Rationale, methods, and assays for identifying human and non-human primate taste specific genes and use thereof in taste modulator and therapeutic screening assays
This invention relates to novel rationale and methods for identifying human and primate taste-specific genes, including genes involved in salty taste perception, especially human salty taste perception, but also genes involved in sweet, bitter, umami, and sour taste perception, and genes involved in other taste cell or taste receptor related activities such as digestive function and digestive related diseases, taste cell turnover, immunoregulation of the oral and digestive tract, and metabolic regulation such as in diabetes and obesity, the genes identified using these methods, and assays for identifying taste modulators (enhancers or blockers) and potential therapeutics using these genes. These compounds have potential application in modulating (enhancing or blocking) taste perception, especially salty taste perception and as potential therapeutics. In addition, this invention relates to novel methods for identifying taste-specific genes that can be used as markers for different taste cell types, including sweet, bitter, umami, sour, salty, and other taste cells in mammals as well as assays that measure the activity of the sweet, bitter, umami, or sour receptor in the presence of these genes to identify modulators of sweet, bitter, umami, and sour taste and to identify therapeutics especially for treating digestive or metabolic disorders, taste loss, and oral infections. Particularly, the genes identified herein and antibodies or oligos thereto can be used as markers to identify and/or purify specific taste cells e.g., from taste cell suspensions by use of FACS or magnetic bead cell selection or other known cell purification and isolation procedures.
1. A method of isolating T1R3 expressing cells comprising:
(i) contacting an impure population of cells containing taste cells with a probe that specifically detects taste cells which express GPR113;
(ii) separating the detected GPR113 expressing taste cells from the impure cell population;
(iii) further detecting among the GPR113 expressing taste cells a subpopulation of taste cells that further express T1R3; and
(iv) isolating said subpopulation of taste cells which express both GPR113 and T1R3.
2. The method of claim 1 , wherein said isolated cells further express TRPM5.
3. The method of claim 1 , wherein said taste cells are immature.
4. The method of claim 1 , wherein said detected cells are separated by FACS or magnetic bead cell separation.
5. The method of claim 1 , wherein said taste cells are human or macaque taste cells.
6. A purified taste cell population, wherein the purified taste cells all express GPR113 and T1R3.
7. The purified cell population of claim 6 , wherein said isolated cells further express TRPM5.
8. The purified cell population of claim 6 , wherein said taste cells are immature.
9. The purified cell population of claim 6 , wherein purified taste cells are human or macaque taste cells.