Distinct phenotype of E-selectin-deficient mice. E-selectin is required for slow leukocyte rolling in vivo

Circ Res. 1996 Dec;79(6):1196-204. doi: 10.1161/01.res.79.6.1196.

Abstract

Leukocyte capture and rolling are mediated by calcium-dependent lectins expressed on most leukocytes (L-selectin) and the vascular endothelium (P- and E-selectin). To study the role of the selectins during inflammation, we have investigated leukocyte rolling in venules of tumor necrosis factor-alpha (TNF-alpha)-treated mouse cremaster muscles in wild-type mice and gene-targeted mice with homozygous deficiency for L-, P-, or E-selectin (L-/-, P-/-, or E-/-, respectively). TNF-alpha treatment induces expression of E-selectin and increases expression of P-selectin on endothelial cells. Consistent with previous reports of redundant P- and E-selectin function, a combination of monoclonal antibodies (mAbs) against P- and E-selectin (RB40.34 and 9A9, respectively) was necessary to block rolling in wild-type mice. The rolling leukocyte flux fraction (percent rolling cells) in L-/- mice was similar to that in wild-type mice, but rolling in these mice was blocked by a P-selectin mAb. The velocity of rolling leukocytes in TNF-alpha-treated wild-type, P-/-, or L-/- mice was 5 to 10 times slower (3 to 7 microns/s) than during trauma-induced rolling (20 to 50 microns/s). In contrast, leukocytes in venules of TNF-alpha-treated E-/- mice rolled significantly faster (12 to 20 microns/s): the rolling leukocyte flux fraction was more than doubled compared with wild-type, L-/-, or P-/- mice; and the number of adherent leukocytes was reduced. Addition of an E-selectin mAb, but not a P-selectin mAb, increased rolling flux fraction and rolling velocity in wild-type mice. Histological analysis revealed that 90% to 95% of all leukocytes interacting (rolling and adherent) with the venular endothelium in TNF-alpha-treated wild-type, L-/-, P-/-, and E-/- mice were granulocytes. These results identify a previously unrecognized phenotype of E-/- mice by establishing that at the site densities prevailing in vivo, E-selectin in responsible for slow (approximately 5 microns/s) granulocyte rolling. E-selectin-dependent slow rolling drastically increases the transit time of leukocytes rolling through an inflamed tissue and thus aids in targeting leukocytes activated by chemoattractants to the inflammatory microenvironment.

Publication types

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

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Cell Adhesion / physiology
  • Cell Movement / physiology
  • E-Selectin / genetics
  • E-Selectin / physiology*
  • Leukocytes / cytology
  • Leukocytes / physiology*
  • Mice
  • Mice, Knockout
  • Muscle, Skeletal / blood supply*
  • Tumor Necrosis Factor-alpha / pharmacology
  • Venules / physiology*

Substances

  • Antibodies, Monoclonal
  • E-Selectin
  • Tumor Necrosis Factor-alpha