In vitro non-specific immunostimulatory effect of alginate oligosaccharides with different molecular weights and compositions on sea cucumber (Apostichopus japonicus) coelomocytes

作者：Wang, Xitao; Wang, Lili; Che, Jian; Li, Xiaoyu; Li, Jianguang; Wang, Jiang; Xu, Yongping^*

来源：Aquaculture, 2014, 434: 434-441.

DOI：10.1016/j.aquaculture.2014.08.021

• Sea cucumber
• Alginate oligosaccharides
• Coelomocyte culture
• Non-specific immunity

In this study, the non-specific immunostimulatory effect of alginate oligosaccharides (AOSs) with three types of molecular weights, namely, A(1) = below 1 kD (polymerization of 2-5), A(2) = 1 kD to 2 kD (polymerization of 5-10), and A(3) = 2 kD to 4 kD (polymerization of 10-20), as well as their two types of corresponding purified uronic acid oligomers (mannuronate and guluronate oligomers) on sea cucumber (Apostichopus japonicus) coelomocyte were investigated in vitro. Coelomocytes cultured in L-15 medium containing different AOS concentrations (0, 50, 100, 200, or 400 pg mL(-1)) were sampled, and non-specific immune responses, such as phagocytic capacity, reactive oxygen species, lysozyme activity, peroxidase activity, total nitric oxide synthase and acid phosphatase activity were determined and compared with those of the control samples (i.e., treatments without immunostimulants) after exposure to AOS for 3, 6, 12, or 24 h. Most of the above mentioned immune parameters were significantly (P < 0.05) improved by treating with the three types of AOSs, however, the significant difference appeared at different concentrations and incubation times depending on the AOS molecular weights. By contrast, the A1 group showed better effects on phagocytic capacity, lysozyme activity, peroxidase activity and total nitric oxide synthase of coelomocytes because of the higher increase, earlier appearance, and longer duration time than those of the Ay and A3 groups. Furthermore, among the significant differences of various molecular weights of the AOS groups relative to the control sample, these immune parameters in mannuronate or guluronate oligomer groups were all significantly higher than those in the control sample (P < 0.05); in addition, the AI mannuronate group had a higher increase in phagocytic activity than that of guluronate, and no significant difference was observed in other immune parameters between corresponding mannuronate and guluronate oligomer groups. These results indicated that AOS could enhance the non-specific immune response of sea cucumber coelomocytes in vitro and provided basic information regarding AOS as a potential immunostimulant in sea cucumber culture.

• 出版日期2014-10-20
• 单位大连理工大学