Figure 1. Morphological analysis and Ig secretion.
On D0, CLL B-cells were stimulated with PMA and CD40L, in combination with the cytokines IL-2, IL-10 and IL-15. On D4, cells were harvested and incubated with IL-2, IL-6, IL-10 and IL-15 for 3 days. A. Upper panel: May-Grunwald-Giemsa staining of CLL B-cells on D0 and stimulated cells on D7. Original magnification: x1000. Scale bar, 5 μm. Lower panel: Cell size and granularity were measured by flow cytometry. Relative cell size was determined by assessing the light diffracted at small angles (detected as forward scatter). Granularity is proportional to the light diffracted at large angles (detected as side scatter). Results are represented as box-and-whisker (min to max) plots (the “+” sign indicate the mean). B. Culture supernatants were harvested on D7. IgM, IgG and IgA secretion was assessed with an ELISA. The results for six experiments are expressed as box-and-whisker (min to max) plots (the “+” sign indicates the mean (in μg per 106 cells)) for IgM secretion and as the mean ± SEM (in μg per 106 cells) for IgG and IgA secretion. Statistical significance was calculated using the Wilcoxon test: *p < 0.05, **p < 0.01, ns, not significant.