Immunomodulatory activity and mechanism of Chinese yam polysaccharide after sulfated modification

It is well known that yam is an important industrial crop resource. Our previous study has demonstrated that sulfated modifications (S-CYP) can improve the immunomodulatory effect of polysaccharide from Chinese yam by activating and maturating RAW264.7 cells, while its mechanism is still unknown. In this study, the underlying mechanisms of S-CYP-induced immunomodulatory effect were examined based on RNA sequencing (RNA-seq), and a co-culture system with Caco-2 cells and RAW264.7 cells. RNA-seq analysis indicated that 1764 expressed genes differentially between the control and S-CYP groups. 13 cellular component terms, 20 biological process terms, and 10 molecular function terms were identified by GO. KEGG analysis showed that MAPK signaling pathways belong to the 20 most significantly affected pathways. Furthermore, S-CYP indirectly affects the immune function of RAW264.7 in co-culture model by increasing secretion of cytokines (IL-1β, TNF-α). These results provide a theoretical basis for exploring S-CYP as an immunomodulatory agent.