Rheumatoid arthritis (RA) is a chronic infl ammatory disease of synovial joints that is associated with cartilage and bone destruction. Death Receptor 3 (DR3), a tumor necrosis factor (TNF) receptor superfamily member, has recently been associated with the pathogenesis of RA. We demonstrate that absence of DR3 confers resistance to the development of adverse bone pathology in experimental antigen-induced arthritis (AIA). DR3 ko mice exhibited a reduction in all histopathological hallmarks of AIA but, in particular, failed to develop subchondral bone erosions and were completely protected from this characteristic of AIA. In contrast, TNF-like protein 1A (TL1A), the ligand for DR3, exacerbated disease in a dose-and DR3-dependent fashion. Analysis of osteoclast number within AIA joint revealed a reduction in areas susceptible to bone erosion in DR3 ko mice, whereas in vitro osteoclastogenesis assays showed that TL1A could directly promote osteoclastogenesis in mouse and man. Treatment with antagonistic anti-TL1A mAb protected animals in a systemic model of RA disease collagen-induced arthritis. We therefore conclude that the DR3 -TL1A pathway regulates joint destruction in two murine models of arthritis and represents a potential novel target for therapeutic intervention in infl ammatory joint disease.

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The tumor necrosis factor (TNF) superfamily protein TNF-like 1A (TL1A) is the ligand for death receptor 3 (DR3). TL1A is induced on activated dendritic cells (DCs) and its expression has been linked to human inflammatory bowel disease. To address how TL1A might influence intestinal inflammation, we generated transgenic mice that constitutively express TL1A on DCs. TL1A transgenic mice developed striking goblet cell hyperplasia in the ileum that was associated with elevated interleukin (IL)-13 levels in the small intestine. IL-13-and IL-17-producing small intestinal lamina propria T cells were increased in TL1A transgenic mice. TL1A also enhanced regulatory T (Treg) cell turnover in vivo and directly stimulated Treg cell proliferation in vitro.The presence of TL1A attenuated the ability of Treg cells to suppress conventional T cells, an effect that required DR3 signaling in either conventional T cells or Treg cells. Our findings identify mechanisms by which chronic DR3 signaling could promote pathogenesis in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the gastrointestinal tract of unclear aetiology of which two major forms are Crohn's disease (CD) and ulcerative colitis (UC). CD and UC are immunologically distinct, although they both result from hyperactivation of proinflammatory pathways in intestines and disruption of intestinal epithelial barrier. Members of the tumour necrosis factor superfamily (TNFSF) are molecules of broad spectrum of activity, including direct disruption of intestinal epithelial barrier integrity and costimulation of proinflammatory functions of lymphocytes. Tumour necrosis factor (TNF) has a well-established pathological role in IBD which also serves as a target in IBD treatment. In this review we discuss the role of TNF and other TNFSF members, notably, TL1A, FasL, LIGHT, TRAIL, and TWEAK, in the pathogenesis of IBD.

TNFRSF25 is a member of the TNF receptor superfamily (TNFRSF) that binds to the TNFlike protein TL1A. Although recent studies have demonstrated a role for TNFRSF25 in regulating CD41 T-cell responses, it remains to be determined if TNFRSF25 functions as a costimulatory receptor for CD8 1 T cells. Here, we demonstrate that ectopic expression of TL1A on mouse plasmacytomas promotes elimination of tumor cells in a CD8 1 T-celldependent manner and renders mice immune to a subsequent challenge with tumor cells.To gain further insight into the role of TNFRSF25 in CD8 1 T-cell responses, we analyzed the effect of TNFRSF25 triggering on OT-I TCR transgenic T cells. We demonstrate that TNFRSF25 triggering in vivo with soluble TL1A promotes the proliferation and accumulation of antigen-specific CD8 1 T cells as well as their differentiation into CTLs. Furthermore, we show that TNFRSF25 also functions as a costimulatory receptor for memory CD8 1 T cells. Thus, TNFRSF25 triggering enhances the secondary expansion of endogenous antigen-specific memory CD8 1 T cells. Our data suggest that TNFRSF25 agonists, such as soluble TL1A, could potentially be used to enhance the immunogenicity of vaccines that aim to elicit human anti-tumor CD8 1 T cells. Results and discussionEctopic expression of TL1A-mediates CD8 1 T-celldependent rejection of J558L tumorsThree transfected J558L tumor cell lines that express relatively high levels of TL1A (Fig. 1A) were combined immediately before inoculation into mice. In T-and B-cell-deficient SCID mice TL1A-expressing J558L tumor cells grew with similar kinetics to control J558L cells transfected with the empty vector (Fig. 1B). In sharp contrast, TL1A-expressing J558L cells, but not control tumor cells, were rejected in immune competent BALB/c mice, demonstrating that tumor rejection requires an adaptive immune response (Fig. 1C). In many cases, TL1A-expressing J558L tumors grew initially following s.c. injection into BALB/c mice, but these tumors regressed and the majority of animals had no detectable tumors 70 days after initial tumor inoculation (Fig. 1C). Mice that rejected the TL1A-expressing J558L tumors were immune to a subsequent challenge with non-transfected J558L tumor cells ( Fig. 1D and Supporting Information Fig. 1A). To assess the role of T-cell subsets in TL1A-mediated tumor rejection, we administered anti-CD4 or anti-CD8 depleting mAbs prior to inoculation with TL1A-expressing J558L tumor cells. Only depletion of CD8 1 T cells resulted in a significant and consistent prevention of tumor cell rejection ( Fig. 1E and Supporting Information Fig. 1B). These results demonstrate that ectopic expression of TL1A can lead to the generation of a protective anti-tumor immune response and implicate a role for TNFRSF25 on CD8 1 T cells in mediating this effect.TNFRSF25 triggering costimulates Ag-specific CD8 1 T cells in vitroTo define more precisely the role of TNFRSF25 triggering in CD8 1 T-cell responses, we used OVA-specific TCR transgenic OT-IT cells as a model to study the effects of ...

Although the skin production of vitamin D is initiated by ultraviolet radiation type B (UVB), the role vitamin D plays in antioxidative or pro-oxidative responses remains to be elucidated.. We have used immortalized human HaCaT keratinocytes as a model of proliferating epidermal cells to test the influence of vitamin D on cellular response to H2O2 or the anti-cancer drug, cisplatin. Incubation of keratinocytes with 1,25(OH)2D3 or its low calcemic analogues, 20(OH)D3, 21(OH)pD or calcipotriol, sensitized cells to ROS resulting in more potent inhibition of keratinocyte proliferation by H2O2 in the presence of vitamin D compounds. These results were supported by cell cycle and apoptosis analyses, and measurement of the mitochondrial transmembrane potentials (MMP), however some unique properties of individual secosteroids were observed. Furthermore, in HaCaT keratinocytes treated with H2O2, 1,25(OH)2D3, 21(OH)pD and calcipotriol stimulated the expression of SOD1 and CAT genes, but not SOD2, indicating a possible role of mitochondria in ROS-modulated cell death. 1,25(OH)2D3 also showed a short-term, protective effect on HaCaT keratinocytes, as exemplified by the inhibition of apoptosis and the maintenance of MMP. However, with prolonged incubation with H2O2 or cisplatin, 1,25(OH)2D3 caused an acceleration in the death of the keratinocytes. Therefore, we propose that lead vitamin D derivatives can protect the epidermis against neoplastic transformation secondary to oxidative or UV-induced stress through activation of vitamin D-signaling. Furthermore, our data suggest that treatment with low calcemic vitamin D analogs or the maintenance of optimal level of vitamin D by proper supplementation, can enhance the anticancer efficacy of cisplatin

BackgroundNK cells are key effector lymphocytes of innate immunity provided with constitutive cytolytic activity, however, their role in human ageing is not entirely understood. The study aimed to analyze the expression of proteins involved in cellular stress response sirtuin 1 (SIRT1), heat shock protein 70 (HSP70) and manganese superoxide dismutase (SOD2) in non-stimulated NK cells of the oldest seniors (n = 25; aged over 85; mean age 88 years) and compare with NK cells of the old (n = 30; aged under 85; mean age 76 years) and the young (n = 32; mean age 21 years) to find potential relationships between the level of expression of these proteins in NK cells and longevity. The concentration of carbonyl groups and 8-isoprostanes in NK cell lysates reflecting the level of oxidative stress was also measured.ResultsThe group of the oldest seniors differed from the other age groups by significantly higher percentage of NK cells expressing SIRT1, HSP70 and SOD2. The concentration of both carbonyl groups and 8-isoprostanes in NK cell extracts remained within the normal range in all age groups. The percentage of NK cells with the expression of, respectively, SIRT1, HSP70 and SOD2 correlated positively with age. Some correlations between expression levels of particular protective proteins SIRT1, HSP70 and SOD2 were observed in the study population.ConclusionsThe increased expression of cellular protective proteins SIRT1, HSP70 and SOD2 in NK cells of the oldest seniors seems to correspond to longevity and the observed correlations may suggest the involvement of these proteins in establishing NK cell homeostasis specific for healthy ageing process.

Clear-cell renal cell carcinoma (ccRCC) is the most common subtype of RCC (70–80%) and is associated with poor prognosis in 40% of cases mainly due to metastasis in the course of the disease. RASSF1, with its isoforms RASSF1A and RASSF1C, is a tumor suppressor gene which has not been fully analyzed in ccRCC yet. The epigenetic downregulation of RASSF1A is commonly associated with promoter hyper-methylation. The aim of the present study was to compare the ccRCC outcomes with the expression of RASSF1A and RASSF1C. Tissues were obtained from 86 ccRCC patients. RASSF1A and RASSF1C mRNA levels were assessed in tumor and matched normal kidney tissue, and in 12 samples of local metastases by quantitative PCR (qPCR). RASSF1A and RASSF1C proteins levels were semi-quantified in 58 samples by western blot analysis and their tissue localization was assessed by immunohistochemistry. Hypermethylation of RASSF1A promoter was measured by high-resolution-melting methylation-specific qPCR. RASSF1A mRNA levels were 4 and 5 times lower in 66% of tumor and 75% metastasized samples. RASSF1A hypermethylation was found in 40% of analyzed T cases. RASSF1A protein expression was 5 or 20 times decreased in 70% tumor and 75% metastatic samples, respectively. RASSF1A hypermethylation, mRNA and protein levels were associated with TNM progression and higher Fuhrman's grading. Decreased RASSF1A expression, hyper-methylation, TNM and Fuhrman's grading were associated with poorer overall survival (OS). Cox hazard ratio (HR) analysis revealed predictor role of RASSF1A mRNA levels on OS and progression-free survival (PFS) in relation to Fuhrman's grading (OS HR=2.25, PFS HR=2.93). RASSF1C levels were increased in ccRCC; no correlations with clinicopathological variables were found. We conclude that RASSF1C gene is not involved in ccRCC progression and we propose that the measurements of RASSF1A mRNA levels in paired tumor-normal kidney tissue could serve as a new prognostic factor in ccRCC.