Allele-specific Expression of a Bitter Taste Receptor

This single-site, within-subject experimental basic research study is designed to analyze the hypothesis that allele-specific expression of the bitter taste receptor T2R38 in taste tissue of individuals heterozygous for the taste receptor gene TAS2R38 correlates with that in nasal epithelium, and is responsible for differences in acyl-homoserine lactone-induced respiratory defenses. Subjects will include 100 predominantly European adults without chronic rhinosinusitis who will be undergoing a sinonasal procedure for reconstructive purposes. All subjects will provide saliva samples for genotyping, from which 25 subjects heterozygous for TAS2R38 (AVI/PAV) will be identified. These individuals will be asked to complete a beverage frequency questionnaire and taste test prior to the procedure that will evaluate for a number of compounds, among them bitter ligands specific to T2R38. Their tongue will also be photographed to evaluate the anatomy of their fungiform papillae, the mushroom-like structures on the tongue which contain taste buds. Subjects will subsequently provide nasal epithelium and taste tissue, which will be processed to 1) evaluate for allele-specific expression of TAS2R38 mRNA in both the taste and nasal tissue, with the nasal tissue concurrently being cultured in an air-liquid interface system to 2) assess the AHL-induced respiratory defenses of ciliary beat frequency (CBF) and nitric oxide (NO) production. Should subjects require a subsequent sinonasal procedure for clinically-determined reasons, taste and nasal tissue will again be obtained and analyzed for TAS2R38 mRNA, allowing for 3) longitudinal evaluation of mRNA expression level.