Identifying regulatory pathways of spleen tyrosine kinase expression in human basophils

Xia Peng; Mingming Zhao; Li Gao; Ranjan Sen; Donald MacGlashan Jr

doi:10.1016/j.jaci.2019.10.005

Identifying regulatory pathways of spleen tyrosine kinase expression in human basophils

J Allergy Clin Immunol. 2020 Mar;145(3):947-957. doi: 10.1016/j.jaci.2019.10.005. Epub 2019 Oct 17.

Authors

Xia Peng¹, Mingming Zhao², Li Gao³, Ranjan Sen⁴, Donald MacGlashan Jr⁵

Affiliations

¹ Asthma and Allergy Center, Johns Hopkins University, Baltimore, Md; Department of Laboratory Medicine, Shanghai General Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.
² Laboratory of Molecular Biology and Immunology, Biomedical Research Center, National Institutes of Health/National Institute on Aging, Baltimore, Md.
³ Asthma and Allergy Center, Johns Hopkins University, Baltimore, Md.
⁴ Department of Laboratory Medicine, Shanghai General Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.
⁵ Asthma and Allergy Center, Johns Hopkins University, Baltimore, Md. Electronic address: dmacglas@jhmi.edu.

Abstract

Background: Expression levels of spleen tyrosine kinase (SYK), a critical signaling tyrosine kinase in basophils, are uniquely low relative to all other circulating leukocytes, and levels are highly variable in the population.

Objective: We sought to determine whether transcriptional regulation of SYK through unique silencing of the SYK gene determines its basophil-specific expression patterns.

Methods: Culture-derived basophils (CD34B cells) were derived from cultures of CD34⁺ progenitor cells by using 2 methods (G1 or G3). Peripheral blood basophils (PBBs; relative SYK protein level = 1), B cells (SYK = 8), CD34B-G1 cells (SYK = 11), and CD34B-G3 cells (SYK = 5) were examined by using assay for transposase-accessible chromatin sequencing (ATAC-seq) methods. In addition, the transcriptomes of 6 cell types, PBBs, peripheral blood eosinophils (SYK = 11), plasmacytoid dendritic cells (SYK = 30), CD34⁺ progenitors (SYK = 11), CD34B-G1 cells, and CD34B-G3 cells, were analyzed for patterns that matched patterns of SYK expression in these cells, with a focus on transcription factors.

Results: ATAC-seq showed that PBBs have multiple open regions in the SYK gene, suggesting a nonsilenced state with 1 region unique to PBBs (low SYK expression), 1 region unique to both PBBs (low SYK expression) and both G1 and G3 CD34B cells (high and moderate SYK expression, respectively), and 5 regions unique to B cells (high SYK expression). SYK expression across the 6 cell types explored showed a unique pattern that was matched to expression patterns of 3 transcription factors: Kruppel-like factor 5 (KLF5), zinc-finger protein 608 (ZNF608), and musculoaponeurotic fibrosarcoma protein (c-MAF).

Conclusions: Two new potential regulatory pathways for SYK expression were identified. One appears independent of transcriptional regulation, and one appears to be dependent on transcriptional control in the SYK gene.

Keywords: Human; allergy; basophil; development; signal transduction.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Basophils / enzymology*
Cells, Cultured
Gene Expression Regulation / immunology*
Humans
Syk Kinase / metabolism*
Transcriptome

Substances

SYK protein, human
Syk Kinase

Abstract

Publication types

MeSH terms

Substances

Grants and funding