Fig. 1

Granulocyte macrophage colony-stimulating factor (GM-CSF) but not colony-stimulating factor (CSF-1) neutralization suppresses antigen-induced arthritis (AIA). AIA-primed mice were treated with PBS, anti-GM-CSF, anti-CSF-1R, anti-CSF-1 or isotype monoclonal antibodies, either prophylactically (days -2 and 0) (a and b) or therapeutically (days 2 and 4) (c and d), with arthritis being induced on day 0 by intra-articular injection of methylated bovine serum albumin (mBSA). Histological analysis of the arthritic joints was performed on day 3 (a and b) and day 7 (c and d) post arthritis induction. a, c Representative H&E (left) and Safranin O/fast green (right) stained sections. b, d Quantification of histological appearances. PG proteoglycan. Data are expressed as mean + SEM, n = 6–12 mice/group; *p < 0.05, **p < 0.01, ***p < 0.001, anti-GM-CSF vs. PBS or IgG2a