Three-dimensional migration of macrophages requires Hck for podosome organization and extracellular matrix proteolysis

Céline Cougoule1,2, Véronique Le Cabec*,1,2, Renaud Poincloux*,14, Talal Al Saati5, Jean-Louis Mège6, Guillaume Tabouret1,2, Clifford A. Lowell7, Nathalie Laviolette-Malirat1,2, and Isabelle Maridonneau-Parini1,2

1 Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie et de Biologie Structurale (IPBS), Département Mécanismes Moléculaires des Infections Mycobactériennes, Toulouse, France;

2 Université de Toulouse; Université Paul Sabatier, IPS, IPBS, Toulouse, France;

3 Membrane and Cytoskeleton Dynamics, CNRS Unité Mixte de Recherche (UMR) 144, Paris, France;

4 Research Center, Institut Curie, Paris, France;

5 Plateau technique d'histopathologie expérimentale de l'IFR-BMT/150, (Génopole, Toulouse Midi-Pyrénées), Toulouse, France;

6 Unité de Recherche sur les Maladies Infectieuses Transmissibles et Emergentes, CNRS UMR 6236, Institut Fédératif de Recherche 48, Université de la Méditerranée, Faculté de Médecine, Marseille, France; and

7 Department of Laboratory Medicine, University of California, San Francisco

 

Correspondence: Isabelle Maridonneau-Parini, IPBS CNRS, UMR5089, 205 Route de Narbonne, F-31077 Toulouse, France;
e-mail: isabelle.maridonneau-parini@ipbs.fr.

 

Abstract

Tissue infiltration of phagocytes exacerbates several human pathologies including chronic inflammations or cancers. However, the mechanisms involved in macrophage migration through interstitial tissues are poorly understood. We investigated the role of Hck, a Src-family kinase involved in the organization of matrix adhesion and degradation structures called podosomes. In Hck–/– mice submitted to peritonitis, we found that macrophages accumulated in interstitial tissues and barely reached the peritoneal cavity. In vitro, 3-dimensional (3D) migration and matrix degradation abilities, 2 protease-dependent properties of bone marrow–derived macrophages (BMDMs), were affected in Hck–/– BMDMs.

These macrophages formed few and undersized podosome rosettes and, consequently, had reduced matrix proteolysis operating underneath despite normal expression and activity of matrix metalloproteases. Finally, in fibroblasts unable to infiltrate matrix, ectopic expression of Hck provided the gain–of–3D migration function, which correlated positively with formation of podosome rosettes. In conclusion, spatial organization of podosomes as large rosettes, proteolytic degradation of extracellular matrix, and 3D migration appeared to be functionally linked and regulated by Hck in macrophages.

Hck, as the first protein combining a phagocyte-limited expression with a role in 3D migration, could be a target for new anti-inflammatory and antitumor molecules.

 

Macrophages infiltrating Matrigel observed by scanning electron microscopy: macrophage (green) proteolytic activity loosens matrix (pink) meshwork to facilitate 3D migration. See the article by Cougoule et al.