Fibroblast-Derived Factors Induce Different Mast Cell Characteristics in Human Myeloid Cell Lines and Peripheral Monocytes

Abstract

Mast cell differentiation markers were studied by culturing monocytic (U937, THP1) a promyelotic (HL60) and a human mast cell line (HMC1) and peripheral human blood monocytes with fibroblast supernatants and feeder layers. Mast cell differentiation occurred on the basis of metachromasia, chloroacetate esterase, expression of mast cell-specific antigens (APAAP) and production of tryptase in all cell types, but to varying degrees and not at all with a FcεRI marker in monocytic lines. Direct cellular contact is thus not necessary for induction of mast cell differentiation by fibroblasts.

Lung epithelial H292 cells induce differentiation of immature human HMC‐1 mast cells by interleukin‐6 and stem cell factor

“…These authors, however, did not test the contribution of IL‐6. In another study, exposure of HMC‐1 cells to fibroblast‐derived medium induced differentiation as measured by tryptase activity of HMC‐1 cells, but no relevant components were identified [ 20].…”

“…medium induced differentiation as measured by tryptase activity of HMC-1 cells, but no relevant components were identi®ed [20].…”

Human Keratinocytes Release Mast Cell Differentiation Factors Other than Stem Cell Factor

“…Histamine was quantified in acid-lysed cells by an automated fluorometric method [5], Enzyme activity of mast cell tryptase was mea sured by cleavage of Z-Gly-Pro-Arg-pNA (4 ni l/) in the presence of heparin (5 mg/ml) and a-l-antitrypsin (2 mg/ml) (all from Sigma) af ter three cycles of freezing and thawing [6].…”

Induction of Human Leukaemic Mast Cell Differentiation by Fibroblast Supernatants, but not by Stem Cell Factor

“…The factor exists in a cell bound and a secreted form, and it stimulates growth and differentiation of diverse cells expressing its receptor, the c-Kit protein, such as melanocytes, haematopoietic stem cells and mast cells [11]. SCF is most likely involved in the differentiation of human mast cells from precursors in tissue and peripheral blood observed previously with fibroblast feeder layers or supernatants [13][14][15][16][17], and recombinant SCF has so far been shown to induce mast cell differentiation from human bone marrow and peripheral blood cells, also during long-time culture, although the cells expressed an immature phenotype [6][7][8]. The exact role of SCF in different stages of mast cell differentiation and maturation remains however unclear.…”

“…As it has still not been possible to obtain purified committed precursors for the study of human mast cell maturation, we decided to examine HMC-1 cells for their ability to express and up-regulate mast cell characteristics in the presence of SCF and L-cell fibroblast supernatants (LCS). LCS has in the past been shown by us to induce mast cell differentiation from rat macrophages and human peripheral blood mononuclear cells [15][16][17] and thus provides a suitable conditioning medium for control of SCF effects on HMC-1 cells.…”