Thermal- and Oxidative Stress Causes Enhanced Release of NKG2D Ligand-Bearing Immunosuppressive Exosomes in Leukemia/Lymphoma T and B Cells

Immune evasion from NK surveillance related to inadequate NK-cell function has been suggested as an explanation of the high incidence of relapse and fatal outcome of many blood malignancies. In this report we have used Jurkat and Raji cell lines as a model for studies of the NKG2D receptor-ligand system in T-and B cell leukemia/lymphoma. Using real-time quantitative RT-PCR and immunoflow cytometry we show that Jurkat and Raji cells constitutively express mRNA and protein for the stress-inducible NKG2D ligands MICA/B and ULBP1 and 2, and up-regulate the expression in a cell-line specific and stress-specific manner. Furthermore, we revealed by electron microscopy, immunoflow cytometry and western blot that these ligands were expressed and secreted on exosomes, nanometer-sized microvesicles of endosomal origin. Acting as a decoy, the NKG2D ligand-bearing exosomes downregulate the in vitro NKG2D receptor-mediated cytotoxicity and thus impair NK-cell function. Interestingly, thermal and oxidative stress enhanced the exosome secretion generating more soluble NKG2D ligands that aggravated the impairment of the cytotoxic response. Taken together, our results might partly explain the clinically observed NK-cell dysfunction in patients suffering from leukemia/lymphoma. The adverse effect of thermal and oxidative stress, enhancing the release of immunosuppressive exosomes, should be considered when cytostatic and hyperthermal anti-cancer therapies are designed

Auxilin is a novel susceptibility gene for congenital heart block which directly impacts fetal heart function

Objective: Neonatal lupus erythematosus (NLE) may develop after transplacental transfer of maternal autoantibodies with cardiac manifestations (congenital heart block, CHB) including atrioventricular block, atrial and ventricular arrhythmias, and cardiomyopathies. The association with anti-Ro/SSA antibodies is well established, but a recurrence rate of only 12%–16% despite persisting maternal autoantibodies suggests that additional factors are required for CHB development. Here, we identify fetal genetic variants conferring risk of CHB and elucidate their effects on cardiac function. Methods: A genome-wide association study was performed in families with at least one case of CHB. Gene expression was analysed by microarrays, RNA sequencing and PCR and protein expression by western blot, immunohistochemistry, immunofluorescence and flow cytometry. Calcium regulation and connectivity were analysed in primary cardiomyocytes and cells induced from pleuripotent stem cells. Fetal heart performance was analysed by Doppler/echocardiography. Results: We identified DNAJC6 as a novel fetal susceptibility gene, with decreased cardiac expression of DNAJC6 associated with the disease risk genotype. We further demonstrate that fetal cardiomyocytes deficient in auxilin, the protein encoded by DNAJC6, have abnormal connectivity and Ca2+ homoeostasis in culture, as well as decreased cell surface expression of the Cav1.3 calcium channel. Doppler echocardiography of auxilin-deficient fetal mice revealed cardiac NLE abnormalities in utero, including abnormal heart rhythm with atrial and ventricular ectopias, as well as a prolonged atrioventricular time intervals. Conclusions: Our study identifies auxilin as the first genetic susceptibility factor in NLE modulating cardiac function, opening new avenues for the development of screening and therapeutic strategies in CHB.publishedVersio

Exosomes and the NKG2D receptor-ligand system in pregnancy and cancer : using stress for survival

Although not obvious at first sight, several parallels can be drawn between pregnancy andcancer. Many proliferative, invasive and immune tolerance mechanisms that supportnormal pregnancy are also exploited by malignancies to establish a nutrient supply andevade or edit the immune response of the host. The human placenta, of crucial importancefor pregnancy success, and its main cells, the trophoblast, share several features withmalignant cells such as high cell proliferation rate, lack of cell-contact inhibition andinvasiveness. Both in cancer and in pregnancy, the immune defense mechanisms,potentially threatening the survival of the tumor or the fetus, are progressively blunted oreven turned into tumor- or pregnancy-promoting players. Amongst immune mechanisms that are meant to protect the host from cancer and can be apotential threat to the fetus, the NKG2D receptor-ligand system stands out as the mostpowerful, stress-inducible “danger detector” system that comprises the activating NK cellreceptor NKG2D and its ligands, the MIC (MHC class I Chain-related proteins A and B)and ULBP (UL-16 Binding Proteins) families. It is the major cytotoxic mechanism in thebody promoting surveillance and homeostasis. In the present thesis we investigate theNKG2D receptor-ligand system in human early normal pregnancy and in theleukemia/lymphoma cell lines Jurkat and Raji and ask the questions “How is the NKG2Dreceptor-ligand system functioning in pregnancy and tumor? How is the danger of cytotoxicattack of the fetus avoided? Why is the immunosurveillance function compromised incancer patients?” We developed a method to isolate and culture villous trophoblast from early human normalplacenta and used it to study the NKG2D receptor-ligand system. We discovered that theNKG2D ligand families of molecules MICA/B and ULBP1-5 are constitutively expressedby the syncytiotrophoblast of the chorionic villi. Using immnunoelectron microscopy, westudied the expression of these molecules at the subcellular level and could show for thefirst time that they are preferably expressed on microvesicles in multivesicular bodies(MVB) of the late endosomal compartment and are secreted as exosomes. Exosomes arenanometer sized microvesicles of endosomal origin, produced and secreted by a great7variety of normal and tumor cells. The exosomes are packages of proteins and ribonucleicacids that function as “mail” or “messengers” between cells conveying different biologicalinformation. We isolated and studied exosomes from placental explant cultures. We foundthat they carry NKG2D ligands on their surface and are able to bind and down-regulate thecognate receptor on NK-, CD8+ and T cells. The down-regulation selectively causedimpairment of the cytotoxic response of the cells but did not affect their lytic ability asmeasured by perforin content and gene transcription. Thus, the NKG2D ligand-bearingexosomes suppress the cytotoxic activity of the cells in the vicinity of the placenta, leavingtheir cytolytic machinery intact, ready to function when the cognate receptor isrestored/recycled. These findings highlight the role of placental exosomes in the fetalmaternalimmune escape and support the view of placenta as an unique immunomodulatoryorgan. Next, we studied the expression and exosomal release of NKG2D ligands by tumor cellsusing the leukemia cell lines Jurkat and Raji as a tumor model. We found that NKG2Dligand-bearing exosomes with similar immunosuppressive properties as placental exosomesare constitutively secreted by the tumor cells, as a mechanism to blunt the cytotoxicresponse of the immune cells and thus protect themselves from cytotoxic attack by the host.Interestingly, we found that thermal- and oxidative stress up-regulates the exosomesecretion and the amount of exosome-secreted NKG2D ligands. Our results imply thattumor therapies that cause stress-induced damage, such as thermotherapy and stripping ofoxygen supply to the tumor, might have a previously unrecognized side effect causingenhanced exosome production and secretion, which in turn suppresses the natural antitumorimmune response and thus should be taken into account when designing an optimaltherapy of cancer patients. In conclusion, we describe a novel stress-inducible mechanism shared by placenta andtumors as an immune escape strategy. We found that placenta- and tumor-derived NKG2Dligand-bearing exosomes can suppress immune responses to promote the survival and wellbeing of the fetus or the tumor. Our work comprises an important contribution to theelucidation of the NKG2D ligand-receptor system and its mode of operation in the humanbody and opens new perspectives for designing novel therapies for infertility and cancer

Kritisk granskning av BBIC:s teori och av barnavårdsutredningar med respektive utan BBIC- : Same same but different?

Syftet med denna studie är att kritiskt-vetenskapligt granska teori och tillämpning rörande den av Socialstyrelsen förespråkade påstådda utredningsmetoden BBIC (Barns Behov I Centrum). Syftet är även att kritiskt granska och jämföra tio LVU- utredningar från 2005 med nio LVU utredningar från 2007 inlämnade till en Länsrätt i Mellansverige för att se om det skett någon förbättring avseende utredningsmetodik i och med BBIC’s införande den 1 september 2006. Detta är den första studien som granskat den bakomliggande forskningen. Det kan konstateras att BBIC inte har någon vetenskaplig förankring. Granskningen av utredningarna i denna studie tyder på att det inte skett någon förbättring av barnavårdsutredningarnas saklighet från 2005 till 2007. Båda grupperna av utredningar måste bedömas som genomgående undermåliga ur saklighetssynpunkt

Musikproducentens skyldigheter och rättigheter vid en skivproduktion

I vårt examensarbete vill vi få en djupare insikt i en musikproducents arbetsprocess vid produktionen av ett musikalbum. Vi antog uppdraget att spela in, producera och mixa en barnproduktion innehållande tretton låtar, vilket är vårt Case. Under arbetets gång har vi även gjort en fallstudie i form av en djupintervju med en etablerad musikproducent. Resultatet blev en fullängdsproduktion som släpps under sommaren 2008

Idéskapandet i produktutvecklingens tidiga faser : en fallstudie av fyra livsmedelsföretag

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I vilken utsträckning tillämpar masstillverkande företag target costing?

Validerat; 20101217 (root

Ambulanssjuksköterskors upplevelse av psykiskt påfrestande situationer i arbetet och stödet efter dessa från arbetsplatsen : En kvalitativ litteraturstudie

Introduktion: Ambulanssjukvården har sedan 1800-talet förändrats, från att vara ett rent transportmedel är i dagsläget ambulanserna utrustade med högteknologisk utrustning och sjuksköterskeutbildad personal. Ambulanssjuksköterskor utsätts ofta för situationer som kan upplevas psykiskt påfrestande. Dessa situationer kan, om de inte bearbetas, leda till sämre mental hälsa med risk för sjukskrivningar och förtidspensionering. Syfte: Syftet med denna studie var att beskriva ambulanssjuksköterskors upplevelser av stöd på arbetsplatsen efter psykiskt påfrestande situationer i arbetet. Metod: Denna studie har en kvalitativ ansats med en beskrivande design. Resultat: Ambulanssjuksköterskor upplever olika situationer som psykiskt påfrestande. Upplevelsen relateras ofta till den egna livssituationen och tidigare erfarenheter. Stödåtgärder finns tillgängliga från arbetsplatsen efter psykiskt påfrestande situationer, men ambulanssjuksköterskorna upplever att ansvaret ofta ligger på individen att söka stöd. Brister upplevs även i stödhanteringen och önskemål finns om förbättringar. Slutsats: Stöd finns på arbetsplatsen men upplevs både vara tillräckligt samtidigt som det upplevs vara i behov av utveckling

Leadership : A Comparative study in Leadership between Personnel managers and other Managers

Sammanfattning Denna C-uppsats i arbetsvetenskap är en kvalitativ studie och baserad på teorier om ledarskap. Syftet med uppsatsen är att undersöka likheter och olikheter mellan personalchefer och andra typer av chefers ledarskap. Inledningsvis presenteras en historisk bakgrund av ledarskapets förändring. Sedan följer grundläggande ledarskapsteorier samt teorier om kommunikation, makt, motivation och genusperspektiv. Dessa teorier är en viktig grund för analys- och resultatavsnittet i uppsatsen. Utifrån dessa teorier utformas en intervjuguide. Datainsamlingen sker genom intervjuer. Totalt genomförs sammanlagt sex intervjuer. Respondenterna är en områdeschef, en affärsområdeschef, en kontorschef samt tre personalchefer. Intervjuerna transkriberas och vi undersöker likheter och olikheter gällande ledarskap mellan personalchefer och övriga chefer. Vi får fram följande teman: synen på ledarskap, att vara ledare, utveckling av ledarskapet, ledarstilar, kommunikation, motivation, makt och ledarskap ur ett genusperspektiv. En sammanfattande diskussion av analys och resultat görs. Uppsatsens slutsats är att personalcheferna, i större utsträckning än de övriga cheferna, inte bara automatiskt bedriver ett chefskap utan också ett ledarskap. Nyckelord: ledarskap, likheter, olikheter, kommunikation, motivation