Vitamin D Treatment Modulates Organic Dust–Induced Cellular and Airway Inflammatory Consequences

Exposure to organic dusts elicits airway inflammatory diseases. Vitamin D recently has been associated with various airway inflammatory diseases, but its role in agricultural organic dust exposures is unknown. This study investigated whether vitamin D reduces organic dust–induced inflammatory outcomes in cell culture and animal models. Organic dust extracts obtained from swine confinement facilities induced neutrophil chemokine production (human IL‐8, murine CXCL1/CXCL2). Neutrophil chemokine induction was reduced in human blood monocytes, human bronchial epithelial cells, and murine lung slices pretreated with 1,25‐(OH) 2 D 3 . Intranasal inhalation of organic dust extract induced neutrophil influx, and CXCL1/CXCL2 release was also decreased in mice fed a relatively high vitamin D diet as compared to mice fed a low vitamin D diet. These findings were associated with reduced tracheal epithelial cell PKCα and PKCε activity and whole lung TLR2 and TLR4 gene expression. Collectively, vitamin D plays a role in modulating organic dust–induced airway inflammatory outcomes. © 2012 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:77‐86, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21467