Osteoclast activity modulates B-cell development in the bone marrow

Cell Res. 2011 Jul;21(7):1102-15. doi: 10.1038/cr.2011.21. Epub 2011 Feb 15.

Abstract

B-cell development is dependent on the interactions between B-cell precursors and bone marrow stromal cells, but the role of osteoclasts (OCLs) in this process remains unknown. B lymphocytopenia is a characteristic of osteopetrosis, suggesting a modulation of B lymphopoiesis by OCL activity. To address this question, we first rescued OCL function in osteopetrotic oc/oc mice by dendritic cell transfer, leading to a restoration of both bone phenotype and B-cell development. To further explore the link between OCL activity and B lymphopoiesis, we induced osteopetrosis in normal mice by injections of zoledronic acid (ZA), an inhibitor of bone resorption. B-cell number decreased specifically in the bone marrow of ZA-treated mice. ZA did not directly affect B-cell differentiation, proliferation and apoptosis, but induced a decrease in the expression of CXCL12 and IL-7 by stromal cells, associated with reduced osteoblastic engagement. Equivalent low osteoblastic engagement in oc/oc mice confirmed that it resulted from the reduced OCL activity rather than from a direct effect of ZA on osteoblasts. These dramatic alterations of the bone microenvironment were disadvantageous for B lymphopoiesis, leading to retention of B-cell progenitors outside of their bone marrow niches in the ZA-induced osteopetrotic model. Altogether, our data revealed that OCLs modulate B-cell development in the bone marrow by controlling the bone microenvironment and the fate of osteoblasts. They provide novel basis for the regulation of the retention of B cells in their niche by OCL activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / cytology*
  • B-Lymphocytes / drug effects
  • Bone Density Conservation Agents / pharmacology
  • Bone Marrow / drug effects
  • Bone Marrow / metabolism
  • Bone Marrow Cells / cytology*
  • Bone Marrow Cells / drug effects
  • Bone Marrow Cells / metabolism
  • Bone and Bones / drug effects
  • Bone and Bones / metabolism
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Chemokine CXCL12 / metabolism
  • Diphosphonates / pharmacology
  • Female
  • Imidazoles / pharmacology
  • Interleukin-7 / metabolism
  • Lymphopoiesis* / drug effects
  • Mice
  • Mice, Inbred BALB C
  • Osteoclasts / cytology*
  • Osteopetrosis / chemically induced
  • Stromal Cells / drug effects
  • Stromal Cells / metabolism
  • Zoledronic Acid

Substances

  • Bone Density Conservation Agents
  • Chemokine CXCL12
  • Diphosphonates
  • Imidazoles
  • Interleukin-7
  • Zoledronic Acid