ABSTRACT
Objective To analyze the immunogenomic characteristics of antibody repertoire in re-sponse to influenza vaccine in order to provide a theoretical basis for further development of antibody. Meth-ods Based on a time-series immunoglobulin heavy chain ( IGH) repertoire sequencing dataset, we analyzed the immunogenomic characteristics of antibody repertoire in response to trivalent influenza vaccine ( TIV ) from three aspects which included the features in complementarity-determining region 3 ( CDR3 ) , antibody mutation and VDJ usage. Results The frequency of antibody mutation increased significantly upon vaccina-tion. Analysis of the CDR3 region indicated that polar and aromatic amino acids had a higher preference. The length of CDR3 region in naive B cells followed a normal distribution, while specific CDR3 sequences with 15 to 18 amino acids in length occupied a dominant position after vaccination. In addition, the VDJ us-age altered obviously and IGHV3-7-derived antibody had a significant response to the vaccine. Response in-tensity reached the peak on day 7 and gradually weakened over time. Conclusion Antibody repertoire evolves dynamically to express specific antibody upon vaccination and the characteristics of immune responses at sequence level could be used to evaluate their effectiveness.
ABSTRACT
Objective:To establish a method of multi-PCR to amplify the complete DNA sequence (CDS) of TCR ? and ? chain of the antigen-specific T lymphocytes in local pathologic specimen of active pulmonary tuberculosis patients, and to analyze ?/? T cell receptor gene rearrangement and CDR3 repertoire.Methods:The lymphocytes in bronchoalveolar lavage (BAL) of active pulmonary tuberculosis patients were separated. Following total RNA extraction, cDNA synthesis, Multi-PCR, recombinant clones construction, and sequencing, the CDS of TCR ? and ? chains from these lymphocytes were analyzed by using software of DNAstar and internet TCR resources.Results:24 of ? chain CDS and 13 of ? chain CDS from 3 samples of BAL were obtained. As for TCR ? chain, AV1S2 (54%), AV12S3 (41%), and AV12S2(5%) appeared frequently. BV2(38%), BV29S1(46%), BV14(3%), and BV4S2(3%) in TCR ? chain appeared more often. There were CDR3 diversities between samples and even in the same sample by amino acid sequence analysis, but there were a few identical or similar amino acid sequences. There was the same amino acid sequence of SVGTGTLHQETQY in CDR3 region of ? chain of BAL sample No.1 and No.2; The sequence of AVRDWAGNMLT appeared in two ? chains of BAL sample No.2 and No.3; Moreover, the sequence of AV…DNN…RLM appeared in ? chains of BAL sample No.2 and No.3.Conclusion:A method of Multi-PCR is used to amplify TCR ? and ? chain CDS of tuberculosis patients. There are characteristic T cell clones to proliferate,with TCR ? and ? chain repertiore skewing in local infective focus. The sequences of CDR3 in different TCR clones are mostly different but there are a few identical or similar sequences in the same patient or even between different patients. The identical amino acid sequences of CDR3 are possibly specific for recognizing MTB polypeptide.