1. The integrin-linked kinase is required for chemokine-triggered high-affinity conformation of the neutrophil β2-integrin LFA-1
- Author
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Peter W. Krenn, Helena Block, Giulia Germena, Barbara Heitplatz, Andreas Margraf, Hermann Haller, Chang Liu, Nadine Ludwig, Dietmar Vestweber, Jan Rossaint, Wiebke Gottschlich, Marika Meyer zu Brickwedde, Barbara Prystaj, Alexander Zarbock, Sina Mersmann, Katharina Thomas, Markus Moser, and Hannes C.A. Drexler
- Subjects
Chemokine ,Neutrophils ,Immunology ,Integrin ,HL-60 Cells ,Protein Serine-Threonine Kinases ,Biochemistry ,Mice ,Cell Adhesion ,Leukocytes ,Animals ,Humans ,Integrin-linked kinase ,Phosphorylation ,Kinase activity ,Protein Kinase C ,Protein kinase C ,biology ,Chemistry ,Kinase ,Membrane Proteins ,Cell Biology ,Hematology ,Acute Kidney Injury ,Lymphocyte Function-Associated Antigen-1 ,Extravasation ,Neoplasm Proteins ,Cell biology ,Disease Models, Animal ,CD18 Antigens ,Reperfusion Injury ,biology.protein ,Chemokines ,BLOOD Commentary ,Signal Transduction - Abstract
Neutrophil adhesion and extravasation into tissue at sites of injury or infection depend on binding of the integrin lymphocyte function–associated antigen 1 (LFA-1) to ICAM-1 expressed on activated endothelial cells. The activation-dependent conformational change of LFA-1 to the high-affinity conformation (H+) requires kindlin-3 binding to the β2-integrin cytoplasmic domain. Here we show that genetic deletion of the known kindlin interactor integrin-linked kinase (ILK) impaired neutrophil adhesion and extravasation in the cremaster muscle and in a clinically relevant model of renal ischemia reperfusion injury. Using in vitro microfluidic adhesion chambers and conformation-specific antibodies, we show that knockdown of ILK in HL-60 cells reduced the conformational change of β2-integrins to the H+ conformation. Mechanistically, we found that ILK was required for protein kinase C (PKC) membrane targeting and chemokine-induced upregulation of its kinase activity. Moreover, PKC-α deficiency also resulted in impaired leukocyte adhesion in bone marrow chimeric mice. Mass spectrometric and western blot analyses revealed stimulation- and ILK-dependent phosphorylation of kindlin-3 upon activation. In summary, our data indicate an important role of ILK in kindlin-3–dependent conformational activation of LFA-1.
- Published
- 2020
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