Figure 3

Mast cells play a partial role in the development of rCNT-triggered asthma. Wild type (WT) C57BL/6 mice and mast cell deficient Kit^W-sh mice in C57BL/6 background were exposed to rCNT for 4 h/day on 4 consecutive days and were sacrificed on day 5. a: BAL cell counts showed that mast cells affect the migration of eosinophils but not neutrophils into the lungs. b: the numbers of PAS⁺ cells did not differ in WT and Kit^W-sh mice indicating that mast cells do not regulate the activation of goblet cells. c: the mRNA expression levels measured in lung tissue revealed a significant down-regulation of Th2 type cytokine Il-13 in Kit^W-sh mice compared with WT mice. PAS⁺ cell counts (b) represent the average of positive cells per 200 μm of bronchus surface counted from three bronchi per mouse in control group and six bronchi per mouse in CNT-exposed groups (n = 7-9). mRNA expression levels in c are presented as fold changes relative to untreated control mice of the corresponding strain (n = 7-9). *P < 0.05; **P < 0.01; ***P < 0.001.