Expression for α, β, and γ chains of FcεRI mRNA by RT-PCR.

Representative results of RT-PCR analysis for α, β, and γ chains of FcεRI and β-actin mRNA are shown. CB-derived MCs (A) expressed less α but not β or γ chain than PB-derived MCs (B). The density and area of these blots were quantitatively determined by using NIH Imagesoftware version 1.62. The expression ratio of FcεRIα to β-actin in CB-derived MCs was 0.22 ± 0.03 (n = 6), whereas that in PB-derived MCs was 1.76 ± 0.31 (n = 3; P < .05), when the cells were pretreated for 48 hours with IgE but not with IL-4. The ratios of FcεRIβ to β-actin and FcRγ to β-actin in CB-derived MCs were, respectively, 0.16 ± 0.05 and 0.21 ± 0.03 (n = 6). Those in PB-derived MCs were 0.21 ± 0.03 and 0.29 ± 0.04 (n = 3; not significant). Similar results were obtained in IL-4–primed MCs, though FcεRIα to β-actin ratio was enhanced by the cytokine in CB-derived MCs (0.55 ± 0.15; n = 6;P < .05).