(Project 1, Portnoy) This proposal is Project 1 within a P01 renewal, entitled ?Intracellular pathogens and innate immunity.? A central problem that we address is how intracellular pathogens are recognized by the host innate immune system and how multiple signals are integrated to induce an appropriate response, and conversely, how pathogens avoid and/or manipulate host responses to promote their pathogenesis. In Project 1, we have chosen to approach this problem by continuing a detailed analysis of Listeria monocytogenes, a facultative intracellular, food-borne pathogen that has been studied for decades as a model system with which to dissect basic aspects of infection & immunity. Previously, we concentrated on macrophage transcriptional responses to infection and learned that L. monocytogenes escapes from a phagosome and secretes a conserved and essential small signaling molecule called c-di-AMP that activates the transcription of the host type I interferon response. In collaboration with the Vance lab, we identified STING as the host cell receptor for both c-di-AMP and other c-di-nucleotides.
In Aim 1, we propose to extend these studies, using bacterial mutants that either synthesize or secrete altered levels of c-di-AMP in combination with mice and host cells that have specific STING mutations that alter downstream signaling.
In Aims 2 and 3, we begin to explore the role of post-transcriptional host responses including ubiquitylation of both bacterial and host proteins and the role played by autophagy.
In Aim 2, we follow-up on preliminary data showing that L. monocytogenes is subject to autophagy at the phagosome, but circumvents it using two determinants, PlcA and ActA. We show that a double PlcA/ActA mutant is trapped by what appears to be LC3-associated phagocytosis (LAP). We will use bacterial and host mutants to determine if this is in fact LAP, how the bacteria avoid it, and finally, what is the role of LAP avoidance during infection and immunity.
In Aim 3, we propose using mass spectrometry-based and bioinformatic tools, available in Core C, to identify the bacterial and host proteins that are ubiquitylated, and high throughput genetic screens to identify the host proteins that mediate ubiquitylation.

Public Health Relevance

(Project 1, Portnoy) The proposed studies will use a broad range of approaches to understand how intracellular pathogens mediate their pathogenesis and how the host immune system prevents disease. These studies will lead to the characterization of host systems of innate immunity that will lead to vaccines and/or therapeutics to prevent and/or treat infectious diseases, with relevance to domestic and global health.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Program Projects (P01)
Project #
5P01AI063302-16
Application #
9733889
Study Section
Special Emphasis Panel (ZAI1)
Project Start
Project End
Budget Start
2019-07-01
Budget End
2020-06-30
Support Year
16
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California Berkeley
Department
Type
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94710
Light, Samuel H; Su, Lin; Rivera-Lugo, Rafael et al. (2018) A flavin-based extracellular electron transfer mechanism in diverse Gram-positive bacteria. Nature 562:140-144
Deng, Weiwen; Lira, Victor; Hudson, Thomas E et al. (2018) Recombinant Listeria promotes tumor rejection by CD8+ T cell-dependent remodeling of the tumor microenvironment. Proc Natl Acad Sci U S A 115:8179-8184
Price, April E; Shamardani, Kiarash; Lugo, Kyler A et al. (2018) A Map of Toll-like Receptor Expression in the Intestinal Epithelium Reveals Distinct Spatial, Cell Type-Specific, and Temporal Patterns. Immunity 49:560-575.e6
Cheng, Mandy I; Chen, Chen; Engström, Patrik et al. (2018) Actin-based motility allows Listeria monocytogenes to avoid autophagy in the macrophage cytosol. Cell Microbiol 20:e12854
Mitchell, Gabriel; Cheng, Mandy I; Chen, Chen et al. (2018) Listeria monocytogenes triggers noncanonical autophagy upon phagocytosis, but avoids subsequent growth-restricting xenophagy. Proc Natl Acad Sci U S A 115:E210-E217
Penn, Bennett H; Netter, Zoe; Johnson, Jeffrey R et al. (2018) An Mtb-Human Protein-Protein Interaction Map Identifies a Switch between Host Antiviral and Antibacterial Responses. Mol Cell 71:637-648.e5
Chen, Chen; Nguyen, Brittney N; Mitchell, Gabriel et al. (2018) The Listeriolysin O PEST-like Sequence Co-opts AP-2-Mediated Endocytosis to Prevent Plasma Membrane Damage during Listeria Infection. Cell Host Microbe 23:786-795.e5
Nguyen, Brittney N; Peterson, Bret N; Portnoy, Daniel A (2018) Listeriolysin O: a phagosome-specific cytolysin revisited. Cell Microbiol :e12988
Price, Jordan V; Jiang, Kallie; Galantowicz, Abigail et al. (2018) Legionella pneumophila Is Directly Sensitive to 2-Deoxyglucose-Phosphate via Its UhpC Transporter but Is Indifferent to Shifts in Host Cell Glycolytic Metabolism. J Bacteriol 200:
Whiteley, Aaron T; Ruhland, Brittany R; Edrozo, Mauna B et al. (2017) A Redox-Responsive Transcription Factor Is Critical for Pathogenesis and Aerobic Growth of Listeria monocytogenes. Infect Immun 85:

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