Analysis of BCR CDR3 repertoire of peripheral blood with HBsAb titer higher than 10 000 mU/ml / 中国免疫学杂志

ABSTRACT

Objective:To acquire potential HBsAb sequences,we have analyzed the BCR CDR3 repertoire of the peripheral blood with HBsAb titer higher than 10 000 mU/ml,which could provide a data basis for follow-up study.Methods:Genomic DNA of pe-ripheral blood mononuclear cells was extracted from samples with HBsAb titer higher than 10 000 mU/ml.We have adopted Illumina Solexa high-throughput sequencing technology of the Adaptive Biotechnologies ImmunoSEQ platform to acquire sequence data.IMGT/High V-QUEST was used to preliminary analyze our sequence data,including usage of IGHV,IGHJ and IGHD gene subgroups,IGHV-J matching,distribution of CDR3 amino acid (AA) length and usage of total CDR3 AA.And these sequences were compared with the HBsAb sequences from NCBI database.Results:Experimental samples have highly selected gene subgroups IGHV3,IGHV4,IGHJ4, IGHJ6,IGHD3,IGHD6,and IGHV3-J4 pairing,IGHV3-J6 pairing.The AA length distributions of CDR3 region were normal distribution with the length of 14/15 AA as the midline.In the regard to amino acid usage in CDR3 region, each sample prior used Alanine, Tyrosine,Glycine,Alanine,Aspartic acid and Serine.The amino acid usages of 107,108,109,113,114 positions were diversified but 105,106,115,116,117 positions taking conservative amino acids usages.We have found 48 unique sequences that have same IGHV, IGHJ and CDR3 AA length with the HBsAb sequences from NCBI database.Conclusion:There were almost the same characteristics of BCR CDR3 repertoire of the peripheral blood with HBsAb titer higher than 10 000 mU/ml.The 48 unique sequences provided a solid data basis for the follow-up study.