Dr. Mehandru and his team have published a number of studies on the mucosal immune system. Most recently, the laboratory has defined the role of the microbiota in instructing lung dendritic cells to induce IgA class switch recombination. With this study, the laboratory has unraveled a key link between antibiotic use, dysbiosis and reduced production of IgA within the lungs. Since low levels of IgA have previously been shown to relate to asthma and other allergic diseases, this in turn provides a novel mechanism behind the rising incidence of these disorders in the western populations. Currently, the laboratory is heavily focused on studying lung immune function that may be affected by microbial communities.