Class I odorant receptors, TAS1R and TAS2R taste receptors, are markers for subpopulations of circulating leukocytes

Journal of Leukocyte Biology: An Official Publication of the Reticuloendothelial Society

关键词: chemosensory GPCR;    olfactory;    saccharin;    lactisole;    siRNA;    blood leukocytes;   

DOI  :  10.1189/jlb.2A0714-331RR

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

Ourcellularimmunesystemhastocopeconstantlywithfoodbornesubstancesthatenterthebloodstreampostprandially.Here,theymayactivateleukocytesviaspecificbutyetmostlyunknownreceptors.EctopicRNAexpressionoutofgenefamiliesofchemosensoryreceptors,i.e.,the∼400ORs,∼25TAS2Rbitter‐tastereceptors,andtheTAS1Rumami‐andsweet‐tastereceptordimersbywhichwetypicallydetectfoodbornesubstances,hasbeenreportedinavarietyofperipheraltissuesunrelatedtoolfactionortaste.Inthepresentstudy,wehavenowdiscovered,bygene‐specificRT‐PCRexperiments,themRNAexpressionofmostoftheClassIORs(TAS1R)andTAS2Rin5differenttypesofbloodleukocytes.Surprisingly,wedidnotdetectClassIIORmRNA.ByRT‐qPCR,weshowthemRNAexpressionofhumanchemosensoryreceptorsandtheircoworthologsinPMN,thussuggestinganevolutionaryconcept.Byimmunocytochemistry,wedemonstratethatsomeolfactoryandtastereceptorsareexpressed,onaverage,in40–60%ofPMNandTorBcellsandlargelycoexpressinthesamesubpopulationofPMN.ThemRNAexpressionandthesizeofsubpopulationsexpressingcertainchemosensoryreceptorsvariedlargelyamongindividualbloodsamples,suggestingaregulatedexpressionofolfactoryandtastereceptorsinthesecells.Moreover,weshowmRNAexpressionoftheirdownstreamsignalingmoleculesanddemonstratethatPTXabolishessaccharin‐or2‐PEA‐inducedPMNchemotacticmigration,indicatingaroleforGi‐typeproteins.Insummary,ourdatasuggest“chemosensory”‐typesubpopulationsofcirculatingleukocytes...

【 授权许可】

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