Abstract: To investigate the effect of bone marrow-derived mast cells (BMMCs) on the cytokines responses of FMDV-VLPs via mannose receptors, the recombinant plasmid pCMV-HA-HBcAg-VP1-VP4 was constructed and transfected into CHO-K1 cells to prepare the foot-and-mouth disease virus-like particles (FMDV-VLPs). The BMMCs treated with the mannose receptor inhibitor Mannan were loaded with FMDV-VLPs, and the BMMCs loaded with VLPs and BMMCs were used as controls. Quantitative cytokine chip was used to detect the content of cytokines secreted by BMMCs in different treatment groups. The results showed that compared with the control group, the levels of IL-1α, IL-2, IL-4, IL-15, IL-17A, IL-21, TNF-α, IFN-γ, CCL-17 and CCL21 of VLP group were all significantly up-regulated (P<0.05) and IL-10 showed no difference, while the levels of IL-1α, IL-2, IL-4, IL-15, IL-17A, TNF-α, IFN-γ, CCL-17 and L-selectin of the iMR-VLP group significantly down-regulated (P<0.05). Of note, the expression of IL-9, IL-10, CCL19 and CCL21 were further up-regulated in the iMR-VLP group. In conclusion, FMDV-VLPs can promote the secretion of a series of cytokines in BMMCs, and the ability to secrete cytokines of BMMCs is inhibited to a certain extent when MR was inhibited. The results indicate that FMDV-VLPs may enhance the secretion of Th1 cytokines through the mannose receptor of BMMCs, effectively inhibit the secretion of IL-10 that can cause immunosuppression, and reduce the formation of CCL19 and CCL21 that mediate the recycling of T cells. The results provide a theoretical basis and new ideas for the development of a new foot-and-mouth disease vaccine based on the roles of mannose receptors expressed on BMMCs.

Key words: mast cell, mannose receptor, foot-and-mouth disease virus-like particles, cytokines, cytokines chip