Cellular analysis of the histamine H4 receptor in human myeloid cells.

TitleCellular analysis of the histamine H4 receptor in human myeloid cells.
Publication TypeJournal Article
Year of Publication2016
AuthorsCapelo, R, Lehmann, C, Ahmad, K, Snodgrass, R, Diehl, O, Ringleb, J, Flamand, N, Weigert, A, Stark, H, Steinhilber, D, Kahnt, AS
JournalBiochem Pharmacol
Volume103
Pagination74-84
Date Published2016 Mar 01
ISSN1873-2968
KeywordsCalcium, Cell Differentiation, Cell Line, Cell Line, Tumor, Cell Polarity, Dendritic Cells, Granulocytes, Humans, Interleukin-3, Interleukin-4, Lipopolysaccharides, Macrophage Activation, Macrophages, Monocytes, Myeloid Cells, Primary Cell Culture, Receptors, G-Protein-Coupled, Receptors, Histamine, Receptors, Histamine H1, Receptors, Histamine H2, Receptors, Histamine H4, RNA, Messenger, Zymosan
Abstract

The human histamine H4 receptor (H4R) is a Gαi/o-coupled receptor which is mainly expressed on hematopoietic cells. Accordingly, the receptor is implicated in the pathology of various diseases such as autoimmune disorders, bronchial asthma and pruritus. Due to complicated receptor pharmacology, the lack of a reliable antibody and limited availability of primary cells expressing the receptor the physiology of this receptor is still poorly understood. Therefore, we aimed to assess absolute receptor mRNA expression and functionality (intracellular Ca(2+) release) in various human myeloid cell types such as granulocytes, monocytes, macrophages and dendritic cells (DCs). This was put into context with the expression of the H1R and H2R. In addition, the influence of various inflammatory stimuli on H4R expression was investigated in macrophages and monocyte-derived DCs. We found that classically activated macrophages treated with pro-inflammatory stimuli down-regulated histamine receptor mRNA expression as did LPS and zymosan A matured monocyte-derived DCs. In contrast, alternatively activated macrophages (IL-4 or IL-13) upregulated H2R and H4R expression compared to controls. Consistent with existing literature, we found eosinophils to be the major source of the H4R. Since availability of primary eosinophils is limited, we developed a cell model based on the differentiated eosinophilic cell line EOL-1, in which H4R pharmacology and physiology may be studied.

DOI10.1016/j.bcp.2016.01.007
Alternate JournalBiochem. Pharmacol.
PubMed ID26774453