α4-integrin-VCAM-1 binding mediates G protein–independent capture of encephalitogenic T cell blasts to CNS white matter microvessels
Peter Vajkoczy, … , Melanie Laschinger, Britta Engelhardt
Peter Vajkoczy, … , Melanie Laschinger, Britta Engelhardt
Published August 15, 2001
Citation Information: J Clin Invest. 2001;108(4):557-565. https://doi.org/10.1172/JCI12440.
View: Text | PDF
Article

α4-integrin-VCAM-1 binding mediates G protein–independent capture of encephalitogenic T cell blasts to CNS white matter microvessels

Abstract

Direct in vivo evidence is still lacking for α4-integrin–mediated T cell interaction with VCAM-1 on blood-brain barrier–endothelium in experimental autoimmune encephalomyelitis (EAE). To investigate a possible α4-integrin–mediated interaction of encephalitogenic T cell blasts with VCAM-1 on the blood-brain barrier white matter endothelium in vivo, we have developed a novel spinal cord window preparation that enabled us to directly visualize CNS white matter microcirculation by intravital fluorescence videomicroscopy. Our study provides the first in vivo evidence that encephalitogenic T cell blasts interact with the spinal cord white matter microvasculature without rolling and that α4-integrin mediates the G protein–independent capture and subsequently the G protein–dependent adhesion strengthening of T cell blasts to microvascular VCAM-1.

Authors

Peter Vajkoczy, Melanie Laschinger, Britta Engelhardt

×

Figure 4

Options: View larger image (or click on image) Download as PowerPoint
Involvement of α4-integrin and VCAM-1 in permanent T lymphoblast adheren...
Involvement of α4-integrin and VCAM-1 in permanent T lymphoblast adherence within spinal cord white matter microvasculature. (a–d) Permanent T lymphoblast adherence in control mice 10 minutes after cell injection. T cell blasts were permanently adherent either within the capillary network (a and b) or within postcapillary venules (c and d). Intravital fluorescence videomicroscopy using epi-illumination techniques. Contrast enhancement of spinal microvasculature using FITC-dextran150 (a and c; arrows mark localization of T cells). Cell Tracker Orange–labeled T lymphocytes (b and d). Bar, 100 μm. (e–j) Permanent T lymphoblast adherence 1 hour after cell injection. Control (e and f), anti–α4-integrin Ab (g and h), anti–VCAM-1 (i and j). Intravital fluorescence videomicroscopy using epi-illumination techniques. Contrast enhancement of spinal microvasculature using FITC-dextran150 (e, g, and i; arrows mark localization of T cells). Cell Tracker Orange–labeled T lymphocytes (f, h, and j). Bar, 100 μm. (k) Quantitative analysis of permanent T lymphoblast adherence. T lymphoblasts permanently adhering within spinal cord white matter microvasculature were counted 10 minutes, 1 hour, and 2 hours after infusion of 3 × 106 PLP-specific T cell blasts by intravital fluorescence videomicroscopy using epi-illumination techniques as described in Methods. Number of mice included in this analysis per group: control, n = 5 mice; antibody-control, n = 2 mice; anti–α4-integrin group, n = 3 mice; and anti–VCAM-1 group, n = 3 mice. Asterisks indicate significant differences. p.i., postinjection.