Abstract:
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.
摘要:
感染对快速增长的水产养殖部门构成了挑战。鞘糖脂是病原体用于附着到宿主以引发感染的细胞膜组分。这里,我们使用质谱和核磁共振技术对来自五个粘膜组织的虹鳟鱼鞘糖脂进行了表征,并在薄层色谱上研究了放射性标记的沙门菌与鞘糖脂的结合。鉴定出12种中性鞘糖脂和14种酸性鞘糖脂。从胃和肠分离的鞘糖脂主要是中性的,而从皮肤中分离出的鞘糖脂,g和幽门盲肠大部分是酸性的。许多酸性结构是聚唾液酸化的,与其他组织相比,皮肤中具有较短的聚糖结构。发现的唾液酸是Neu5Ac和Neu5Gc。大多数鞘糖脂具有等球蛋白和神经节核心链,或者这些的组合。虹鳟鱼鞘糖脂聚糖上的表位在上皮位点之间不同,导致病原体结合的差异。一个主要的末端表位是岩藻糖,以α1-3键与GalNAc连接,但也以HexNAc-(Fucc-)HexNAc-R的形式发生。沙门氏菌已显示与g和肠中的中性鞘糖脂结合。本研究首次对虹鳟鱼鞘糖脂进行了全面研究,并分析了salmonicida与鞘糖脂的结合。结构信息为识别干扰病原体定植过程的方式铺平了道路,以防止水产养殖中的感染,并有助于了解沙门氏菌感染机制。