Inflammasomes are multi-protein complexes that assemble in the cytosol in response to infection or other noxious stimuli. Inflammasomes serve as platforms to activate inflammatory caspase proteases such as Caspase-1. Active Caspase-1 initiates inflammation by cleaving pro-IL1B and pro-IL18 cytokines into their active and secreted forms. Active Caspase-1 can also trigger a lytic form of cell death, called pyroptosis, by cleaving and activating a pore-forming protein called Gasdermin D. Inflammasomes play critical roles in initiating host defense against diverse viral, bacterial, fungal and protozoan pathogens. In addition, genetic evidence from humans and mice has established that inappropriate inflammasome activation can cause severe autoimmune and inflammation-driven diseases. However, the molecular mechanisms of how inflammasomes detect pathogens and become activated remain poorly understood. This proposal focuses on the NLRP1 inflammasome, which appears to have a novel but poorly understood mechanism of activation. Prior studies have demonstrated that mouse NLRP1 is activated by a toxin produced by Bacillus anthracis, but how this occurs and whether there are pathogen-encoded activators of human NLRP1 remains unclear. To address these gaps in our knowledge, this proposal has two aims: 1. Determine the biochemical mechanism of NLRP1 activation; 2. Identify novel pathogen-associated enzymes that activate NLRP1. Completion of these aims will increase our understanding of the mechanisms by which the innate immune system detects and responds to pathogens.

Public Health Relevance

Inflammation is a physiological process that underlies numerous human diseases including infectious diseases, cancers, neurodegenerative diseases and autoimmune diseases. The fundamental mechanisms that trigger inflammation remain poorly understood. This project will determine fundamental molecular mechanisms by which inflammation is initiated, thereby laying the groundwork for therapeutic targeting of inflammatory processes in the future.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
2R37AI075039-11
Application #
9596336
Study Section
Immunity and Host Defense (IHD)
Program Officer
Jiang, Chao
Project Start
2008-07-01
Project End
2023-06-30
Budget Start
2018-07-01
Budget End
2019-06-30
Support Year
11
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of California Berkeley
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704