Inhaled inactivated-Mycobacterium phlei modulates γδT cell function and alleviates airway inflammation in a mouse model of asthma.

BACKGROUND Mycobacterium bovis Bacille Calmette-Guérin (BCG) and other mycobacterial infections suppress airway hyperresponsiveness and eosinophilic inflammation in asthma.γδT cells are important modulators of airway function and allergic inflammation. Vγ1+γδT cells increase eosinophilic airway inflammation and airway hyperresponsiveness, while Vγ4+γδT reduce airway hyperresponsiveness. The objective of this investigation was to determine the role of γδT cells and its subsets in the treatment of inhaled inactivated-Mycobacterium phlei for asthma. METHODS OVA-sensitised mice were treated with aerosol Mycobacterium phlei after OVA challenge. Pathological HE staining was performed to measure lung inflammation, flow cytometric analysis was used to assess the intracellular cytokines of each γδT cell, and quantitative real-time PCR was performed to assess Vγ1 mRNA and Vγ4 mRNA expression. RESULTS Airway inflammation was attenuated by treatment with inhaled inactivated-Mycobacterium phlei. IL-10+γδT cells, IFN-γ+γδT cells,Vγ4 mRNA expression were significantly increased. CONCLUSIONS Our results indicate that inhalation of Mycobacterium phlei can modulate γδT cell function, the proportion of different γδT cell subsets and reduce airway inflammation in asthmatic mice.