Chitinases and Transforming Growth Factor Beta (TGFB) in Human Asthma

This is a cross-sectional study in patients with asthma and healthy controls in which we will analyze how the expression or function of CHIT1, AMCase, and TGFb pathway genes in the asthmatic airway is affected by genetic variation in these genes. We propose detailed phenotyping of the asthmatic subjects and the healthy controls, including collection of induced sputum, exhaled air and detailed physiologic measures including measures of airflow, lung volumes, and methacholine responsiveness as well as collection of airway cells and tissues by bronchoscopy. We will determine the relative expression of CHIT1 and AMCase in specific lung compartments (large airways, small airways, epithelial cells, macrophages) and the effects of genetic variants in CHIT1 and AMCase on expression of splice variants and levels of chitinase activity in the airway. These human samples will also allow us to determine if any of the multiple TGFb pathway genes analyzed show differential expression in the lung in asthma.