In vitro effects of five recombinant antigens of Eimeria maxima on maturation, differentiation and immunogenic functions of Dendritic cells derived from Chicken spleen

ABSTRACT Eimeria maxima possess integral families of immunogenic constituents that promote differentiation of immune cells during host-parasite interactions. Dendritic cells (DCs) have an irreplaceable role in the modulation of the host immunity. However, the selection of superlative antigen with immune stimulatory efficacies on host DCs is lacking. In this study, five recombinant proteins of Eimeria maxima (Em), including Em14-3-3, rhomboid family domain containing proteins (ROM) EmROM1 and EmROM2, Microneme protein 2 (EmMIC2) and Em8 were identified to stimulate chicken splenic derived dendritic cells in vitro. The cultured populations were incubated with recombinant proteins, and typical morphologies of stimulated DCs were obtained. Dendritic cell-associated markers major histocompatibility complex (MHC) class II, CD86, CD11c, and CD1.1, were showed up-regulatory expressions by flow cytometry assay. Immunofluorescence assay revealed that recombinant proteins could bind with the surface of chicken splenic derived dendritic cells. Moreover, quantitative real-time PCR (QRT-PCR) results showed that distinct genes expressions of Toll-like receptors and Wnt signaling pathway were up-regulated after the co-incubation of recombinant proteins with DCs. The ELISA results indicated that the DCs produced a significant higher level of IL-12 and IFN-γ secretions after incubation with recombinant proteins. Whereas TGF-β was significantly increased with rEmROM1, rEmROM2, and rEmMIC2 as compared to control groups, and IL-10 did not show significant alteration. Taken together, these results concluded that among five potential recombinant antigens, rEm14-3-3 could promote immunogenic functions of chicken splenic derived DCs more efficiently, which might represent an effective molecule for inducing the host Th1-mediated immune response against Eimeria infection.