CXCL10 stabilizes T cell–brain endothelial cell adhesion leading to the induction of cerebral malaria
Elizabeth W. Sorensen, … , Thorsten R. Mempel, Andrew D. Luster
Elizabeth W. Sorensen, … , Thorsten R. Mempel, Andrew D. Luster
Published April 19, 2018
Citation Information: JCI Insight. 2018;3(8):e98911. https://doi.org/10.1172/jci.insight.98911.
View: Text | PDF
Research Article Immunology Infectious disease

CXCL10 stabilizes T cell–brain endothelial cell adhesion leading to the induction of cerebral malaria

Abstract

Malaria remains one of the world’s most significant human infectious diseases and cerebral malaria (CM) is its most deadly complication. CM pathogenesis remains incompletely understood, hindering the development of therapeutics to prevent this lethal complication. Elevated levels of the chemokine CXCL10 are a biomarker for CM, and CXCL10 and its receptor CXCR3 are required for experimental CM (ECM) in mice, but their role has remained unclear. Using multiphoton intravital microscopy, CXCR3 receptor– and ligand–deficient mice and bone marrow chimeric mice, we demonstrate a key role for endothelial cell–produced CXCL10 in inducing the firm adhesion of T cells and preventing their cell detachment from the brain vasculature. Using a CXCL9 and CXCL10 dual-CXCR3-ligand reporter mouse, we found that CXCL10 was strongly induced in the brain endothelium as early as 4 days after infection, while CXCL9 and CXCL10 expression was found in inflammatory monocytes and monocyte-derived DCs within the blood vasculature on day 8. The induction of both CXCL9 and CXCL10 was completely dependent on IFN-γ receptor signaling. These data demonstrate that IFN-γ–induced, endothelium-derived CXCL10 plays a critical role in mediating the T cell–endothelial cell adhesive events that initiate the inflammatory cascade that injures the endothelium and induces the development of ECM.

Authors

Elizabeth W. Sorensen, Jeffrey Lian, Aleksandra J. Ozga, Yoshishige Miyabe, Sophina W. Ji, Shannon K. Bromley, Thorsten R. Mempel, Andrew D. Luster

×

Figure 1

Imaging T cells interacting with the brain vasculature in WT and Cxcr3–/– mice.

Options: View larger image (or click on image) Download as PowerPoint
Imaging T cells interacting with the brain vasculature in WT and Cxcr3–/...
(A) Brains of mice were imaged by multiphoton intravital microscopy with Qtracker 655 (gray) used to reveal patent blood vessels. GFP+ T cells were tracked in the brains of uninfected and day 8 Plasmodium berghei ANKA–infected (PbA–infected) DPE-GFP and DPE-GFP Cxcr3–/– mice. The tracks in the example fields of view (FOVs) were color-coded according to the length of time visualized (0 to ~30 minutes). GFP+ perivascular macrophages were masked to more clearly visualize the tracked T cells. Scale bars: 70 μm. See corresponding Supplemental Video 1. (B) Quantification of T cells visible during the entire length of the video, intravascularly and in the brain parenchyma of DPE-GFP (blue symbols) and DPE-GFP Cxcr3–/– (red symbols) uninfected or day 8 infected mice. Each data point is from a different mouse. (C) Mean track velocity, (D) instantaneous 3D velocity, and (E) arrest coefficient of T cells in the brains of DPE-GFP and DPE-GFP Cxcr3–/– mice day 8 following PbA infection. Numbers shown just below the violin plot represent the total number of T cells analyzed in C and E and the total number of velocity data points analyzed in D. Velocity measurements were made using Imaris software and arrest coefficient calculated using MATLAB software. The numbers of mice/group total from 3 independent experiments were as follows: infected DPE-GFP = 9, infected DPE-GFP Cxcr3–/– = 9, uninfected DPE-GFP= 7, and uninfected DPE-GFP Cxcr3–/– = 7. (F) Still image displaying the full track length of CD4+ (red) and CD8+ (cyan) T cells interacting with the brain vasculature on day 8 in PbA-infected WT mice during video acquisition. Anti-CD4-PE and anti-CD8-BV421 mAbs were injected retro-orbitally 2 hours prior to imaging. Qtracker 655 (gray) was used to reveal patent blood vessels. Scale bar: 70 μm. See corresponding Supplemental Video 2. (G) Quantification of the relative numbers of CD4-PE+ and CD8-BV421+ T cells as well as CD4-BV421+ and CD8-PE+ T cells interacting with the brain vasculature during the entire length of the video. Red symbols = PE-conjugated mAb and cyan = BV421-conjugated mAb. Matching symbols represent data from the same animal. n = 16 mice total from 6 independent experiments. Groups were compared using either (B–D) Krukal-Wallis with Dunn’s multiple comparison tests, (E) Mann-Whitney test, or (G) Wilcoxon’s test. Bars or lines represent the median in all plots. Violin plots contain box plots that display the median, 25th and 75th percentiles, and whiskers that represent the 95% confidence interval.