State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, 235 Nanjing East Road, Nanchang 330047, China.
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science (Peking University), Ministry of Education, Beijing, China.
Food Chem. 2022 Apr 16;374:131586. doi: 10.1016/j.foodchem.2021.131586. Epub 2021 Nov 11.
Various structural types of polysaccharides are recognized by toll-like receptor 4 (TLR4). However, the mechanism of interaction between the polysaccharides with different structures and TLR4 is unclarified. This review summarized the primary structure of polysaccharides related to TLR4, mainly including molecular weight, monosaccharide composition, glycosidic bonds, functional groups, and branched-chain structure. The optimal primary structure for interacting with TLR4 was obtained by the statistical analysis. Besides, the dual-directional regulation of TLR4 signaling cascade by polysaccharides was also elucidated from an immune balance perspective. Finally, the 3D interaction model of polysaccharides to TLR4-myeloid differentiation factor 2 (MD2) complex was hypothesized according to the LPS-TLR4-MD2 dimerization model and the polysaccharides solution conformation. The essence of polysaccharides binding to TLR4-MD2 complex is a multivalent non-covalent bond interaction. All the arguments summarized in this review are intended to provide some new insights into the interaction between polysaccharides and TLR4.
各种结构类型的多糖可被 Toll 样受体 4（TLR4）识别。然而，不同结构的多糖与 TLR4 相互作用的机制尚不清楚。本综述总结了与 TLR4 相关的多糖的一级结构，主要包括分子量、单糖组成、糖苷键、官能团和支链结构。通过统计分析获得了与 TLR4 相互作用的最佳一级结构。此外，还从免疫平衡的角度阐明了多糖对 TLR4 信号级联的双向调节。最后，根据 LPS-TLR4-MD2 二聚化模型和多糖溶液构象，假设了多糖与 TLR4-髓样分化因子 2（MD2）复合物的 3D 相互作用模型。多糖与 TLR4-MD2 复合物结合的本质是多价非共价键相互作用。本综述中总结的所有论点旨在为多糖与 TLR4 相互作用提供一些新的见解。
