Research advances in immune repertoire and high-throughput sequencing in primary biliary cholangitis / 临床肝胆病杂志

Primary biliary cholangitis (PBC) is an autoimmune liver disease with unclear pathogenesis.The amino acid composition and sequence in the complementarity-determining region 3 of T cell receptor (TCR) and B cell receptor (BCR) are highly diverse, which forms a large antigen recognition receptor repertoire, i.e., immune repertoire.In recent years, second-generation sequencing techniques combined with multiplex PCR or amplicon rescue multiplex PCR have been used to study the features of immune repertoire in PBC patients, and it has been found that PBC patients have clonal expansion of specific CD4+ T lymphocytes, clonal diversity of B lymphocytes, somatic hypermutation, and reduction in class switch, as well as increase in clonal diversity after treatment with ursodeoxycholic acid.These findings need to be confirmed by large-scale in vivo and in vitro studies and different immune repertoire research strategies.

Characteristics of IgH-CDR3 repertoire of peripheral B cells in a patient with primary biliary cholangitis: a preliminary study using high-throughput sequencing / 中华肝脏病杂志

Objective@#To analyze the characteristics of immunoglobulin heavy chain complementarity-determining region (IgH-CDR3) repertoire of peripheral B cells in a patient with primary biliary cholangitis (PBC) and to investigate the diversity of the immune system.@*Methods@#Arm-PCR was used to amplify the IgH-CDR3 region of circulating B cells isolated from a PBC patient, and high-throughput sequencing was used to analyze the amplified product. The characteristics of immune repertoire were analyzed by bioinformatics.@*Results@#In total, 329219 sequence reads were generated from the sample, with 325540 total CDR3 sequences and 72774 distinct CDR3 sequences, and the D50 of IGH-CDR3 was 7.7. The dominant CDR3 length of the sample was 45 nt (9.6%); the N addition with the highest frequency ranged from 13 to 14 nt (5.25%); the J trimming with the highest frequency was 0 nt (12.7%); the three most frequent V alleles were V4-59 (9.5%), V3-23 (8.1%), and V1-69 (6.4%).@*Conclusion@#The diversity of IgH-CDR3 repertoire is relatively low in this patient with PBC, with several B-cell clonal expansions. The specificity needs to be further verified after increasing the sample size.