UMMS Affiliation

University of Massachusetts Medical School, Department of Physiology

Publication Date

2-28-2002

Document Type

Article

Subjects

Acrylic Resins; Animals; Cells, Cultured; Lysophospholipids; Macrophages; Mice; Mice, Inbred C3H; Microfilaments; Opsonin Proteins; Particle Size; *Phagocytosis; Receptors, Fc; Stress, Mechanical; rac1 GTP-Binding Protein

Disciplines

Cell Biology | Cellular and Molecular Physiology | Physiology

Abstract

Phagocytosis is an actin-based process used by macrophages to clear particles greater than 0.5 microm in diameter. In addition to its role in immunological responses, phagocytosis is also necessary for tissue remodeling and repair. To prevent catastrophic autoimmune reactions, phagocytosis must be tightly regulated. It is commonly assumed that the recognition/selection of phagocytic targets is based solely upon receptor-ligand binding. Here we report an important new criterion, that mechanical parameters of the target can dramatically affect the efficiency of phagocytosis. When presented with particles of identical chemical properties but different rigidity, macrophages showed a strong preference to engulf rigid objects. Furthermore, phagocytosis of soft particles can be stimulated with the microinjection of constitutively active Rac1 but not RhoA, and with lysophosphatidic acid, an agent known to activate the small GTP-binding proteins of the Rho family. These data suggest a Rac1-dependent mechanosensory mechanism for phagocytosis, which probably plays an important role in a number of physiological and pathological processes from embryonic development to autoimmune diseases.

Rights and Permissions

Citation: J Cell Sci. 2002 Feb 15;115(Pt 4):849-56.

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Journal of cell science

PubMed ID

11865040

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