102 research outputs found

    TGF-β1 and IL-4 induce CCL11 production

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    Transforming growth factor (TGF)-β1 is a multifunctional cytokine, which can control certain functions of various kinds of cells. However, it is unclear whether TGF-β1 affects T-cell migration in periodontal lesions. The aim of this study was to examine the effects of TGF-β1 on the production of C-C chemokine ligand (CCL)11, which is a T-helper 2-type chemokine, in human periodontal ligament cells (HPDLC). Interleukin (IL)-4 induced CCL11 production, but TGF-β1 did not, in HPDLC. However, TGF-β1 enhanced CCL11 production in IL-4-stimulated HPDLC. Western blot analysis showed that the signal transducer and activator of transcription 6 (STAT6) pathway was highly activated in HPDLC that had been stimulated with both IL-4 and TGF-β1. Mitogen-activated protein kinase activation did not differ between the HPDLC treated with a combination of IL-4 and TGF-β1 and those treated with IL-4 or TGF-β1 alone. Moreover, a STAT6 inhibitor significantly inhibited CCL11 production in HPDLC that had been stimulated with IL-4 and TGF-β1. The current study clearly demonstrated that TGF-β1 enhanced IL-4-induced CCL11 production in HPDLC. The STAT6 pathway is important for CCL11 production in IL-4- and TGF-β1-treated HPDLC

    Role of transforming growth factor-β1 in down-regulating TNF production by alveolar macrophages during asbestos-induced pulmonary fibrosis

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    Activation of alveolar macrophages (AM) for tumour necrosis factor production is suppressed initially during the inflammatory response to fibrogenic dusts. We investigated the mechanisms involved in TNF suppression, notably the role of other AM-derived mediators including prostaglandin E2 (PGE2), transforming growth factor-β1 (TGF-β1), and interleukin 6 (IL-6). The action of PGE2 and TGF-β1, on AM was different. At physiologically relevant doses (25–300 pg/ml), PGE2 did not cause significant inhibition of Hpopolysaccharide (Lps)-induced TNF release by AM in vitro but stimulated IL-6 (up to six fold), an inhibitor of AM-derived TNT. In contrast, TGF-β1 (0.5–50 ng/ml) inhibited both LPS-induced TNT and IL-6 release by 50% but had no effect on PGE2 production by AM. To determine the respective contribution of these different inhibitors in TNF suppression, AM from rats exposed to fibrogenic asbestos for weeks were treated with neutralizing antibody against TGF-β1 or indomethacin, an inhibitor of PGE2 synthesis. Treatment of rat AM with anti-TGF-β1 but not indomethacin, abrogated the observed TNT suppression. These results suggest that an autocrine, TGF-β1-dependent mechanism is involved in the down-regulation of TNF production by rat AM from animals with lung fibrosis

    Flavone acetic acid (FAA) with recombinant interleukin-2 (rIL-2) in advanced malignant melanoma. III: Cytokine studies.

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    Twelve patients undergoing IL-2 and flavone acetic acid (FAA) combination immunotherapy for advanced melanoma were studied throughout treatment for the induction of measurable levels of bioactive TNF, GM-CSF and IL-6 in their serum. This was to assess the extent of secondary cytokine induction in these patients and the possible role of such cytokines in both the toxic and therapeutic responses. The nature of the treatment schedule enabled these cytokines to be measured in response to FAA alone, FAA/IL-2 and FAA alone following IL-2/FAA activation of target cells. A small rise in the serum levels of these cytokines was seen on the initial course of FAA/IL-2 but this was minor compared to the marked elevation in levels 2-8 h following the initiation of the third course of FAA given with or without IL-2 and at a time point which coincided with maximum toxicity in those patients who experienced it. These results show that FAA alone can induce cytokine release from primed target cells. This may be associated with the therapeutic effect and/or toxicity of the agent

    Differential expression of mycobacterial antigen MPT64, apoptosis and inflammatory markers in multinucleated giant cells and epithelioid cells in granulomas caused by Mycobacterium tuberculosis

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    The development of granulomas is a major histopathological feature of tuberculosis. Very little information is available concerning the physiology and functions of different cell types in the tuberculous granulomas. The aim of this study was to compare the epithelioid cells (ECs) and multinucleated giant cells (MGCs) in the granulomas caused by Mycobacterium tuberculosis complex organisms. Lymph node biopsies from 30 cases of lymphadenitis were studied for expression of the secreted mycobacterial protein MPT64, caspase 3 as a marker of apoptosis, apoptosis-related proteins (Fas Ligand, Fas and Bax) and inflammatory cytokines (interleukin-10, transforming growth factor-β (TGF-β), tumour necrosis factor-α and interferon-γ) by immunohistochemistry. MGCs more often contained M. tuberculosis secretory antigen MPT64 (p < 0.001) and expressed more TGF-β (p = 0.004) than ECs. The total number of apoptotic MGCs was higher than the number of apoptotic ECs (p = 0.04). Interestingly, there was a significant negative correlation between apoptosis and MPT64 expression in MGCs (r = −0.569, p = 0.003), but not in ECs, implying that the heavy antigen load would lead to inhibition of apoptosis in these cells. When compared with ECs, higher percentage of MGCs expressed Fas Ligand and Fas (p < 0.004). The role of MGCs may thus be different from surrounding ECs and these cells by virtue of higher mycobacterial antigen load, more TGF-β and reduced apoptosis may contribute towards persistence of infection
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