Bruton’s tyrosine kinase inhibition effectively protects against human IgE-mediated anaphylaxis
Melanie C. Dispenza, Rebecca A. Krier-Burris, Krishan D. Chhiba, Bradley J. Undem, Piper A. Robida, Bruce S. Bochner
Melanie C. Dispenza, Rebecca A. Krier-Burris, Krishan D. Chhiba, Bradley J. Undem, Piper A. Robida, Bruce S. Bochner
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Research Article Immunology

Bruton’s tyrosine kinase inhibition effectively protects against human IgE-mediated anaphylaxis

Abstract

No known therapies can prevent anaphylaxis. Bruton’s tyrosine kinase (BTK) is an enzyme thought to be essential for high-affinity IgE receptor (FcεRI) signaling in human cells. We tested the hypothesis that FDA-approved BTK inhibitors (BTKis) would prevent IgE-mediated responses including anaphylaxis. We showed that irreversible BTKis broadly prevented IgE-mediated degranulation and cytokine production in primary human mast cells and blocked allergen-induced contraction of isolated human bronchi. To address their efficacy in vivo, we created and used what we believe to be a novel humanized mouse model of anaphylaxis that does not require marrow ablation or human tissue implantation. After a single intravenous injection of human CD34+ cells, NSG-SGM3 mice supported the population of mature human tissue-resident mast cells and basophils. These mice showed excellent responses during passive systemic anaphylaxis using human IgE to selectively evoke human mast cell and basophil activation, and response severity was controllable by alteration of the amount of allergen used for challenge. Remarkably, pretreatment with just 2 oral doses of the BTKi acalabrutinib completely prevented moderate IgE-mediated anaphylaxis in these mice and also significantly protected against death during severe anaphylaxis. Our data suggest that BTKis may be able to prevent anaphylaxis in humans by inhibiting FcεRI-mediated signaling.

Authors

Melanie C. Dispenza, Rebecca A. Krier-Burris, Krishan D. Chhiba, Bradley J. Undem, Piper A. Robida, Bruce S. Bochner

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Figure 1

BTKis abrogate IgE-mediated mast cell and basophil activation and cytokine production in vitro.

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BTKis abrogate IgE-mediated mast cell and basophil activation and cytoki...
(A) Human SDMCs were passively sensitized with 50 ng/mL human biotinylated IgE overnight, then pretreated with BTKis for 15 minutes and activated for 1 hour with 100 ng/mL streptavidin to cross-link IgE. Percentage of total β-hexosaminidase (β-hex) release was determined via colorimetric assay. n = 4–5 using SDMCs from different donors. (B) SDMCs were treated with BTKis and activated as above, then incubated with fluorescently labeled antibodies against LAMP1 and CD203c before analysis by flow cytometry. Percentage of LAMP1+ and mean MFI of CD203c were measured in cKit+ cells. n = 4 different donors. (C) SDMCs were treated with BTKis for 15 minutes and then washed before IgE cross-linking as above. Twenty-four hours later, cytokine concentrations as indicated were assayed in supernatants using a fluorescent multiplex assay. n = 3–7 different donors. Dotted lines indicate basal secretion by unstimulated cells. (D) To determine the duration of BTKis’ effects, SDMCs were exposed to 1 μM BTKis for 15 minutes and washed at the indicated time points before activation with IgE and assessment of β-hex release as above. n = 3 different donors. (E) The indicated BTKis were added to anticoagulated human whole-blood samples for 15 minutes before activation with anti-FcεRIα antibody (solid lines) or fMLP (dashed lines) as a control. Basophil activation was assessed by CD63 surface upregulation by flow cytometry. n = 4–6 different donors. All data are displayed as means ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 compared with vehicle-treated cells by 2-way ANOVA with repeated measures.