Profile of EP receptors expressed by hMCs. (A) Total RNA was extracted from 8-week-old hMCs derived in the presence of SCF, IL-6, and IL-10, and samples were subjected to RT-PCR with primers specific for each indicated receptor. Positive control (from genomic DNA) and negative control (from non-reverse-transcribed RNA) are displayed. (B) Eight-week-old hMCs were fixed, permeabilized, and stained with affinity-purified polyclonal antibodies specific for the indicated receptor proteins. IL-4 priming did not change the levels of expression of any EP receptor (not shown). Bold tracings indicate EP receptors; light tracings, control IgG. MFI indicates mean fluorescence intensity. RT-PCR data in panel A and flow cytometry in panel B are from experiments representative of 8 and 3 performed, respectively, each using the cells of a different donor.