title: Growth in methylcellulose of human mast cells in hematopoietic colonies stimulated by steel factor, a c-kit ligand.
abstract: We examined the effect of Steel factor (SLF) on the development of human mast cells in hematopoietic colonies from cord blood mononuclear cells in methylcellulose culture. When cord blood cells were cultured for 3 weeks, SLF increased the cellular tryptase levels detected in total cultured cells. It also stimulated the formation of small-cell colonies consisting mainly of polymorphonuclear granulocytes and immature blastoid cells in a concentration-dependent manner but not the formation of colonies consisting of large macrophagic cells. A low percentage of tryptase-positive mast-cell-like cells was found in 39 out of 100 granulocyte/blastoid cell colonies. Four of the 100 colonies contained 10-20% tryptase-positive cells, but we failed to observe colonies consisting of > 20% of tryptase-positive cells. These results suggest that the effect of SLF on mast cell growth is brought on by stimulating the growth of primitive hematopoietic progenitors.
authors.affiliation: Division of Allergy, National Children's Medical Research Center, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: N
authors.initials: N
authors.lastname: Sakaguchi
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Tsubaki
authors.forename: T
authors.initials: T
authors.lastname: Numazaki
authors.forename: M
authors.initials: M
authors.lastname: Ebisawa
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: R
authors.initials: R
authors.lastname: Ozawa
authors.forename: H
authors.initials: H
authors.lastname: Yanagi
authors.forename: A
authors.initials: A
authors.lastname: Akasawa
mesh_terms: D015815:Cell Adhesion Molecules / Q000494:pharmacology*; D002455:Cell Division; D002478:Cells, Cultured; D053818:Chymases; D003114:Colony-Forming Units Assay; D005312:Fetal Blood; D006098:Granulocytes / Q000166:cytology; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000201:enzymology; D006801:Humans; D008407:Mast Cells / Q000166:cytology* / Q000201:enzymology; D008747:Methylcellulose; D011518:Proto-Oncogene Proteins; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases; D016184:Receptors, Colony-Stimulating Factor; D012697:Serine Endopeptidases / Q000378:metabolism; D019089:Stem Cell Factor; D053802:Tryptases
chemical_list: D015815:Cell Adhesion Molecules; D016298:Hematopoietic Cell Growth Factors; D011518:Proto-Oncogene Proteins; D016184:Receptors, Colony-Stimulating Factor; D019089:Stem Cell Factor; D008747:Methylcellulose; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; D053802:Tryptases