Fig. 2

IL-9 provides survival to RA SF neutrophils. a FACS plots show reduced annexin V on CD15-gated neutrophils (upper panel, Leishman’s stain image of neutrophils in inset) in presence of rIL-9 and cumulative data is shown in line graph (lower right panel, n = 7). b Cumulative bar graph shows reduction in apoptosis of RA SF-derived neutrophils in the presence of RA SF and rIL-9, addition of anti-IL9 antibody in RA SF increased apoptosis (n = 8, mean ± SEM; p < 0.006). c Western blot image shows MCL-1 expression in SF-derived neutrophils under different conditions (media, rIL-9, anti-IL-9, RA SF). MCL-1 increases with rIL-9 (lane 2), RA SF (lane 4) and reduces upon blocking of endogenous IL-9 present in RA SF (lane no 3). Data are representative of two different experiments performed. d Relative (MCL-1/β-actin) densitometry bar graph of the experiment (n = 3, mean ± SEM, unpaired t test, *p < 0.05,**p < 0.001,***p < 0.0001). IL interleukin, IL-9R interleukin 9 receptor, MCL-1 induced myeloid leukemia cell differentiation protein, RA rheumatoid arthritis, SF synovial fluid, Th T helper