Isolation and phenotypic characterization of a multinucleated tartrate-resistant acid phosphatase-positive bone marrow macrophage

This study identifies differences in expression of several osteoclast and macrophage genes, as well as functional differences between PT- and OPN-adherent cells. We conclude that the OPN-adherent cells display osteoclast characteristics, especially with regard to expression of matrix-degrading enzymes, whereas the PT-adherent cell might represent a unique TRAP-positive multinucleated bone marrow macrophage implicated in immune recognition and phagocytosis.