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The role of LFA‐1 in osteoclast development induced by co‐cultures of mouse bone marrow cells and MC3T3‐G2/PA6 cells
Author(s) -
TaniIshii N.,
Penninger J. M.,
Matsumoto G.,
Teranaka T.,
Umemoto T.
Publication year - 2002
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1034/j.1600-0765.2002.00610.x
Subject(s) - osteoclast , bone marrow , bone resorption , stromal cell , cell adhesion molecule , lymphocyte function associated antigen 1 , microbiology and biotechnology , monoclonal antibody , chemistry , biology , antibody , immunology , endocrinology , intercellular adhesion molecule 1 , in vitro , cancer research , biochemistry
Interactions between leukocyte function‐associated antigen‐1 (LFA‐1) and intercellular adhesion molecule‐1 (ICAM−1) influence the development of osteoclasts. However, little is known about how these adhesion molecules are involved in the process of osteoclast development. This study evaluated the role of LFA‐1 and its ligands in osteoclast development and bone resorption. Co‐cultures of bone marrow cells from LFA‐1‐deficient mice and MC3T3‐G2/PA6 (PA6) cells were cultured in the presence of 1α,25(OH) 2 D 3 and dexamethasone for 7 days. The number of TRAP‐positive cells that were generated by bone marrow cells from LFA‐1‐deficient mice was smaller than that generated by bone marrow cells from wild‐type mice. In addition, the bone‐resorbing activity of osteoclast‐like cells that were generated from LFA‐1‐deficient mice was lower than that generated by osteoclast‐like cells from wild‐type mice. Immunofluorescence flow cytometry showed that osteoclast stromal PA6 cells expressed the cell adhesion molecules, ICAM‐1 and VCAM‐1. When monoclonal antibodies to mice VCAM‐1, CD11b or CD18 were added separately to the co‐culture system, the number of TRAP‐positive cells that were generated from LFA‐1‐deficient mice was 20–30% smaller than that generated from wild‐type mice. The formation of TRAP‐positive cells from both LFA‐1 deficient and wild‐type mice was especially inhibited by anti‐CD18 antibody, in comparison to the addition of normal IgG serum. These results suggest that LFA‐1 adhesion molecules play a role in osteoclast development by affecting adhesion between stromal cells and osteoclast progenitors before the occurrence of ODF‐ODF receptor signaling. CD18 appears to be a key adhesion molecule in cell‐to‐cell contacts during the early stage of osteoclast development.