Differences in the transcriptomes of IgMhigh and IgMlow human memory B cells

We have previously shown that circulating human CD19+CD27+ IgMhigh IgDlow B cells are phenotypically and functionally different compared with CD19+CD27+ IgMlow IgDhigh B cells. Here, we compare their transcriptomes. IgMhigh and IgMlow subsets of human CD27+ B cells were FACS purified from blood samples of four volunteers and RNA was extracted and processed for hybridization to the Affymetrix Human Clariom D Assay to compare their transcriptomes. The experiment is comprised of 16 Human Clariom D arrays, profiling RNA obtained from B cells from the blood of four healthy volunteer donors (39, 40, 41, and 42). Five populations of B cells were FACS purified from each donor: Naïve (IgD+IgM+CD27-), Switch (IgD-IgM-CD27+), IgMonly (IgD-IgM+CD27+), IgMhigh (IgD+IgM++CD27+) and IgMlow (IgD+IgM+CD27+). For volunteer 40 only the IgMlow population was included. The transcriptome from IgMlow was compared with IgMhigh and simultaneously the transcriptome of both populations were compared with other populations of B cells as controls.