Positive allosteric modulation of the A2aR for treatment of acute inflammation

Information

  • Research Project
  • 8637857
  • ApplicationId
    8637857
  • Core Project Number
    R21AI105518
  • Full Project Number
    1R21AI105518-01A1
  • Serial Number
    105518
  • FOA Number
    PA-11-261
  • Sub Project Id
  • Project Start Date
    12/1/2013 - 10 years ago
  • Project End Date
    11/30/2015 - 8 years ago
  • Program Officer Name
    PALKER, THOMAS J.
  • Budget Start Date
    12/1/2013 - 10 years ago
  • Budget End Date
    11/30/2014 - 9 years ago
  • Fiscal Year
    2014
  • Support Year
    01
  • Suffix
    A1
  • Award Notice Date
    11/29/2013 - 10 years ago

Positive allosteric modulation of the A2aR for treatment of acute inflammation

DESCRIPTION (provided by applicant): The adenosine A2a receptor (A2aR) plays a critical role in controlling inflammation. Endogenous adenosine is elevated at inflamed sites, where it engages the A2aR to down-regulate the inflammatory response and limit tissue damage. While activation of the A2aR with synthetic orthosteric agonists attenuates inflammation in animal models of disease, this therapeutic approach is limited by adverse effects due to unintended activation of the A2aR outside the target tissue. The current research is designed to explore an alternative approach: the targeted enhancement of the A2aR via positive allosteric modulation, which is expected to have a focused effect at disease sites where endogenous adenosine is elevated. The goal of this proposal is to demonstrate that the A2aR is amenable to positive allosteric modulation, and that such modulation will mount a discernible anti-inflammatory response. These studies will make use of a recently identified positive allosteric modulator of the A2aR, AEA061, as well as human and mouse primary cells and an engineered cell line (CHO-hA2aR) stably expressing the human A2aR (hA2aR). Specific Aim 1 is to demonstrate that the A2aR is amenable to positive allosteric modulation. First, to determine whether the increased cAMP production upon positive allosteric modulation of the A2aR in CHO-hA2aR cells is a direct consequence of A2aR activation, AEA061-induced A2aR-dependent Gas activation will be measured by quantifying GTPg35S incorporation into the Gas subunit. Second, to investigate whether functional enhancement of the A2aR by AEA061 is due to altered orthosteric agonist binding kinetics, equilibrium-binding experiments will be performed to evaluate the adenosine affinity and Bmax at the hA2aR in the presence and absence of AEA061. Third, to examine allosteric modulator-mediated pathway-biased signaling, we will compare the effect of AEA061 on Gas-driven cAMP and Gaq/11-driven inositol phosphate production in CHO-hA2bR cells. Specific Aim 2 is to determine whether positive allosteric modulation of the A2aR alters inflammatory cytokine and chemokine production/release in vitro and in vivo. To evaluate the in vitro effects of positive allosteric modulation, cytokine productio by LPS-stimulated human and mouse monocytes will be quantified in the presence and absence of AEA061. To assess in vivo effects, plasma inflammatory cytokine and chemokine levels of LPS-challenged control and A2aR-deficient mice with and without AEA061 treatment will be determined. Additional in vivo studies will assess the influence of positive allosteric modulation on disease progression in a rodent model of chronic inflammatory arthritis. If successful, we will have validated that increasing A2aR responsiveness to endogenous adenosine with the administration of a positive allosteric modulator, that has no intrinsic abilityto activate the A2aR, is an effective strategy to reduce progression of disease characterized by inflammation.

IC Name
NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
  • Activity
    R21
  • Administering IC
    AI
  • Application Type
    1
  • Direct Cost Amount
    150000
  • Indirect Cost Amount
    142500
  • Total Cost
    292500
  • Sub Project Total Cost
  • ARRA Funded
    False
  • CFDA Code
    855
  • Ed Inst. Type
  • Funding ICs
    NIAID:292500\
  • Funding Mechanism
    Non-SBIR/STTR RPGs
  • Study Section
    III
  • Study Section Name
    Innate Immunity and Inflammation Study Section
  • Organization Name
    MOLECULAR MEDICINE RESEARCH INSTITUTE
  • Organization Department
  • Organization DUNS
    015535594
  • Organization City
    SUNNYVALE
  • Organization State
    CA
  • Organization Country
    UNITED STATES
  • Organization Zip Code
    940854708
  • Organization District
    UNITED STATES