Go to The Journal of Clinical Investigation
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Transfers
  • Advertising
  • Job board
  • Contact
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Immunology
    • Metabolism
    • Nephrology
    • Oncology
    • Pulmonology
    • All ...
  • Videos
  • Collections
    • Resource and Technical Advances
    • Clinical Medicine
    • Reviews
    • Editorials
    • Perspectives
    • Top read articles
  • JCI This Month
    • Current issue
    • Past issues

  • Current issue
  • Past issues
  • Specialties
  • In-Press Preview
  • Editorials
  • Viewpoint
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Transfers
  • Advertising
  • Job board
  • Contact
Macrophage P2X4 receptors augment bacterial killing and protect against sepsis
Balázs Csóka, … , Pál Pacher, György Haskó
Balázs Csóka, … , Pál Pacher, György Haskó
Published June 7, 2018
Citation Information: JCI Insight. 2018;3(11):e99431. https://doi.org/10.1172/jci.insight.99431.
View: Text | PDF
Research Article Cell biology

Macrophage P2X4 receptors augment bacterial killing and protect against sepsis

  • Text
  • PDF
Abstract

The macrophage is a major phagocytic cell type, and its impaired function is a primary cause of immune paralysis, organ injury, and death in sepsis. An incomplete understanding of the endogenous molecules that regulate macrophage bactericidal activity is a major barrier for developing effective therapies for sepsis. Using an in vitro killing assay, we report here that the endogenous purine ATP augments the killing of sepsis-causing bacteria by macrophages through P2X4 receptors (P2X4Rs). Using newly developed transgenic mice expressing a bioluminescent ATP probe on the cell surface, we found that extracellular ATP levels increase during sepsis, indicating that ATP may contribute to bacterial killing in vivo. Studies with P2X4R-deficient mice subjected to sepsis confirm the role of extracellular ATP acting on P2X4Rs in killing bacteria and protecting against organ injury and death. Results with adoptive transfer of macrophages, myeloid-specific P2X4R-deficient mice, and P2rx4 tdTomato reporter mice indicate that macrophages are essential for the antibacterial, antiinflammatory, and organ protective effects of P2X4Rs in sepsis. Pharmacological targeting of P2X4Rs with the allosteric activator ivermectin protects against bacterial dissemination and mortality in sepsis. We propose that P2X4Rs represent a promising target for drug development to control bacterial growth in sepsis and other infections.

Authors

Balázs Csóka, Zoltán H. Németh, Ildikó Szabó, Daryl L. Davies, Zoltán V. Varga, János Pálóczi, Simonetta Falzoni, Francesco Di Virgilio, Rieko Muramatsu, Toshihide Yamashita, Pál Pacher, György Haskó

×

Figure 7

Ivermectin, an allosteric activator of P2X4Rs improves survival, decreases bacterial burden and organ injury in mice after sepsis, and augments bacterial killing by macrophages.

Options: View larger image (or click on image) Download as PowerPoint
Ivermectin, an allosteric activator of P2X4Rs improves survival, decreas...
(A) Ivermectin-treated WT mice showed improved survival compared with vehicle-treated (Veh-treated) WT mice. The survival of ivermectin-treated P2X4R–/– and Veh-treated P2X4R–/– mice was comparable. WT and P2X4R–/– mice were injected with 10 mg/kg ivermectin or its vehicle and subjected to CLP. The survival of mice was monitored for 7 days. *P < 0.05, P2X4R–/– injected with vehicle (n = 21) vs. WT injected with vehicle (n = 25); ***P < 0.001, WT injected with ivermectin (n = 20) vs. WT injected with vehicle (n = 25). (B and C) Bacterial burden was determined by counting the number of CFUs on blood agar plates after serial dilution of blood and peritoneal lavage samples. Blood and lavage fluid were collected at 16 hours after CLP. *P < 0.05 vs. Veh (Veh and 10 mg/kg ivermectin; n = 10 and 9, respectively). (D) BUN was determined from plasma of ivermectin- or Veh-treated mice 16 hours after CLP. *P < 0.05 vs. Veh; n = 10 and 9, respectively. (E and F) Ivermectin increases intracellular killing of E. coli in cultured macrophages. Peritoneal macrophages were infected with E. coli for 90 minutes and then pulsed with ATP for 5 minutes. ATP was then removed, and the macrophages were incubated with ivermectin for 30 minutes. Thereafter, the ivermectin was removed and the cells were incubated in medium containing gentamicin for another 2 hours. The cells were then lysed, and serial dilutions of intracellular content were spread onto LB agar plates. *P < 0.05 (n = 5–6); **P < 0.01 (n = 5–6). Data are expressed as mean ± SEM. All results are representatives of 3 experiments. Mortality curves were analyzed using Kaplan-Meier curve and log rank test and in the rest of the experiments one-way ANOVA followed by Mann Whitney test or two-tailed Student’s t test was used.

Copyright © 2023 American Society for Clinical Investigation
ISSN 2379-3708

Sign up for email alerts