Polymorphonuclear leukocyte integrin profile in vascular atherosclerotic disease

Abstract

Leukocyte-endothelial interactions could have a pathogenic role in atherogenesis. Adhesion molecules expressed by endothelial cells, such as intercellular adhesion molecule 1 (ICAM-1), interact with leukocyte integrins mediating the firm adhesion of leukocytes to endothelium which is followed by their transendothelial migration. The aim of our research was to evaluate polymorphonuclear leukocyte (PMN) integrin expression, at baseline and after activation, in a group of subjects with chronic vascular atherosclerotic disease (VAD). In 27 subjects with VAD we examined, at baseline and after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA), the PMN integrin pattern (CD11a, CD11b, CD11c, CD18) using indirect immunofluorescence and a flow cytometer. At baseline VAD subjects showed an increase of CD11a and CD18 and a decrease of CD11b and CD11c as compared to normal subjects. After activation, in normal subjects, we found an increase in the expression of all integrins, while in VAD subjects we observed an increase of CD11b and CD11c and a decrease of CD11a and CD18. In VAD subjects, at baseline, the upregulation of CD11a and CD18 may reflect PMN in vivo activation; after in vitro activation, the decrease of CD11a may be related to the lack of cytoplasmic deposits of this molecule, while CD18 might be internalized. The integrin behaviour pattern in chronic VAD deserves further investigation, considering that integrins are potential targets of therapeutical strategies, with the aim of preventing the atherosclerotic plaque progression and acute ischaemic events.