Regulation of interleukin-5-induced beta2-integrin adhesion of human eosinophils by phosphoinositide 3-kinase.
We examined the role of phosphoinositide 3-kinase (PI3K) in integrin-mediated eosinophil adhesion. Deltap85, a dominant-negative form of the class IA PI3K adaptor subunit, was fused to an HIV-TAT protein transduction domain (TAT-Deltap85). Recombinant TAT-Deltap85 inhibited interleukin (IL)-5-stimulated phosphorylation of protein kinase B, a downstream target of PI3K. beta(2)-Integrin-dependent adhesion caused by IL-5 to the plated intracellular adhesion molecule-1 surrogate, bovine serum albumin, was inhibited by TAT-Deltap85 in a concentration-dependent manner. Similarly, two PI3K inhibitors, wortmannin and LY294002, blocked eosinophil adhesion to plated bovine serum albumin. By contrast, beta(1)-integrin-mediated eosinophil adhesion to vascular cell adhesion moelcule-1 was not blocked by TAT-Deltap85, wortmannin, or LY294002. Rottlerin, a protein kinase C (PKC)-delta inhibitor, also blocked beta(2)-integrin adhesion of eosinophils caused by IL-5, whereas beta(1) adhesion to vascular cell adhesion molecule-1 was not affected. IL-5 caused translocation of PKCdelta from the cytosol to cell membrane; inhibition of PI3K by wortmannin blocked translocation of PKCdelta. Western blot analysis demonstrated that extracellular signal-regulated kinase phosphorylation, a critical intermediary in adhesion elicited by IL-5, was blocked by inhibition of either PI3K or PKC-delta. These data suggest that extracellular signal-regulated kinase-mediated adhesion of beta(2)-integrin caused by IL-5 is mediated in human eosinophils by a class IA PI3K through activation of a PKCdelta pathway.
Sano
Masaaki
M
Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, IL 60637, USA.
Leff
Alan R
AR
Myou
Shigeharu
S
Boetticher
Evan
E
Meliton
Angelo Y
AY
Learoyd
Jonathan
J
Lambertino
Anissa T
AT
Munoz
Nilda M
NM
Zhu
Xiangdong
X
D000730:Androstadienes / Q000378:metabolism / Q000494:pharmacology; D015153:Blotting, Western; D018821:CD18 Antigens / Q000378:metabolism*; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism; D002469:Cell Separation; D002867:Chromones / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004804:Eosinophils / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015696:Gene Products, tat / Q000235:genetics; D005799:Genes, Dominant; D016325:HIV Long Terminal Repeat; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology; D015151:Immunoblotting; D047468:Immunoprecipitation; D015848:Interleukin-5 / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000378:metabolism; D051745:Protein Kinase C-delta; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism; D015398:Signal Transduction; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D000077191:Wortmannin
D000730:Androstadienes; D018821:CD18 Antigens; D002867:Chromones; D048049:Extracellular Signal-Regulated MAP Kinases; D015696:Gene Products, tat; D015848:Interleukin-5; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D020033:Protein Isoforms; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012710:Serum Albumin, Bovine; D019010:Vascular Cell Adhesion Molecule-1; D000077191:Wortmannin; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C497258:PRKCD protein, human