Effects of Lactobacillus rhamnosus on asthma with an adoptive transfer of dendritic cells in mice.

Aim This study was designed to investigate whether the protective effects of Lactobacillus rhamnosus (Lcr35) on allergic asthma are associated with the adoptive transfer of dendritic cells (DCs) and regulatory T cells (Tregs), using a mouse experimental model of asthma. Methods and Results BALB/c mice were orally administered Lcr35 or intravenously treated with in vivo Lcr35-treated DCs daily and were then sensitized and challenged with ovalbumin (OVA) in accordance with a model of asthma protocol. Both the oral application of Lcr35 and intravenous administration of Lcr35-treated DCs suppressed all aspects of the asthmatic response, including bronchial hyperresponsiveness (BHR), total cell counts in the bronchoalveolar lavage (BAL) fluid, the production of OVA-specificimmunoglobulin E (IgE), and pulmonary eosinophilic inflammation. The mechanism of action of Lcr35 is related to Tregs, which suppress the Th2 response in the respiratory organs, and this is mediated by DCs in the mouse model of asthma. Conclusions These results confirm that the mechanism underlying the effects of Lcr35 on asthma involves the adoptive transfer of DCs. Significance and Impact of the Study This finding broadens the possibility that Lcr35 has potential as an alternative therapeutic approach to the treatment of human asthma.