312 research outputs found

    A novel malaria vaccine candidate antigen expressed in Tetrahymena thermophila

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    Development of effective malaria vaccines is hampered by the problem of producing correctly folded Plasmodium proteins for use as vaccine components. We have investigated the use of a novel ciliate expression system, Tetrahymena thermophila, as a P. falciparum vaccine antigen platform. A synthetic vaccine antigen composed of N-terminal and C-terminal regions of merozoite surface protein-1 (MSP-1) was expressed in Tetrahymena thermophila. The recombinant antigen was secreted into the culture medium and purified by monoclonal antibody (mAb) affinity chromatography. The vaccine was immunogenic in MF1 mice, eliciting high antibody titers against both N- and C-terminal components. Sera from immunized animals reacted strongly with P. falciparum parasites from three antigenically different strains by immunofluorescence assays, confirming that the antibodies produced are able to recognize parasite antigens in their native form. Epitope mapping of serum reactivity with a peptide library derived from all three MSP-1 Block 2 serotypes confirmed that the MSP-1 Block 2 hybrid component of the vaccine had effectively targeted all three serotypes of this polymorphic region of MSP-1. This study has successfully demonstrated the use of Tetrahymena thermophila as a recombinant protein expression platform for the production of malaria vaccine antigens

    Intensive consolidation therapy compared with standard consolidation and maintenance therapy for adults with acute myeloid leukaemia aged between 46 and 60 years: final results of the randomized phase III study (AML 8B) of the European Organization for Research and Treatment of Cancer (EORTC) and the Gruppo Italiano Malattie Ematologiche Maligne dell’Adulto (GIMEMA) Leukemia Cooperative Groups

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    The most effective post-remission treatment to maintain complete remission (CR) in adults aged between 46 and 60 years with acute myeloid leukaemia (AML) is uncertain. Previously untreated patients with AML in CR after induction chemotherapy with daunorubicin and cytarabine were randomized between two intensive courses of consolidation therapy containing high-dose cytarabine, combined with amsacrine or daunorubicin and a standard consolidation and maintenance therapy containing standard dose cytarabine and daunorubicin. One hundred fifty-eight CR patients were assigned to the intensive group and 157 patients to the standard group. After a median follow-up of 7.5 years, the 4-year survival rate was 32 % in the intensive group versus 34 % in the standard group (P = 0.29). In the intensive group, the 4-year relapse incidence was lower than in the standard group: 55 and 75 %, respectively (P = 0.0003), whereas treatment-related mortality incidence was higher: 22 versus 3 % (P < 0.0001). Two intensive consolidation courses containing high-dose cytarabine as post-remission treatment in patients with AML aged between 46 and 60 years old did not translate in better long-term outcome despite a 20 % lower relapse incidence. Better supportive care and prevention of treatment-related complications may improve the overall survival after intensified post-remission therapy in this age group

    Determinants of lenalidomide response with or without erythropoiesis-stimulating agents in myelodysplastic syndromes:the HOVON89 trial

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    A randomized phase-II study was performed in low/int-1 risk MDS (IPSS) to study efficacy and safety of lenalidomide without (arm A) or with (arm B) ESA/G-CSF. In arm B, patients without erythroid response (HI-E) after 4 cycles received ESA; G-CSF was added if no HI-E was obtained by cycle 9. HI-E served as primary endpoint. Flow cytometry and next-generation sequencing were performed to identify predictors of response. The final evaluation comprised 184 patients; 84% non-del(5q), 16% isolated del(5q); median follow-up: 70.7 months. In arm A and B, 39 and 41% of patients achieved HI-E; median time-to-HI-E: 3.2 months for both arms, median duration of-HI-E: 9.8 months. HI-E was significantly lower in non-del(5q) vs. del(5q): 32% vs. 80%. The same accounted for transfusion independency-at-week 24 (16% vs. 67%), but similar in both arms. Apart from presence of del(5q), high percentages of bone marrow lymphocytes and progenitor B-cells, a low number of mutations, absence of ring sideroblasts, and SF3B1 mutations predicted HI-E. In conclusion, lenalidomide induced HI-E in patients with non-del(5q) and del(5q) MDS without additional effect of ESA/G-CSF. The identified predictors of response may guide application of lenalidomide in lower-risk MDS in the era of precision medicine. (EudraCT 2008-002195-10).</p

    Survival improvement over time of 960 s-AML patients included in 13 EORTC-GIMEMA-HOVON trials

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    We report the outcomes of secondary acute myeloid leukemia (s-AML) patients included in one of 13 European Organisation for Research and Treatment of Cancer (EORTC) collaborative AML trials using intensive remission-induction chemotherapy. Among 8858 patients treated between May 1986 and January 2008, 960 were identified as having s-AML, either after MDS (cohort A; n = 508), occurring after primary solid tumors or hematologic malignancies other than MDS (cohort B; n = 361), or after non-malignant conditions or with a history of toxic exposure (cohort C; n = 91). Median age was 64 years, 60 years and 61 years in cohort A, B and C, respectively. Among patients ≤60 years and classified in the cohorts A or B (n = 367), the 5-year overall survival (OS) rate was 28%. There was a systematic improvement in the 5-year OS rate over three time periods (p 60 years of age (n = 502), the OS was dismal, and there was no improvement over time

    Gut CD4+ T cell phenotypes are a continuum molded by microbes, not by TH archetypes

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    CD4+ effector lymphocytes (Teff) are traditionally classified by the cytokines they produce. To determine the states that Teff cells actually adopt in frontline tissues in vivo, we applied single-cell transcriptome and chromatin analyses to colonic Teff cells in germ-free or conventional mice or in mice after challenge with a range of phenotypically biasing microbes. Unexpected subsets were marked by the expression of the interferon (IFN) signature or myeloid-specific transcripts, but transcriptome or chromatin structure could not resolve discrete clusters fitting classic helper T cell (TH) subsets. At baseline or at different times of infection, transcripts encoding cytokines or proteins commonly used as TH markers were distributed in a polarized continuum, which was functionally validated. Clones derived from single progenitors gave rise to both IFN-γ- and interleukin (IL)-17-producing cells. Most of the transcriptional variance was tied to the infecting agent, independent of the cytokines produced, and chromatin variance primarily reflected activities of activator protein (AP)-1 and IFN-regulatory factor (IRF) transcription factor (TF) families, not the canonical subset master regulators T-bet, GATA3 or RORγ

    Status of Biodiversity in the Baltic Sea

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    The brackish Baltic Sea hosts species of various origins and environmental tolerances. These immigrated to the sea 10,000 to 15,000 years ago or have been introduced to the area over the relatively recent history of the system. The Baltic Sea has only one known endemic species. While information on some abiotic parameters extends back as long as five centuries and first quantitative snapshot data on biota (on exploited fish populations) originate generally from the same time, international coordination of research began in the early twentieth century. Continuous, annual Baltic Sea-wide long-term datasets on several organism groups (plankton, benthos, fish) are generally available since the mid-1950s. Based on a variety of available data sources (published papers, reports, grey literature, unpublished data), the Baltic Sea, incl. Kattegat, hosts altogether at least 6,065 species, including at least 1,700 phytoplankton, 442 phytobenthos, at least 1,199 zooplankton, at least 569 meiozoobenthos, 1,476 macrozoobenthos, at least 380 vertebrate parasites, about 200 fish, 3 seal, and 83 bird species. In general, but not in all organism groups, high sub-regional total species richness is associated with elevated salinity. Although in comparison with fully marine areas the Baltic Sea supports fewer species, several facets of the system's diversity remain underexplored to this day, such as micro-organisms, foraminiferans, meiobenthos and parasites. In the future, climate change and its interactions with multiple anthropogenic forcings are likely to have major impacts on the Baltic biodiversity

    Carbon and nitrogen stable isotope values in freshwater, brackish and marine fish bone collagen from Mesolithic and Neolithic sites in central and northern Europe

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    The aim of this research is to examine the isotopic characterisation of archaeological fish species as it relates to freshwater, brackish and marine environments, trophic level and migration patterns, and to determine intraspecies variation within and between fish populations in different locations within central and northern Europe. Carbon and nitrogen stable isotope analysis was undertaken on collagen extracted from 72 fish bone samples from eight Mesolithic and Neolithic archaeological sites in this region. Thirty-six (50%) of the specimens analysed produced results with acceptable carbon to nitrogen atomic ratios (2·9–3·6). The fish remains encompassed a wide spectrum of freshwater, brackish and marine taxa (n = 12), which were reflected in the δ13C values (−24·5 to −7·8‰). The freshwater/brackish fish (pike, Esox lucius; perch, Perca fluviatilis; zander, Sander lucioperca) had δ13C values that ranged from −24·2 to −19·3‰, whereas the brackish/marine fish (spurdog, Squalus acanthias; flatfish, Pleuronectidae; codfish, Gadidae; garfish, Belone belone; mackerel, Scomber scombrus) ranged from −14·9 to −9·4‰. Salmonidae, an anadromous taxon, and eel (Anguilla anguilla), a catadromous species, had carbon isotope values consistent with marine origin, and no evidence of freshwater residency (−12·7 to −11·7‰). The δ15N values had a range of 6·2‰ (6·5–12·7‰) indicating that these fish were on average feeding at 1·7 trophic levels higher than their producers in these diverse aquatic environments. These results serve as an important ecological baseline for the future isotopic reconstruction of the diet of human populations dating to the late Mesolithic and early Neolithic of the region

    Integrated analyses of single-cell atlases reveal age, gender, and smoking status associations with cell type-specific expression of mediators of SARS-CoV-2 viral entry and highlights inflammatory programs in putative target cells

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    The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, creates an urgent need for identifying molecular mechanisms that mediate viral entry, propagation, and tissue pathology. Cell membrane bound angiotensin-converting enzyme 2 (ACE2) and associated proteases, transmembrane protease serine 2 (TMPRSS2) and Cathepsin L (CTSL), were previously identified as mediators of SARS-CoV2 cellular entry. Here, we assess the cell type-specific RNA expression of ACE2, TMPRSS2, and CTSL through an integrated analysis of 107 single-cell and single-nucleus RNA-Seq studies, including 22 lung and airways datasets (16 unpublished), and 85 datasets from other diverse organs. Joint expression of ACE2 and the accessory proteases identifies specific subsets of respiratory epithelial cells as putative targets of viral infection in the nasal passages, airways, and alveoli. Cells that co-express ACE2 and proteases are also identified in cells from other organs, some of which have been associated with COVID-19 transmission or pathology, including gut enterocytes, corneal epithelial cells, cardiomyocytes, heart pericytes, olfactory sustentacular cells, and renal epithelial cells. Performing the first meta-analyses of scRNA-seq studies, we analyzed 1,176,683 cells from 282 nasal, airway, and lung parenchyma samples from 164 donors spanning fetal, childhood, adult, and elderly age groups, associate increased levels of ACE2, TMPRSS2, and CTSL in specific cell types with increasing age, male gender, and smoking, all of which are epidemiologically linked to COVID-19 susceptibility and outcomes. Notably, there was a particularly low expression of ACE2 in the few young pediatric samples in the analysis. Further analysis reveals a gene expression program shared by ACE2(+)TMPRSS2(+) cells in nasal, lung and gut tissues, including genes that may mediate viral entry, subtend key immune functions, and mediate epithelial-macrophage cross-talk. Amongst these are IL6, its receptor and co-receptor, IL1R, TNF response pathways, and complement genes. Cell type specificity in the lung and airways and smoking effects were conserved in mice. Our analyses suggest that differences in the cell type-specific expression of mediators of SARS-CoV-2 viral entry may be responsible for aspects of COVID-19 epidemiology and clinical course, and point to putative molecular pathways involved in disease susceptibility and pathogenesis
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