| Abstract: | Objective To investigate regulatory effect of the Lentivirus-mediated-GATA-3 RNAi （si-GATA-3）on the Th1/Th2 imbalance in a murine model of allergic rhinitis in vitro. Methods The lentiviral vector SI-GATA-3 with GATA-3 gene mediated by RNAi was developed and packaged, purified and titrated. BALB/C mice were randomly divided into AR group and normal control group. The allergic rhinitis model of BALB/C mice was developed by using ovalbumin （OVA）. The peripheral blood of BALB/C mice was collected and their mononuclear cells （PBMCs） were isolated. The PBMCs were randomly divided into three groups, namely, si-GATA-3 group, si-NC group and AR group. si-GATA-3, si-NC and normal saline were used to intervene PBMCs in allergic rhinitis mice for 72 h, and normal saline was used to replace si-GATA-3 to intervene PBMCs in normal control mice. PBMCs and cell culture supernatant were separated after the intervention. The relative expression levels of GATA-3 mRNA, T-bet mRNA and GATA-3, T-bet protein in PBMCs were detected by fluorescence quantitative qPCR and Western bloting, respectively. The contents of IL-4 and IFN-γ in supernatant of cell culture were determined by ELISA. Results The RNAi mediated lentiviral vector si-GATA-3 with a titer of 5×108 TU/mL was successfully deeloped. The allergic rhinitis mice models were established successfully. The relative expression levels of GATA-3 mRNA and GATA-3 protein and the content of IL-4 in supernatant of PBMCs in si-GATA-3 group were significantly lower than those in AR group and si-NC group （P < 0.01）, and the expression levels of GATA-3 in AR group and si-NC group were significantly higher than those in normal control group （P < 0.01）. There was no difference between AR group and si-NC group （P > 0.05）. The relative expression of T-bet mRNA and T-bet protein in si-GATA-3 group was significantly higher than that in AR group and si-NC group （P < 0.01）, and the expression of T-bet mRNA and T-bet protein in AR group and si-NC group was significantly lower than that in control group （P < 0.01）. There was no difference between AR group and si-NC group （P > 0.05）. However, the content of IFN-γ in cell culture supernatant of si-GATA-3 group was higher than that of normal control group （P < 0.05）, and the content of IFN-γ in AR and si-NC groups was significantly higher than that of normal control group and si-GATA-3 group （P < 0.01）. There was no significant difference in IFN-γ expression between AR group and si-NC group （P > 0.05）. Conclusions si-GATA-3 could down-regulate the relative expression of GATA-3 mRNA , GATA-3 protein and IL-4 level in Th2 cells, and up-regulate the relative expression of T-bet mRNA and T-bet protein in Th1 cells. Therefor, it can effectively correct the immune imbalance of Th2/Th1 in PBMCs in mouse AR model. |
