Sepsis is a clinical syndrome, which complicates severe infection. It remains the leading cause of morbidity and mortality in critically ill patients. Current concepts suggest that organ failure and mortality in sepsis are caused by inappropriate regulation of host defenses and the immune system. This manifests as an inability to control bacterial growth and dissemination, and excessive inflammation, processes that are interrelated and are due, in a large part, to macrophage dysfunction. Danger-associated molecular patterns (DAMP)s comprise a diverse group of molecules that accumulate in the extracellular space in response to bacteria-mediated tissue destruction, trauma, and burns, all of which are associated with sepsis. ATP is a major DAMP, which is released from the intracellular into the extracellular space through connexins and pannexins during inflammation, infection, shock, and sepsis. Extracellular ATP binds to and signals through P2 receptors to modulate immune function. Our preliminary data with mice deficient in P2 receptors, as well as pharmacological receptor and channel ligands establish that ATP release through connexin/pannexin channels and subsequent P2 receptor activation are crucial for the control of mortality, bacterial killing and dissemination and inflammation following cecal ligation and puncture, a clinically relevant model of polymicrobial sepsis. Mechanistically, we show that ATP and one of the P2 receptors, the P2X4 receptor, protects against sepsis by directly increasing the killing of bacteria by macrophages. Based on these data, we hypothesize that ATP governs the host's response to sepsis by signaling through P2 receptors on macrophages. To address this hypothesis, we will pursue the following Specific Aims: 1. Identify the mechanisms that support ATP release during sepsis. 2. Dissect the mechanisms by which P2X4 receptor stimulation augments the killing of sepsis- causing extracellular bacteria by macrophages. 3. Identify the monocyte/macrophage populations that are targets of P2 receptor-mediated immune regulation in sepsis. The overarching goal here is to delineate the role of P2 receptors in protecting against severe infection and to determine whether these receptors can be specifically targeted to manage patients with sepsis.

Public Health Relevance

Sepsis is a devastating illness resulting in multiple organ failure and death and it is the leading cause of morbidity and mortality in critical care units in hospitals. We are studying the function of P2 adenosine triphosphate receptors, which are molecules found on the surface of immune cells, in regulating the course of sepsis. By elucidating how P2 receptors modulate immune and organ function during sepsis, we can utilize this information to develop new pharmacologic approaches targeting P2 receptors to treat patients suffering from sepsis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM066189-16
Application #
9774058
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Zhao, Xiaoli
Project Start
2002-07-01
Project End
2021-07-31
Budget Start
2019-08-01
Budget End
2020-07-31
Support Year
16
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Anesthesiology
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Haskó, György; Antonioli, Luca; Cronstein, Bruce N (2018) Adenosine metabolism, immunity and joint health. Biochem Pharmacol 151:307-313
Csóka, Balázs; Németh, Zoltán H; Szabó, Ildikó et al. (2018) Macrophage P2X4 receptors augment bacterial killing and protect against sepsis. JCI Insight 3:
Antonioli, Luca; Blandizzi, Corrado; Pacher, Pál et al. (2018) Quorum sensing in the immune system. Nat Rev Immunol 18:537-538
Csóka, Balázs; Németh, Zoltán H; Duerr, Claudia U et al. (2018) Adenosine receptors differentially regulate type 2 cytokine production by IL-33-activated bone marrow cells, ILC2s, and macrophages. FASEB J 32:829-837
Csóka, Balázs; Tör?, Gábor; Vindeirinho, Joana et al. (2017) A2A adenosine receptors control pancreatic dysfunction in high-fat-diet-induced obesity. FASEB J 31:4985-4997
Antonioli, Luca; Yegutkin, Gennady G; Pacher, Pál et al. (2016) Anti-CD73 in cancer immunotherapy: awakening new opportunities. Trends Cancer 2:95-109
Csóka, Balázs; Németh, Zoltán H; Tör?, Gábor et al. (2015) Extracellular ATP protects against sepsis through macrophage P2X7 purinergic receptors by enhancing intracellular bacterial killing. FASEB J 29:3626-37
Antonioli, Luca; Blandizzi, Corrado; Csóka, Balázs et al. (2015) Adenosine signalling in diabetes mellitus--pathophysiology and therapeutic considerations. Nat Rev Endocrinol 11:228-41
Csóka, Balázs; Németh, Zoltán H; Tör?, Gábor et al. (2015) CD39 improves survival in microbial sepsis by attenuating systemic inflammation. FASEB J 29:25-36
Antonioli, Luca; Haskó, György; Fornai, Matteo et al. (2014) Adenosine pathway and cancer: where do we go from here? Expert Opin Ther Targets 18:973-7

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