Human and murine recombinant c-kit ligands support the development of human mast cells from umbilical cord blood cells: ultrastructural identification.
The recently identified ligand for c-kit, a protooncogene encoded by the W locus in mice, is a member of the tyrosine kinase receptor family with growth factor activity for mouse mast cells. Mature human mast cells regularly develop from agranular precursors in cord blood in long-term cocultures of cord blood and murine fibroblasts. Since the c-kit ligand is a product of murine fibroblasts, we examined the growth effect of recombinant human c-kit ligand (stem cell factor), of recombinant murine c-kit ligand (mast cell growth factor), and of a partially purified fraction derived from mouse fibroblast culture supernatant on the mast cell lineage of humans by electron microscopy in 8-week cultures of cord blood cells. We found that immature mast cells which developed in cultures containing the recombinant ligand for c-kit of human or murine origin as well as the naturally occurring c-kit ligand in 3T3 fibroblast supernatants were identical. Thus, each of these sources of the c-kit ligand exerted identical effects on the ontogeny of human mast cells as they develop from their agranular precursors in cord blood. Full maturity of factor-supported mast cells did not occur.
Dvorak
A M
AM
Department of Pathology, Beth Israel Hospital, Boston, Mass 02215.
Mitsui
H
H
Ishizaka
T
T
D016475:3T3 Cells / Q000378:metabolism; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology; D016298:Hematopoietic Cell Growth Factors / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D008407:Mast Cells / Q000166:cytology* / Q000648:ultrastructure; D051379:Mice; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D019089:Stem Cell Factor
D016298:Hematopoietic Cell Growth Factors; D011994:Recombinant Proteins; D019089:Stem Cell Factor