TCRβ repertoire of CD4+ and CD8+ T cells is distinct in richness, distribution, and CDR3 amino acid composition

[摘要] TheTCRrepertoireservesasareservoirofTCRsforrecognizingallpotentialpathogens.TwomajortypesofTcells,CD4+andCD8+,thatusethesamegeneticelementsandprocesstogenerateafunctionalTCRdifferintheirrecognitionofpeptideboundtoMHCclassIIandI,respectively.However,itiscurrentlyuncleartowhatextenttheTCRrepertoireofCD4+andCD8+Tcellsisdifferent.Here,wereportacomparativeanalysisoftheTCRβrepertoiresofCD4+andCD8+Tcellsbyuseofa5′rapidamplificationofcDNAends–PCR–sequencingmethod.WefoundthatTCRβrichnessofCD4+Tcellsrangesfrom1.2to9.8×104andisapproximately5timesgreater,onaverage,thanthatofCD8+Tcellsineachstudysubject.Furthermore,therewaslittleoverlapinTCRβsequencesbetweenCD4+(0.3%)andCD8+(1.3%)Tcells.FurtheranalysisshowedthatCD4+andCD8+TcellsexhibiteddistinctpreferencesforcertainaminoacidsintheCDR3,andthiswasconfirmedfurtherbyasupportvectormachineclassifier,suggestingthattherearedistinctanddiscernibledifferencesbetweenTCRβCDR3inCD4+andCD8+Tcells.Finally,weidentified5–12%oftheuniqueTCRβsthatshareanidenticalCDR3withdifferentvariablegenes.Together,ourfindingsrevealthedistinctfeaturesoftheTCRβrepertoirebetweenCD4+andCD8+TcellsandcouldpotentiallybeusedtoevaluatethecompetencyofTcellimmunity...

[学科分类] 生理学

[关键词] Human;TCR diversity;supervised learning;RACE;RNAseq