Mucous cell metaplasia and alveolitis in response to anti-CCL2 mAb treatment in T-bet-/-mice 21 days post-exposure. A) Cells stained with AB/PAS were quantitated for mucin protein expression using ImageJ (NIH) analysis for percentage of positive stained area per total area in mice treated with IgG2B Isotype Control or anti-CCL2 mAb and exposed to either a 0.1% pluronic solution or NiNPs. B) MUC5AC and C) MUC5B whole lung mRNA expression were quantitated using qRT-PCR analysis. D) Cross sections of lungs stained with trichrome were scored for parenchymal lesions in WT and T-bet-/- mice 21 days after initial NiNP exposure. Lungs were scored in a blinded manner by three independent reviewers. E) Soluble collagen content was measured using the Sircol Assay kit in whole lung homogenates and expressed as μg/mg of protein. F) Whole lung col1a2 mRNA expression measured by qRT-PCR. *p < 0.05, **p < 0.01, ***p < 0.001 compared to the time matched control group of the same genotype or as indicated. Data are the mean values ± SEM (n = 3–5 animals/group).