白糖蛋白通过与寄生虫的粘附凝集素结合，从而防止阿米巴对宿主上皮细胞的附着和细胞溶解，在重要的宿主防御中起作用。
Establishment of adherence by Entamoeba histolytica is mediated by a 170-kD Gal/GalNAc inhibitable lectin and is required for cytolysis and phagocytosis of mammalian target cells. We studied the biochemical mechanisms of the in vitro interaction between rat and human colonic mucins and axenic E. histolytica trophozoites. Crude mucus prevented amebic adherence to Chinese hamster ovary (CHO) cells by up to 70%. Purification of the colonic mucins by Sepharose 4B chromatography, nuclease digestion, and cesium chloride gradient centrifugation resulted in a 1,000-fold enrichment of the inhibitory mucins. Purified rat mucin inhibited amebic adherence to and cytolysis of homolgous rat colonic epithelial cells. Oxidation and enzymatic cleavage of rat mucin Gal and GalNAc residues completely abrogated mucin inhibition of amebic adherence. The binding of rat 125I-mucin to amebae was galactose specific, saturable, reversible, and pH dependent. A monoclonal antibody specific for the 170-kD amebic Gal/GalNAc lectin completely inhibited the binding of rat 125I-mucin. Rat mucin bound to Affigel affinity purified the amebic lectin from conditioned medium. Colonic mucin glycoproteins act as in important host defense by binding to the parasite''s adherence lectin, thus preventing amebic attachment to and cytolysis of host epithelial cells.