Tian Tian-Tian, Wang Jie, Pan Yi-Ru, Han Xue-Qing, Hu Ya-Zhen, Li Jie, Zhang Yong-An, Zhang Xu-Jie
National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, China.
National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, China; Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Wuhan, China; Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
Int J Biol Macromol. 2025 Apr;300:140263. doi: 10.1016/j.ijbiomac.2025.140263. Epub 2025 Jan 23.
Chinese yam polysaccharide (CYP) is an effective immunostimulant, however, its efficacy in grass carp, an important commercial fish species in Asia, remains untested. Here, our study evaluated the immunostimulatory effects of CYP on IgM B cells in vitro and on humoral immunity and immune defense against Aeromonas hydrophila infection in vivo. In vitro stimulation experiments showed that CYP could induce the secretion of IgM antibodies, because it could stimulate the proliferation and differentiation of head kidney IgM B cells. Moreover, CYP could also enhance the phagocytic activity of IgM B cells. When grass carp were intragastrically administrated (i.g.) with CYP, the serum IgM level increased, as did the capacity of serum IgM to bind to peptidoglycan (PGN) and lipopolysaccharide (LPS), indicating that CYP induced natural IgM production in grass carp. Correspondingly, the serum bactericidal ability to A. hydrophila enhanced. Immune protection experiments showed that CYP could protect grass carp from A. hydrophila infection in vivo, because the mortality rate and gut Aeromonas load of grass carp significantly decreased after CYP administration. Taken together, our study reveals immunostimulatory effects of CYP in grass carp, laying important foundation for the usage of CYP to control diseases in grass carp aquaculture.
山药多糖（CYP）是一种有效的免疫刺激剂，然而，其在亚洲重要商业鱼类草鱼中的功效仍未得到验证。在此，我们的研究评估了CYP在体外对IgM B细胞的免疫刺激作用以及在体内对体液免疫和抗嗜水气单胞菌感染的免疫防御作用。体外刺激实验表明，CYP能够诱导IgM抗体的分泌，因为它可以刺激头肾IgM B细胞的增殖和分化。此外，CYP还可以增强IgM B细胞的吞噬活性。当草鱼经口灌胃给予CYP时，血清IgM水平升高，血清IgM与肽聚糖（PGN）和脂多糖（LPS）结合的能力也升高，这表明CYP诱导草鱼产生天然IgM。相应地，血清对嗜水气单胞菌的杀菌能力增强。免疫保护实验表明，CYP可以在体内保护草鱼免受嗜水气单胞菌感染，因为给予CYP后草鱼的死亡率和肠道气单胞菌载量显著降低。综上所述，我们的研究揭示了CYP在草鱼中的免疫刺激作用，为CYP在草鱼养殖中控制疾病的应用奠定了重要基础。
