Heterogeneity of murine bone marrow-derived mast cells: analysis of their proteinase content.
The expression of granule proteinases by murine bone marrow-derived mast cells (BMMC) grown in vitro was compared with that of serosal mast cells (SMC) from the peritoneal cavity. The granules in a proportion of BMMC (0.4-13%) and in all SMC were labelled with fluorescent antibodies against rat mast cell protease I (RMCP I). The granules of 1-47% of BMMC and 100% of SMC were labelled with antibodies against a 30,000 molecular weight (MW) murine intestinal mast cell proteinase (MIMCP). Four antigens from BMMC, ranging in MW from 28,000 to 32,000 and a single 28,000 antigen from SMC were detected on Western blot using anti-MIMCP antibodies. Only the 28,000 MW antigens from BMMC and SMC were visualized in blots probed with anti-RMCP I. BMMC grown in the presence of conditioned medium from activated splenocytes or from the WEHI-3B myelomonocytic cell line contained 52-118 ng and 3-25 ng MIMCP/10(6) cells respectively, whereas SMC lacked detectable MIMCP. The selective labelling of the 28,000 MW antigens in BMMC and SMC with anti-RMCP I and the variable expression of this antigen in BMMC as detected by immunofluorescence indicates that BMMC are not a homogeneous population of cells.
Newlands
G F
GF
Moredun Research Institute, Edinburgh, U.K.
Lammas
D A
DA
Huntley
J F
JF
MacKellar
A
A
Wakelin
D
D
Miller
H R
HR
D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D010450:Endopeptidases / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D008407:Mast Cells / Q000201:enzymology*; D051379:Mice; D008815:Mice, Inbred Strains; D010529:Peritoneal Cavity / Q000166:cytology
D010450:Endopeptidases