Helper T cell immune responses induced by the Brucella abortus transcriptional regulator GntR in a mouse model

Abstract:

[Objective] The Th1 and Th2-type immune responses induced by the Brucella gntR gene were analyzed by prokaryotic expression of gntR. [Methods] To clone and express gntR gene of Brucella, a pair of primers for the gntR gene of Brucella S2308 was designed based on published GenBank sequence. The gntR gene was amplified by molecular cloning technology from Brucella S2308 and then cloned into pET-30a vector and transformed to E. coli BL21. The expression of GntR protein was analyzed by SDS-PAGE. The GntR recombinant protein (rGntR) was purified by AKTAxpress intelligent multidimensional purification system. The rGntR immunoreactivity was analyzed by Western blotting. Cytokines IFN-γ, IL-2, IL-4 and IL-5 in murine macrophages (RAW 264.7) and splenocytes stimulated with rGntR were detected by ELISA kit. Mice were immunized with rGntR and IFN-γ, IL-4 and IgG in serum of mice were detected by ELISA kit. [Results] The full-length gntR gene was 735 bp, encoding 245 amino acids. SDS-PAGE showed that rGntR appeared in the approximately 35 kDa position. The band was single after purification. WB indicated that rGntR had good immunoreactivity. The rGntR could induce higher levels of IFN-γ, IL-4 and IgG in host cells and mice. [Conclusion] The rGntR could induce helper T cells (Th1 and Th2-type) immune responses in vivo and in vitro. This study provides scientific basis for the development of brucellosis vaccines.