Figure 5: FcεRIβ and MS4A6A exhibit redundancy in FcεRIα surface expression.

A-F Following the same approach as with FcεRIβ, splice switching oligonucleotides (SSO) were successfully employed to eliminate the expression of the full length variant of MS4A6A and splicing was switched to the truncated form. Exon skipping was rapidly and selectively achieved in both LAD2 MCs and primary human MCs derived from umbilical cord blood (CMBCs) and lung (HLMCs). (A) Selective and efficient exon skipping of both FcεRIβ and MS4A6A shown by RT-PCR of LAD2 MCs; (B) Western blot data demonstrating that full length FcεRIβ and MS4A6A proteins are reduced after exon skipping (arrows) after 24 hours (left panels), 48 hours (middle panels) and 5 days (right panels). B actin was used as a loading control; (C) Total number of viable LAD2 cells after treatment with a standard control, FcεRIβ and MS4A6A SSOs for exon skipping; (D) The percentage of viable cells after SSO treatment shows little effect; (E) Flow cytometric analysis of surface expression of FcεRIα in LAD2 cells treated with SSOs for individual and combined exon skipping; (F) QRT-PCR of FcεRI α and γ subunits expression in LAD2 cells treated with FcεRIβ or MS4A6 SSOs. Black bars represent standard control oligonucleotide. Blue bars represent FcεRIβ SSO. Green bars represent MS4A6A SSO. Red bars represent FcεRIβ + MS4A6A SSOs. Data are the mean±SEM from at least three independent experiments. **P < 0.01, **** P < 0.0001, n.s. = not significant, ANOVA with post-test.