T-cell and B-cell repertoire diversity are selectively skewed in children with idiopathic nephrotic syndrome revealed by high-throughput sequencing

Background Clinical studies suggest that the dysfunction of T cells and B cells may play an essential role in the pathogenesis of idiopathic nephrotic syndrome(INS),but laboratory evidence is lacking.Therefore,this study explored T-cell receptor(TCR)and B-cell receptor(BCR)profiling in children with idiopathic nephrotic syndrome.Methods High-throughput sequencing technology was used to profile the TCR and BCR repertoires in children with INS.Peripheral blood was collected from ten INS patients,including five vinculin autoantibody-positive patients and five vin-culin autoantibody-negative patients,before and after treatment.TCR and BCR libraries were constructed by 5'-RACE and sequenced by a DNBSEQ-T7 sequencer,and sequence analyses were performed using ReSeqTools,FastP,MiXCR,and VDJtools.Results The TRA(T-cell receptorα),TRG(T-cell receptor y),and IGH(immunoglobulin heavy chain)repertoires of the INS group were occupied by highly abundant clonotypes,whereas small clonotypes occupied the healthy group,especially TRA.A significant increase in the Shannon-Weaver index was observed for the TRA and TRG repertoires after treatment in vinculin autoantibody-negative patients,but a significant increase in the IGH repertoire after treatment was observed in vinculin autoantibody-positive patients.The frequency of some V-J pairs was significantly enriched in steroid-sensitive nephrotic syndrome patients.The usage frequency of the V and J genes was skewed in patients,which seemed not related to immunosuppressive therapy.However,after effective treatment,dynamic changes in the size of the individual clonotype were observed.Conclusion T-cell and B-cell immunity contribute to the pathogenesis of different INSs.