Abstract

P2X7 receptor activation induces the release of different cellular proteins, such as CD14, a glycosylphosphatidylinositol (GPI)-anchored protein to the plasma membrane important for LPS signaling via TLR4. Circulating CD14 has been found at elevated levels in sepsis, but the exact mechanism of CD14 release in sepsis has not been established. Here we show for first time that P2X7 receptor induces the release of CD14 in extracellular vesicles, resulting in a net reduction in macrophage plasma membrane CD14 that functionally affects LPS, but not monophosphoryl lipid A, pro-inflammatory cytokine production. Also, we found that during a murine model of sepsis, P2X7 receptor activity is important for maintaining elevated levels of CD14 in biological fluids and a decrease in its activity results in higher bacterial load and exacerbated organ damage, ultimately leading to premature deaths. Our data reveal that P2X7 is a key receptor for helping to clear sepsis because it maintains elevated concentrations of circulating CD14 during infection.

Data availability

All data generated or analysed during this study are included in the manuscript and provided as raw data as single values for all Figures.

Article and author information

Author details

  1. Cristina Alarcón-Vila

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
  2. Alberto Baroja-Mazo

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
  3. Carlos de Torre-Minguela

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3314-3203
  4. Carlos M Martínez

    Pathology Platform, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3307-1326
  5. Juan J Martínez-García

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
  6. Helios Martínez-Banaclocha

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
  7. Carlos García-Palenciano

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    Competing interests
    The authors declare that no competing interests exist.
  8. Pablo Pelegrin

    Molecular Inflammation and Experimental Surgery, Biomedical Research Institute of Murcia IMIB-Arrixaca, Murcia, Spain
    For correspondence
    pablo.pelegrin@imib.es
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9688-1804

Funding

European research council (614578)

  • Pablo Pelegrin

European Research council (899636)

  • Carlos García-Palenciano
  • Pablo Pelegrin

Ministerio de Economía y Competitividad (SAF2017-88276-R)

  • Pablo Pelegrin

Fundacion Seneca (20859/PI/18)

  • Carlos García-Palenciano
  • Pablo Pelegrin

Fundacion Seneca (21081/PDC/19)

  • Pablo Pelegrin

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: All experimental protocols for animal handling were refined and approved by the Animal Health Service of the General Directorate of Fishing and Farming of the Council of Murcia (Servicio de Sanidad Animal, Dirección General de Ganadería y Pesca, Consejería de Agricultura y Agua Región de Murcia, permit reference A1320140201). Mice were used in accordance with the Hospital Clínico Universitario Virgen Arrixaca animal experimentation guidelines (Permit Number 221116/1/PE), and Spanish national (Royal Decree 1201/2005 and Law 32/2007) and EU (86/609/EEC and 335 2010/63/EU) legislation. All surgery was performed under sodium pentobarbital anesthesia, and every effort was made to minimize suffering.

Human subjects: The samples and data from patients included in this study were provided by the Biobanco en Red de la Región de Murcia (PT13/0010/0018), which is integrated into the Spanish National Biobanks Network (B.000859) and approved by the clinical ethics committee of the Clinical University Hospital Virgen de la Arrixaca (reference numbers PI13/00174, 2019-9-4-HCUVA, 2019-12-15-HCUVA and 2019-12-471 14-HCUVA). All study procedures were conducted in accordance with the declaration of Helsinki. Whole peripheral blood samples were collected after receiving written informed consent from intraabdominal sepsis patients at the Surgical Critical Unit from the Clinical University Hospital Virgen de la Arrixaca.

Copyright

© 2020, Alarcón-Vila et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,321
    views
  • 289
    downloads
  • 30
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Cristina Alarcón-Vila
  2. Alberto Baroja-Mazo
  3. Carlos de Torre-Minguela
  4. Carlos M Martínez
  5. Juan J Martínez-García
  6. Helios Martínez-Banaclocha
  7. Carlos García-Palenciano
  8. Pablo Pelegrin
(2020)
CD14 release induced by P2X7 receptor restrict inflammation and increases survival during sepsis
eLife 9:e60849.
https://doi.org/10.7554/eLife.60849

Share this article

https://doi.org/10.7554/eLife.60849

Further reading

    1. Immunology and Inflammation
    2. Microbiology and Infectious Disease
    Gregory T Walker, Araceli Perez-Lopez ... Manuela Raffatellu
    Research Article Updated

    The chemokine CCL28 is highly expressed in mucosal tissues, but its role during infection is not well understood. Here, we show that CCL28 promotes neutrophil accumulation in the gut of mice infected with Salmonella and in the lung of mice infected with Acinetobacter. Neutrophils isolated from the infected mucosa expressed the CCL28 receptors CCR3 and, to a lesser extent, CCR10, on their surface. The functional consequences of CCL28 deficiency varied between the two infections: Ccl28−/− mice were highly susceptible to Salmonella gut infection but highly resistant to otherwise lethal Acinetobacter lung infection. In vitro, unstimulated neutrophils harbored pre-formed intracellular CCR3 that was rapidly mobilized to the cell surface following phagocytosis or inflammatory stimuli. Moreover, CCL28 stimulation enhanced neutrophil antimicrobial activity, production of reactive oxygen species, and formation of extracellular traps, all processes largely dependent on CCR3. Consistent with the different outcomes in the two infection models, neutrophil stimulation with CCL28 boosted the killing of Salmonella but not Acinetobacter. CCL28 thus plays a critical role in the immune response to mucosal pathogens by increasing neutrophil accumulation and activation, which can enhance pathogen clearance but also exacerbate disease depending on the mucosal site and the infectious agent.

    1. Evolutionary Biology
    2. Immunology and Inflammation
    Shang Geng, Xing Lv ... Tianjun Xu
    Research Article

    The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape life’s evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5’ppp-RNA virus in a lower vertebrate fish, Miichthys miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and Gallus gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5’ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5’ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.