IL-10 producing type 1 regulatory T cells (Tr1 cells) play an important role in immune regulation; thus, Tr1 cell induction and expansion are potential approaches to treat immune-mediated disorders. However, the mechanisms controlling Tr1 cell differentiation and function are largely unknown. During our previous funding cycle we found that the transcription factor AHR controls Tr1 cell differentiation. In addition, we recently found that IL-27 and AHR control the expression of the ectonucleotidase CD39 in Tr1 cells and dendritic cells (DCs). CD39 degrades pro-inflammatory extracellular adenosine triphosphate (eATP) into adenosine monophosphate (AMP); AMP is then used by the ecto-5'-nucleotidase CD73 to synthesize immunosuppressive adenosine. Our preliminary data suggest that hypoxia and eATP (both of which are detected in inflamed tissues) suppress Tr1 cell differentiation in a HIF1?-dependent manner. Moreover, preliminary experiments suggest that CD39 contributes to the suppressive activity of Tr1 cells independently of IL-10, through the production of adenosine in cooperation with CD73 expressed by responder T cells (Tresp) and DCs. Based on these observations, we hypothesize that the balance between AHR/CD39 and eATP/HIF1? activation controls Tr1 cell differentiation, stability and function.
Our specific aims are:
Specific Aim 1 : Hw does AHR/CD39 and eATP/HIF1? activation control Tr1 cell differentiation? Our preliminary data suggest that eATP and hypoxia (metabolic features of inflamed tissues) suppress Tr1 cell differentiation by inhibiting AHR through a mechanism mediated by the transcription factor HIF1?. Thus, we propose to: 1) Examine the role of CD39 on limiting the inhibitory effects of eATP on Tr1 cell differentiation. 2) Analyze the effects of eATP and hypoxia on AHR signaling and Tr1 cell differentiation, and the role of HIF1? in these effects. 3) Study the effects of eATP and hypoxia on the transcriptional program of Tr1 cells.
Specific Aim 2 : How does CD39 expressed by Tr1 cells contribute to their suppressive function? Our preliminary data suggest that CD39 participates in the suppressive function of Tr1 cells. Thus, we propose to: 1) Study the function of CD39 on Tr1 suppressive activity. 2) Analyze the effects of eATP depletion on Tr1 cell stability and function. 3) Examine the contribution of adenosine generated by CD73 in Tresp in cooperation with CD39 expressed by Tr1 cells on their suppressive function.
Specific Aim 3 : What is the role of DCs on Tr1 cell differentiation and function? IL-27 signaling in DCs limits inflammation in a CD39-dependent manner. Our preliminary data suggest that CD39 and CD73 in DCs control Tr1 cell differentiation and function. Thus, we propose to: 1) Study the role of CD39 expressed by DCs on Tr1 cell generation and stability. 2) Analyze the role of CD39 and CD73 in DCs on Tr1 suppressive function. In summary, this project studies positive (AHR/CD39) and negative (eATP/HIF1?) regulators of Tr1 cell differentiation, their physiological roles and their potential value for the therapeutic modulation of Tr1 cells.

Public Health Relevance

Autoimmune diseases are caused by the uncontrolled activity of the immune system. This project proposes to use in vitro and in vivo experimental systems to study the molecular mechanisms that control the immune response and to identify potential targets for therapeutic intervention in immune-mediated diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
High Priority, Short Term Project Award (R56)
Project #
2R56AI093903-06A1
Application #
9330498
Study Section
Special Emphasis Panel (ZRG1-IMM-J (91))
Program Officer
Ramachandra, Lakshmi
Project Start
2011-03-01
Project End
2017-07-31
Budget Start
2016-08-16
Budget End
2017-07-31
Support Year
6
Fiscal Year
2016
Total Cost
$412,750
Indirect Cost
$162,750
Name
Brigham and Women's Hospital
Department
Type
DUNS #
030811269
City
Boston
State
MA
Country
United States
Zip Code
02115
Gutiérrez-Vázquez, Cristina; Quintana, Francisco J (2018) Regulation of the Immune Response by the Aryl Hydrocarbon Receptor. Immunity 48:19-33
Xie, Anyan; Robles, René J; Mukherjee, Samiran et al. (2018) HIF-1?-induced xenobiotic transporters promote Th17 responses in Crohn's disease. J Autoimmun 94:122-133
Rothhammer, Veit; Borucki, Davis M; Kenison, Jessica E et al. (2018) Detection of aryl hydrocarbon receptor agonists in human samples. Sci Rep 8:4970
Wheeler, Michael A; Rothhammer, Veit; Quintana, Francisco J (2017) Control of immune-mediated pathology via the aryl hydrocarbon receptor. J Biol Chem 292:12383-12389
Gabriely, Galina; Wheeler, Michael A; Takenaka, Maisa C et al. (2017) Role of AHR and HIF-1? in Glioblastoma Metabolism. Trends Endocrinol Metab 28:428-436
Quintana, Francisco J (2017) Astrocytes to the rescue! Glia limitans astrocytic endfeet control CNS inflammation. J Clin Invest 127:2897-2899
Rothhammer, Veit; Kenison, Jessica E; Tjon, Emily et al. (2017) Sphingosine 1-phosphate receptor modulation suppresses pathogenic astrocyte activation and chronic progressive CNS inflammation. Proc Natl Acad Sci U S A 114:2012-2017
Quintana, Francisco J; Prinz, Marco (2017) A gut feeling about multiple sclerosis. Proc Natl Acad Sci U S A 114:10528-10529
Longhi, Maria Serena; Vuerich, Marta; Kalbasi, Alireza et al. (2017) Bilirubin suppresses Th17 immunity in colitis by upregulating CD39. JCI Insight 2:
Takenaka, Maisa C; Quintana, Francisco J (2017) Tolerogenic dendritic cells. Semin Immunopathol 39:113-120

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