Related Experiment Video
Updated: Aug 4, 2026
Digestion of Whole Mouse Eyes for Multi-Parameter Flow Cytometric Analysis of Mononuclear Phagocytes
Published on: June 17, 2020
Macrophage expression of P2X7 controls autoimmune uveitis
Paul-Alexandre Déchelle-Marquet1, Yueshen Che1, Camille Roux1
1Sorbonne University, INSERM, CNRS, Institut de la Vision, UMR_S 968, 17 rue Moreau, Paris, F-75012, France.
Abstract:
The release of danger-associated molecular patterns (DAMPs) such as ATP from stressed or damaged cells is a key initiator of sterile inflammation. In autoimmune diseases, extracellular ATP acts as a potent pro-inflammatory signal by activating the purinergic receptor P2X7, which is expressed on both mononuclear phagocytes (MPs) and T cells-key drivers of pathological processes. While it is well established that P2X7 mediates ATP-dependent immune activation, its cell-specific contributions to innate versus adaptive immunity in autoimmune conditions remain unclear, especially in autoimmune uveitis. Here we used the experimental autoimmune uveoretinitis (EAU) mouse model to delineate the cellular mechanisms underlying P2X7's role in autoimmune responses. Using a combination of multiple cell-specific conditional models and transcriptomic approaches, we showed a pivotal role forP2X7 expressed by MPs in orchestrating T-cell mediated autoimmune responses. P2X7 deficiency in MPs decreased disease severity. Additionally, cell-specific transcriptomic analyses, including single-cell analyses, revealed that P2X7 exerted distinct modulatory effects across monocyte-derived macrophages (MdM) versus microglia. In MdM, lack of P2X7 was associated with reduced expression of genes related to the inflammasome, phagocytosis pathways, and components of the complement system, leading to a marked decrease in pathogenic Th17 cell frequency in the retina. In microglia, P2X7 deficiency instead particularly impacted an IFN-responsive microglial subset that is normally characteristic of EAU. By specifically deleting P2X7 in microglia, we demonstrate its role in driving pathogenic processes in this cell population. These findings suggest that inhibition of P2X7 could be a promising therapeutic strategy in autoimmune neuroinflammatory disorders.
Insights
Extracellular ATP signals through P2X7 receptors on immune cells, driving autoimmune diseases like uveitis. Targeting P2X7 on myeloid cells, particularly macrophages, reduces inflammation and pathogenic T cells, offering a potential therapeutic strategy.
Area of Science:
- Immunology
- Neuroinflammation
- Autoimmune Diseases
Background:
- Extracellular ATP (adenosine triphosphate) released from stressed cells initiates sterile inflammation.
- The purinergic receptor P2X7 (P2X7R) mediates ATP's pro-inflammatory effects, particularly on mononuclear phagocytes (MPs) and T cells, which are crucial in autoimmune conditions.
- The precise cell-specific roles of P2X7 in innate versus adaptive immunity during autoimmune diseases, such as autoimmune uveitis, remain incompletely understood.
Purpose of the Study:
- To investigate the cell-specific functions of P2X7 in the pathogenesis of autoimmune responses, focusing on autoimmune uveitis.
- To delineate the mechanisms by which P2X7 expressed on different myeloid cell populations influences T cell-mediated autoimmunity.
Main Methods:
- Utilized the experimental autoimmune uveoretinitis (EAU) mouse model.
- Employed multiple cell-specific conditional knockout models and transcriptomic analyses, including single-cell RNA sequencing.
- Analyzed the impact of P2X7 deficiency in myeloid cells on immune cell populations and gene expression profiles within the retina.
Main Results:
- P2X7 expression on mononuclear phagocytes (MPs) plays a critical role in orchestrating T cell-mediated autoimmune responses, with P2X7 deficiency in MPs reducing disease severity.
- P2X7 exerts distinct effects on monocyte-derived macrophages (MdMs) and microglia.
- In MdMs, P2X7 deficiency led to reduced inflammasome and phagocytosis pathway gene expression, decreasing pathogenic Th17 cell frequency.
- In microglia, P2X7 deficiency impacted an interferon-responsive subset crucial for EAU pathogenesis.
Conclusions:
- P2X7 on myeloid cells, especially macrophages, is pivotal in driving autoimmune uveitis pathogenesis.
- Targeting P2X7 in myeloid cells, including microglia, presents a potential therapeutic strategy for autoimmune neuroinflammatory disorders.
- Understanding cell-specific P2X7 functions provides insights into distinct immune regulatory mechanisms in autoimmune diseases.
