Gr-1+ cells contribute to TLR4-mediated pathogenesis in antibody-induced arthritis. To induce antibody-induced arthritis, mice were injected with K/BxN serum (150 μL) twice (A-C). (A) Toll-like receptor (TLR)4-/- mice were adoptively transferred with spleen cells (spc) from wild type (WT) mice some Gr-1+ cell- (GD), macrophage- (MD), and mast cell- (MsD) depleted, one day prior to K/BxN serum transfer. Ankle thickness and clinical scores were monitored in each group and compared with those in wild type (WT) and TLR4-/- (TLR4-/-) mice (n = 3). (B) Interferon (IFN)-γ, transforming growth factor (TGF)-β, interleukin (IL)-12p35 and IL-1β transcript levels in the joints of each group 10 days after K/BxN serum transfer (n = 3) were measured by real-time PCR. (C) Intracellular IL-12 expression in Gr-1+ cells from WT mice, some of which had been injected with LPS, was measured 10 days after K/BxN serum transfer (n = 3). The results shown are representative of three repeated independent experiments. n.s., not significant; * P < 0.05, ** P < 0.01, *** P < 0.001.
Kim and Chung Arthritis Research & Therapy 2012 14:R210 doi:10.1186/ar4048