Evidence for preferential Ig gene usage and differential TdT and exonuclease activities in human naïve and memory B cells

Abstract

Memory B cells and the antibodies they encode are important for protective immunity against infectious pathogens. Characterization of naïve and memory B cell antibody repertoires will elucidate the molecular basis for the generation of antibody diversity in human B cells and the optimization of antibody structures that bind microbial antigens. In this study we aimed to investigate the influence of antigenic selection on the antibody genes of the two CD27 + memory B cell subsets, comparing them with the naïve repertoire in CD27 − cells. We analyzed and compared the Ig heavy chain gene transcripts in three recently defined circulating naïve and memory B cell subsets

Immunodominance of the VH1–46 Antibody Gene Segment in the Primary Repertoire of Human Rotavirus-Specific B Cells Is Reduced in the Memory Compartment through Somatic Mutation of Nondominant Clones

“…Consistent with previous studies of randomly selected naive or memory B cells, analysis of H chain CDR3 regions suggested significantly shorter CDR3 lengths in RV-specific IgD ϩ CD27 ϩ memory B cells than in naive cells (24,25). As shown in Fig.…”

High-throughput antibody sequencing reveals genetic evidence of global regulation of the naïve and memory repertoires that extends across individuals

“…These data support emerging evidence that the IgM memory repertoire is genetically distinct from the IgG memory repertoire and that this difference is likely the result of different stimuli. 9,11 Finally, the three Circos plots reveal the increased oligoclonality of both memory subsets compared with naïve. The colored ribbons in each plot represent V H -J H pairings that comprise at least 1% of the total subset repertoire.…”

“…The primers were selected for their ability to produce accurate, reproducible amplification of both naïve and mutated antibody repertoires, 12,13 and the variable gene use of our repertoire closely matched repertoire analysis in which amplification was performed on single B cells. 9 prominence of each V(D)J recombination within the repertoire of each cell subset (Figures 1a-c). These plots revealed a large number of trends that were apparent only when analyzing the repertoire in the context of complete V(D)J recombinations.…”

“…Despite the tendency of pathogen-specific antibody responses to exhibit biased germline gene repertoires, [16][17][18] the frequency of gene family use in naïve and memory subsets is remarkably consistent across individuals. 9,11 Further, alteration of this gene family homeostasis in the circulating B-cell repertoire is associated with disease states. [19][20][21][22] In recent work, long-lived plasma cells were shown to contain significantly fewer autoreactive B cells than the circulating IgG memory subset, and this difference was attributed to differential repertoire regulation within the two subsets.…”

“…8 Previous analysis of the antibody gene repertoire in peripheral blood B-cell subsets did not detect significant differences in germline V, D or J gene segment usage between the naïve and memory populations. 9 This finding was somewhat surprising, as it was expected that the memory subset might contain an altered germline gene repertoire that was biased by antigen selection. Although more narrowly focused work was previously able to identify differential J H gene use in memory subsets, 10 this study only analyzed the fraction of sequences that contain the V H 6 gene segment and not the total repertoire.…”