Figure 3.

PolyP levels are lower in primary normal plasma cells and other B-cell populations. (A) Flow cytometry analysis of B-cell populations isolated from human tonsils. Cells were analyzed after simultaneous labeling with anti-CD38 phycoerythrin and anti-CD20 fluoroscein isothiocyanate antibodies. The dot plot represents a typical pattern of CD20/CD38 expression in human tonsil B cells, in which different subsets are indicated: plasma cells (PC), germinal center (GC) and mantle zone (MZ) B cells. The measurements from one representative sample of five are shown. (B) Fixed samples of labeled tonsil B cells, as described in panel (A), were incubated in the absence (Control) or presence of DAPI (+DAPI). Cell fluorescence of gated PC in the FL3 channel was determined. The geometric mean fluorescence intensities (MFI) are indicated. The measurements from one representative sample of five are shown. (C) Differences in the geometric MFI (ΔMFI) in the FL3 channel, after the addition of DAPI, for the different B-cell subsets: plasma cells (PC), germinal center (GC) and mantle zone (MZ) B cells. Results represent the mean ± SD of the measurements made in the samples of five patients. The asterisk indicates significant differences in comparison with data from U266 HMCL and primary MC, determined by the t test (P<0.05).