Abstract
During a respiratory tract infection, the first interaction between the pathogen and host occurs at the mucosal interface. Microfold (M) cells, specialized antigen sampling cells associated with the mucosa and recently identified in the respiratory tract (Kim, D.Y, et al., 2011), are considered the gateway of the initial immune response because they are constantly binding and taking up soluble and inert antigens as well as commensals and pathogens. To determine how M cells contribute to the generation of an appropriate immune response against an invading pathogen, we investigated the response of villous M cells to the respiratory pathogen B. bronchiseptica using a co-culture system and in the murine nasal cavity. Since M cells must quickly respond to initiate a mucosal immune response following the binding of an antigen, we measured changes in mRNA encoding the cytokines and chemokines interleukin-4, interleukin-17, macrophage inflammatory protein 1 α, and tumor necrosis factor-α in culture as well as the ability of B. bronchiseptica to adhere to M cells. To directly measure the response of M cells to B. bronchiseptica in vivo, laser capture microdissection was used to isolate M cells, and gene expression changes were compared during different stages of B. bronchiseptica infection. These results will inform our understanding of the initial interactions between Bordetella and host cells, which will impact the development of an appropriate immune response.
