Bioinformatic analysis of antibody repertoire development in response to influenza vaccination
Objective 
To analyze the immunogenomic characteristics of antibody repertoire in response to influenza vaccine in order to provide a theoretical basis for further development of antibody. 
 
 
Methods 
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 vaccination. 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 usage altered obviously and IGHV3-7-derived antibody had a significant response to the vaccine. Response intensity 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. 
 
 
Key words: 
Vaccine; Antibody repertoire; B cell; Complementarity-determining region 3 (CDR3); Immune response