Transitional B cells from human cord blood and peripheral blood mononuclear cells.

Transitional B cells were FACS-sorted based on expression of surface markers, CD19, CD24, CD38 and staining by Rhodamine 123. (A) Total cells were gated based on lymphocyte morphology, followed by gates on viable CD19+CD3- cells, and finally Rhodamine 123 fluorescence. (B and C) Expression of sIgD, CD21, CD23, CD5, and sIgM are shown as histogram plots of median fluorescence intensity (MFI) for high (B) and low (C) Rhodamine 123 staining B cells. (D) Freshly isolated PBMCs were labeled with fluorochrome-conjugated antibodies against CD19, CD24, CD38, CD21, CD23, IgD, and IgM. Total cells were gated based on lymphocyte morphology, followed by viable CD19+ cells, and CD38hi CD24hi expression. Expression of CD23, sIgM, CD21, and sIgD by these CD38hi CD24hi transitional B cells are shown as MFI histogram plots (shaded histograms are isotype controls).