Jan Naujoks
Published: 2013-10-30
Total Pages: 23
Get eBook
The detection of bacterial pathogens by the innate immune system is mediated by various pattern recognition receptors that sense microbial molecules such as cell wall components, virulence factors or nucleic acids. Bacterial DNA is recognized by Toll-like receptor 9 (TLR9) at endosomal compartments and by cyclic GMP-AMP synthase, polymerase III/RIG-I, AIM2-like receptors (ALRs), DNA helicases as well as other incompletely characterized proteins in the host cell cytosol. Depending on the receptor and specific engagement of the adapter molecules MyD88, STING, MAVS or ASC, sensing of bacterial DNA triggers expression of NF-κB-dependent proinflammatory genes, type I IFN responses, and/or inflammasome activation. Whereas inflammatory gene expression and inflammasome activation are required for an effective host defense to most bacterial infections, type I IFNs appear to play a regulatory role and can be beneficial or detrimental for the host. This chapter summarizes the current knowledge about the mechanisms of DNA sensing and its function in bacterial infections.