NOTCH-induced rerouting of endosomal trafficking disables regulatory T cells in vasculitis
Ke Jin, … , Jorg J. Goronzy, Cornelia M. Weyand
Ke Jin, … , Jorg J. Goronzy, Cornelia M. Weyand
Published September 22, 2020
Citation Information: J Clin Invest. 2021;131(1):e136042. https://doi.org/10.1172/JCI136042.
View: Text | PDF
Research Article Autoimmunity Immunology Article has an altmetric score of 4

NOTCH-induced rerouting of endosomal trafficking disables regulatory T cells in vasculitis

Abstract

The aorta and the large conductive arteries are immunoprivileged tissues and are protected against inflammatory attack. A breakdown of immunoprivilege leads to autoimmune vasculitis, such as giant cell arteritis, in which CD8+ Treg cells fail to contain CD4+ T cells and macrophages, resulting in the formation of tissue-destructive granulomatous lesions. Here, we report that the molecular defect of malfunctioning CD8+ Treg cells lies in aberrant NOTCH4 signaling that deviates endosomal trafficking and minimizes exosome production. By transcriptionally controlling the profile of RAB GTPases, NOTCH4 signaling restricted vesicular secretion of the enzyme NADPH oxidase 2 (NOX2). Specifically, NOTCH4hiCD8+ Treg cells increased RAB5A and RAB11A expression and suppressed RAB7A, culminating in the accumulation of early and recycling endosomes and sequestering of NOX2 in an intracellular compartment. RAB7AloCD8+ Treg cells failed in the surface translocation and exosomal release of NOX2. NOTCH4hiRAB5AhiRAB7AloRAB11AhiCD8+ Treg cells left adaptive immunity unopposed, enabling a breakdown in tissue tolerance and aggressive vessel wall inflammation. Inhibiting NOTCH4 signaling corrected the defect and protected arteries from inflammatory insult. This study implicates NOTCH4-dependent transcriptional control of RAB proteins and intracellular vesicle trafficking in autoimmune disease and in vascular inflammation.

Authors

Ke Jin, Zhenke Wen, Bowen Wu, Hui Zhang, Jingtao Qiu, Yanan Wang, Kenneth J. Warrington, Gerald J. Berry, Jorg J. Goronzy, Cornelia M. Weyand

×

Figure 3

NOTCH4 signaling promotes vascular inflammation.

Options: View larger image (or click on image) Download as PowerPoint
NOTCH4 signaling promotes vascular inflammation. To induce vasculitis, N...
To induce vasculitis, NSG mice were engrafted with human arteries and reconstituted with a mixture of PBMCs and CD8+ Tregs as in Figure 1. Prior to the adoptive transfer, NOTCH4 signaling in healthy, induced CD8+ Tregs was enhanced by transfecting them with an N4ICD-containing vector (A–F). Alternatively, NOTCH4 signaling in patient-derived CD8+ Tregs was suppressed by siRNA transfection (G–L). Human arteries were explanted and examined by IHC staining, tissue transcriptome analysis, and flow cytometry of extracted T cells. (A and B) Numbers of human CD4+ T cells in the spleen and in the engrafted artery analyzed by FACS. (C and D) Tissue-infiltrating T cells were isolated from the inflamed arteries, and IFN-γ and IL-17 production were assessed by intracellular staining and flow cytometry. (E) Tissue-infiltrating T cells in the arteries analyzed by immunostaining for CD3 (green). Nuclei marked with DAPI. Representative images from 6 grafts. Scale bars: 20 μm. (F) Tissue transcriptome in explanted arteries analyzed by RT-PCR. (G and H) Numbers of human CD4+ T cells in the spleen and in the human arteries analyzed by FACS. (I and J) Flow cytometric staining of intracellular IFN-γ and IL-17 in T cells extracted from explanted human arteries. (K) Tissue-infiltrating T cells in the arteries analyzed by immunostaining for CD3 (green). Nuclei marked with DAPI. Representative images from 6 grafts. Scale bars: 20 μm. (L) Tissue transcriptome analysis in explanted arteries by RT-PCR. All data are mean ± SEM from 6 samples. *P < 0.05; **P < 0.01 by paired Mann-Whitney-Wilcoxon rank test.