Crude polysaccharides from Cistanche deserticola Y.C. Ma as an immunoregulator and an adjuvant for foot-and-mouth disease vaccine

[Display omitted] •CPCD potently activated dendritic cells through TLR-2/TLR-4-related downstream MAPKs and NF-κB pathway.•CPCD effectively induced stronger humoral and cellular responses through DC activation.•CPCD have the potential as an polysaccharide adjuvant for FMDV.•CPCD is a safe and efficacious an immunoregulator. Cistanche deserticola Y. C. Ma (CD) are ideal herbal remedies for health problems. In this study, modulator activities of CPCD on activating dendritic cells (DCs) and the adjuvant potential for foot-and-mouth disease vaccine (FMDV) was evaluated. CPCD without cytotoxicity induced DC activation via upregulating the phenotypic markers and antigen uptake. TLR-2 or TLR-4 antibodies suppressed levels of CPCD-mediated CD40 and CD86 as well as IL-6 and IL-1β in DCs. CPCD induced the phosphorylation of MAPKs related molecules and NF-κB. When co-injected intramuscularly with FMDV in mice, CPCD increased FMDV-specific antibody, lymphocyte proliferation, effector T-cells. Specifically, CPCD elicited Th1 response, as indicated by the higher expressions of CD4+ IFN-γ, CD8+ IFN-γ and CTL response. CPCD enhanced the expressions of MHC-II, CD80, CD86 and CD40 in DCs and lowered Tregs frequency. Therefore, CPCD could effectively stimulate stronger humoral and cellular responses by modulating DC activation through TLR-2/TLR-4 related MAPKs and NF-κB pathways.