Transcriptional profiling of mast cell and basophil responses to differential stimuli identifies unique gene signatures.

Abstract

Abstract Mast cells (MC) and basophils (BΦ) are key effector cells in allergy that are developmentally related. Functionally, they both release mediators like histamine and granule proteases. However, studies also suggest that MC and BΦ have non-redundant roles in allergic diseases. Their ability to respond to IL-33—an epithelium-derived cytokine that helps initiate allergic inflammation—is not well understood. To fully characterize the transcriptional responses and heterogeneity of MC and BΦ, we performed large-scale comparative microarrays of bone marrow-derived mast cells (BMMCs) and basophils (BMBs) either at rest, upon IgE activation, or upon IL-33 activation. Hierarchical clustering demonstrated that BMMCs had activation-specific transcriptional signatures. IgE-crosslinking upregulated 1803 unique genes including Ccl7, Fxyd6, and Cd33; while IL-33 stimulation induced 1918 genes including Il1b, Cd72, and Tnfaip2. Focused bioinformatics pathway analysis demonstrated IgE-activation aligned with pathways relating to complement activation and CD137 signaling, while IL-33 initiated responses in the NF-κB and IL-10 signaling pathways. Furthermore, BMBs activated via IgE-crosslinking induced type 2 immune response genes like Il2, Il4, Ccl17 and Il13 which were surprisingly absent in IL-33 stimulated BMBs. Further analysis revealed cell-specific transcriptional signatures with 4360 genes that were significant in BMBs but not in BMMCs after IgE activation, and 1645 after IL-33 stimulation. Here we show that MC and BΦ have cell-specific and activation-specific transcriptional responses, and our data suggest novel gene networks and pathways that may shape how the immune system responds to allergens and innate cytokines.