Transcriptome analysis of mouse IgG1 memory B cell subsets

IgE plays an essential role in the pathogenesis of allergies and its production is strongly regulated. A transient IgE germinal center phase and lack of IgE memory cells limit the generation of pathogenic IgE, but this can be overcome by sequential switching of IgG1 cells to IgE. We investigated which population of IgG1 cells can give rise to IgE-producing cells in memory responses. We identified three populations of IgG1 memory B cells (DP:CD73+CD80+, SP:CD73-CD80+, DN:CD73-CD80-) that generate IgE plasma cells of high or low affinity, but none gives rise to IgE germinal center cells or IgE memory cells. The two memory IgG1 populations differ however in their ability to differentiate into IgG1 plasma cells and germinal center cells, and to expand the IgG1 memory B cell pool. To explore the molecular mechanisms that may explain the distinct functions of IgG1 memory B cell subsets we compared their expression by transcriptome analysis using next generation sequencing. mRNA profiles of quadruplicates of double positive (DP:CD73+CD80+), single positive (SP:CD73-CD80+), double negative (DN:CD73-CD80-) IgG1 memory B cells along with IgG1 germinal center (GC) cells and naïve B cells were generated using Illumina high throughput sequencing.