Figure 7.

Endothelial ACKR1 Facilitates Decisive Luminal-to-Abluminal TEM

(A) Confocal images showing a neutrophil (arrow) migrating through an EC junction in a TNF-stimulated cremasteric venule of a WT mouse IF stained for MRP14, VE-Cadherin, and ACKR1. Luminal (top) and cross-sectional images (bottom) along dashed line; representative of 3 independent experiments; scale bars, 5 μm.

(B) Scheme illustrating the generation of chimeric mice exhibiting Lyz2-EGFP-ki hematopoietic cells (GFP⁺ neutrophils) and WT or Ackr1^−/− non-hematopoietic cells.

(C–F) Quantification of neutrophil extravasation (C), adhesion to ECs (D), initiating TEM (E), and undergoing complete or aborted TEM (F) in cremaster muscles of WT and Ackr1^−/− chimeras after local PBS or TNF injection (n = 3–8 mice per group, 26 independent experiments) as analyzed by confocal IVM. Means ± SEM, ^∗p < 0.05, ^∗∗∗p < 0.001 relative to WT chimeras and #p < 0.05, ##p < 0.01, ###p < 0.001 as indicated.

See also Figure S6.