Fig. 2.

The CMP^FcεRI+ fraction in the bone marrow has mast cell potential. (a-c) Flow cytometry analysis of CMP^FcεRI-, CMP^FcεRI+ and GMP cells cultured with rhIL-3 and rhIL-6 up to 21 days. (a) Flow cytometry plots of representative cultures, showing the percentages of CD117⁻, CD117⁺, and CD117^hi cells in each plot. (b) Percentage of CD117^hi FcεRI⁺ cells at days 5–6. (c) Two of the samples in panel b were followed for up to 21 days under culture with rhIL-3 and rhIL-6. The percentage of CD117^hi cells was analysed on days 5–6, 13–14, and 19–21. (d) Representative images of CMP^FcεRI-, CMP^FcεRI+ and GMP cells cultured with rhIL-3 and rhIL-6 for 5 days, followed by rhIL-6 and SCF until day 13–14, showing tryptase staining (red) and granules by May-Grünwald Giemsa (MGG) staining. (e) Quantification of tryptase-positive cells at days 13–14 and 17–21. CMP^FcεRI-, CMP^FcεRI+ cells were analysed from Ctrl29, SM28, SM32, SM33, and MDS30. GMPs were analysed from SM32 and SM33. The bars and lines in panel b, c and d represent the means ± SEM. One-way ANOVA with Tukey's multiple comparison was used in panel b, **P < .01, ***P < .001. Images were captured using an Olympus XC10 camera (Olympus, Tokyo, Japan). The image width corresponds to 29 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)