TY - JOUR
T1 - Rolling neutrophils form tethers and slings under physiologic conditions in vivo
AU - Marki, Alex
AU - Buscher, Konrad
AU - Mikulski, Zbigniew
AU - Pries, Axel
AU - Ley, Klaus
N1 - Funding Information:
This work was supported by U.S. National Institutes of Health Grant P01 HL078784. A.M. was supported by American Heart Association Postdoctoral Fellowship 17POST33410940.
Publisher Copyright:
© 2017 Society for Leukocyte Biology.
PY - 2018/1
Y1 - 2018/1
N2 - Human and mouse neutrophils are known to form tethers when rolling on selectins in vitro. Tethers are ∼0.2 μm thin, ∼5–10 μm-long structures behind rolling cells that can swing around to form slings that serve as self-adhesive substrates. Here, we developed a mouse intravital imaging method, where the neutrophil surface is labeled by injecting fluorescently labeled mAb to Ly-6G. Venules in the cremaster muscle of live mice were imaged at a high frame rate using a confocal microscope equipped with a fast resonant scanner. We observed 270 tethers (median length 3.5μm) and 31 slings (median length 6.9 µm) on 186 neutrophils of 15 mice. Out of 199 tether break events, 123 were followed by immediate acceleration of the rolling cell, which shows that tethers are load-bearing structures in vivo. In venules with a high wall shear stress (WSS; > 12 dyn/cm 2 ), median rolling velocity was higher (19 μm/s), and 43% of rolling neutrophils had visible tethers. In venules with WSS < 12 dyn/cm 2 , only 26% of rolling neutrophils had visible tethers. We conclude that neutrophil tethers are commonly present and stabilize rolling in vivo.
AB - Human and mouse neutrophils are known to form tethers when rolling on selectins in vitro. Tethers are ∼0.2 μm thin, ∼5–10 μm-long structures behind rolling cells that can swing around to form slings that serve as self-adhesive substrates. Here, we developed a mouse intravital imaging method, where the neutrophil surface is labeled by injecting fluorescently labeled mAb to Ly-6G. Venules in the cremaster muscle of live mice were imaged at a high frame rate using a confocal microscope equipped with a fast resonant scanner. We observed 270 tethers (median length 3.5μm) and 31 slings (median length 6.9 µm) on 186 neutrophils of 15 mice. Out of 199 tether break events, 123 were followed by immediate acceleration of the rolling cell, which shows that tethers are load-bearing structures in vivo. In venules with a high wall shear stress (WSS; > 12 dyn/cm 2 ), median rolling velocity was higher (19 μm/s), and 43% of rolling neutrophils had visible tethers. In venules with WSS < 12 dyn/cm 2 , only 26% of rolling neutrophils had visible tethers. We conclude that neutrophil tethers are commonly present and stabilize rolling in vivo.
KW - Load-bearing
KW - P-selectin
KW - PSGL-1
KW - Venule
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U2 - 10.1189/jlb.1AB0617-230R
DO - 10.1189/jlb.1AB0617-230R
M3 - Article
C2 - 28821572
AN - SCOPUS:85040605693
SN - 0741-5400
VL - 103
SP - 67
EP - 70
JO - Journal of Leukocyte Biology
JF - Journal of Leukocyte Biology
IS - 1
ER -