Bacterial growth and division requires constant degradation and reassembly of the peptidoglycan cell wall. This process generates small peptidoglycan fragments that can be released by the bacteria and sensed by host cells, often inducing an inflammatory response. In infections caused by Neisseria gonorrhoeae, Bordetella pertussis, or Shigella flexneri, peptidoglycan fragments are thought to induce a large inflammatory response that exacerbates disease or is largely responsible for the cell damage occurring during the disease. In the organ culture model of gonococcal pelvic inflammatory disease, these peptidoglycan fragments recapitulate the tissue damage seen in women with the disease. The mechanisms for toxic peptidoglycan fragment production and subsequent release are not known for any of the bacteria that release these fragments. Furthermore bacteria can affect the host response by processing the peptidoglycan in different ways, resulting in detection and signaling through different pathways. In N. gonorrhoeae the composition of released peptidoglycan fragments is different from that which makes up the cell wall, suggesting that the bacteria may specifically process peptidoglycan fragments from cell wall degradation to produce specific products that alter or effect host cell processes. In these studies we will identify enzymes important for the production and release of toxic peptidoglycan fragments by N. gonorrhoeae, characterize the function of these enzymes, produce mutants defective in enzyme function and thus defective in toxic fragment production, and determine the effects of different released peptidoglycan fragments in gonococcal infection of primary human neutrophils and Fallopian tube tissue.
Peptidoglycan fragments cause inflammatory responses that exacerbate disease in several bacterial infections. These studies will determine the mechanisms by which these virulence factors are created in the bacterial pathogen Neisseria gonorrhoeae and generate mutants that will be used to determine the molecular mechanisms by which such peptidoglycan fragments cause this destructive response.
|Schaub, Ryan E; Dillard, Joseph P (2017) Digestion of Peptidoglycan and Analysis of Soluble Fragments. Bio Protoc 7:|
|Ragland, Stephanie A; Schaub, Ryan E; Hackett, Kathleen T et al. (2017) Two lytic transglycosylases in Neisseria gonorrhoeae impart resistance to killing by lysozyme and human neutrophils. Cell Microbiol 19:|
|Lenz, Jonathan D; Hackett, Kathleen T; Dillard, Joseph P (2017) A Single Dual-Function Enzyme Controls the Production of Inflammatory NOD Agonist Peptidoglycan Fragments by Neisseria gonorrhoeae. MBio 8:|
|Lenz, Jonathan D; Stohl, Elizabeth A; Robertson, Rosanna M et al. (2016) Amidase Activity of AmiC Controls Cell Separation and Stem Peptide Release and Is Enhanced by NlpD in Neisseria gonorrhoeae. J Biol Chem 291:10916-33|
|Bhoopalan, Senthil V; Piekarowicz, Andrzej; Lenz, Jonathan D et al. (2016) nagZ Triggers Gonococcal Biofilm Disassembly. Sci Rep 6:22372|
|Schaub, Ryan E; Chan, Yolande A; Lee, Mijoon et al. (2016) Lytic transglycosylases LtgA and LtgD perform distinct roles in remodeling, recycling and releasing peptidoglycan in Neisseria gonorrhoeae. Mol Microbiol 102:865-881|
|Krasity, Benjamin C; Troll, Joshua V; Lehnert, Erik M et al. (2015) Structural and functional features of a developmentally regulated lipopolysaccharide-binding protein. MBio 6:e01193-15|
|Stohl, Elizabeth A; Lenz, Jonathan D; Dillard, Joseph P et al. (2015) The Gonococcal NlpD Protein Facilitates Cell Separation by Activating Peptidoglycan Cleavage by AmiC. J Bacteriol 198:615-22|
|Woodhams, Katelynn L; Chan, Jia Mun; Lenz, Jonathan D et al. (2013) Peptidoglycan fragment release from Neisseria meningitidis. Infect Immun 81:3490-8|