Involvement of alpha5beta1 integrins in interleukin 8 production induced by oral viridans streptococcal protein I/IIf in cultured endothelial cells.
Using human endothelial cells, we define a mechanism that accounts for the induction of interleukin 8 (IL-8) by protein I/IIf, an adhesin from Streptococcus mutans serotype f. We report that protein I/IIf interactions with endothelial cells increased the tyrosine phosphorylation of three cellular components with relative mass of 145,000, 125,000 and 70,000 in endothelial cells. These proteins were identified as phospholipase Cgamma (PLCy), focal adhesion kinase (FAK) and paxillin after immunoprecipitation with monoclonal antibodies (mAbs) and immunoblotting with antiphosphotyrosine mAbs. These results suggested that beta1 integrins could be one of the components implicated in the modulin activity of protein I/IIf. By incubating protein I/IIf with either purified alpha5beta1 integrins or with alpha5beta1 integrins overexpressing CHO cells, we demonstrated that alpha5beta1 integrins act as cell receptors for protein I/IIf. We also showed that protein I/IIf interactions with alpha5beta1 integrins lead to IL-8 secretion. Using specific inhibitors, we demonstrated that protein I/IIf-induced IL-8 release involves mitogen-activated protein kinases (MAPKs), and that PLCgamma and PKC also seem to contribute to protein I/IIf stimulation. However, PI-3K activation is not involved in IL-8 release. Altogether, these results indicate that, after binding to alpha5beta1 integrins, protein I/IIf induces IL-8 release by activating the MAPKs signalling pathways.
Al-Okla
S
S
INSERM U392, Université Louis Pasteur de Strasbourg, Faculté de Pharmacie, Illkirch, France.
Chatenay-Rivauday
C
C
Klein
J P
JP
Wachsmann
D
D
D018829:Adhesins, Bacterial / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D047310:Apigenin; D001426:Bacterial Proteins / Q000378:metabolism / Q000494:pharmacology*; D016227:Benzoquinones; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019833:Genistein / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D015151:Immunoblotting; D016023:Integrins / Q000378:metabolism*; D016209:Interleukin-8 / Q000096:biosynthesis*; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D047029:Lactams, Macrocyclic; D008562:Membrane Glycoproteins; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000378:metabolism; D051419:Paxillin; D051966:Phospholipase C gamma; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D011809:Quinones / Q000494:pharmacology; D019030:Receptors, Vitronectin; D017828:Rifabutin / Q000031:analogs & derivatives; D013295:Streptococcus mutans / Q000502:physiology; D013873:Thionucleotides / Q000494:pharmacology; D010738:Type C Phospholipases / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D016227:Benzoquinones; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D016023:Integrins; D016209:Interleukin-8; D007527:Isoenzymes; D047029:Lactams, Macrocyclic; D008562:Membrane Glycoproteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011809:Quinones; D019030:Receptors, Vitronectin; C055764:S-layer proteins; D013873:Thionucleotides; C094340:integrin alphavbeta1; D006153:Guanosine Diphosphate; D017828:Rifabutin; D014443:Tyrosine; C020754:herbimycin; C023427:guanosine 5'-O-(2-thiodiphosphate); D047310:Apigenin; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D020928:Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma