B lymphocytes inhibit human osteoclastogenesis by secretion of TGFβ

✍ Scribed by M. Neale Weitzmann; Simone Cenci; Jeff Haug; Chris Brown; John DiPersio; Roberto Pacifici

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 139 KB
• Volume: 78
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/(sici)1097-4644(20000801)78:2<318::aid-jcb13>3.0.co;2-n

✦ Synopsis

The role of B lymphocytes in osteoclast (OC) formation is controversial, because both stimulatory and inhibitory effects of B-lineage cells on osteoclastogenesis and life span have been reported. In this study, we have investigated the effects of mature B cells on human osteoclastogenesis using cultures of peripheral blood stem cells (PBSC), a system that generates functional OCs in the absence of stromal cells. We report that B cells inhibit the formation of OCs and shorten the life span of mature OCs by secreting transforming growth factor ␤ (TGF␤), a factor that induces apoptosis in these cells. The antiosteoclastogenic effects of B cells are abolished by addition of anti-TGF␤ antibody to osteoclast cultures and mimicked by treatment of B cell-deprived PBSC cultures with recombinant TGF␤, thus confirming TGF␤ as the B cell produced antiosteoclastogenic activity. Thus, the ability of B cells to downregulate osteoclastogenesis by secretion of the apoptotic cytokine TGF␤ provides new insights into the ability of immune cells to regulate OC formation under basal and inflammatory conditions.