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CD44 Antibodies Inhibit Osteoclast Formation
Author(s) -
Kania Janice R.,
KehatStadler Talia,
Kupfer Stuart R.
Publication year - 1997
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.1997.12.8.1155
Subject(s) - osteoclast , bone resorption , antibody , bone marrow , stromal cell , haematopoiesis , cd44 , monoclonal antibody , resorption , microbiology and biotechnology , biology , chemistry , receptor , immunology , cancer research , in vitro , endocrinology , biochemistry , stem cell
Osteoclast differentiation is a complex process requiring multiple factors and sequential regulation. We have determined that CD44, a cell surface glycoprotein that is known to function as an adhesion receptor, is involved in this process. By immunocytochemistry, we show that CD44 is expressed in mouse osteoclasts that develop in primary cultures of bone marrow cells treated with 1α,25‐dihydroxyvitamin D 3 . Monoclonal antibodies to CD44 inhibit osteoclast formation in bone marrow cultures in a dose‐ and time‐dependent manner. In contrast, CD44 Fab monomer antibodies have no effect on osteoclast development, suggesting that the inhibition of differentiation by the whole antibodies is facilitated by cross‐linking of CD44 molecules. Cocultures of spleen cells and ST2 bone marrow stromal cells indicate that hematopoietic cells mediate the CD44 antibody inhibitory effect. CD44 antibodies do not inhibit osteoclast resorption of calcified matrix, indicating that CD44 is not absolutely required for resorption activity. These observations demonstrate that CD44 may play a role in osteoclast formation and suggest mechanisms by which CD44 antibody effects are mediated.