Figure 3

Treatment with siNPRA and imiquimod cream reduced allergic airway hyperreactivity, lung eosinophilia and pathology. (A) Transdermally-delivered siNPRA reduces airway hyperreactivity. Mice were sensitized to OVA, given the indicated treatments and challenged with OVA intranasally. AHR to methacholine challenge was recorded 24 h later in a whole-body plethysmograph which measures the enhanced pause (PENH). The PENH values for each methacholine concentration were averaged and expressed as a percentage of the PBS baseline reading. Results shown are averages of two separate experiments with standard deviations (*, P < 0.05). (B) Decrease in eosinophil numbers by siNPRA-imiquimod treatment. BAL cells were air dried and stained with a modified Wright's stain. Total cell numbers were approximately the same in each group and the number of eosinophils is given as percentage of the total. Treatment by siNPRA-imiquimod cream significantly reduced eosinophils in the BAL compared to controls Results shown are averages of two separate experiments with standard deviations (**, P < 0.01). (C) Reduction of lung inflammation by siNPRA-imiquimod cream. Lungs were removed, fixed in formalin and sectioned. Slides were stained with hematoxylin and eosin. Treatment with siNPRA caused a substantial decrease in lung inflammation, goblet cell hyperplasia and infiltration of inflammatory cells compared to the OVA control group and the group treated with scrambled siNPRA (scr-siNPRA) nanoparticles. Lung sections from naïve animals without any treatment show normal healthy lungs.