Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have established a unique variant cell line, MC/9.IL-4, which continuously proliferates in the presence of interleukin-4 (IL-4), from a murine interleukin-3 (IL-3)-dependent mast cell line, MC/9 (referred to as MC/9.IL-3). Compared with MC/9.IL-3 cells, MC/9.IL-4 cells are smaller, lack cytoplasmic granules and metachromasia, carry a very small amount of histamine, and express fewer high-affinity IgE receptors (IgERs) and IL-3 receptors. To further characterize MC/9.IL-4, we developed a novel method to enrich cell type-specific cDNAs by cDNA library subtraction and applied it for MC/9.IL-3 versus MC/9.IL-4. Sequence analysis of cDNA clones isolated by this technique showed that MC/9.IL-4 cells specifically express CD8 alpha and expression of mast cell-specific proteases and major histocompatibility complex class II (MHCII) is considerably decreased. It was also noted that responsiveness to the IL-3-agonistic antibody F9 and expression of the transcription factor GATA-2 is diminished in MC/9.IL-4, indicating that MC/9.IL-4 have lost major characteristics of the bone marrow-derived cultured mast cells. Because other T-cell marker antigens, CD8 beta, CD4, Thy-1, were not detected on MC/9.IL-4 cells, MC/9.IL-4 cells may represent an unknown class of hematopoietic cells that express CD8 alpha. This cell line will be useful in studies of IL-4-mediated signal transduction, as well as transcriptional regulation of mast cell characteristic genes. This study also demonstrates the effective use of the cDNA library subtraction strategy to characterize unknown types of hematopoietic cells at the molecular level.
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PMID:Characterization of cell phenotype by a novel cDNA library subtraction system: expression of CD8 alpha in a mast cell-derived interleukin-4-dependent cell line. 801 17

In the present work, we explored the cytokine-dependent regulation of bone marrow-derived mast cell (BMMC) antigen-presenting cell (APC) function, and co-stimulation requirements, and analyzed the nature of antigens presented to T cells. We observed an up-regulation of the APC function of mast cells induced by granulocyte/macrophage-colony-stimulating factor (GM-CSF) and a complete abrogation by interferon (IFN)-gamma. Expression of co-stimulatory molecules CD80 and CD86 was suggested by the ability of mast cells to activate purified lymph node-derived T cells. Indeed, addition of the fusion protein mCTLA4-Ig strongly inhibited antigen presentation by mast cells to normal T cells and to the T cell hybridoma 3DO-54.8. The regulatory mechanisms of APC function by GM-CSF and IFN-gamma were investigated by measuring CD80 and CD86 transcripts in mast cells. GM-CSF-treated must cells showed a strong increase in the expression of both CD80 and CD86 transcripts, whereas in IFN-gamma-treated mast cells, this expression was completely abrogated. Thus, up- and down-regulation of CD80 and CD86 expression by GM-CSF and IFN-gamma is directly correlated to the APC function. In addition, we analyzed antigen presentation by mast cells of endogenous self-antigens. Mast cells failed to activate anti-I-A or anti-I-E-specific T cell hybridomas and alloreactive T cells in primary mixed lymphocyte reactions (MLR). Furthermore, mast cells did not present the mouse beta 2-microglobulin (m beta 2-m) peptide 25-40, constitutively expressed on B cells. However, mast cells, especially those treated with GM-CSF, activated an anti-m beta 2-m-specific T cell hybridoma in the presence of exogenous peptide. The minor lymphocyte-stimulating antigen-1 Mls-1a is a viral superantigen (vSAG) encoded by the the mouse mammary tumor provirus-7 (MMTV-7). Mast cells, despite a reasonable amount of major histocompatibility complex class II on the cell surface and the presence of MMTV transcripts predicted to encode the vSAG, cannot stimulate in vivo or in vitro V beta 6+ T cells specific for Mls-1a. In contrast, mast cells could present the exogenous bacterial SAG, staphylococcal enterotoxin B (SEB), to specific V beta 8+ T cells. The selective ability of mast cells to present exogenous antigens may have physiological relevance in that mast cells could participate in immune response regulatory mechanisms by discriminating self from nonself.
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PMID:Exogenous and endogenous antigens are differentially presented by mast cells to CD4+ T lymphocytes. 889 68

It is generally thought that mast cells influence T-cell activation nonspecifically through the release of inflammatory mediators. In this report, we provide evidence that mast cells may also affect antigen-specific T-cell responses by internalizing immunoglobulin E-bound antigens for presentation to antigen-specific T cells. Surprisingly, T-cell activation did not require that mast cells express major histocompatibility complex class II, indicating that mast cells were not involved in the direct presentation of the internalized antigens. Rather, the antigen captured by mast cells is presented by other major histocompatibility complex class II(+) antigen-presenting cells. To explore how this may occur, we investigated the fate of mast cells stimulated by antigen and found that FcepsilonRI crosslinking enhances mast cell apoptosis. Cell death by antigen-captured mast cells was required for efficient presentation because protection of mast cell death significantly decreased T-cell activation. These results suggest that mast cells may be involved in antigen presentation by acting as an antigen reservoir after antigen capture through specific immunoglobulin E molecules bound to their FcepsilonRI. This mechanism may contribute to how mast cells impact the development of T-cell responses.
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PMID:Indirect involvement of allergen-captured mast cells in antigen presentation. 1803 7

To evaluate the effects of the transcription factor GATA-1 on determining cell fate between dendritic cell (DC) and mast cell (MC) lineages, GATA-1 was exogenously expressed in bone marrow-derived (BM) DCs. Exogenous expression of GATA-1 by a retrovirus in BMDCs inhibited expression of CD11c, CD80, CD86, and major histocompatibility complex class II with suppression of antigen-presenting ability and morphological changes toward granulocyte-like cells. Transcription of MC proteases and c-kit was markedly upregulated by GATA-1. Expression of IRF-4 and -8 was markedly suppressed, whereas PU.1 mRNA level was not affected by GATA-1. Chromatin immunoprecipitation assay showed that recruitment of PU.1 on the IRF-8 promoter was reduced in GATA-1-expressing DCs. These results indicate that GATA-1 suppresses PU.1 function but not PU.1 transcription. Thus, GATA-1 appears to determine cell fate by regulating several cell-specific transcription factors.
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PMID:Suppressive effects of transcription factor GATA-1 on cell type-specific gene expression in dendritic cells. 2040 20