Section B Project B03

Exploring the protective role of eosinophils in bone loss caused by inflammatory arthritis

An inflammatory milieu, as in RA, favors osteoclast development, leading to low bone mass with increased fracture risk. Type-2 immunity-related cytokines, which are highly secreted by eosinophils, have consistently been shown to suppress osteoclast differentiation and function. However, the role of eosinophils in regulating bone health has received little attention. Our initial findings indicate that eosinophils inhibit osteoclast formation and activity. This is supported by the observation that mice without eosinophils (ΔdblGATA mice) present enhanced bone loss in experimental arthritis due to an increase in osteoclasts. This project aims to understand the cellular and molecular basis for the inhibitory effects of eosinophils on osteoclasts and to decipher the role of eosinophils in regulating arthritic bone loss in mice and humans to discover new therapeutic strategies to address this condition.