Regulation of ROR-gt in colonic inflammation

Information

  • Research Project
  • 9616856
  • ApplicationId
    9616856
  • Core Project Number
    R01DK115668
  • Full Project Number
    5R01DK115668-02
  • Serial Number
    115668
  • FOA Number
    PA-16-160
  • Sub Project Id
  • Project Start Date
    3/1/2018 - 6 years ago
  • Project End Date
    2/28/2022 - 2 years ago
  • Program Officer Name
    PERRIN, PETER J
  • Budget Start Date
    3/1/2019 - 5 years ago
  • Budget End Date
    2/29/2020 - 4 years ago
  • Fiscal Year
    2019
  • Support Year
    02
  • Suffix
  • Award Notice Date
    3/5/2019 - 5 years ago

Regulation of ROR-gt in colonic inflammation

ABSTRACT Dysregulated ROR-?t-mediated IL-17 expression is strongly associated with chronic inflammation. However, the molecular mechanisms by which ROR-?t functions and how its stability is regulated remain elusive. Our preliminary studies suggest that under steady-state conditions in the gut, ROR-?t is sumoylated in Th17 cells by UBC9 (SUMO-E2 ligase) and TRIM55 (SUMO-E3 ligase). Additionally, we found that under steady-state conditions, a novel NCOA6-HDAC2 repressor complex binds to ROR-?t. Upon T cell receptor stimulation, de- sumoylation removes this repressor complex, resulting in IL-17 transcription. To prevent a prolonged Th17 response following stimulation, ROR-?t is phosphorylated by the kinase Pak2, which promotes Itch-mediated ROR-?t ubiquitination and subsequent degradation. Based on these findings we hypothesize that that ubiquitination and sumoylation of ROR-?t are critical molecular events that regulate Th17 responses and that can be targeted therapeutically. In AIM 1, we will determine the mechanism by which sumoylation of ROR-?t represses IL-17 transcription. By using newly generated CD4 T cell-specific TRIM55-/- mice, we will investigate the mechanism by which the NCOA6/HDAC2 complex utilizes histone deacetylation to repress IL-17 expression. In AIM 2, we will determine the mechanism by which phosphorylation promotes Itch-mediated ROR-?t ubiquitination. Using Pak2-/- mice, we will investigate how the phosphorylation-dependent conformational change of ROR-?t promotes its degradation. In AIM 3, we will target the Itch-ROR-?t-IL-17 pathway to inhibit excessive inflammation. We will test the therapeutic potential of a small-molecule Itch activator to inhibit colonic inflammation. Completion of these studies will lead to a clear understanding of the molecular mechanisms by which ROR-?t function and its stability are regulated to prevent chronic inflammation. This knowledge should lead to improved therapeutic strategies to target the ROR-?t-IL-17 pathway in human inflammatory diseases.

IC Name
NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
  • Activity
    R01
  • Administering IC
    DK
  • Application Type
    5
  • Direct Cost Amount
    225000
  • Indirect Cost Amount
    135968
  • Total Cost
    360968
  • Sub Project Total Cost
  • ARRA Funded
    False
  • CFDA Code
    847
  • Ed Inst. Type
  • Funding ICs
    NIDDK:360968\
  • Funding Mechanism
    Non-SBIR/STTR RPGs
  • Study Section
    III
  • Study Section Name
    Innate Immunity and Inflammation Study Section
  • Organization Name
    BAYLOR RESEARCH INSTITUTE
  • Organization Department
  • Organization DUNS
    145745022
  • Organization City
    DALLAS
  • Organization State
    TX
  • Organization Country
    UNITED STATES
  • Organization Zip Code
    75201
  • Organization District
    UNITED STATES