Impact of Bacillus Calmette-Guérin Moreau vaccine on lung remodeling in experimental asthma

We analyzed the effects of different administration routes and application times of the BCG-Moreau strain on airway and lung inflammation and remodeling in a murine model of allergic asthma. BALB/c mice (n = 168) were divided into two groups. The first group received BCG-Moreau strain while the second group received saline using the same protocol. BCG or saline were intradermally or intranasally injected one or two months before the induction of asthma. Mice were further sensitized and challenged with ovalbumin or received saline. Twenty-four hours after the last challenge, BCG prevented the triggering of pro-inflammatory cytokines, probably by increasing Foxp3 and interleukin (IL)-10, modulating eosinophil infiltration and collagen fiber deposition, thus reducing airway hyperresponsiveness. In conclusion, BCG-Moreau prevented lung remodeling in the present model of allergic asthma, regardless of administration route and time of vaccination. These beneficial effects may be related to the increase in regulatory T cells and to IL-10 production in tandem with decreased Th2 cytokines (IL-4, IL-5, and IL-13).