MCP-1-stimulated monocyte attachment to laminin is mediated by beta 2-integrins.
Migration of monocytes to sites of inflammation involves a series of attachments and detachments to extracellular matrix proteins. We examined the capacity of a chemokine, monocyte chemoattractant protein-1 (MCP-1), to regulate attachment of human monocytes to laminin, collagen I, collagen IV, or fibronectin. MCP-1 increased monocyte attachment to laminin in a dose- and time-dependent manner and stimulated a lesser increase to the other matrix proteins. Function-blocking monoclonal antibodies (MAbs) to the integrin beta 2-subunit (CD18), including Fab' fragments and alpha M (CD11b) blocked > 70% of attachment, whereas MAbs to the beta 1-integrin subunit reduced attachment by < 30%. This suggests that the CD11b/CD18 integrin is the predominant molecule involved in adhesion of MCP-1-stimulated monocytes to laminin. The association of CD11b with F-actin illustrated by confocal microscopy further supports this concept. In contrast, when monocytes were stimulated with the beta 1-stimulatory MAb TS2/16, monocyte adhesion to laminin occurred through beta 1-integrins. Thus MCP-1 can stimulate monocyte attachment to laminin, and this process is mediated through beta 2-integrins, principally CD11b/CD18.
Jiang
Y
Y
Department of Oral Biology, Boston University School of Graduate Dentistry, Boston University School of Medicine 02118.
Zhu
J F
JF
Luscinskas
F W
FW
Graves
D T
DT
D000911:Antibodies, Monoclonal; D002448:Cell Adhesion; D018932:Chemokine CCL2; D002630:Chemotactic Factors / Q000494:pharmacology*; D016207:Cytokines / Q000494:pharmacology; D016326:Extracellular Matrix Proteins; D006801:Humans; D016023:Integrins / Q000145:classification / Q000502:physiology*; D007797:Laminin; D018613:Microscopy, Confocal; D009000:Monocytes / Q000502:physiology*
D000911:Antibodies, Monoclonal; D018932:Chemokine CCL2; D002630:Chemotactic Factors; D016207:Cytokines; D016326:Extracellular Matrix Proteins; D016023:Integrins; D007797:Laminin