An IgE+ B-cell is largely clonally related to an IgG1+ B-cell in allergic patients
In total, three VDJ gene transcripts were successfully amplified from IgE+ B-cells, representing the smallest isotype group when disregarding IgG3 and IgG4. Where two VDJ gene transcripts of IgE+ B-cells derived from one tolerant donor were not closely related to another amplified VDJ gene transcript derived from the same donor, the VDJ gene transcript of one IgE+ B-cell originating from an allergic donor (Pt-10) was nearly identical to the gene transcript of an IgG1+ B-cell derived from an unrelated allergic donor (Pt-04). These two sequences differed only in one silent mutation within the FR4 region and one non-silent mutation within the FR2 region, pointing towards clonal relationship between IgE+ and IgG1+ B-cells and conserved clones between unrelated donors (Figure 3C). This finding supports the hypothesis that the IgE memory is stored in IgG1+ B-cells and to lesser extent in B-cells of another isotype20, 21.