Phagocytosis and allogeneic T cell stimulation by cultured human osteoblast-like cells.

BACKGROUND/AIMS The antigen phenotype of human osteoblast-like cells suggests that they are related to other cellular populations and may also have immunologic functions in common. METHODS Flow cytometry and transmission electron microscopy were used to show the phagocytotic activity of osteoblast-like cells in culture. The allogeneic stimulation of T cells by human osteoblast-like cells was determined by the measurement of T cell proliferation. RESULTS We demonstrated in vitro that human osteoblast-like cells isolated from normal bone specimens obtained during mandibular osteotomy can phagocytose particles of different nature and size and can stimulate allogeneic T cells. Phagocytosis of microorganisms (E.coli, Klebsiella or C. albicans) was observed, although at a very low rate of activity in comparison with the phagocytosis of latex particles. CONCLUSION Our results suggest that human osteoblast-like cells may perform immunologic functions and act as antigen presentation cells.