title: Integrin linked kinase (ILK) regulates podosome maturation and stability in dendritic cells.
abstract: Podosomes are integrin-based adhesions fundamental for stabilisation of the leading lamellae in migrating dendritic cells (DCs) and for extracellular matrix (ECM) degradation. We have previously shown that soluble factors and chemokines such as SDF 1-a trigger podosome initiation whereas integrin ligands promote podosome maturation and stability in DCs. The exact intracellular signalling pathways that regulate the sequential organisation of podosomal components in response to extracellular cues remain largely undetermined. The Wiskott Aldrich Syndrome Protein (WASP) mediates actin polymerisation and the initial recruitment of integrins and associated proteins in a circular configuration surrounding the core of filamentous actin (F-actin) during podosome initiation. We have now identified integrin linked kinase (ILK) surrounding the podosomal actin core. We report that DC polarisation in response to chemokines and the assembly of actin cores during podosome initiation require PI3K-dependent clustering of the Wiskott Aldrich Syndrome Protein (WASP) in puncta independently of ILK. ILK is essential for the clustering of integrins and associated proteins leading to podosome maturation and stability that are required for degradation of the subjacent extracellular matrix and the invasive motility of DCs across connective tissue barriers. We conclude that WASP regulates DCs polarisation for migration and initiation of actin polymerisation downstream of PI3K in nascent podosomes. Subsequently, ILK mediates the accumulation of integrin-associated proteins during podosome maturation and stability for efficient degradation of the subjacent ECM during the invasive migration of DCs.
authors: Department of Physiology, Facultad de Medicina, Universidad de Alcalá, Campus Universitario s/n, Alcalá de Henares, Madrid 28871, Spain.
authors: Mercedes
authors: M
authors: Griera
authors: Cancer Biology Department, Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Madrid 28029, Spain.
authors: Ester
authors: E
authors: Martin-Villar
authors: Cellular and Molecular Department, Centro Nacional de Biotecnología (CNB-CSIC), Madrid 28049, Spain.
authors: Inmaculada
authors: I
authors: Banon-Rodríguez
authors: Wolfson Centre for Gene Therapy, Molecular Immunology Unit, Institute of Child Health, University College London, WC1N UK.
authors: Michael P
authors: MP
authors: Blundell
authors: Randall Division of Cell & Molecular Biophysics, King's College London, London SE1 1UL, UK.
authors: Gareth E
authors: GE
authors: Jones
authors: Cellular and Molecular Department, Centro Nacional de Biotecnología (CNB-CSIC), Madrid 28049, Spain.
authors: Ines M
authors: IM
authors: Anton
authors: Wolfson Centre for Gene Therapy, Molecular Immunology Unit, Institute of Child Health, University College London, WC1N UK.
authors: Adrian J
authors: AJ
authors: Thrasher
authors: Department of Physiology, Facultad de Medicina, Universidad de Alcalá, Campus Universitario s/n, Alcalá de Henares, Madrid 28871, Spain.
authors: Manuel
authors: M
authors: Rodriguez-Puyol
authors: Department of Haemato-oncology, King's College London, London SE5 9NU, UK. Electronic address: yolanda.calle@kcl.ac.uk.
authors: Yolanda
authors: Y
authors: Calle
mesh_terms: D000818:Animals; D021961:Cell Membrane Structures / Q000201:enzymology; D002465:Cell Movement / Q000502:physiology; D003713:Dendritic Cells / Q000166:cytology* / Q000201:enzymology* / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014162:Transfection; D051316:Wiskott-Aldrich Syndrome Protein / Q000378:metabolism; D000099200:Scaffold Protein ILK
chemical_list: D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D051316:Wiskott-Aldrich Syndrome Protein; D000099200:Scaffold Protein ILK; C495768:Was protein, mouse
keywords: Dendritic cell; ILK; PI3K; Podosome; WASP