CD44 occupancy prevents macrophage multinucleation.
Cells of the mononuclear phagocyte lineage have the capability to adhere to and fuse with each other and to differentiate into osteoclasts and giant cells. To investigate the macrophage adhesion/fusion mechanism, we focused our attention on CD44, a surface glycoprotein known to play a role in hematopoietic cell-cell adhesion. We report that CD44 expression by macrophages is highly and transiently induced by fusogenic conditions both in vitro and in vivo. We show that CD44 ligands, hyaluronic acid, chondroitin sulfates, and osteopontin prevent macrophage multinucleation. In addition, we report that the recombinant extracellular domain of CD44 binds fusing macrophages and prevents multinucleation in vitro. These data suggest that CD44 may control the mononucleated status of macrophages in tissues by virtue of mediating cell-cell interaction.
Sterling
H
H
Yale University School of Medicine, Departments of Cell Biology and Orthopaedics and Rehabilitation, New Haven, Connecticut 06510, USA.
Saginario
C
C
Vignery
A
A
D000818:Animals; D019556:COS Cells; D002448:Cell Adhesion; D002459:Cell Fusion; D015726:Giant Cells / Q000166:cytology*; D018960:Hyaluronan Receptors / Q000096:biosynthesis / Q000502:physiology*; D006820:Hyaluronic Acid / Q000494:pharmacology; D008024:Ligands; D016676:Macrophages, Alveolar / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley
D018960:Hyaluronan Receptors; D008024:Ligands; D006820:Hyaluronic Acid