Spatial distribution of the β2 integrin (CD11b/CD18) and L‐selectin (CD62L) adherence receptors on human neutrophils by Conventional Optical Scanning Microscopy (COSM)
Issue title: Selected papers of the Euromech Colloquium No. 420, Mechanobiology of Cells and Tissues
Affiliations: Mécanique et Ingénierie Cellulaire et Tissulaire, Equipe LEMTA UMR CNRS 7563 et IFR 111 Bioingénierie CNRS – UHP‐INPL‐CHU, Faculté de Médecine, BP 184, 54505 Vandoeuvre‐lès‐Nancy, Cedex, France
Note: [] Address for correspondence: Jean‐François Stoltz, Mécanique et Ingénierie Cellulaire et Tissulaire, UMR CNRS 7563, Faculté de Médecine, B.P. 184, 54505 Vandoeuvre‐lès‐Nancy Cedex, France. Tel.: +33 03 83 59 26 41; Fax: +33 03 83 59 26 43; E‐mail: [email protected]‐nancy.fr.
Abstract: Receptors such as CD62L and CD11b/CD18, are transmembrane glycoproteins which regulate leukocyte adhesive phenotype. Flow cytometry (FCM) makes it possible to assess a characterization of the cell activation level by receptor quantifying, but that technique does not integrate other factors of adherence regulation, such as spatial distribution and molecular conformation. Our study consisted in exploring the main adherence receptors on Polymorphonuclear Neutrophils (PMN) that were simultaneously analyzed by FCM and Conventional Optical Scanning Microscopy (COSM). FCM analysis showed that TNFα induce a decrease in CD62L expression and an increase in β2 integrins. COSM analysis distinguished three stages of cellular distribution of CD11b/CD18 within resting PMN: most of them (about 80%) had homogeneous distribution (heterogeneous spots distributed over the entire cell surface), for 10–15% of the cells, there was a crown distribution around the widest cell diameter and in less that 10% of them receptor distribution was polarized. CD62L was in the form of heterogeneous spots distributed in a circle on the surface on non‐stimulated PMN. PMN stimulation by TNFα was associated to a randomized clustering involving both selectin and β2 integrin. Three‐dimensional analysis elicited data not shown by quantitative cytometry. For a single averaged value of the density determined by FMC, various spatial distributions of adherence receptors are found on the surface of non‐stimulated PMN. The characterization of the leukocyte adhesive phenotype has to integrate adherence receptors density as well as their spatial distribution.
Keywords: 3D microscopy, polymorphonuclear neutrophil, adherence receptors
Journal: Biorheology, vol. 40, no. 1-3, pp. 167-172, 2003
