| Allergic asthma was characterized by airway inflammation cause by persistend Th2 immune response. The cytokine milieu during Ag presentation was the most critical factors for determining Th1/Th2 differentiation. IL-12 and IFN-γ producted by DCs can induce naive T helper cells differentiation into Th1 subset. T-bet is a specific transcription in promoting INF-γ expression. There are no experiments to comfirm whether T-bet modified dendritic cells could elevate IFN-γ. If it is true that T-bet modifed dendritic cells could elevate IFN-γ, the T-bet modifed dendritic cells could be applied to improve the level of IFN-γ in the cytokine milieu during Ag presentation and reverse the Th2 immune repsonse. However, all the therapeutic tools available now could not regulate Th polarisation on the Ag presentation level and there are no related studies consulted before.Therefore, in this sudy, we examined the possibility of modulating ovalbumin(OVA)-induced inflammation by downregulatethe Th2 immune responses in allergic asthma on the Ag presentation level investigeting whether an adenovirus-mediated T-bet gene tranfer would promote the IFN-γ expression in dendritic cells and whether the T-bet geng modified dendritic cells could prove beneficial in reversing the course of asthma.The cDNA encoding the mouse t-bet was obtained by RT-PCR, followed by amplification of DNA fragment with high fidelity PCR system. The pAdnoe-T-bet recombinant adenovirus vector was built with BD Adeno-X? system.The 293A cell line was applied to pachage and propagate the recombinant adenoviral-based vectors to produce Ad-T-bet and Ad-LacZ recombinant adenovirus. The mature dendritic cells were generated with bulk-culture method and infected with the recombinant adenovirus-mediated T-bet and LacZ gene. The IFN-γ in the supernatant of dendritic cells was quantified elevatedly by ELISA. OVA-sensitized BALB/c mice treated with the T-bet gene modified dendritic cells exhibit significantly lower levels of...
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