Platelet/polymorphonuclear leukocyte adhesion: a new role for SRC kinases in Mac-1 adhesive function triggered by P-selectin.
Adhesion of polymorphonuclear leukocytes (PMNLs) to activated platelets requires a P-selectin-triggered, tyrosine kinase-dependent adhesiveness of Mac-1 and is accompanied by tyrosine phosphorylation of a 110-kd protein (P-110) in PMNLs. Inhibitors of SRC tyrosine kinases were found to inhibit PMNL adhesion to activated platelets or to P-selectin expressing Chinese hamster ovary (CHO-P) cells and the tyrosine phosphorylation of P-110. Adhesion of PMNLs to activated platelets or to CHO-P cells stimulated activity of LYN and HCK. Monoclonal antibody blockade of P-selectin or beta2-integrins reduced the activation of both kinases. In PMNLs either adherent to platelets or aggregated by P-selectin-IgG chimera, Mac-1 was rapidly redistributed to the Triton X-100-insoluble cytoskeletal fraction, and large clusters of Mac-1 colocalized with patches of F-actin at the sites of cell-cell contact. In PMNLs stimulated by P-selectin-IgG chimera, SRC kinase inhibition impaired Mac-1 clustering, F-actin accumulation, and CD18 redistribution to the cytoskeleton. Disruption of the actin filament network by cytochalasin D prevented PMNL-platelet adhesion and P-selectin-induced PMNL aggregation and impaired the clustering of Mac-1. In agreement with the requirement for the beta2-integrin in the functional up-regulation of LYN and HCK, integrin blockade by monoclonal antibodies resulted in a complete inhibition of P-selectin-induced Mac-1 clustering and F-actin accumulation. Taken together, the results indicate that, after an initial P-selectin-triggered beta2-integrin interaction with the ligand, SRC kinases are activated and allow the remodeling of cytoskeleton-integrin linkages and integrin clustering that finally strengthen cell-cell adhesion. This model highlights a new role for SRC kinases in a regulatory loop by which the Mac-1 promotes its own adhesive function.
Piccardoni
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P
Department of Vascular Medicine and Pharmacology, "G.Bizzozero" Laboratory of Blood and Vascular Cell Interactions, Istituto di Ricerche Farmacologiche Mario Negri, Consorzio Mario Negri Sud, Santa Maria Imbaro, Italy. piccardo@cmns.mnegri.it
Sideri
R
R
Manarini
S
S
Piccoli
A
A
Martelli
N
N
de Gaetano
G
G
Cerletti
C
C
Evangelista
V
V
D000199:Actins / Q000378:metabolism; D000818:Animals; D018821:CD18 Antigens / Q000494:pharmacology; D016466:CHO Cells; D002448:Cell Adhesion; D006224:Cricetinae; D003599:Cytoskeleton / Q000378:metabolism; D005246:Feedback; D006801:Humans; D016177:Macrophage-1 Antigen / Q000187:drug effects / Q000494:pharmacology / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*; D019007:P-Selectin / Q000235:genetics / Q000494:pharmacology; D010973:Platelet Adhesiveness / Q000187:drug effects*; D011505:Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000378:metabolism; D051572:Proto-Oncogene Proteins c-hck; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D019061:src-Family Kinases / Q000187:drug effects / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology
D000199:Actins; D018821:CD18 Antigens; D016177:Macrophage-1 Antigen; D019007:P-Selectin; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; C496631:HCK protein, human; D051572:Proto-Oncogene Proteins c-hck; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases