Expression of T-bet and efficiency of BCG intervention in asthmatic mice

Objective To observe the expression of T-bet in ovalbumin (OVA) sensitized and asthmatic mice, and the effect of BCG intervention in these mice. Methods Kunming male mice were randomly divided into sensitized group, asthmatic group, BCG group, and control group. The sensitized and asthmatic mice models were established by OVA sensitization and challenge . The expression of T-bet in lung tissue was assessed by Western blot method. The levels of IFN-γ and IL-4 in bronchoalveolar lavage fluid (BALF) were assessed by ELISA. Results The expression of T-bet in lung tissue of mice was significantly reduced in sensitized group (0.463 ± 0.369) than in control group (1.896 ± 0.402). There was no significantly difference between sensitized group and asthmatic group ( 0.658 ± 0.345) while significant increase was observed in BCG group (1.322 ± 0.349) . Compared with control group, the level of IFN-γ in BALF in sensitized group (15.50 ± 2.25 pg/ml) significantly decreased, and the level of IL-4 in BALF in sensitized group (39.90 ± 2.12 pg/ml) significantly increased. Compared with sensitized group, the level of IFN-γ in BALF in asthmatic group (12.64 ± 2.92 pg/ml) had no significantly difference, and the level of IL-4 in BALF (48.34 ± 3.83 pg/ml) significantly increased. In BCG group, the level of IFN-γ significantly increased, while the level of IL-4 significantly decreased. Conclusions The expression of T-bet in lung tissue is significantly decreased in OVA sensitized mice, but has no further decrease in asthmatic mice. After BCG intervention, the expression of T-bet in lung tissue significantly increases. The level of IFN-γ in BALF decreases in sensitized mice, and has no further decrease in asthmatic mice. The level of IL-4 increases in sensitized mice and further increases in asthmatic mice. After BCG intervention, the level of IFN-γ significantly increases, while the level of IL-4 significantly decreases.