PTGDS and Increased total eosinophil count: To elucidate whether the poly IC-induced augmentation of airway eosinophilia depends on a mechanism via mast cell-derived PGD2, the effect of poly IC was examined for KitW/KitW-v mice that had been reconstituted with BMMCs from hPGD2S−/−mice (Figure 4B) [25].