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Fc-receptor-mediated phagocytosis is regulated by mechanical properties of the targetPhagocytosis 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.
Document ID
Document Type
Reprint (Version printed in journal)
Beningo, Karen A. (University of Massachusetts Medical School, Department of Physiology 377 Plantation, Room 327, Worcester, MA 01605, United States)
Wang, Yu-li
Date Acquired
August 21, 2013
Publication Date
February 15, 2002
Publication Information
Publication: Journal of cell science
Volume: 115
Issue: Pt 4
ISSN: 0021-9533
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
NASA Program Fundamental Space Biology
Non-NASA Center
NASA Discipline Cell Biology