TNF-induced macrophages have higher OC forming potential than M-CSF-induced macrophages.

<p>(A) M-, T-, and R-OCPs cultured from BMCs from a 4-month-old C57Bl6 mouse were stained with the fluorescent-labeled antibodies as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135728#pone.0135728.g001" target="_blank">Fig 1</a>. Ly6C⁺Gr1^- and Ly6C^-Gr1^- populations from CD11b^<b>+</b>F4/80^<b>+</b> cells were sorted by flow cytometry. (B) The sorted cell populations were seeded in 96-well plates (4x10⁴ cells/well) and treated with RANKL or TNF in the presence of M-CSF for 2 additional days to generate mature OCs, which were stained for TRAP activity. (C) Quantitation of numbers of OCs formed from each sorted population in (B), 4 wells per group, *p < 0.05, **p < 0.01. The experiment was repeated twice with similar results. M = M-CSF, P = PBS, R = RANKL, T = TNF, R+T = RANKL+TNF.