Microangiectasias: structural regulators of lymphocyte transmigration

Proc Natl Acad Sci U S A. 2003 Jun 10;100(12):7231-4. doi: 10.1073/pnas.1232173100. Epub 2003 Jun 2.


The migration of lymphocytes into inflammatory tissue requires the migrating cell to overcome mechanical forces produced by blood flow. A generally accepted hypothesis is that these forces are overcome by a multistep sequence of adhesive interactions between lymphocytes and endothelial cells. This hypothesis has been recently challenged by results demonstrating wall shear stress on the order of 20 dyn/cm(2) in vivo and infrequent lymphocyte-endothelial adhesion at wall shear stress >1-2 dyn/cm(2) in vitro. Here, we show that lymphocyte slowing and transmigration in the skin is associated with microangiectasias, i.e., focal structural dilatations of microvessel segments. Microangiectasias are inducible within 4 days of the onset of inflammation and lead to a greater than 10-fold local reduction in wall shear stress. These findings support the hypothesis that a preparatory step to lymphocyte transmigration involves structural adaptations in the inflammatory microcirculation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Cell Adhesion
  • Cell Movement / physiology*
  • Endothelium, Vascular / pathology
  • Endothelium, Vascular / physiopathology
  • Hemodynamics
  • In Vitro Techniques
  • Inflammation / blood
  • Inflammation / pathology*
  • Lymphocytes / pathology*
  • Lymphocytes / physiology*
  • Microcirculation / pathology
  • Microcirculation / physiopathology
  • Microscopy, Electron, Scanning
  • Microscopy, Video
  • Sheep