Effect of Intranasal T-bet Plasmid Transfer on Th1/Th2 Balance in Spleen MNC in a Established Murine Allergic Asthmatic Model / 中山大学学报(医学科学版)

ABSTRACT

[Objective] This study was designed to determine Th1, Th2 cell numbers and investigate T-bet mRNA, GATA-3 mRNA expression of spleen MNC in a mufine asthmatic model which intended to understand effect of airway T-bet plasmid gene transfer on Th differentiation. [ Methods] A mouse asthmatic model was established by sensitization with ovalbumin (OVA). Thirty-two C57BL/6 mice were divided into four groups (8 mice in each group) the normal control group (group A ), the asthmatic model group (group B), the pcDNA3 plasmid group (group C), the pcDNA3-T-bet group (group D). All animals were sensitized and challenged with OVA, except group A normal saline was applied. The group C was intranasally administered 50 μg pcDNA3 plasmid at 24 h before intranasal challenges, and the 50 μg pcDNA3-T-bet plasmid for the mice of group D. We investigated Th1 and Th2 cell numbers by FACS and T-bet, GATA-3mRNA expression of spleen mononuclear cells (MNC) by semi-quantitative PCR in the four groups. [Result] Th1 percent in spleen MNC of pcDNA3-T-bet treated mice was significantly increased ([2.29±1.551% vs. [1.93±1.141%, P<0.05), while Th2 percent was significantly decreased ([0.93±0.64]% vs. [1.63±0.59]%), compared with that of the asthmatic control group mice by FACS. Spleen MNC was detected a high level of T-bet mRNA expression (0.53±0.027 vs. 0.28±0.035, P<0.05) and a low level of GATA-3 mRNA expression (0.24±0.022 vs. 0.58±0.038, P<0.05) after pcDNA3-T-bet treatment by RT-PCR. There was no significant change between the pcDNA3 plasmid group and the asthmatic model group. [Conclusion] The intranasal transfer of pcDNA3-T-bet plasmid was effective in modulating the imbalance of Th1/Th2 in mice asthma model, which provides a novel therapeutic strategy for transferring transcriptional factor in allergic asthma.