Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mast cells at immature stages of development were identified in human tissues by electron microscopic techniques. General morphologic criteria of immaturity (such as a high apparent nuclear:cytoplasmic ratio and small cell size), the presence of few granules (those present being smaller than those in mature mast cells) and a lack of features of mast cell activation were used together to determine the level of maturity. Mast cells were identified as being of the T or TC type by immunogold staining with polyclonal rabbit IgG anti-chymase and murine monoclonal anti-tryptase primary antibodies and the appropriate gold-labeled secondary antibodies. Only those cells with tryptase-positive granules were recognized as mast cells. Immature T mast cell granules contained the same characteristic discrete scrolls found in their mature counterparts and all stained positive for tryptase. The presence of trace amounts of chymase in a minority of these granules, as in mature T mast cells, could not be ruled out. The majority of granules in immature TC mast cells had one or more amorphous electron-dense cores rather than the grating and lattice substructures characteristic of granules in mature TC mast cells. Secretory granules in immature TC mast cells stained positively for tryptase and chymase. Occasional immature TC mast cells contained a complete granule or a portion of a granule with the substructure characteristic of mature TC mast cells, favoring the concept that these TC mast cell forms are developmentally related. Essentially all mast cells in foreskin of newborns appeared immature, whereas 10, 5, 10, and 15% of the mast cells in adult lung, foreskin, bowel mucosa and bowel submucosa, respectively, appeared immature. The distribution of T and TC types of immature mast cells seemed to parallel that of the mature mast cell types. These compositional and ultrastructural differences between immature T and TC types of mast cells suggest that from the time granule formation begins, and possibly before this time, each type of human mast cell follows a distinct developmental pathway.
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PMID:Ultrastructural analysis of maturing human T and TC mast cells in situ. 264 87

Human cultured mast cells (HCMCs) grown from cord blood mononuclear cells in the presence of stem cell factor (SCF) and interleukin-6 (IL-6) expressed tryptase but no or low chymase in their cytoplasm. The addition of IL-4 to these cells strikingly increased chymase expression. Consequently, the activity of chymase was significantly higher in IL-4-treated mast cells than that in IL-4-nontreated mast cells, whereas the activity of tryptase and histamine content were comparable in both cells. Electron microscopic immunocytochemistry also showed that secretary granules containing chymase increased in IL-4-treated mast cells. Interestingly, the IL-4-induced increase of chymase expression in HCMCs was accompanied by morphological maturation of the cells. Cytoplasmic projections were few in IL-4-nontreated HCMCs, and a small number of secretary granules were observed, most of which were empty or partially filled with discrete scrolls with rough particles showing immaturity. In contrast, IL-4-treated HCMCs had extremely abundant cytoplasmic projections and had many secretary granules filled with electron-dense crystal materials. Taken together, immature HCMCs grown only with SCF and IL-6 expressed tryptase with no or a low amount of chymase, and addition of IL-4 promoted cell maturation together with the expression of both tryptase and a high amount of chymase. Our findings will raise a possibility of a linear pathway of human mast cell development from tryptase single positive mast cells into tryptase and chymase double positive mast cells as the cells mature and will suggest that this maturation process is promoted by IL-4.
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PMID:Interleukin-4 promotes the development of tryptase and chymase double-positive human mast cells accompanied by cell maturation. 941 84