A 58-year-old woman with osteoporosis is enrolled in a study evaluating bone remodeling at the cellular level. Bone marrow biopsy shows an abundance of mononuclear monocyte-lineage cells in the remodeling compartment. However, very few multinucleated osteoclasts are present on the trabecular surface, and urinary NTx — a marker of bone resorption — is markedly suppressed. The investigators determine that a soluble protein secreted by osteoblasts at this site is responsible for preventing the conversion of precursor cells into mature, resorbing osteoclasts.
Which of the following best describes the mechanism by which this osteoblast-derived protein is suppressing osteoclast formation?