IL-13 as well as IL-4 induces monocytes/macrophages and a monoblastic cellline (UG3) to differentiate into multinucleated giant cells in the presence of M-CSF

The formation of multinucleated giant cells (MGCs) from monocytes/macrophag es is controlled by various cytokines whose crucial roles are not fully und erstood. In this study, we found that interleukin (IL)-13 as well as IL-4 i nduced peripheral blood monocytes (PBMs) and monoblastic cell line, UG3, to differentiate into MGCs in the presence of macrophage colony-stimulating f actor (M-CSF), while IL-2, IL-7 or IL-10 did not. The presence of M-CSF was essential to this MGC formation, because IL-3 or granulocyte-macrophage co lony-stimulating factor (GM-CSF) could not replace M-CSF. IL-4 and IL-13 ha ve been known to inhibit the formation of osteoclast-like cells in the pres ence of stroma cells or osteoblastic cells. But in our system without strom a cells, IL-4 or IL-13 induced some of characteristics of osteoclasts such as tartrate-resistant acid phosphatase (TRAP) activity, vitronectin recepto r (vit-R) expression and resorptive activity for hydroxyapatite, but not th e expression of receptors for parathyroid hormone or calcitonin. These resu lts suggest possible involvement of IL-4 and IL-13 in MGCs and osteoclasts development, and UG3 may be useful to further investigate the roles of IL-4 and IL-13 in the formation and physiology of MGCs, and the relationship be tween these MGCs and osteoclasts. (C) 1998 Academic Press.