RBL-2H3 cells are an imprecise model for mast cell mediator release

Abstract

Objective: The cell line, RBL-2H3, has been widely used as a mast cell model though much of the data is contradictory. The aim of this study is to assess the RBL-2H3 cell line as an in vitro model for degranulation studies.

Methods: RBL-2H3 cells were stimulated with either dinitrophenylated-IgE, calcium ionophore A23187, compound 48/80, mast cell degranulating peptide or lipopolysaccharide and mediator (histamine, beta-hexosaminidase, interleukin-13 and TNF-alpha) release was analysed. Toll-like receptors (TLR) mRNA expression in RBL-2H3 cells and rat peritoneal mast cells (RPMC) were compared by RT-PCR. TLR4 and CD14 surface proteins in RBL-2H3 were analysed by FACS.

Results: Mediator release was dependent on media composition and degranulation was stimulated by IgE and A23187. Degranulation was inhibited by quercetin, but not by cromoglycate or ketotifen. Transcripts encoding TLR3-5 and 6 were detected in RBL-2H3 cells whereas TLR1-6 and TLR8 were clearly seen in RPMC. While proteins were detected for TLR4 in RBL-2H3 cells, CD14 was largely absent.

Conclusions: While RBL-2H3 cells may be useful as a model for mast cell IgE-mediated degranulation, other aspects may not be representative and they may share similarities with basophils rather than with other histamine-releasing cell types.