title: The role of integrin alpha D beta2 (CD11d/CD18) in monocyte/macrophage migration.
abstract: Integrin alpha(D)beta(2) (CD11d/CD18) is a multiligand macrophage receptor with recognition specificity identical to that of the major myeloid cell-specific integrin alpha(M)beta(2) (CD11b/CD18, Mac-1). Despite its prominent upregulation on inflammatory macrophages, the role of alpha(D)beta(2) in monocyte and macrophage migration is unknown. In this study, we have generated model and natural cell lines expressing different densities of alpha(D)beta(2) and examined their migration to various extracellular matrix proteins. When expressed at a low density, alpha(D)beta(2) on the surface of recombinant HEK293 cells and murine IC-21 macrophages cooperates with beta(1)/beta(3) integrins to support cell migration. However, its increased expression on the alpha(D)beta(2)-expressing HEK293 cells and its upregulation by PMA on the IC-21 macrophages result in increased cell adhesiveness and inhibition of cell migration. Furthermore, ligation of alpha(D)beta(2) with anti-alpha(D) blocking antibodies restores beta(1)/beta(3)-driven cell migration by removing the excess alpha(D)beta(2)-mediated adhesive bonds. Consistent with in vitro data, increased numbers of inflammatory macrophages were recovered from the inflamed peritoneum of mice after the administration of anti-alpha(D) antibody. These results demonstrate that the density of alpha(D)beta(2) is critically involved in modulating macrophage adhesiveness and their migration, and suggest that low levels of alpha(D)beta(2) contribute to monocyte migration while alpha(D)beta(2) upregulation on differentiated macrophages may facilitate their retention at sites of inflammation.
authors.affiliation: Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA. yakubv@ccf.org
authors.forename: Valentin P
authors.initials: VP
authors.lastname: Yakubenko
authors.forename: Nataly
authors.initials: N
authors.lastname: Belevych
authors.forename: Daria
authors.initials: D
authors.lastname: Mishchuk
authors.forename: Aleksey
authors.initials: A
authors.lastname: Schurin
authors.forename: Stephen C-T
authors.initials: SC
authors.lastname: Lam
authors.forename: Tatiana P
authors.initials: TP
authors.lastname: Ugarova
mesh_terms: D000818:Animals; D000906:Antibodies; D018845:CD11 Antigens / Q000378:metabolism*; D018821:CD18 Antigens / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D002465:Cell Movement; D006801:Humans; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism*; D010537:Peritoneum / Q000166:cytology / Q000378:metabolism
chemical_list: D000906:Antibodies; D018845:CD11 Antigens; D018821:CD18 Antigens