Fig. 5.

IL-4 + IL-10 suppresses mast cell development and survival in cultures of human umbilical cord blood cells. Erythrocyte-depleted human cord blood cells were cultured for 21 days in SCF-containing medium, with IL-4 and/or IL-10 added where indicated. On Day 21, cell number (A) and viability (B) were determined using trypan blue exclusion. Percent mast cells (C) and mast cell number (D) were determined using toluidine blue staining. Data shown are from triplicate samples harvested from one of two independent experiments that yielded similar results. *, P < .025, for all comparisons with control condition (“None”). Note that IL-4 + IL-10 also has P < .025 when compared with IL-4 or IL-10.