Neutrophil chemorepulsion in defined interleukin-8 gradients in vitro and in vivo

WG Tharp, R Yadav, D Irimia… - Journal of leukocyte …, 2006 - academic.oup.com
WG Tharp, R Yadav, D Irimia, A Upadhyaya, A Samadani, O Hurtado, SY Liu, S Munisamy…
Journal of leukocyte biology, 2006academic.oup.com
We report for the first time that primary human neutrophils can undergo persistent,
directionally biased movement away from a chemokine in vitro and in vivo, termed
chemorepulsion or fugetaxis. Robust neutrophil chemorepulsion in microfluidic gradients of
interleukin-8 (IL-8; CXC chemokine ligand 8) was dependent on the absolute concentration
of chemokine, CXC chemokine receptor 2 (CXCR2), and was associated with polarization of
cytoskeletal elements and signaling molecules involved in chemotaxis and leading edge …
Abstract
We report for the first time that primary human neutrophils can undergo persistent, directionally biased movement away from a chemokine in vitro and in vivo, termed chemorepulsion or fugetaxis. Robust neutrophil chemorepulsion in microfluidic gradients of interleukin-8 (IL-8; CXC chemokine ligand 8) was dependent on the absolute concentration of chemokine, CXC chemokine receptor 2 (CXCR2), and was associated with polarization of cytoskeletal elements and signaling molecules involved in chemotaxis and leading edge formation. Like chemoattraction, chemorepulsion was pertussis toxin-sensitive and dependent on phosphoinositide-3 kinase, RhoGTPases, and associated proteins. Perturbation of neutrophil intracytoplasmic cyclic adenosine monophosphate concentrations and the activity of protein kinase C isoforms modulated directional bias and persistence of motility and could convert a chemorepellent to a chemoattractant response. Neutrophil chemorepulsion to an IL-8 ortholog was also demonstrated and quantified in a rat model of inflammation. The finding that neutrophils undergo chemorepulsion in response to continuous chemokine gradients expands the paradigm by which neutrophil migration is understood and may reveal a novel approach to our understanding of the homeostatic regulation of inflammation.
Oxford University Press