title: Polymicrobial interactions stimulate resistance to host innate immunity through metabolite perception.
abstract: Bacteria in the human oral cavity often grow in an attached multispecies biofilm community. Members of this community display defined interactions that have an impact on the physiology of the individual and the group. Here, we show that during coculture growth with streptococci, the oral pathogen Aggregatibacter actinomycetemcomitans displays enhanced resistance to killing by host innate immunity. The mechanism of resistance involves sensing of the streptococcal metabolite hydrogen peroxide by A. actinomycetemcomitans, which stimulates a genetic program resulting in enhanced expression of the complement resistance protein ApiA. The oxidative stress response regulator OxyR mediates induction of apiA transcription, and this induction is required for coculture resistance to killing by human serum. These findings provide evidence that interaction between community members mediates prokaryotic resistance to host innate immunity and reinforce the need to understand how polymicrobial growth affects interaction with the host immune system.
authors.affiliation: Section of Molecular Genetics and Microbiology, University of Texas, Austin, TX 78712, USA.
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Ramsey
authors.forename: Marvin
authors.initials: M
authors.lastname: Whiteley
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology; D001483:Base Sequence; D001769:Blood; D018920:Coculture Techniques; D003165:Complement System Proteins / Q000502:physiology; D004269:DNA, Bacterial; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D020560:Proteobacteria / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D003165:Complement System Proteins; D006861:Hydrogen Peroxide