Search results for "Tumor necrosis factor-alpha"

Liver-infiltrating and circulating CD4+ T cells in chronic hepatitis C: immunodominant epitopes, HLA-restriction and functional significance.

2008

The aim was to assess the specificity and functional significance of liver-infiltrating and peripheral blood T cells in chronic hepatitis C. Peripheral blood mononuclear cells hepatitis C virus from 50 of 58 (86.2%) patients with chronic hepatitis C virus infection and 6 of 28 (21.4%) controls showed a proliferative T cell response to at least one of 16 synthetic peptides covering highly conserved regions of the core, envelope (El) and non-structural regions (NS4) of hepatitis C virus. However, six immunodominant peptides were exclusively recognized by the proliferating blood mononuclear cells from 46 patients with chronic hepatitis C virus infection (79.3%). Fine specificity and HLA-restri…

Is TNF-α really involved in giant cell arteritis pathogenesis?

2013

Giant cell arteritis (GCA) is the most frequent vasculitis in people >50 years, and glucocorticoids (GC) remain the cornerstone of the treatment. However, this long-term treatment is responsible for numerous GC-related complications.1 Thus, reliable GC-sparing drugs need to be explored. Seror et al 2 have recently reported the inefficacy of adalimumab, a humanised anti-TNF-α therapy, as a GC-sparing drug in the treatment of GCA. These clinical results contrast with previous studies reporting a production of TNF-α by giant cells and macrophages in GCA lesions.3 However, recent advance in the knowledge of GCA pathogenesis have shown that macrophages and giant cells are not involved in the fir…

Antibodies against tumor necrosis factor (TNF) induce T-cell apoptosis in patients with inflammatory bowel diseases via TNF receptor 2 and intestinal…

2011

Background & Aims The anti–tumor necrosis factor (TNF) antibodies infliximab, adalimumab, and certolizumab pegol have proven clinical efficacy in Crohn's disease. Here, we assessed the effects of anti-TNF antibodies on apoptosis in inflammatory bowel disease (IBD). Methods CD14 + macrophages and CD4 + T cells were isolated from peripheral blood and lamina propria mononuclear cells from patients with IBD and control patients. Cell surface markers and apoptosis were assessed by immunohistology and fluorescence-activated cell sorting techniques. Results Lamina propria CD14 + macrophages showed significantly more frequent and higher membrane-bound TNF (mTNF) expression than CD4 + T cells in IBD…

Methotrexate specifically modulates cytokine production by T cells and macrophages in murine collagen-induced arthritis (CIA): a mechanism for methot…

1999

SUMMARYImmunosuppressive therapy with methotrexate (MTX) has been established as effective treatment for patients with rheumatoid arthritis. To analyse the therapeutic potential and mechanisms of action of MTX, we determined serum cytokine levels and cytokine production by splenic T cells and macrophages in untreated and MTX-treated mice. Furthermore, we assessed the role of MTX in a murine model of experimental arthritis induced by collagen type II (CIA). MTX reduced spontaneous and IL-15-induced tumour necrosis factor (TNF) production by splenic T cells but not by macrophages from healthy mice in vitro in a dose-dependent manner. In contrast, interferon-gamma (IFN-γ) production was less s…

Impaired immune response to Candida albicans in aged mice

2006

The prevalence of opportunistic fungal infections has increased dramatically among the aged population in recent years. This work investigated the effect of ageing on murine defences against Candida albicans. Aged C57BL/6 mice that were experimentally infected intravenously had a significantly impaired survival and a higher tissue fungal burden compared with young mice. In vitro production of tumour necrosis factor (TNF)-α by macrophages from aged mice in response to yeast cells and hyphae of C. albicans was significantly lower than production by macrophages from young mice. In vitro production of cytokines, such as TNF-α and gamma interferon (IFN-γ), by antigen-stimulated splenocytes from …

Dendritic Cells Lose Ability to Present Protein Antigen after Stimulating Antigen-Specific T Cell Responses, despite Upregulation of MHC Class II Exp…

2000

Abstract Immature dendritic cells (DC) take up, process and present protein antigens; mature DC are specialized for stimulating primary T cell responses with increased expression of MHC class II and co-stimulatory molecules, but are incapable of processing and presenting soluble protein. The current study examined whether maturation of DC is triggered by T cell recognition of antigens presented by immature DC. Human DC derived from CD34+ progenitor cells by culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-6 (IL-6) in serum-free medium could prime naive CD4+ T cells to keyhole limpet hemocyanin (KLH) and ovalbumin (OVA). The cultured DC retained the abil…

Mycophenolate mofetil for treatment of active inflammatory bowel disease. Clinical and immunological studies.

1998

Contrary roles of IL-4 and IL-12 on IL-10 production and proliferation of human tumour reactive T cells.

1997

The cytokine profile of tumour reactive T cells is likely to play a central role in their function. However, little is known about how cytokine patterns of tumour reactive T cells can be regulated. Here, the authors investigated the influence of exogenous regulatory cytokines in addition to interleukin-2 (IL-2) on cytokine patterns and the proliferation of T cells recognizing an autologous sarcoma cell line. In this system, IL-4 and IL-12 showed the most polarizing influences on tumour reactive T cells. Exogenous IL-4 induced a predominant production of IL-4 while decreasing the interferon-gamma (IFN-gamma) and IL-10 production by tumour reactive T cells. It also stimulated the growth of tu…

Cachexia: a therapeutic approach beyond cytokine antagonism

2002

Cachexia is seen in a number of chronic diseases, and it is always associated with a poor prognosis. Irrespective of etiology, the development of cachexia appears to share a common pathophysiological pathway. This includes induction of proteasome-dependent myofibril-degradation, which is thought to be secondary to stimulation by enhanced levels of pro-inflammatory cytokines. Elevation of tumor necrosis factor-alpha (TNFalpha) and other plasma cytokines has been demonstrated in many conditions associated with cachexia. Despite improved pathophysiological understanding, a specific treatment for cachexia has not yet been established. Whilst direct TNFalpha antagonism has therapeutic appeal, th…

cIAP1 regulates TNF-mediated cdc42 activation and filopodia formation

2013

International audience; umour necrosis factor-α (TNF) is a cytokine endowed with multiple functions, depending on the cellular and environmental context. TNF receptor engagement induces the formation of a multimolecular complex including the TNFR-associated factor TRAF2, the receptor-interaction protein kinase RIP1 and the cellular inhibitor of apoptosis cIAP1, the latter being essential for NF-κB activation. Here, we show that cIAP1 also regulates TNF-induced actin cytoskeleton reorganization through a cdc42-dependent, NF-κB-independent pathway. Deletion of cIAP1 prevents TNF-induced filopodia and cdc42 activation. The expression of cIAP1 or its E3-ubiquitin ligase-defective mutant restore…