Single-cell molecular profiling provides a high-resolution map of basophil and mast cell development.

Fiona K Hamey,Evangelia Diamanti,Berthold Göttgens,Winnie W Y Lau,Nicola K Wilson,Iwo Kucinski,Joakim S Dahlin,Xiaonan Wang

doi:10.1111/all.14633

Fiona K Hamey, Evangelia Diamanti + Show 6 more

Open Access

https://doi.org/10.1111/all.14633

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Abstract

BackgroundBasophils and mast cells contribute to the development of allergic reactions. Whereas these mature effector cells are extensively studied, the differentiation trajectories from hematopoietic progenitors to basophils and mast cells are largely uncharted at the single‐cell level.MethodsWe performed multicolor flow cytometry, high‐coverage single‐cell RNA sequencing analyses, and cell fate assays to chart basophil and mast cell differentiation at single‐cell resolution in mouse.ResultsAnalysis of flow cytometry data reconstructed a detailed map of basophil and mast cell differentiation, including a bifurcation of progenitors into two specific trajectories. Molecular profiling and pseudotime ordering of the single cells revealed gene expression changes during differentiation. Cell fate assays showed that multicolor flow cytometry and transcriptional profiling successfully predict the bipotent phenotype of a previously uncharacterized population of peritoneal basophil‐mast cell progenitors.ConclusionsA combination of molecular and functional profiling of bone marrow and peritoneal cells provided a detailed road map of basophil and mast cell development. An interactive web resource was created to enable the wider research community to explore the expression dynamics for any gene of interest.

Highlights

Mast cells are sentinel cells that are strategically positioned throughout the body and allow rapid triggering of the immune system upon infections.[1]
By subsetting the data for pertinent progenitor populations, we identified a distinct differentiation trajectory with a gene expression profile characteristic of basophils and mast cells (HDC and MS4A2), which was separate from other myelo-erythroid lineages (Figure 4G-H, Figure S6)
Single-cell transcriptomics coupled with index sorting of thousands of bone marrow HSPCs has previously been used to chart erythrocyte and granulocyte-monocyte differentiation.[18,19]

Summary

| INTRODUCTION

Mast cells are sentinel cells that are strategically positioned throughout the body and allow rapid triggering of the immune system upon infections.[1]. Activation of mast cells results in prompt release of proteases and histamine from the cytoplasmic granules as well as synthesis of cytokines and chemokines. These mediators in turn cause inflammation, vasodilation, and leukocyte recruitment to the site of triggering.[1] the functions of mature basophils and mast cells have been studied in great detail. We combine multicolor flow cytometry-based index sorting with high-coverage scRNA-seq to investigate the basophil-mast cell bifurcation and the differentiation into each respective lineage. The analysis is accompanied with the generation of a user-friendly web resource that allows gene expression to be explored across the single-cell landscape. The current resource provides a detailed road map of the developmentally related basophils and mast cells, whose activation contributes to allergic diseases

| METHODS

| DISCUSSION

Findings

11. Human Cell Atlas