Early postnatal exposure to allergen and ozone leads to hyperinnervation of the pulmonary epithelium.
Airway injury in infant monkeys exposed to ozone and/or house dust mite allergen (HDMA) is associated with a loss of epithelial innervation. In this study, we evaluated for persistence/recovery of the altered epithelial innervation. Thirty-day-old rhesus monkeys were exposed to repeated episodes of HDMA and/or ozone from 1 to 6 months of age and subsequently allowed to recover for 6 months in the absence of further ozone exposure and/or minimal HDMA challenge (sufficient to maintain allergen sensitization). At 1 year of age, nerve density in intrapulmonary airways was immunohistochemically evaluated using antibodies directed against protein gene product 9.5. Hyperinnervation and irregular epithelial nerve distribution was observed in both HDMA- and ozone-exposed groups; most prominent alterations were observed in animals exposed to HDMA plus ozone. Therefore, while adaptive mechanisms exist that re-establish epithelial innervation following cessation or diminution of exposure to HDMA and/or ozone, the recovery is associated with persistent proliferative mechanisms that result in hyperinnervation of the airways.
Kajekar
Radhika
R
Center for Comparative Respiratory Biology and Medicine, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. rkajekar@ucdavis.edu
Pieczarka
Emily M
EM
Smiley-Jewell
Suzette M
SM
Schelegle
Edward S
ES
Fanucchi
Michelle V
MV
Plopper
Charles G
CG
D000485:Allergens / Q000633:toxicity*; D000818:Animals; D004848:Epithelium / Q000187:drug effects / Q000294:innervation; D006967:Hypersensitivity / Q000503:physiopathology*; D007150:Immunohistochemistry; D008168:Lung / Q000187:drug effects* / Q000294:innervation*; D008253:Macaca mulatta; D008297:Male; D018613:Microscopy, Confocal; D010083:Oxidants, Photochemical / Q000633:toxicity*; D010126:Ozone / Q000633:toxicity*; D039981:Pyroglyphidae / Q000276:immunology
D000485:Allergens; D010083:Oxidants, Photochemical; D010126:Ozone