SLC10A4 regulates IgE-mediated mast cell degranulation in vitro and mast cell-mediated reactions in vivo

Hanna Pettersson,Jörgen Jonsson,Viktor Persson,Klas Kullander,Jenny Hallgren,Annika Westin,Christiane Peuckert,Behdad Zarnegar

doi:10.1038/s41598-017-01121-8

Abstract

Mast cells act as sensors in innate immunity and as effector cells in adaptive immune reactions. Here we demonstrate that SLC10A4, also referred to as the vesicular aminergic-associated transporter, VAAT, modifies mast cell degranulation. Strikingly, Slc10a4−/− bone marrow-derived mast cells (BMMCs) had a significant reduction in the release of granule-associated mediators in response to IgE/antigen-mediated activation, whereas the in vitro development of mast cells, the storage of the granule-associated enzyme mouse mast cell protease 6 (mMCP-6), and the release of prostaglandin D2 and IL-6 were normal. Slc10a4-deficient mice had a strongly reduced passive cutaneous anaphylaxis reaction and a less intense itching behaviour in response to the mast cell degranulator 48/80. Live imaging of the IgE/antigen-mediated activation showed decreased degranulation and that ATP was retained to a higher degree in mast cell granules lacking SLC10A4. Furthermore, ATP was reduced by two thirds in Slc10a4−/− BMMCs supernatants in response to IgE/antigen. We speculate that SLC10A4 affects the amount of granule-associated ATP upon IgE/antigen-induced mast cell activation, which affect the release of granule-associated mast cell mediators. In summary, SLC10A4 acts as a regulator of degranulation in vitro and of mast cell-related reactions in vivo.

Highlights

Mast cells are immune cells which play a central role in allergic reactions[1]
bone marrow-derived mast cells (BMMCs) were stained with the secondary anti-goat antibody alone. (E) Quantitative western blot analysis of mouse mast cell protease 6 (mMCP-6) expression in BMMCs derived from Wild type (WT) and Slc10a4−/− mice
Cross-linking of IgE bound to the FcεRI by antigen causes strong mast cell activation, which results in the degranulation of mast cells and in the generation of lipid mediators and cytokines

Summary

Introduction

Mast cells are immune cells which play a central role in allergic reactions[1]. The most well-characterized pathway of mast cell activation is the IgE/antigen-mediated activation of the high-affinity receptor for IgE, FcεRI. Two studies have established that SLC10A4 is co-expressed with the carriers of acetylcholine (VAChT) and monoamines (VMAT2) on synaptic vesicles, both in the central and peripheral nervous systems[10, 16]. This suggested the presence of SLC10A4 in other monoamine-containing secretory granules, which was supported by the identification of the SLC10A4 protein in rat peritoneal mast cells[19]. We show that the SLC10A4 protein impacts the degranulation process of mast cells in vitro and regulates mast cell-mediated responses in vivo

Methods

Results

Conclusion