Lack of expression of the tryptase mouse mast cell protease 7 in mast cells of the C57BL/6J mouse.
Although the steady-state level of the mouse mast cell protease (mMCP) 7 transcript is below detection in the serosal and mucosal mast cells of the BALB/cJ mouse, the IL-3-dependent, bone marrow-derived mast cells (mBMMC) of this strain and four other strains contain a high steady-state level of the mMCP-7 transcript. To further analyze the expression of this mast cell tryptase, a mMCP-7-specific IgG was obtained by immunizing a rabbit with a 19-residue synthetic peptide that corresponds to its unique amino acid sequence at residues 160 to 178 (anti-mMCP-7(160-178). In a SDS-PAGE/immunoblot analysis of lysates of BALB/cJ mBMMC, anti-mMCP-7(160-178) IgG recognized a diffuse 31- to 36-kDa protein, which shifted to a sharp 27-kDa protein after treatment with N-glycanase. As assessed immunohistochemically, mMCP-7 protein is present not only in the secretory granules of BALB/cJ mBMMC, but also in the ear mast cells of this strain. In contrast, the ear mast cells of the C57BL/6J mouse do not contain detectable levels of mMCP-7 protein, although the ear mast cells of both mouse strains contain mMCP-5 protein. Because mMCP-7 mRNA and protein also were not detected in mBMMC from the C57BL/6J mouse, the failure of the ear mast cells of this strain to express mMCP-7 is most likely a consequence of an intrinsic abnormality in the mast cell-committed progenitor cells themselves, or in the bone marrow microenvironment that induces its mast cell progenitor cells to express this tryptase.
Ghildyal
N
N
Department of Medicine, Harvard Medical School, Boston, MA 02115.
Friend
D S
DS
Freelund
R
R
Austen
K F
KF
McNeil
H P
HP
Schiller
V
V
Stevens
R L
RL
D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D001854:Bone Marrow Cells; D053818:Chymases; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000276:immunology; D008407:Mast Cells / Q000201:enzymology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000235:genetics / Q000493:pharmacokinetics; D012704:Serous Membrane / Q000166:cytology; D053802:Tryptases
D007074:Immunoglobulin G; D012333:RNA, Messenger; C509190:Tpsb2 protein, mouse; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; C509222:Tpsab1 protein, mouse; D053802:Tryptases