445 research outputs found

    Application of the pMHC array to characterise tumour antigen specific T cell populations in leukaemia patients at disease diagnosis

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    Immunotherapy treatments for cancer are becoming increasingly successful, however to further improve our understanding of the T-cell recognition involved in effective responses and to encourage moves towards the development of personalised treatments for leukaemia immunotherapy, precise antigenic targets in individual patients have been identified. Cellular arrays using peptide-MHC (pMHC) tetramers allow the simultaneous detection of different antigen specific T-cell populations naturally circulating in patients and normal donors. We have developed the pMHC array to detect CD8+ T-cell populations in leukaemia patients that recognise epitopes within viral antigens (cytomegalovirus (CMV) and influenza (Flu)) and leukaemia antigens (including Per Arnt Sim domain 1 (PASD1), MelanA, Wilms’ Tumour (WT1) and tyrosinase). We show that the pMHC array is at least as sensitive as flow cytometry and has the potential to rapidly identify more than 40 specific T-cell populations in a small sample of T-cells (0.8–1.4 x 106). Fourteen of the twenty-six acute myeloid leukaemia (AML) patients analysed had T cells that recognised tumour antigen epitopes, and eight of these recognised PASD1 epitopes. Other tumour epitopes recognised were MelanA (n = 3), tyrosinase (n = 3) and WT1126-134 (n = 1). One of the seven acute lymphocytic leukaemia (ALL) patients analysed had T cells that recognised the MUC1950-958 epitope. In the future the pMHC array may be used provide point of care T-cell analyses, predict patient response to conventional therapy and direct personalised immunotherapy for patients

    Serum profiling identifies ibrutinib as a treatment option for young adults with B‐cell acute lymphoblastic leukaemia

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    Acute lymphoblastic leukaemia (ALL) is a haematological malignancy that is characterized by the uncontrolled proliferation of immature lymphocytes. 80% of cases occur in children where ALL is well understood and treated. However it has a devastating affects on adults, where multi-agent chemotherapy is the standard of care with allogeneic stem cell transplantation for those who are eligible. New treatments are required to extend remission and prevent relapse to improve patient survival rates. We used serum profiling to compare samples from presentation adult B-ALL patients with age- and sex-matched healthy volunteer (HV) sera and identified 69 differentially recognised antigens (P ≀ 0·02). BMX, DCTPP1 and VGLL4 showed no differences in transcription between patients and healthy donors but were each found to be present at higher levels in B-ALL patient samples than HVs by ICC. BMX plays a crucial role in the Bruton's Tyrosine Kinase (BTK) pathway which is bound by the BTK inhibitor, ibrutinib, suggesting adult B-ALL would also be a worthy target patient group for future clinical trials. We have shown the utility of proto-array analysis of B-ALL patient sera, predominantly from young adults, to help characterise the B-ALL immunome and identified a new target patient population for existing small molecule therapy

    Point-of-care diagnostic assay for the detection of Zika virus using the recombinase polymerase amplification method.

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    The sudden and explosive expansion of Zika virus (ZIKV) from the African continent through Oceania and culminating in the outbreak in South America has highlighted the importance of new rapid point-of-care diagnostic tools for the control and prevention of transmission. ZIKV infection has devastating consequences, such as neurological congenital malformations in infants born to infected mothers and Guillain-BarrĂ© syndrome in adults. Additionally, its potential for transmission through vector bites, as well as from person to person through blood transfusions and sexual contact, are important considerations for prompt diagnosis. Recombinase polymerase amplification (RPA), an isothermal method, was developed as an alternative field-applicable assay to PCR. Here we report the development of a novel ZIKV real-time reverse transcriptase RPA (RT-RPA) assay capable of detecting a range of different ZIKV strains from a variety of geographical locations. The ZIKV RT-RPA was shown to be highly sensitive, being capable of detecting as few as five copies of target nucleic acid per reaction, and suitable for use with a battery-operated portable device. The ZIKV RT-RPA demonstrated 100 % specificity and 83 % sensitivity in clinical samples. Furthermore, we determined that the ZIKV RT-RPA is a versatile assay that can be applied to crude samples, such as saliva and serum, and can be used as a vector surveillance tool on crude mosquito homogenates. Therefore, the developed ZIKV RT-RPA is a useful diagnostic tool that can be transferred to a resource-limited location, eliminating the need for a specialized and sophisticated laboratory environment and highly trained staff

    Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition

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    Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie

    Cytokine Production but Lack of Proliferation in Peripheral Blood Mononuclear Cells from Chronic Chagas' Disease Cardiomyopathy Patients in Response to T. cruzi Ribosomal P Proteins

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    Background:Trypanosoma cruzi ribosomal P proteins, P2ÎČ and P0, induce high levels of antibodies in patients with chronic Chagas' disease Cardiomyopathy (CCC). It is well known that these antibodies alter the beating rate of cardiomyocytes and provoke apoptosis by their interaction with ÎČ1-adrenergic and M2-muscarinic cardiac receptors. Based on these findings, we decided to study the cellular immune response to these proteins in CCC patients compared to non-infected individuals.Methodology/Principal findings:We evaluated proliferation, presence of surface activation markers and cytokine production in peripheral blood mononuclear cells (PBMC) stimulated with P2ÎČ, the C-terminal portion of P0 (CP0) proteins and T. cruzi lysate from CCC patients predominantly infected with TcVI lineage. PBMC from CCC patients cultured with P2ÎČ or CP0 proteins, failed to proliferate and express CD25 and HLA-DR on T cell populations. However, multiplex cytokine assays showed that these antigens triggered higher secretion of IL-10, TNF-α and GM-CSF by PBMC as well as both CD4+ and CD8+ T cells subsets of CCC subjects. Upon T. cruzi lysate stimulation, PBMC from CCC patients not only proliferated but also became activated within the context of Th1 response. Interestingly, T. cruzi lysate was also able to induce the secretion of GM-CSF by CD4+ or CD8+ T cells.Conclusions/Significance:Our results showed that although the lack of PBMC proliferation in CCC patients in response to ribosomal P proteins, the detection of IL-10, TNF-α and GM-CSF suggests that specific T cells could have both immunoregulatory and pro-inflammatory potential, which might modulate the immune response in Chagas' disease. Furthermore, it was possible to demonstrate for the first time that GM-CSF was produced by PBMC of CCC patients in response not only to recombinant ribosomal P proteins but also to parasite lysate, suggesting the value of this cytokine to evaluate T cells responses in T. cruzi infection.Fil: Longhi, Silvia Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica; ArgentinaFil: Atienza, Augusto. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejĂ­a"; ArgentinaFil: Perez Prados, Graciela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. FernĂĄndez"; ArgentinaFil: Buying, Alcinette. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Balouz, Virginia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de Investigaciones BiotecnolĂłgicas. Universidad Nacional de San MartĂ­n. Instituto de Investigaciones BiotecnolĂłgicas; ArgentinaFil: Buscaglia, Carlos Andres. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de Investigaciones BiotecnolĂłgicas. Universidad Nacional de San MartĂ­n. Instituto de Investigaciones BiotecnolĂłgicas; ArgentinaFil: Santos, Radleigh. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Tasso, Laura MĂłnica. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Bonato, Ricardo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejĂ­a"; ArgentinaFil: Chiale, Pablo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejĂ­a"; ArgentinaFil: Pinilla, Clemencia. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Judkowski, Valeria A.. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Gomez, Karina Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular "Dr. HĂ©ctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica; Argentin

    The more the merrier? Increasing group size may be detrimental to decision-making performance in nominal groups

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    <div><p>Demonstrability—the extent to which group members can recognize a correct solution to a problem—has a significant effect on group performance. However, the interplay between group size, demonstrability and performance is not well understood. This paper addresses these gaps by studying the joint effect of two factors—the difficulty of solving a problem and the difficulty of verifying the correctness of a solution—on the ability of groups of varying sizes to converge to correct solutions. Our empirical investigations use problem instances from different computational complexity classes, NP-Complete (NPC) and PSPACE-complete (PSC), that exhibit similar solution difficulty but differ in verification difficulty. Our study focuses on nominal groups to isolate the effect of problem complexity on performance. We show that NPC problems have higher demonstrability than PSC problems: participants were significantly more likely to recognize correct and incorrect solutions for NPC problems than for PSC problems. We further show that increasing the group size can actually <i>decrease</i> group performance for some problems of low demonstrability. We analytically derive the boundary that distinguishes these problems from others for which group performance monotonically improves with group size. These findings increase our understanding of the mechanisms that underlie group problem-solving processes, and can inform the design of systems and processes that would better facilitate collective decision-making.</p></div

    The Trypanosoma cruzi vitamin C dependent peroxidase confers protection against oxidative stress but is not a determinant of virulence.

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    BACKGROUND: The neglected parasitic infection Chagas disease is rapidly becoming a globalised public health issue due to migration. There are only two anti-parasitic drugs available to treat this disease, benznidazole and nifurtimox. Thus it is important to identify and validate new drug targets in Trypanosoma cruzi, the causative agent. T. cruzi expresses an ER-localised ascorbate-dependent peroxidase (TcAPx). This parasite-specific enzyme has attracted interest from the perspective of targeted chemotherapy. METHODOLOGY/PRINCIPAL FINDINGS: To assess the importance of TcAPx in protecting T. cruzi from oxidative stress and to determine if it is essential for virulence, we generated null mutants by targeted gene disruption. Loss of activity was associated with increased sensitivity to exogenous hydrogen peroxide, but had no effect on susceptibility to the front-line Chagas disease drug benznidazole. This suggests that increased oxidative stress in the ER does not play a significant role in its mechanism of action. Homozygous knockouts could proceed through the entire life-cycle in vitro, although they exhibited a significant decrease in their ability to infect mammalian cells. To investigate virulence, we exploited a highly sensitive bioluminescence imaging system which allows parasites to be monitored in real-time in the chronic stage of murine infections. This showed that depletion of enzyme activity had no effect on T. cruzi replication, dissemination or tissue tropism in vivo. CONCLUSIONS/SIGNIFICANCE: TcAPx is not essential for parasite viability within the mammalian host, does not have a significant role in establishment or maintenance of chronic infections, and should therefore not be considered a priority for drug design
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