Wang Huimei, Wu Hanyue, Zhang Haotian, Zhu Yufei, Hou Qihang, Yang Xiaojun, Long Fangyu, Yang Xin
College of Animal Science and Technology, Northwest A&F University, Yangling 712100, PR China.
Dayu Biological Industry Development Research Institute in Xi 'an, PR China.
Int J Biol Macromol. 2025 Sep;321(Pt 1):146271. doi: 10.1016/j.ijbiomac.2025.146271. Epub 2025 Jul 23.
The aim of this study was to structurally characterize exopolysaccharide EPS2 extracted from Lactiplantibacillus plantarum PA01, and to investigate its immunological activity in vitro and in vivo. Structural characterization revealed that EPS2 was mainly comprised of mannose, glucose and a trace of galactose, arabinose, and glucosamine, with a molecular weight of 73.34 kDa. By methylation and NMR analysis, the backbone of EPS2 was composed of 2,6)-α-D-Manp→ and 6)-α-D-Manp (1→, with three different branch at O-2 of →2,6)-α-D-Manp. The in vitro results indicated that EPS2 promoted proliferation, phagocytosis and the secretion of NO and cytokines in RAW264.7 cells by activating MAPK pathway via pattern recognition receptors TLR2, TLR4, and MR. Meanwhile, in vivo results showed that EPS2 treatment alleviated spleen damage, enhanced lymphocyte proliferation, and mitigated myelosuppression in cyclophosphamide induced mice. These results suggested that EPS2 efficiently enhance the immunomodulatory activity of macrophages and immunosuppressed mice. In summary, the current work provided a solid foundation for the potential utilization of EPS2 as an immunomodulator.
本研究的目的是对从植物乳杆菌PA01中提取的胞外多糖EPS2进行结构表征，并研究其在体外和体内的免疫活性。结构表征显示，EPS2主要由甘露糖、葡萄糖以及微量的半乳糖、阿拉伯糖和氨基葡萄糖组成，分子量为73.34 kDa。通过甲基化和核磁共振分析，EPS2的主链由2,6)-α-D-甘露糖基→和6)-α-D-甘露糖基(1→组成，在→2,6)-α-D-甘露糖基的O-2处有三个不同的分支。体外实验结果表明，EPS2通过模式识别受体TLR2、TLR4和MR激活MAPK途径，促进RAW264.7细胞的增殖、吞噬作用以及NO和细胞因子的分泌。同时，体内实验结果显示，EPS2处理可减轻环磷酰胺诱导的小鼠脾脏损伤，增强淋巴细胞增殖，并减轻骨髓抑制。这些结果表明，EPS2能有效增强巨噬细胞和免疫抑制小鼠的免疫调节活性。总之，目前的工作为EPS2作为免疫调节剂的潜在应用提供了坚实的基础。
