DOCK2 regulates MRGPRX2/B2-mediated mast cell degranulation and drug-induced anaphylaxis

Kazufumi Kunimura; Sayaka Akiyoshi; Takehito Uruno; Keisuke Matsubara; Daiji Sakata; Kenji Morino; Kenichiro Hirotani; Yoshinori Fukui

doi:10.1016/j.jaci.2023.01.029

DOCK2 regulates MRGPRX2/B2-mediated mast cell degranulation and drug-induced anaphylaxis

J Allergy Clin Immunol. 2023 Jun;151(6):1585-1594.e9. doi: 10.1016/j.jaci.2023.01.029. Epub 2023 Feb 17.

Authors

Kazufumi Kunimura¹, Sayaka Akiyoshi², Takehito Uruno², Keisuke Matsubara², Daiji Sakata², Kenji Morino², Kenichiro Hirotani², Yoshinori Fukui²

Affiliations

¹ Department of Immunobiology and Neuroscience, Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan. Electronic address: kunimura@bioreg.kyushu-u.ac.jp.
² Department of Immunobiology and Neuroscience, Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.

PMID: 36804596
DOI: 10.1016/j.jaci.2023.01.029

Abstract

Background: Drug-induced anaphylaxis is triggered by the direct stimulation of mast cells (MCs) via Mas-related G protein-coupled receptor X2 (MRGPRX2; mouse ortholog MRGPRB2). However, the precise mechanism that links MRGPRX2/B2 to MC degranulation is poorly understood. Dedicator of cytokinesis 2 (DOCK2) is a Rac activator predominantly expressed in hematopoietic cells. Although DOCK2 regulates migration and activation of leukocytes, its role in MCs remains unknown.

Objective: We aimed to elucidate whether-and if so, how-DOCK2 is involved in MRGPRX2/B2-mediated MC degranulation and anaphylaxis.

Methods: Induction of drug-induced systemic and cutaneous anaphylaxis was compared between wild-type and DOCK2-deficient mice. In addition, genetic or pharmacologic inactivation of DOCK2 in human and murine MCs was used to reveal its role in MRGPRX2/B2-mediated signal transduction and degranulation.

Results: Induction of MC degranulation and anaphylaxis by compound 48/80 and ciprofloxacin was severely attenuated in the absence of DOCK2. Although calcium influx and phosphorylation of several signaling molecules were unaffected, MRGPRB2-mediated Rac activation and phosphorylation of p21-activated kinase 1 (PAK1) were impaired in DOCK2-deficient MCs. Similar results were obtained when mice or MCs were treated with small-molecule inhibitors that bind to the catalytic domain of DOCK2 and inhibit Rac activation.

Conclusion: DOCK2 regulates MRGPRX2/B2-mediated MC degranulation through Rac activation and PAK1 phosphorylation, thereby indicating that the DOCK2-Rac-PAK1 axis could be a target for preventing drug-induced anaphylaxis.

Keywords: DOCK2; Drug-induced anaphylaxis; MRGPRB2; MRGPRX2; PAK1; Rac; mast cell; phosphorylation; secretory granules.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anaphylaxis* / chemically induced
Animals
Cell Degranulation
Drug Hypersensitivity* / metabolism
GTPase-Activating Proteins / metabolism
Guanine Nucleotide Exchange Factors / genetics
Guanine Nucleotide Exchange Factors / metabolism
Humans
Mast Cells / metabolism
Mice
Nerve Tissue Proteins / genetics
Nerve Tissue Proteins / metabolism
Receptors, G-Protein-Coupled / genetics
Receptors, G-Protein-Coupled / metabolism
Receptors, Neuropeptide / genetics
Receptors, Neuropeptide / metabolism

Substances

Receptors, Neuropeptide
Receptors, G-Protein-Coupled
DOCK2 protein, human
Guanine Nucleotide Exchange Factors
GTPase-Activating Proteins
MRGPRX2 protein, human
Nerve Tissue Proteins
DOCK2 protein, mouse