FOXP3+ macrophage represses acute ischemic stroke-induced neural inflammation
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Updated: Jun 17, 2026
Three-dimensional Confocal Analysis of Microglia/macrophage Markers of Polarization in Experimental Brain Injury
Published on: September 4, 2013
Wei Cai1, Mengyan Hu1, Chunyi Li1
1Department of Neurology, Mental and Neurological Disease Research Center, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Abstract:
Proper termination of cell-death-induced neural inflammation is the premise of tissue repair in acute ischemic stroke (AIS). Macrophages scavenge cell corpses/debris and produce inflammatory mediators that orchestrate immune responses. Here, we report that FOXP3, the key immune-repressive transcription factor of Tregs, is conditionally expressed in macrophages in stroke lesion. FOXP3 ablation in macrophages results in detrimental stroke outcomes, emphasizing the beneficial role of FOXP3+ macrophages. FOXP3+ macrophages are distinct from the M1 or M2 subsets and display superactive efferocytic capacity. With scRNAseq and analysis of FOXP3-bound-DNA isolated with CUT & RUN, we show that FOXP3 facilitates macrophage phagocytosis through enhancing cargo metabolism. FOXP3 expression is controlled by macroautophagic/autophagic protein degradation in resting macrophages, while initiation of LC3-associated phagocytosis (LAP) competitively occupies the autophagic machineries, and thus permits FOXP3 activation. Our data demonstrate a distinct set of FOXP3+ macrophages with enhanced scavenging capability, which could be a target in immunomodulatory therapy against AIS.Abbreviations: ADGRE1/F4/80: adhesion G protein-coupled receptor E1; AIF1/Iba1: allograft inflammatory factor 1; AIS: acute ischemic stroke; ARG1: arginase 1; ATP: adenosine triphosphate; BECN1/Beclin1: Beclin 1, autophagy related; BMDM: bone marrow-derived macrophages; CKO: conditional knockout; CSF1/M-CSF: colony stimulating factor 1 (macrophage); CSF2/GM-CSF: colony stimulating factor 2; CSF3/G-CSF: colony stimulating factor 3; CUT & RUN: cleavage under targets and release using nuclease; CyD: cytochalasin D; DAMP: danger/damage-associated molecular pattern; DIL: dioctadecyl-3,3,3,3-tetramethylin docarbocyanine; ELISA: enzyme linked immunosorbent assay; GO: Gene Ontology; FCGR3/CD16: Fc receptor, IgG, low affinity III; HMGB1: high mobility group box 1; IFNG/IFNγ: interferon gamma; IP: immunoprecipitation; KEGG: Kyoto Encyclopedia of Genes and Genomes; ITGAM/CD11b: integrin subunit alpha M; ITGAX/CD11c: integrin subunit alpha X; LAP: LC3-associated phagocytosis; LC-MS: liquid chromatography-mass spectrometry; LPS: lipopolysaccharide; MRC1/CD206: mannose receptor, C type 1; O4: oligodendrocyte marker O4; PBMC: peripheral blood mononuclear cells; RBC: red blood cells; PTPRC/CD45: protein tyrosine phosphatase, receptor type, C; RBFOX3/NeuN: RNA binding protein, fox 1 homolog (C. elegans) 3; RUBCN/Rubicon: RUN domain and cysteine-rich domain containing, Beclin 1-interacting protein; scRNAseq: single cell RNA sequencing; SQSTM1/p62 (sequestosome 1); TGFB/TGFβ: transforming growth factor, beta; tMCAO: transient middle cerebral artery occlusion; TNF/TNFα: tumor necrosis factor; Treg: regulatory T cell.
Insights
FOXP3+ macrophages enhance tissue repair after acute ischemic stroke by improving debris clearance. Their activation is regulated by autophagy, offering a novel therapeutic target for stroke immunomodulation.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Proper resolution of inflammation is crucial for tissue repair following acute ischemic stroke (AIS).
- Macrophages play a key role in clearing cellular debris and orchestrating immune responses post-stroke.
Purpose of the Study:
- To investigate the role of FOXP3, typically found in regulatory T cells (Tregs), in macrophages during AIS.
- To elucidate the mechanisms by which FOXP3 influences macrophage function and stroke outcomes.
Main Methods:
- Conditional knockout of FOXP3 in macrophages in a mouse model of AIS.
- Single-cell RNA sequencing (scRNAseq) and Cleavage Under Targets and Release Using Nuclease (CUT & RUN) to analyze FOXP3+ macrophages.
- Investigation of the regulation of FOXP3 expression by macroautophagy and LC3-associated phagocytosis (LAP).
Main Results:
- FOXP3 is conditionally expressed in macrophages within the stroke lesion, and its ablation worsens stroke outcomes.
- FOXP3+ macrophages exhibit enhanced efferocytic capacity, distinct from M1 or M2 phenotypes, and facilitate phagocytosis via improved cargo metabolism.
- FOXP3 activation is regulated by the interplay between macroautophagy and LAP, where LAP competitively inhibits autophagic degradation of FOXP3.
Conclusions:
- FOXP3+ macrophages represent a distinct subset with potent scavenging capabilities, crucial for beneficial outcomes in AIS.
- The findings highlight a novel mechanism controlling FOXP3 expression in macrophages through autophagic pathways.
- Targeting FOXP3+ macrophages presents a promising immunomodulatory strategy for treating acute ischemic stroke.
