Surface membrane proteins of Biomphalaria glabrata embryonic cells bind fucosyl determinants on the tegumental surface of Schistosoma mansoni primary sporocysts
Surface membrane proteins of Biomphalaria glabrata embryonic cells bind fucosyl determinants on the tegumental surface of Schistosoma mansoni primary sporocysts
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DOI：
10.1645/ge-954r.1
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发表时间：
2007-08-01
影响因子：
1.3
通讯作者：
Yoshino, Timothy P.
中科院分区：
文献类型：
--
作者：
Castillo, Maria G.;Wu, Xiao-Jun;Yoshino, Timothy P.
先前的观察表明，在体外粘附的光滑双脐螺胚胎（Bge）细胞的曼氏血吸虫孢子囊幼虫阶段的岩藻依聚糖，L-岩藻糖的硫酸化聚合物，强烈抑制，表明凝集素样Bge细胞受体在孢子囊结合相互作用的作用。在本研究中，在粘附阻断研究中使用了对寄生虫体上发现的3种主要聚糖决定簇具有特异性的单克隆抗体，LacdiNAc、岩藻糖基化LacdiNAc（LDNF）和刘易斯X抗原，以进一步分析宿主-寄生虫界面的分子相互作用。结果表明，只有抗LDNF抗体显着降低蜗牛Bge细胞粘附到孢子囊表面，表明岩藻糖基决定簇可能是重要的幼虫-宿主细胞的相互作用。亲和色谱分离岩藻糖基反应性Bge细胞蛋白从岩藻聚糖结合琼脂糖4 B显示存在的多肽范围从6至200 kDa的含岩藻聚糖的缓冲液洗脱后。在引入岩藻聚糖缓冲液之前，用葡聚糖（Dex）和硫酸葡聚糖（DexS）预洗脱Bge蛋白结合亲和柱，作为基于非特异性糖或负电荷相互作用的蛋白结合的对照。通过岩藻依聚糖洗脱释放的多肽（类似于35-150 kDa）的子集被鉴定为Bge表面膜蛋白，代表推定的岩藻糖基结合蛋白。远蛋白质印迹分析也表明Bge细胞和孢子囊被膜蛋白之间的结合反应。发现这些寄生虫结合BGE细胞蛋白也岩藻多糖反应表明这些分子可能参与介导细胞与孢子囊皮层碳水化合物的相互作用。它的结论是，Bge细胞的表面蛋白（S），可能发挥作用，促进宿主细胞粘附到幼虫岩藻糖基化的初级孢子囊表面。
Previous observations that in vitro adherence of Biomphalaria glabrata embryonic (Bge) cells to sporocyst larval stages of Schistosoma mansoni was strongly inhibited by fucoidan, a sulfated polymer Of L-fucose, suggested a role for lectinlike Bge cell receptors in sporocyst binding interactions. In the present investigation, monoclonal antibodies with specificities to 3 major glycan determinants found on schistosomes, LacdiNAc, fucosylated LacdiNAc (LDNF), and the Lewis X antigen, were used in adhesion blocking studies to further analyze the molecular interactions at the host-parasite interface. Results showed that only the anti-LDNF antibody significantly reduced snail Bge cell adhesion to the surface of sporocysts, suggesting that fucosyl determinants may be important in larval-host cell interactions. Affinity chromatographic separation of fucosyl-reactive Bge cell proteins from fucoidan-bound Sepharose 4B revealed the presence of polypeptides ranging from 6 to 200 kDa after elution with fucoidan-containing buffer. Pre-elution of the Bge protein-bound affinity column with dextran (Dex) and dextran sulfate (DexS) before introduction of the fucoidan buffer served as controls for protein binding based on nonspecific sugar or negative charge interactions. A subset of polypeptides (similar to 35-150 kDa) released by fucoidan elution was identified as Bge surface membrane proteins, representing putative fucosyl-binding proteins. Far-western blot analysis also demonstrated binding reactivity between Bge cell and sporocyst tegumental proteins. The finding that several of these parasite-binding Bge cell proteins were also fucoidan-reactive suggests the possible involvement of these molecules in mediating cellular interactions with sporocyst tegumental carbohydrates. It is concluded that Bge cells have surface protein(s) that may be playing a role in facilitating host cell adhesion to the surface of schistosome primary sporocysts through larval fucosylated glycoconjugates.