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

Abstract

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. RBL-2H3 cells were stimulated with either dinitrophenylated-IgE, calcium ionophore A23187, compound 48/80, mast cell degranulating peptide or lipopolysaccharide and mediator (histamine, β-hexosaminidase, interleukin-13 and TNF-α) 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. Mediator release was dependant 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. 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.