[T-bet gene modified dendritic cells abrogate and reverse the airway inflammation in allergic asthma: experiment with mice].

Objective: To explore the feasibility of the therapeutic strategy to use T-bet gene modified dendritic cells (DCs) to reverse the course of asthma.

Methods: (1) Mature DCs were derived from mononuclear cells obtained from femur of BALB/c mouse and divided into 3 groups, T-bet group transfected with recombinant adenovirus Ad-T-bet containing T-bet gene, LacZ group transfected with recombinant adenovirus Ad-LacZ containing LacZ gene, and control group. Seven days later ELISA was used to detect the interferon (IFN)-gamma level in the culture fluid. (2) Airway inflammation abrogating trial. Twenty-four BALB/c mice were sensitized with intraperitoneal injection of ovalbumin (OVA) (on day 1 and 15) to establish asthma models, and then randomly divided into 3 equal groups: T-bet group injected intravenously with T-bet-modified DCs on day 27, LacZ group injected with LacZ-modified DCs, and model control group without intravenous injection. Two days later the model mice began to undergo challenge by inhalation of OVA twice (on day 29 - 31). Eight mice were used as control group treated with PBS. On day 37 all mice were killed, ELISA was used to detect the blood interleukin (IL)-4 and IFN-gamma levels, and microscopy was conducted to observe the airway inflammation. (3) Airway inflammation reversing trial. Another 24 model mice were divided into 3 equal groups as well: re-challenged T-bet group injected intravenously with T-bet-modified DCs on day 27 and 42, re-challenged LacZ group injected intravenously with LacZ-modified DCs on day 27 and 42, and model control group. Since the day 45 OVA inhalation was given once a day for successive 3 days. On day 49 these mice were all killed to undergo the tests as mentioned above.

Results: The IFN-gamma level in the culture fluid of the T-bet gene modified DCs was (15.24 +/- 4.75) ng/ml, significantly higher than that of the LacZ gene modified DCs and control DCs [(3.08 +/- 0.61) and (2.35 +/- 0.41) ng/ml respectively, both P < 0.01]. The IFN-gamma in mice blood plasma of T-bet groups in abrogating and reversing trial were (130.2 +/- 10.5) and (145.7 +/- 16.7) pg/ml respectively, both significantly higher than those of the abrogating and reversing trial normal control groups [(25.0 +/- 6.5) and (24.6 +/- 5.9) pg/ml respectively], asthmatic model control groups [(20.7 +/- 4.5) and (16.5 +/- 7.0) pg/ml respectively] and LacZ groups [(17.6 +/- 7.0) and (24.2 +/- 9.0) pg/ml respectively] (all P < 0.01). However, the IL-4 levels in mice blood plasma of T-bet groups were both significantly lower than those of asthmatic model control groups and LacZ groups (all P < 0.01). The airway inflammation of T-bet groups were remarkable milder than those of the model control groups and LacZ groups.

Conclusion: The asthma management strategy based on T-bet gene modified DCs is feasible with the plausible mechanism that the T-bet gene modified DCs regulate the T cells differentiation and polarization on the antigen presenting level.