Taste Receptors: Regulators of Sinonasal Innate Immunity

Abstract

Taste receptors in the oral cavity guide our preferences for foods, preventing toxic ingestions and encouraging proper nutrient consumption. More recently, expression of taste receptors has been demonstrated in other locations throughout the body, including the airway, gastrointestinal tract, pancreas, and brain. The extent and specific roles of extraoral taste receptors are largely unknown, but a growing body of evidence suggests that taste receptors in the airway serve a critical role in sensing bacteria and regulating innate immunity. This review will focus on the function of bitter and sweet taste receptors in the human airway, with particular emphasis on T2R38, a bitter taste receptor found in sinonasal ciliated cells, and the bitter and sweet receptors found on specialized sinonasal solitary chemosensory cells. The importance of these novel taste receptor‐immune circuits in the human airway and their clinical relevance in airway disease will also be reviewed.

In Vivo Biofilm Formation, Gram‐Negative Infections and TAS2R38 Polymorphisms in CRSw NP Patients

“…Previous studies demonstrated that individuals with a nonfunctional T2R38 allele having significantly blunted NO and ciliary responses following exposure to gram‐negative quorum‐sensing molecules are infected with gram‐negative bacteria, such as Pseudomonas aeruginosa , and develop CRS. Therefore these individuals are more likely to need surgery than those with functional receptor alleles …”

“…Therefore these individuals are more likely to need surgery than those with functional receptor alleles. 8,13 Based on this hypothesis, we compared the microbiology of sinonasal mucosa of PAV/PAV patients to those with other genotypes. Our findings confirmed data in the literature in which gram-negative infections are mainly associated with the AVI haplotype.…”

“…For example, activation of the bitter taste receptor TAS2R38 is associated with innate bacterial defense mechanisms. These generate the calcium‐dependent production of nitric oxide (NO), which is known as a bactericidal mediator and leads to increased mucociliary clearance …”

“…These generate the calcium-dependent production of nitric oxide (NO), which is known as a bactericidal mediator and leads to increased mucociliary clearance. 8,9 Genetic variations of the bitter taste receptor TAS2R38, expressed in the cilia of the human sinonasal epithelial cells (HSEC), seem to be associated with susceptibility to upper respiratory tract infections and CRS. [10][11][12][13][14] Polymorphisms in the TAS2R38 gene produce changes in the amino acid residues at positions 49, 262, and 296, generating two common haplotypes: 1) the functional, "taster," allele of the TAS2R38 encodes proline, alanine, and valine (PAV); and 2) the nonfunctional, "nontaster," allele of the receptor encodes alanine, valine, and isoleucine (AVI), respectively.…”

Relationship between chronic rhinosinusitis exacerbation frequency and asthma control

“…Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinus mucosa that causes a significant detriment to quality of life, results in billions of dollars in related costs, and has a largely unknown pathophysiology, although multiple possible mechanisms have been proposed . The natural history of CRS includes chronic nasal and extranasal symptoms as well as acute and transient increases in symptoms referred to as acute exacerbations of CRS (AECRS) .…”