CC16 and TNF-α relative mRNA expression in lung homogenates. (A) Non sensitized (NS/UFP) and sensitized (S/UFP) mice exposed to EC-UFP, and NS/UFP treated with NAC (NS/NAC/UFP); (B) sensitized and challenged mice (S/OVA), treated with NAC (S/NAC/OVA), or exposed to EC-UFP 24 h prior to OVA challenge (S/UFP/OVA), and treated with NAC (S/NAC/UFP/OVA). NAC treatment was performed prior to and close to mid EC-UFP exposure. Untreated mice served as baseline controls (dotted line). The lungs were retrieved 24 h after EC-UFP/filtered air exposure. Data presented as mean ± SD (n = 3-6/group). *p < 0.05, **p < 0.01 vs untreated; #p < 0.05, ##p < 0.01 NS/UFP, S/UFP, S/OVA, S/NAC/UFP/OVA vs S/UFP/OVA.