(A) Chemical structure of C3G. (B) Human and mouse ASMCs (hASMCs and mASMCs) were treated for 24 hours with IL-17A in the presence of DMSO (vehicle control) or the indicated concentrations of C3G. The concentrations of CXCL1 (GROα in humans and KC in mice) in the culture medium were measured by ELISA. Results are presented as a percentage of the amount of CXCL1 in the culture medium of DMSO-treated cells, which was set at 100%. Data are representative of 3 independent experiments. Error bars represent the SEM of technical replicates. (C and D) Eight-week-old WT C57BL/6 female mice (n = 5 per group) were subjected to the HDM-CFA acute asthma model. PBS (Control), DEX, C3G, or a combination of DEX and C3G were administered to the mice (as described in Methods). Twenty-four hours after challenging, total and neutrophil counts in the BAL were quantified (C). Representative BAL cells were prepared by cytospin and lung tissues were stained with H&E (D). All scale bars (red): 100 μm. (E) mRNA expression of lung tissues was quantified by real-time PCR. (F and G) OVA_323–339-specific Th17 cells were adoptively transferred into 8-week-old female C57BL/6 mice (n = 5 mice per treatment group), which were treated as described in Methods. Twenty-four hours after the last challenge, total cell and neutrophil counts in the BAL were quantified. AU, fold induction relative to unchallenged control mice. Data represent mean ± SEM. One-way ANOVA was performed, followed by Tukey’s multiple-comparisons test. The multiplicity-adjusted P values were calculated for the indicated comparisons. The above data are representative of 3 independent experiments.