The immune system must be able to mount a response against pathogens and transformed cells while remaining tolerant to healthy host tissue. A key process for ensuring this self-tolerance is the negative selection of self-reactive thymocytes. Expression of Programmed Death-1 (PD-1), a co-inhibitory member of the CD28 family associated with dampened peripheral immune responses,was found to be upregulated in 20-40% of thymocytes undergoing negative selection in the HYcd4model of thymic development. Although analysis of gene and protein expression directly ex vivo indicates that PD-1- and PD-1+ thymocytes are equally apoptotic, PD-1+ thymocytes appear to be protected from apoptosis in an in vitro stimulation assay. Analysis of HYcd4PD-1-/- mice indicates that thymocytes receive a higher intensity signal in the absence of PD-1. Future work utilizing HYcd4PD-1-/- mice will increase our understanding of the role of PD-1 in thymic negative selection. / Immunology

IL-2 has multiple functions in T cell-mediated adaptive immunity. The stringent control of its expression is important for T cell activation, proliferation and the subsequent T cell clone contraction. Our lab has recently shown that the transcriptional repressor Blimp-1 is part of a negative feedback loop which controls IL-2 gene expression in mice. Understanding the molecular mechanisms of this signaling loop in T cells might help us to better understand the regulation as well as the role of IL-2 in T cell immunity. The human ortholog to murine Blimp-1 is termed PRDI-BF1 (each encoded by the respective Prdm1 gene). Both genes contain five zinc finger regions, whereby the first two zinc fingers are dispensable for DNA binding. In case of the human protein they are instead required to recruit the G9?Ñ methyltransferase to the gene promotor. We found that the human wild-type PRDI-BF1 protein suppressed IL-2 production in murine T cells, while deletion of the first two zinc fingers abolished this ability. Thus, a similar Blimp-1-mediated methylation mechanism might exist in IL-2 gene silencing. IL-2/IL-2R signaling is indispensable for Blimp-1 induction. PI-3Kinase and Stat5 are downstream of the IL-2 receptor complex and are known to contribute to IL-2 inhibition in T cells from C57BL/6 mice. However, activating only these two pathways are still not sufficient to induce Blimp-1 or suppress IL-2 expression in in IL-2R beta-/- mice. The Blimp-1-dependent IL-2 self regulatory loop is not functional in IL-2R beta-/-mice. In order to conveniently study this dysregulation we crossed these mice with a GFP transgenic strain in which the GFP transgene is under the control of IL-2 promoter sequence. In IL-2R beta-/-IL-2p-GFP mice about five times as many spleenic CD4+ T cells transcribe IL-2pGFP, compared to the littermate IL-2R beta+/-IL-2p-GFP control animals. And most of the GFP cells demonstrate activated phenotype (CD44HighCD62Llow). Blimp-1 is known as a master regulator of B cell terminal differentiation. Since a recent report indicated that IL-2 signaling via STAT5 constrains Th17 Cell differentiation, we speculated that Blimp-1 might play a similar role in effector T cell differentiation. In order to evaluate this possibility, activated CD4+ T cells from C57BL/6 mice were transduced with Blimp-1 and cultured under Th17 polarizing conditions. Blimp-1 overexpression in did not change the profile of IL-17 production.

Potato chips are very popular in the United States. Recently, an enormous interest in developing snacks from fruits and vegetables with high quality has been assessed. Mango, due to its characteristic flavor and nutritional value, is excellent for snack production. Osmotic dehydration (OD) as a pre-treatment and vacuum frying (1.33 kPa) processes were proposed to obtain high quality mango chips. Mango ?Tommy Atkins? slices were pre-treated with different OD concentrations (40, 50, and 65w/v), times (45, 60, and 70 min), and temperatures (22, 40, and 57oC). Physical and chemical properties (aw, pH, oBrix, sugar gain, water loss, and shrinkage) after OD were studied. The pre-treated slices were vacuum fried (1.33 kPa) at 120, 130, and 138oC and product quality attributes (PQA) (oil content, texture, porosity, color, microstructure, and carotenoid content) were determined. Microstructure of the chips was analyzed using an environmental scanning electron microscope. Effect of frying temperatures at optimum OD (65 w/v at 40oC) times was tested. The consumer tests showed that samples were all acceptable. The best mango chips process was the one with 65 w/v concentration for 60 min (pre-treatment) and vacuum frying at 120oC. Kinetic studies on oil content, texture, porosity, color, and carotenoid retention were performed. Oil absorption was modeled by a fractional conversion kinetic model. Absorption rate constant increased with frying temperature. Diameter changes in the chips, although not significant (P>0.05), followed an initial expansion to later decrease. Thickness of the slices increased (puffed) (around 60%) with time for all frying temperatures. Texture changes were for two frying periods: (1) water removal and crust formation and (2) slices became tougher and crispier and the end of frying. Porosity in the samples increased with frying, and a fractional conversion best described this phenomenon. Color *a (redness) increased with frying time and temperature and was modeled using a logistic model. Color *b (yellowness) increased up to 30 s of frying and then decreased. Carotenoids degradation followed a first order model, with a significant (P<0.05) decrease with frying temperature. Mango chips fried under atmospheric fryer had less carotenoid retention (25%) than with a vacuum fryer.

La protéine Tax du virus HTLV-1 a les propriétés d'un oncogène viral et joue un rôle important dans l'induction de la transformation cellulaire menant à l'ATL. L'activité oncogène de Tax résulte d'effets pléiotropes sur divers mécanismes cellulaires y compris l'activation de l'expression de gènes cellulaires spécifiques par la voie NF-B et la dérégulation de la progression du cycle cellulaire. Dans ce travail, nous avons mis en évidence que Tax est une protéine hautement modifiée dans diverses lignées cellulaires y compris dans les lymphocytes T transformés par HTLV-1. L'ensemble des modifications post-traductionnelles de Tax forment une suite hiérarchisée qui contrôlent la localisation intracellulaire de Tax, sa capacité d'activer les kinases IKK et la voie de signalisation des facteurs NF-B et sa capacité d'induire un arrêt dans la progression de la mitose. En effet, la phosphorylation de Tax contrôle son ubiquitination et son passage dans le noyau où elle est sumoylée et acétylée. L’ubiquitination et la sumoylation de Tax agissent de manière concertée pour permettre l’activation de l’expression des gènes par la voie NF-B tandis que son acétylation permet de lever le blocage induit en fin de mitose. Les effets exercés par les modifications post-traductionnelles sur les fonctions oncogènes de la protéine Tax suggèrent que ces modifications pourraient être des cibles thérapeutiques pour le développement de traitements contre l'ATL.

Statistikfrån 2012 visade att 346 679 personer i Sverige har sjukdomen diabetes, detta omfattar cirka 4% av befolkningen och av dessa har cirka 50 000 personer diabetes typ 1. Forskning har visat att diabetiker har lägre livskvalitet än övrig befolkning. Livskvaliteten påverkas av fysisk hälsa, psykologiskt tillstånd, grad av självständighet och sociala relationer. Tonåringar med diabetes typ 1 upplever sig annorlunda jämfört med sina vänner och det är betydelsefullt att identifiera faktorer som påverkar livskvaliteten. Syftet med studien var att belysa faktorer som påverkar livskvaliteten hos tonåringar med diabetes typ 1. Studien genomfördes som en litteraturstudie och 13 vetenskapliga artiklar analyserades. Resultatet av studien visar att HbA1c, psykiskt välbefinnande, närstående, behandling och kontroll av sjukdomen påverkar livskvaliteten hos tonåringar med diabetes typ 1. För att kunna hjälpa tonåringar att höja livskvaliteten är det av stor betydelse att identifiera de faktorer som påverkar livskvaliteten. Vidare forskning bör fokusera på evidens för hur de faktorer som påverkar livskvaliteten kan påverkas.

BACKGROUND: Endothelial dysfunction is a principal player in the development of allograft vasculopathy and allograft failure. The hallmark of endothelial dysfunction is impaired nitric oxide bioavailability. Recent evidence implicates endothelin-1 as an integral component of endothelial dysfunction. Immunosuppressive drugs have also been associated with the development of graft vasculopathy. We speculated that endothelin-1 results in endothelial dysfunction by impairing nitric oxide homeostasis and is a player in hypoxia and reperfusion induced vasomotor injury. In addition, we hypothesized that endothelin-1 antagonism with bosentan will limit hypoxia and reperfusion injury and prevent immunosuppressive drug injury. METHODS: We utilized human saphenous vein endothelial cells to evaluate the effects of endothelin-1, hypoxia and reperfusion on endothelial function, protein kinase modulation and cell survival. We also employed a rodent model of chronic drug therapy to assess the effect of cyclosporine and rapamycin treatment on vasomotor function. We investigated the role of nitric oxide augmentation and bosentan in preventing hypoxia and reperfusion injury and in limiting immunosuppressive drug induced vasomotor dysfunction. RESULTS: Elevated endothelin-1 levels resulted in impaired nitric oxide release and endothelial function. The effects of endothelin-1 as well as hypoxia and reperfusion were mediated by altered protein kinase B and protein kinase C activity resulting in endothelial dysfunction. We revealed that endothelin-1 is a key player in hypoxia and reperfusion induced endothelial injury. The immunosuppressive drug cyclosporine induced vasomotor dysfunction while rapamycin preserved vessel homeostasis. Vasomotor dysfunction was characterized by impaired nitric oxide and endothelin-1 homeostasis. Bosentan limited the deleterious effects of endothelin-1, hypoxic injury, reperfusion injury and cyclosporine induced vasomotor impairment. CONCLUSIONS: Our study revealed that endothelin-1 exposure as well as hypoxia and reperfusion results in endothelial dysfunction by altering specific protein kinase C isoform activities and inhibiting protein kinase B. Cyclosporine induced vasomotor dysfunction was mediated by altered nitric oxide and endothelin-1 homeostasis while rapamycin was endothelial protective. Bosentan proved to be an effective therapy at preventing endothelin-1, hypoxia and reperfusion and cyclosporine induced endothelial dysfunction. Protein kinase C modulation as well as bosentan may prove to be NOVEL therapies to prevent endothelial injury during cardiac transplantation.

Protein transduction domains (PTDs) are short peptide sequences that can transport wide varieties of cargo across cell membranes. This study assessed the transduction ability of fusion proteins containing optimised variants of the PTD from HIV-1 transactivator of transcription (Tat). Uptake of Tat-PTDs was determined by fluorescent microscopy using the fluorescent protein Venus as a tag, and also by using fusion proteins containing caspase-7 and RhoA bound to Tat-PTD. Upon entering the cytosol the latter two induce apoptosis and the formation of cytoplasmic extensions, morphological changes easily observed by microscopy. It was found that PTDs with two, three or four sequential Tat-PTD domains could bind to the surface of two of the five cell lines tested. Fluorescent microscopy, however, indicated that the fluorescent constructs remained on the cell surface. As well, PTDs bound to caspase-7 or RhoA did not induce any visible morphological changes in the cells.

With increasing computational power, simulations of regional climate are now becoming possible on convective-resolving grids, thus eliminating the need for a convective parameterization. In the present study, a series of seasonal calculations using the Weather Research and Forecasting (WRF) model are computed at 4-km grid spacing, which reasonably resolves most convective systems. Simulations are computed for both the DJF and MAM seasons as averaged over 2005-2008, with a model domain covering the majority of the Amazon Basin and the adjacent South American coastline. Precipitation statistics are computed and compared to satellite rainfall retrieval data from the 13-year Tropical Rainfall Measuring Mission (TRMM) record. For comparison, a set of companion simulations with 12-km grid spacing are also computed, using the Kain-Fritsch convective parameterization. As compared to the 12-km runs, the 4-km simulations show significant improvement in the overall mean rain rate, the rain rate probability distributions, and the diurnal evolution and timing of precipitation. Both the 4-km and 12-km cases capture the coastal propagating signal and the interior basin-wide diurnal oscillation; however, the 4-km case shows better timing and evolution statistics. Compared to TRMM, the 4-km case rains too infrequently, but is more likely to produce rain events at high rain rates, thus resulting in a similar overall average rain rate. Overall, the present calculations show significant promise for computing regional rainfall patterns on convective-resolving grids.

Protein transduction domains (PTDs) are short peptide sequences that can transport wide varieties of cargo across cell membranes. This study assessed the transduction ability of fusion proteins containing optimised variants of the PTD from HIV-1 transactivator of transcription (Tat). Uptake of Tat-PTDs was determined by fluorescent microscopy using the fluorescent protein Venus as a tag, and also by using fusion proteins containing caspase-7 and RhoA bound to Tat-PTD. Upon entering the cytosol the latter two induce apoptosis and the formation of cytoplasmic extensions, morphological changes easily observed by microscopy. It was found that PTDs with two, three or four sequential Tat-PTD domains could bind to the surface of two of the five cell lines tested. Fluorescent microscopy, however, indicated that the fluorescent constructs remained on the cell surface. As well, PTDs bound to caspase-7 or RhoA did not induce any visible morphological changes in the cells.

BACKGROUND: Endothelial dysfunction is a principal player in the development of allograft vasculopathy and allograft failure. The hallmark of endothelial dysfunction is impaired nitric oxide bioavailability. Recent evidence implicates endothelin-1 as an integral component of endothelial dysfunction. Immunosuppressive drugs have also been associated with the development of graft vasculopathy. We speculated that endothelin-1 results in endothelial dysfunction by impairing nitric oxide homeostasis and is a player in hypoxia and reperfusion induced vasomotor injury. In addition, we hypothesized that endothelin-1 antagonism with bosentan will limit hypoxia and reperfusion injury and prevent immunosuppressive drug injury. METHODS: We utilized human saphenous vein endothelial cells to evaluate the effects of endothelin-1, hypoxia and reperfusion on endothelial function, protein kinase modulation and cell survival. We also employed a rodent model of chronic drug therapy to assess the effect of cyclosporine and rapamycin treatment on vasomotor function. We investigated the role of nitric oxide augmentation and bosentan in preventing hypoxia and reperfusion injury and in limiting immunosuppressive drug induced vasomotor dysfunction. RESULTS: Elevated endothelin-1 levels resulted in impaired nitric oxide release and endothelial function. The effects of endothelin-1 as well as hypoxia and reperfusion were mediated by altered protein kinase B and protein kinase C activity resulting in endothelial dysfunction. We revealed that endothelin-1 is a key player in hypoxia and reperfusion induced endothelial injury. The immunosuppressive drug cyclosporine induced vasomotor dysfunction while rapamycin preserved vessel homeostasis. Vasomotor dysfunction was characterized by impaired nitric oxide and endothelin-1 homeostasis. Bosentan limited the deleterious effects of endothelin-1, hypoxic injury, reperfusion injury and cyclosporine induced vasomotor impairment. CONCLUSIONS: Our study revealed that endothelin-1 exposure as well as hypoxia and reperfusion results in endothelial dysfunction by altering specific protein kinase C isoform activities and inhibiting protein kinase B. Cyclosporine induced vasomotor dysfunction was mediated by altered nitric oxide and endothelin-1 homeostasis while rapamycin was endothelial protective. Bosentan proved to be an effective therapy at preventing endothelin-1, hypoxia and reperfusion and cyclosporine induced endothelial dysfunction. Protein kinase C modulation as well as bosentan may prove to be NOVEL therapies to prevent endothelial injury during cardiac transplantation.