Fig. 2

Pericytes accumulate in the airway wall in response to chronic allergic inflammation. A Female C57/Bl6 mice (6–8 weeks old) were subjected to intranasal delivery of sterile PBS (10 µl) or house dust mite extract (HDM; 25 µg in 10 µl) 5 days a week for 5 consecutive weeks. At the end of the protocol, the lungs were removed and bronchoalveolar lavage (BAL) fluid was collected. B Total inflammatory cell infiltrates were enumerated and C–E immune cell differentials were determined using hematoxylin and eosin stained cytospin preparations of BAL fluid. F Hematoxylin and eosin staining of paraffin-embedded lung sections demonstrated perivascular and peribronchial inflammatory infiltration in HDM exposed mice. G Immunostaining of frozen lung sections revealed peribronchial accumulation of NG2+ pericytes (green) coexpressing αsmooth muscle actin (αSMA, red) in the airway wall of HDM-exposed mice (black arrows). H Immunostaining for the pericyte markers NG2 (green) and PDGFRβ (red) revealed pericyte uncoupling from the pulmonary vasculature of HDM-exposed mice (white arrows). I Lung tissue was digested and pericytes were obtained by magnetic sorting, then subjected to a Transwell assay using fetal calf serum (FCS) as the chemoattractant. n = 10 per group, representative of four independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001. Scale bar 25 µm. AW: airway; BV: blood vessel; HDM: house dust mite; PBS: phosphate-buffered saline