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1.
Immunol Lett ; 57(1-3): 47-51, 1997 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-9232424

RESUMEN

In IgE allergic diseases both mast cells and T lymphocytes play an important role. Whereas mast cels have been implicated in immediate allergic responses, T lymphocytes mediate subsequent late phase responses and chronic inflammation. Here we review possible links between the early mast cell activation and the later T lymphocyte stimulation. Products from mast cells were found to exert effects on T lymphocytes. Human Mast Cell line-1 (HMC-1) mast cells modulated proliferation and cytokine production of a human CD8+ T-cell clone in vitro. Activated mast cells seemed to drive this CD8+ T-cell clone towards a more pronounced T (helper) 1 type of response, simultaneously decreasing T-cell numbers. It is hypothesized that this might be a negative feed back mechanism operating in allergic subjects, by which the Th2-driven IgE production and eosinophilia are counteracted.


Asunto(s)
Asma/inmunología , Linfocitos T CD8-positivos/inmunología , Citocinas/biosíntesis , Mastocitos/inmunología , Animales , Linfocitos T CD8-positivos/citología , División Celular , Línea Celular , Humanos , Mastocitos/citología
2.
Clin Exp Allergy ; 30(8): 1104-12, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10931117

RESUMEN

BACKGROUND: Immature mast cells migrate into tissues where they differentiate into mature mast cells under the influence of local factors. In the airways of asthmatics increased numbers of chronically activated mast cells are located nearby the airway epithelium. OBJECTIVE: The aim of this study was to evaluate whether and, if so, which products released by epithelial cells may affect mast cell proliferation and differentiation. METHODS: We performed in vitro studies using the human lung mucoepidermoid carcinoma-derived H292 cell line and the immature human mast cell line, HMC-1. Proliferation was assessed by 3H-thymidine incorporation. Differentiation of HMC-1 cells was inferred from tryptase production. RESULTS: Exposure of HMC-1 cells to medium conditioned for 48 h by H292 cells resulted in a reduction of proliferation with 65 +/- 4.9% (mean +/- SEM, n = 9) at day 5. Culturing HMC-1 cells for 8 days in the presence of H292-conditioned medium resulted in morphological changes indicative of differentiation, and in a 3.0 +/- 0.4-fold increase of tryptase production (P = 0.0039, n = 9). Conditioned medium from H292 cells that were stimulated by LPS also inhibited HMC-1 proliferation. Inhibitory antibodies against two mediators from H292 cells, interleukin-6 (IL-6) and stem cell factor (SCF), abolished the increase in HMC-1 tryptase production induced by H292-conditioned medium. Recombinant human (rh) IL-6, but not rhSCF, reduced HMC-1 proliferation with 44% and 13% at day 3 and 5, respectively. Surprisingly, rhIL-6 did not increase HMC-1 tryptase production significantly whereas incubation with rhSCF did (1.5 +/- 0.1-fold, P = 0.002, n = 10) although the increase was less than observed for conditioned medium. CONCLUSION: Epithelial-derived IL-6 and SCF are implicated in differentiation of HMC-1 cells but additional factors are not excluded. As activated primary bronchial epithelial cells also express IL-6 and SCF, it should be considered that these cells are involved in mast cell differentiation within the airways, particularly in diseases where epithelial cells are activated, such as asthma.


Asunto(s)
Células Epiteliales/fisiología , Interleucina-6/fisiología , Pulmón/fisiología , Mastocitos/fisiología , Factor de Células Madre/fisiología , Anticuerpos/farmacología , Diferenciación Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Quimasas , Medios de Cultivo Condicionados , Gránulos Citoplasmáticos/efectos de los fármacos , Gránulos Citoplasmáticos/metabolismo , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Humanos , Interleucina-6/genética , Interleucina-6/inmunología , Interleucina-6/farmacología , Pulmón/citología , Mastocitos/efectos de los fármacos , Mastocitos/enzimología , Proteínas Recombinantes/farmacología , Serina Endopeptidasas/metabolismo , Factor de Células Madre/genética , Factor de Células Madre/inmunología , Factor de Células Madre/farmacología , Factores de Tiempo , Triptasas , Células Tumorales Cultivadas
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