Role of Taste Receptors in Innate Immunity and Oral Health

Taste receptors are receptor proteins that detect ligands belonging to the 5 taste modalities: sweet, bitter, sour, salty, and umami. Taste receptors are not restricted to taste cells in taste buds; rather, they are distributed throughout the entire body. For example, solitary chemosensory cells (SCCs) and tuft cells express taste signal proteins and are present in several mucosae. In the airways, SCCs sense bacteria, allergens, viruses, and noxious stimuli and drive evasive behavior, neuroinflammation, and antibacterial responses. In the gut, tuft cells detect helminth infection and bacterial dysbiosis and initiate type II immune responses characterized by tissue remodeling. In the gingiva, SCCs detect oral pathogenic bacteria, evoke innate immune responses and release antimicrobial compounds in the epithelium, and regulate the microbiome composition. This review summarizes the most recent research on extragustatory taste receptors and their function in antibacterial defense. We also discuss how these findings have provided insights into the development of potential therapeutic strategies for mucosal bacterial infection and dental diseases.

Biocide triclosan impairs byssus formation in marine mussels Mytilus galloprovincialis

The effects of the biocide Triclosan, used in personal care products and known as a common environmental contaminant, on byssal apparatus were studied in the marine mussel Mytilus galloprovincialis. Experimental evidences indicated that an exposure for 7 days at a concentration of 10 μg/L induced marked alterations in the byssus gland resulting in a significant delay in byssus regrowth and in a decrease in threads resistance to traction. Such alterations in animals exposed to tidal and waves action would cause a significant loss in ecological fitness and severely impact on mussel survival. Triclosan release in coastal environments therefore should be more carefully monitored to prevent drastic consequences.