We previously demonstrated that 2-hydroxypropyltrimethyl ammonium chloride chitosan(HACC)promoted the production of nitric oxide(NO)and proinflammatory cytokines by activating the mitogen-activated protein kinases(MAPK)and Janus kinase(JAK)/STAT pathways in RAW 264.7 cells,indicating good immunomodulatory activity of HACC.In this study,to further investigate the immunomodulatory mechanisms of HACC,we determined the roles of phosphatidylinositol 3-kinase(PI3K)/Akt,activating protein(AP-1)and nuclear factor kappa B(NF-κB)in HACC-induced activation of RAW 264.7 cells by the west blotting.The results suggest that HACC promoted the phosphorylation of p85 and Akt.Furthermore,c-Jun and p65 were also increased after the treatment of RAW 264.7 cells with HACC,indicating the translocation of NF-κB and AP-1 from cytoplasm to nucleus.In addition,as scanning electron microscopy(SEM)analysis shows,the cell morphology changed after HACC treatment.These fi ndings indicate that HACC activated MAPK,JAK/STAT,and PI3K/Akt signaling pathways dependent on AP-1 and NF-κB activation in RAW 264.7 cells,ultimately leading to the increase of NO and cytokines.