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-gamma) that induce apoptosis, or programmed cell death, of damaged epithelial cells. Death-associated protein-3 (DAP3) is involved in mediating IFN-gamma-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) (>250 IU/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-gamma. 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.