Role of CD11/CD18 in shear rate-dependent leukocyte-endothelial cell interactions in cat mesenteric venules

• Published in: The Journal of clinical investigation Vol. 87; no. 5; pp. 1798 - 1804
• Main Authors: PERRY, M. A, GRANGER, D. N
• Format: Journal Article
• Language: English
• Published: Ann Arbor, MI American Society for Clinical Investigation 01-05-1991
• Subjects: Animals; Antibodies, Monoclonal - immunology; Antigens, Differentiation - physiology; Arterioles - cytology; Biological and medical sciences; Cats; CD11 Antigens; CD18 Antigens; Cell Adhesion; Endothelium, Vascular - cytology; Erythrocytes - physiology; Fundamental and applied biological sciences. Psychology; Inflammation; Leukocytes - physiology; Mesenteric Veins; Microcirculation - cytology; Molecular and cellular biology; Receptors, Leukocyte-Adhesion - physiology; Stress, Mechanical; Fissipedia; Carnivora; Vertebrata; Endothelial cell; Mammalia; Leukocyte; Animal; Cat; Cell cell interaction; Inflammation; Adhesion
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI115200

In vivo microscopy was used to assess the relationships among shear rate (and shear stress), leukocyte rolling velocity, and leukocyte adherence in a cat mesentery preparation. Shear rate in individual venules and arterioles of 25-35 microns diameter were varied over a wide range by graded occlusion of an arterial loop. There was a linear decline in leukocyte rolling velocity (Vwbc) as red cell velocity (Vrbc) was reduced. The ratio Vwbc/Vrbc remained constant despite variations in shear stress from 5-25 dyn/cm2. A reduction in shear stress was associated with an increased leukocyte adherence, particularly when Vwbc was reduced below 50 microns/s. Reduction in wall shear rate below 500 s-1 in arterioles allowed 1-3 leukocytes to adhere per 100 microns length of vessel, while venules exposed to the same shear rates had 5-16 adherent leukocytes. In arterioles, leukocyte rolling was only observed at low shear rates. At shear rates less than 250 s-1 leukocyte rolling velocity was faster in arterioles than venules, and the ratio Vwbc/Vrbc for arterioles was 0.08 +/- 0.02, which was fourfold higher than the ratio obtained in venules at similar shear rates. Pretreatment with the CD18-specific antibody (mAb) IB4 increased leukocyte rolling velocity in venules by approximately 20 microns/s at red cell velocities below 2,000 microns/s. mAb IB4 largely prevented the leukocyte adherence to arterioles and venules, and increased the ratio Vwbc/Vrbc observed in venules at low shear elicit a CD18-dependent adhesive interaction between leukocytes and microvascular endothelium, and that differences in shear rates cannot explain the greater propensity for leukocyte rolling and adhesion in venules than arterioles.