壳聚糖能增强水生动物体内杀菌酶类的活性和吞噬细胞的吞噬能力，提高水生动物的非特异性免疫能力。壳聚糖还可以促进抗体生成，提高水生动物的特异性免疫能力。然而目前关于其调节水生动物免疫力的机制尚鲜有报道。根据在陆生动物方面的研究推断，壳聚糖调节动物免疫力的主要机制可能是通过调节免疫细胞中一氧化氮（NO）和前列腺素-2（PGE2）的生成来增强机体的免疫功能。

It was found that chitosan could improve the non-specific immune function of aquatic animals through enhancing the activities of antimicrophyte enzymes and the phagocytosis ability of phagocyte. Chitosan could also promote the production of antibody, thus improved the specific immune function of aquatic animals. However, there were few studies on its regulation mechanism in the aquatic animals. The studies in the terrestrial animals field indicated that the improvement of immune function by adding chitosan might result mainly from regulating the NO and PGE2 production in immune cells. ［Chinese Journal of Animal Nutrition, 2010，22（3）:544-550］