Effect of CpG oligodeoxynucleotides on airway inflammation and transcription factor GATA-3 mRNA expression in asthmatic mice

[Objective] To investigate the effect of CpG oligodeoxynucleotides(CpG ODN) on airway inflammation and transcription factor GATA-3 mRNA expression in asthmatic mice.[Methods] Fourty female BALB/C mice were randomly divided into four groups(10 mice in each group): saline control group(group A); asthmatic group(group B); CpG ODN intervention group (group C); GpC ODN control group(group D). Mice were sensitized by intraperitoneally injection of OVA/alum on days 0, 7, 14, and 21, and subsequently received nebulized 2% OVA on days 25, 26, 27 and 28. Groups C and D were treated with CpG ODN or GpC ODN(50 μg/mouse) intraperitoneally 24 h before OVA inhalation challenges. All the mice were killed 24 h after the final OVA challenge, bronchoalveolar lavage fluid (BALF)were collected for counting total inflammatory cells and the percentage of eosinophils, IFN-γ, IL-4 and IL-5concentrations in BALF were detected using an enzyme-linked immunosorbent assay, transcription factor GATA-3 mRNA expression in lung tissue was detected by reverse transcription-polymerase chain reaction. [Results] The total inflammatory cells, percentage of eosinophils, concentrations of IL-4, IL-5 and IFN-γ in BALF in each group were as follows: in group A they were (7.46±1.77)×105/mL, (0.75±0.48)%, (26.9±4.6)pg/mL, (41.7±5.1)pg/mL, (110.4±12.1)pg/mL respectively; in group B they were (21.68±4.40)×105/mL, (9.50±1.13)%, (267.6±24.5)pg/mL, (218.2±15.2)pg/mL, (47.9±9.6)pg/mL respectively; in group C they were (8.98±2.23)×105/mL, (2.90±0.86)%, (85.9± 8.1)pg/mL, (63.0±9.6)pg/mL, (221.0±29.9)pg/mL respectively; in group D they were (20.41±3.47)×105/mL, (9.60±1.30)%, (260.7± 15.7)pg/mL, (205.1±15.8)pg/mL, (52.2±10.7)pg/mL respectively. Group B was significantly different from group A(P 0.01), group C was significantly different from group B(P 0.01), group D was not significantly different from group C(P 0.05). The GATA-3 mRNA expression was reduced in lung tissue in group C compared with group B, group C was obviously different from group B(P 0.01), but there was no difference between group D and group B(P 0.05).[Conclusions] This study suggests that CpG ODN could inhibit production of Th2 cytokines, down-regulate GATA-3 mRNA expression, and relieve the allergic inflammation of airway in asthmatic mice.