The Functional Importance of CD177 on Neutrophil in Interaction with Endothelium

Abstract

This study sheds light on the characterisation of CD177 and identification of CD177s counter receptor on endothelium. We could demonstrate that PECAM-1 on endothelial cells functions directly as the counter receptor for CD177 by following observations; 1. Our recombinant CD177-Fc fusion protein, which was produced in insect cells, reacted with 130 KDa molecules on endothelium. 2. Screening with different mabs identified the 130 KDa protein as endothelial PECAM-1. 3. Biochemical and immunological studies using recombinant CD177-Fc fusion protein confirmed that endothelial PECAM-1 functions directly as the counter-receptor for CD177. 4. Functional studies in vitro demonstrated that purified CD177 protein inhibits CD177 mediated cell adhesion to immobilized PECAM-1 protein as well as neutrophil migration through endothelial cells. These results indicate that CD177 can act as cell adhesion molecule involving neutrophil-endothelial interaction. This observation may provide a new concept in understanding the multi-step process of transendothelial migration.In the future, this concept should be studied in different in vitro as well as in vivo model in more detail.