Association between genetic variation in the gene for death-associated protein-3 (DAP3) and adult asthma

Lung epithelium plays a central role in modulation of the lung inflammatory response, and lung repair and airway epithelial cells are targets in asthma and viral infection. Activated T lymphocytes release cytokines such as interferon-gamma (IFN-γ) that induce apoptosis, or programmed cell death, of damaged epithelial cells. Death-associated protein-3 (DAP3) is involved in mediating IFN-γ-induced cell death. To assess the possible involvement of genetic variants of DAP3 with asthma, we searched for single-nucleotide polymorphisms (SNPs) in the gene and conducted a case-control study with 1,341 subjects. We found a strong association between bronchial asthma (BA) in adults (P = 0.0051, odds ratio = 1.87, 95% CI= 1.20-2.92), whereas no association was found with childhood asthma. The tendency was more prominent in patients with higher serum total immunoglobulin E (IgE) (>250IU/ml) (P = 0.00061, odds ratio = 2.40, 95% CI= 1.44-4.00). DAP3 was expressed in normal bronchial epithelial cells, and the expression was induced by IFN-γ. These results indicated that specific variants of the DAP3 gene might be associated with the mechanisms responsible for adult BA and contribute to airway inflammation and remodeling.