Mast Cell FcεRI-Induced Early Growth Response 2 Regulates CC Chemokine Ligand 1–Dependent CD4+ T Cell Migration

Mast cells and basophils are developmentally related cells whose activation is a hallmark of allergy. Functionally, mast cells and basophils overlap in their ability to produce several mediators, including histamine and granule proteases, but studies have increasingly demonstrated non-redundant roles. To characterize the transcriptional heterogeneity of mast cells and basophils upon their activation, we performed large-scale comparative microarrays of murine bone marrow–derived mast cells (BMMCs) and basophils (BMBs) at rest, upon an adaptive-type activation (IgE crosslinking), or upon an innate-type activation (IL-33 stimulation). Hierarchical clustering demonstrated that BMMCs and BMBs shared specific activation-associated transcriptional signatures but differed in others, both between cell type and between activation mode. In BMMCs, IgE crosslinking upregulated 785 genes including Egr2, Ccl1, and Fxyd6, while IL-33 stimulation induced 823 genes including Ccl1, Egr2, and Il1b. Focused bioinformatics pathway analysis demonstrated that IgE activation aligned with processes such as oxidative phosphorylation, angiogenesis, and the p53 pathway. The IL-33–activated transcriptome was enriched in genes commonly altered by NF-κB in response to TNF, by IL-6 via STAT3, and in response to IFNγ. Furthermore, BMBs activated via IgE crosslinking selectively induced immune response genes Ccl1, Il3, and Il2 compared to IL-33–stimulated BMBs. Principal-component analysis revealed key cell- and activation-specific clustering. Overall, our data demonstrate that mast cells and basophils have cell- and activation-specific transcriptional responses and suggest that context-specific gene networks and pathways may shape how the immune system responds to allergens and innate cytokines.

Section: Discussionmentioning

confidence: 99%

Transcriptional Heterogeneity of Mast Cells and Basophils upon Activation

Chhiba

Hsu

Berdnikovs

et al. 2017

“…EMSA and Western blotting were performed as previously described (25). The following double-stranded oligonucleotides (Sigma-Aldrich) were used in EMSA: NFAT binding consensus sequence (N) on mouse IL-13 promoter 5′-AAG GTG TTT CCC CAA GCC TTT CCC-3′, and NF-κB binding consensus sequences on mouse IL-6 promoter 5′-TTATCAAATGTGGGATTTTCCCAT-3′.…”

Section: Methodsmentioning

confidence: 99%

“…Mice were sensitized with anti-DNP IgE and challenged with DNFB as previously described (25, 26). The thickness of the footpad or ear was measured after 24 hrs.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Calpain-1 Contributes to IgE-Mediated Mast Cell Activation

Chen

Liu

et al. 2014

Self Cite

Mast cells play a central role in allergy through secretion of both preformed and newly synthesized mediators. Mast cell mediator secretion is controlled by a complex network of signaling events. Despite intensive studies, signaling pathways in the regulation of mast cell mediator secretion remain incompletely defined. Here, we examined the role of calpain in IgE-dependent mast cell activation. IgE-mediated activation of mouse bone marrow-derived mast cells (BMMCs) enhanced calpain activity. Inhibition of calpain activity by a number of calpain inhibitors reduced IgE-mediated mast cell degranulation both in vitro and in vivo. Calpain inhibitors blocked IgE-mediated TNF and IL-6 production in vitro and reduced late-phase allergic response in vivo. Importantly, mouse calpain-1 null BMMCs showed reduced IgE-mediated mast cell degranulation in vitro and in vivo, diminished cytokine and chemokine production in vitro, and impaired late-phase allergic response in vivo. Further studies revealed that calpain-1-deficiency led to specific attenuation of IκB-NF-κB pathway and IKK-SNAP23 pathway, while calcium flux, MAP kinases, Akt, and NFAT pathway proceed normally in IgE-activated calpain-1 null mast cells. Thus, calpain-1 is identified as a novel regulator in IgE-mediated mast cell activation and could serve as a potential therapeutic target for the management of allergic inflammation.

“…HMC-1 cells were pretreated with tyrosine kinase inhibitors, PKC412 (final concentration 1 mM; Cayman Chemical, Ann Arbor, MI) and/or dasatinib (final concentration 1 mM; Synkinase, San Diego, CA) for 4 h, and then nuclear protein was extracted. EMSA was performed as previously described (27). The following synthesized double-stranded oligonucleotides (Sigma-Aldrich) were used: NFAT binding consensus sequence, 59-AAGGTGTTTCCCCA-AGCCTTTCCC-39; Egr1 binding consensus sequence, 59-GGATCCAGCG-GGGGCGAGCGGGGGGCAGCG-39; and NF-kB binding consensus sequence, 59-TTATCAAATGTGGGATTTTCCCAT-39.…”

Section: Emsamentioning

confidence: 99%

Calcineurin–Rcan1 Interaction Contributes to Stem Cell Factor–Mediated Mast Cell Activation

Li²,

MacNeil³

et al. 2013

Self Cite

The receptor for stem cell factor (SCF) is expressed on mast cells and hematopoietic progenitors. SCF-induced signaling pathways remain incompletely defined. In this study, we identified calcineurin and regulator of calcineurin 1 (Rcan1) as novel components in SCF signaling. Calcineurin activity was induced in SCF-stimulated primary mouse and human mast cells. NFAT was activated by SCF in bone marrow–derived mast cells (BMMCs) and mouse bone marrow cells, which contain hematopoietic progenitors. SCF-mediated activation also induced expression of Rcan1 in BMMCs. Rcan1-deficient BMMCs showed increased calcineurin activity and enhanced transcriptional activity of NF-κB and NFAT, resulting in increased IL-6 and TNF production following SCF stimulation. These results suggest that Rcan1 suppresses SCF-induced activation of calcineurin and NF-κB. We further demonstrated that SCF-induced Rcan1 expression is dependent on the transcription factor early growth response 1 (Egr1). Interestingly, SCF-induced Egr1 was also suppressed by Rcan1, suggesting a negative regulatory loop between Egr1 and Rcan1. Together, our findings revealed that calcineurin contributes to SCF-induced signaling, leading to NFAT activation, which, together with NF-κB and Egr1, is suppressed by Rcan1. Considering the wide range of biological functions of SCF, these novel regulatory mechanisms in SCF signaling may have broad implications.