Two-dimensional gel electrophoretic profile of rat basophilic leukemia (RBL) and mast cells

RBL cells are not differentiated, but resemble mucosal mast cells (MMC). Two-dimensional (2-D) gel electrophoresis following isoelectric focusing (IEF) was performed using purified rat peritoneal mast cells and RBL cells. Certain similarities were identified with silver staining between mast cells and stationary phase (72 hr) RBL cells. RBL cells were also labelled with [35S]-cysteine in order to study the specific expression of proteins during logarithmic or stationary growth phases. Only stationary phase RBL cells appeared to specifically express three proteins of 42, 55 and 93 kD and were still capable of secreting histamine in response to immunoglobulin E (IgE) and specific antigen. These results suggest that specific RBL cell proteins may be used as markers for further analysis of their maturation/differentiation.