epidermal-growth-factor and Leukemia--T-Cell

Epithelial cells appear to play an important role in the initiation and maintenance of autoimmune lesions in the salivary glands of patients with Sjogren's syndrome. Therefore, the detailed study of immunological function of salivary gland epithelial cells (SGEC) may provide useful information for the understanding of Sjögren's syndrome pathogenesis. In this report we aimed to formulate a protocol for the establishment of human non-neoplastic SGEC lines as a tool for the study of the physiology and pathophysiology of these cells. Pointing towards a practical approach, we sought to establish SGEC lines from quite a limited amount of biopsy tissue obtained during the diagnostic evaluation of patients. Herein, the favorable conditions for the long-term maintenance of human non-neoplastic SGEC lines are presented and involve the successive application of a serum-containing and a serum-free culture medium, supplemented with essential epithelial growth factors. This protocol has been found reliable and convenient, as attested by the reproducible establishment of non-neoplastic SGEC lines. The analysis of SGEC phenotypic features, as well as a coculture system for the study of interactions between epithelial cells and lymphocytes, are also described. Such techniques may provide valuable means for the functional and molecular investigation of human SGEC and particularly for the study of Sjögren's syndrome and other disorders of glandular epithelia.

Topics: Apoptosis; Autoimmune Diseases; Biopsy; CD4-Positive T-Lymphocytes; Cell Communication; Cell Culture Techniques; Cell Division; Coculture Techniques; Culture Media; Culture Media, Serum-Free; Epidermal Growth Factor; Epithelial Cells; Humans; Leukemia, T-Cell; Phenotype; Reproducibility of Results; Salivary Glands; Sjogren's Syndrome; T-Lymphocytes; Time Factors

The mechanism by which IFN-gamma inhibits tumor cell growth has not been fully understood. Here we report that IFN-gamma up-regulated the expression of Fas and Fas ligand (FasL) on HT29 cells, a human colon adenocarcinoma cell line, and subsequently induced apoptosis of these cells. The kinetics of cell death in IFN-gamma-treated HT29 cells paralleled the increase in the levels of Fas and FasL expression. We further show that IFN-gamma up-regulated the expression of Fas and FasL in STAT1-transfected U3A cells but not in STAT1-deficient U3A cells. Correspondingly, IFN-gamma induced cell death in STAT1-transfected U3A cells but not in STAT1-deficient U3A cells. IFN-gamma-induced cell death was inhibited by caspase-1 inhibitors. Our results suggest that cell growth inhibition by IFN-gamma is due to apoptosis mediated by Fas and FasL interaction.

Topics: Antineoplastic Agents; Apoptosis; Caspase 1; Cell Division; Cysteine Endopeptidases; DNA Fragmentation; DNA-Binding Proteins; DNA, Neoplasm; Epidermal Growth Factor; Fas Ligand Protein; fas Receptor; Fibroblast Growth Factors; HT29 Cells; Humans; Interferon-gamma; Leukemia, T-Cell; Membrane Glycoproteins; Platelet-Derived Growth Factor; STAT1 Transcription Factor; Trans-Activators; Transfection; Tumor Necrosis Factor-alpha; Up-Regulation