Effect of flow on polymorphonuclear leukocyte/endothelial cell adhesion

Abstract

The effect of flow on the adhesion of polymorphonuclear leukocytes (PMNL) to vascular endothelium was investigated using a parallel plate chamber with a well-defined flow field. Washed PMNL were perfused over a monolayer of primary human umbilical vein endothelial cells (HUVEC) pretreated with formyl-methionyl-leucyl-phenylalanine (FMLP, 1 x 10-7 mol/L) for five minutes. In other experiments HUVEC were pretreated with interleukin 1 (IL 1, 2 U/mL) for four hours. PMNL adhesion to stimulated and control HUVEC was measured over a physiologic range of wall shear stresses. PMNL adhesion to nylon-coated surface was also studied. At a wall shear stress of 0.98 dynes/cm2, 283 ± 37.3 PMNL/mm2 (mean ± SEM) adhered to FMLP-treated HUVEC while 195 ± 20.3 PMNL/mm2 adhered to control HUVEC. At 1.96 dynes/cm2, 68 ± 14.1 PMNL/mm2 adhered to FMLP-treated HUVEC and 42 ± 6.0 PMNL/mm2 adhered to control HUVEC. At 3.92 dynes/cm2, virtually no PMNL adherence was noted on either control or FMLP-treated HUVEC. On IL 1-treated HUVEC at 1.96 dynes/cm2, 371 ± 25.8 PMNL/mm2 adhered while 28 ± 2.9 PMNL/mm2 adhered to control HUVEC. PMNL adhesion to IL 1-treated and control HUVEC dropped to 10.2 ± 3.8 and 6.8 ± 3.5 PMNL/mm2, respectively, at 3.01 dynes/cm2. The effect of flow on PMNL adhesion appears to be an important factor in determining the outcome of the PMNL/HUVEC adhesive interaction under these experimental conditions.