Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Box 440, Medicinaregatan 9C, Gothenburg 405 30, Sweden.
Department of Biological and Environmental Sciences, Box 463, Medicinareg 7B, University of Gothenburg, Gothenburg 405 30, Sweden.
Glycobiology. 2024 Jul 26;34(9). doi: 10.1093/glycob/cwae055.
Infections pose a challenge for the fast growing aquaculture sector. Glycosphingolipids are cell membrane components that pathogens utilize for attachment to the host to initiate infection. Here, we characterized rainbow trout glycosphingolipids from five mucosal tissues using mass spectrometry and nuclear magnetic resonance and investigated binding of radiolabeled Aeromonas salmonicida to the glycosphingolipids on thin-layer chromatograms. 12 neutral and 14 acidic glycosphingolipids were identified. The glycosphingolipids isolated from the stomach and intestine were mainly neutral, whereas glycosphingolipids isolated from the skin, gills and pyloric caeca were largely acidic. Many of the acidic structures were poly-sialylated with shorter glycan structures in the skin compared to the other tissues. The sialic acids found were Neu5Ac and Neu5Gc. Most of the glycosphingolipids had isoglobo and ganglio core chains, or a combination of these. The epitopes on the rainbow trout glycosphingolipid glycans differed between epithelial sites leading to differences in pathogen binding. A major terminal epitope was fucose, that occurred attached to GalNAc in a α1-3 linkage but also in the form of HexNAc-(Fuc-)HexNAc-R. A. salmonicida were shown to bind to neutral glycosphingolipids from the gill and intestine. This study is the first to do a comprehensive investigation of the rainbow trout glycosphingolipids and analyze binding of A. salmonicida to glycosphingolipids. The structural information paves the way for identification of ways of interfering in pathogen colonization processes to protect against infections in aquaculture and contributes towards understanding A. salmonicida infection mechanisms.
感染对快速发展的水产养殖业构成了挑战。糖脂是病原体用于附着在宿主上引发感染的细胞膜成分。在这里，我们使用质谱和核磁共振技术对来自五种粘膜组织的虹鳟糖脂进行了表征，并研究了放射性标记的鲑鱼气单胞菌与糖脂在薄层色谱上的结合。鉴定出 12 种中性和 14 种酸性糖脂。从胃和肠中分离出的糖脂主要是中性的，而从皮肤、鳃和幽门盲囊中分离出的糖脂则主要是酸性的。与其他组织相比，皮肤中的许多酸性结构带有较短的聚糖结构，并且具有多唾液酸化。发现的唾液酸为 Neu5Ac 和 Neu5Gc。大多数糖脂具有等球蛋白和神经节苷脂核心链，或两者的组合。虹鳟糖脂糖基上的表位在不同的上皮部位存在差异，导致病原体结合的差异。主要的末端表位是岩藻糖，它以α1-3 键的形式与 GalNAc 相连，但也以 HexNAc-(Fuc-)HexNAc-R 的形式存在。鲑鱼气单胞菌被证明能与来自鳃和肠的中性糖脂结合。这项研究首次对虹鳟糖脂进行了全面研究，并分析了鲑鱼气单胞菌与糖脂的结合。该结构信息为识别干扰病原体定植过程的方法铺平了道路，以防止水产养殖中的感染，并有助于理解鲑鱼气单胞菌感染机制。
