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Dominicin, a macrocyclic peptide isolated from the marine sponge Eurypon laughlini, has been synthesized for the first time by solid-phase peptide synthesis. The strategy uses oxime resin and takes...

L’idée de reporter l’âge normal3 de la retraite au Canada s’inscrit dans un questionnement politique plus large concernant les défis posés par le vieillissement de la population. Soucieux de contrôler les coûts et de mitiger l’effet du ralentissement de la croissance de la main d’oeuvre, certains décideurs proposent de repousser l’âge normal de la retraite afin d’assurer la pérennité du Régime de pensions du Canada. C’est dans ce contexte que cette analyse propose une nouvelle méthode d’estimation du nombre d’années potentielles de travail perdues avant 65 ans, en fonction des retraites volontaires, involontaires et relatives à la mortalité, de 1977 à 2014 au Canada. Alors que la mortalité chez les hommes et les retraites involontaires chez les femmes étaient les principales sources d’années de travail perdues avant 65 ans dans les premières années étudiées, la chute de l’âge effectif de la retraite observée jusqu’au milieu des années 1990 était par contre principalement alimentée par les retraites volontaires. Ces départs volontaires sont aussi responsables du report de la retraite constaté dans les vingt dernières années. Dans l’éventualité où les décideurs publics plancheraient sur de nouvelles politiques touchant la retraite, les résultats obtenus dans cette analyse montrent qu’il est important de tenir compte de la prépondérance des facteurs qui incitent les travailleuses et travailleurs canadiens à quitter le marché de l’emploi en fin de carrière., The idea of raising the statutory retirement age in Canada is part of a wider policy debate around the challenges posed by population ageing. Some political leaders, concerned to keep costs under control and to mitigate the effects of slower growth in the labour force, argue in favour of raising the retirement age to maintain the viability of the Canadian pension system. In this context, our analysis provides a new method of estimating the number of potential working years lost before the age of 65 between 1977 and 2014 in Canada, taking account of voluntary and involuntary retirement and mortality. While mortality among men and involuntary retirement among women were the main causes of working years lost before the age of 65 in the earlier years of the period studied, the fall in the effective retirement age observed until the mid-1990s was mainly due to voluntary early retirement. Voluntary retirement has also been responsible for the postponement of the retirement age seen in the last 20 years. The findings of our study show that when public policy makers come to deliberate on changes to the public pensions system, it is important to take into account the relative weight of these different factors influencing men and women to leave the labour market at the end of their working lives.

International audience; Fragment-based lead discovery has emerged over the last decades as one of the most powerful techniques for identifying starting chemical matter to target specific proteins or nucleic acids in vitro. However, the use of such low-molecular-weight fragment molecules in cell-based phenotypic assays has been historically avoided because of concerns that bioassays would be insufficiently sensitive to detect the limited potency expected for such small molecules and that the high concentrations required would likely implicate undesirable artifacts. Herein, we applied phenotype cell-based screens using a curated fragment library to identify inhibitors against a range of pathogens including Leishmania, Plasmodium falciparum, Neisseria, Mycobacterium, and flaviviruses. This proof-of-concept shows that fragment-based phenotypic lead discovery (FPLD) can serve as a promising complementary approach for tackling infectious diseases and other drug-discovery programs.

Mass spectrometry is a valued method to evaluate the metabolomics content of a biological sample. The recent advent of rapid ionization technologies such as Laser Diode Thermal Desorption (LDTD) and Direct Analysis in Real Time (DART) has rendered high-throughput mass spectrometry possible. It is used for large-scale comparative analysis of populations of samples. In practice, many factors resulting from the environment, the protocol, and even the instrument itself, can lead to minor discrepancies between spectra, rendering automated comparative analysis difficult. In this work, a sequence/pipeline of algorithms to correct variations between spectra is proposed. The algorithms correct multiple spectra by identifying peaks that are common to all and, from those, computes a spectrum-specific correction. We show that these algorithms increase comparability within large datasets of spectra, facilitating comparative analysis, such as machine learning.

Mortiamides A-D (1-4) are head-to-tail cyclic heptapeptides that were identified from a novel Mortierella sp. isolate obtained from marine sediments from Northern Canada. Herein we report the first total synthesis of mortiamides A-D (1-4) on a solid support by concomitant cyclization/cleavage without any oligomerization side reactions, and overall yields up to 48%. We also report on the antiplasmodial activity of mortiamides A-D (1-4). We show that three out of the four tested mortiamides (A, B and D) have moderate antiplasmodial activity, while mortiamide D (4) exhibits low micromolar activity.

Invasion of human red blood cells by the malaria parasite Plasmodium falciparum is an essential step in the development of the disease. Consequently, the molecular players involved in host cell invasion represent important targets for inhibitor design and vaccine development. The process of merozoite invasion is a succession of steps underlined by the sequential secretion of the organelles of the apical complex. However, little is known with regard to how their contents are exocytosed. Here, we identify a phosphoinositide‐binding protein conserved in apicomplexan parasites and show that it is important for the attachment and subsequent invasion of the erythrocyte by the merozoite. Critically, removing the protein from its site of action by knock sideways preferentially prevents the secretion of certain types of micronemes. Our results therefore provide evidence for a role of phosphoinositide lipids in the malaria invasion process and provide further insight into the secretion of microneme organelle populations, which is potentially applicable to diverse apicomplexan parasites.

This article reports on a conference workshop conducted at CYTO 2018. During the workshop a new Open Science forum "CYTO Lab Hacks" has been launched within the International Society for the Advancement of Cytometry (ISAC). Its goal is to serve as an open, transparent, sustainable and accessible forum for innovation-exchange in cytometry. Here we report the captured status quo, the perceived requirements of the members in relation to open innovation sharing and dissemination and publicize the format of "CYTO Lab Hacks".

Dihydroartemisinin-piperaquine (DHA-PPQ), the current frontline artemisinin combination therapy used to treat Plasmodium falciparum malaria in multiple Southeast Asian countries, is now increasingly failing in Cambodia, where artemisinin resistance is nearly fixed, which suggests that PPQ resistance has emerged and is spreading rapidly in the Greater Mekong Subregion. Recent reports have shown that amplification of the genes encoding plasmepsins 2 and 3 is a molecular marker of PPQ resistance; however, whether these enzymes play a role in the mechanism of resistance is currently unknown. We show here that inactivating the genes encoding plasmepsin 2 or 3 individually in P. falciparum reference strain 3D7 results in hypersusceptibility to PPQ. Interestingly, no significant differences in the susceptibility to other antimalarials were observed, which suggests specific roles of plasmepsins 2 and 3 in PPQ susceptibility. The piperaquine hyper-sensitivity of the plasmepsin-2-and-3-inactivated lines provides direct evidence that these enzymes modulate parasite susceptibility to PPQ in the context of a single copy of PfMDR1 and independent of Kelch13 mutations conferring artemisinin resistance.

Aging is associated with hyporesponse to vaccination, whose mechanisms remain unclear. In this study hepatitis B virus (HBV)-naive older adults received three vaccines, including one against HBV. Here we show, using transcriptional and cytometric profiling of whole blood collected before vaccination, that heightened expression of genes that augment B-cell responses and higher memory B-cell frequencies correlate with stronger responses to HBV vaccine. In contrast, higher levels of inflammatory response transcripts and increased frequencies of pro-inflammatory innate cells correlate with weaker responses to this vaccine. Increased numbers of erythrocytes and the haem-induced response also correlate with poor response to the HBV vaccine. A transcriptomics-based pre-vaccination predictor of response to HBV vaccine is built and validated in distinct sets of older adults. This moderately accurate (area under the curve≈65%) but robust signature is supported by flow cytometry and cytokine profiling. This study is the first that identifies baseline predictors and mechanisms of response to the HBV vaccine., Ageing is associated with poor responses to vaccines but the underlying mechanism remains unclear. Here the authors use a systems-based approach to define molecular signatures present before vaccination that correlate with non-responsiveness to hepatitis B vaccination in healthy, elderly adults.

The design of a panel to identify target cell subsets in flow cytometry can be difficult when specific markers unique to each cell subset do not exist, and a combination of parameters must be used to identify target cells of interest and exclude irrelevant events. Thus, the ability to objectively measure the contribution of a parameter or group of parameters toward target cell identification independent of any gating strategy could be very helpful for both panel design and gating strategy design. In this article, we propose a discriminative information measure evaluation (DIME) based on statistical mixture modeling; DIME is a numerical measure of the contribution of different parameters towards discriminating a target cell subset from all the others derived from the fitted posterior distribution of a Gaussian mixture model. Informally, DIME measures the "usefulness" of each parameter for identifying a target cell subset. We show how DIME provides an objective basis for inclusion or exclusion of specific parameters in a panel, and how ranked sets of such parameters can be used to optimize gating strategies. An illustrative example of the application of DIME to streamline the gating strategy for a highly standardized carboxyfluorescein succinimidyl ester (CFSE) assay is described.

The molecular events involved in the establishment and maintenance of CD4+ central memory and effector memory T cells (TCM and TEM, respectively) are poorly understood. In this study, we demonstrate that ex vivo isolated TCM are more resistant to both spontaneous and Fas-induced apoptosis than TEM and have an increased capacity to proliferate and persist in vitro. Using global gene expression profiling, single cell proteomics, and functional assays, we show that the survival of CD4+ TCM depends, at least in part, on the activation and phosphorylation of signal transducer and activator of transcription 5a (STAT5a) and forkhead box O3a (FOXO3a). TCM showed a significant increase in the levels of phosphorylation of STAT5a compared with TEM in response to both IL-2 (P < 0.04) and IL-7 (P < 0.002); the latter is well known for its capacity to enhance T cell survival. Moreover, ex vivo TCM express higher levels of the transcriptionally inactive phosphorylated forms of FOXO3a and concomitantly lower levels of the proapoptotic FOXO3a target, Bim. Experiments aimed at blocking FOXO3a phosphorylation confirmed the role of this phosphoprotein in protecting TCM from apoptosis. Our results provide, for the first time in humans, an insight into molecular mechanisms that could be responsible for the longevity and persistence of CD4+ TCM.

Serine hydroxymethyltransferase (SHMT) catalyses the reversible conversion of serine and tetrahydrofolate to glycine and methylene-tetrahydrofolate. The recent completion of the genome sequence of Leishmania major revealed the presence of two genes coding for two isoforms of this protein. In silico analysis showed that one isoform had an extension at its N-terminus and was predicted to localize to the mitochondrion. The situation is different in other kinetoplastid parasites with only one SHMT encoding gene in Trypanosoma cruzi and no SHMT encoding gene in Trypanosoma brucei. The two L. major SHMT genes were cloned in frame with the green fluorescent protein and the resulting fusion proteins showed differential localization: the short form (SHMT-S) was found in the cytosol while the long one (SHMT-L) was found in an organelle that has hallmarks of the parasite mitochondrion. Indeed, SHMT-L had a similar cellular fractionation pattern as the mitochondrial HSP60 as determined by digitonin fractionation. Both SHMT-S and SHMT-L genes were expressed preferentially in the amastigote stage of the parasite and the RNA levels of SHMT-L could be modulated by glycine, serine, and folate. Overexpression of SHMT-S increased resistance to the antifolate methotrexate and to a lower level to the inhibitor thiosemicarbazide in a rich folate containing medium. These findings suggest that folate metabolism is compartmentalised in Leishmania and that SHMT RNA levels are responsive to environmental conditions.

Plasmodium falciparum, the causative agent of the deadliest form of malaria, and human immunodeficiency virus type-1 (HIV-1) are among the most important health problems worldwide, being responsible for a total of 4 million deaths annually 1 . Due to their extensive overlap in developing regions, especially Sub-Saharan Africa, co-infections with malaria and HIV-1 are common, but the interplay between the two diseases is poorly understood. Epidemiological reports have suggested that malarial infection transiently enhances HIV-1 replication and increases HIV-1 viral load in co-infected individuals 2,3 . Because this viremia stays high for several weeks after treatment with antimalarials, this phenomenon could have an impact on disease progression and transmission. The cellular immunological mechanisms behind these observations have been studied only scarcely. The few in vitro studies investigating the impact of malaria on HIV-1 have demonstrated that exposure to soluble malarial antigens can increase HIV-1 infection and reactivation in immune cells. However, these studies used whole cell extracts of P. falciparum schizont stage parasites and peripheral blood mononuclear cells (PBMC), making it hard to decipher which malarial component(s) was responsible for the observed effects and what the target host cells were 4,5 . Recent work has demonstrated that exposure of immature monocyte-derived dendritic cells to the malarial pigment hemozoin increased their ability to transfer HIV-1 to CD4+ T cells 6,7 , but that it decreased HIV-1 infection of macrophages 8 . To shed light on this complex process, a systematic analysis of the interactions between the malaria parasite and HIV-1 in different relevant human primary cell populations is critically needed. Several techniques for investigating the impact of HIV-1 on the phagocytosis of micro-organisms and the effect of such pathogens on HIV-1 replication have been described. We here present a method to investigate the effects of P. falciparum-infected erythrocytes on the replication of HIV-1 in human primary monocyte-derived macrophages. The impact of parasite exposure on HIV-1 transcriptional/translational events is monitored by using single cycle pseudotyped viruses in which a luciferase reporter gene has replaced the Env gene while the effect on the quantity of virus released by the infected macrophages is determined by measuring the HIV-1 capsid protein p24 by ELISA in cell supernatants.

Background The immunogenicity of an autologous dendritic cell (DC) anti-HIV therapy, AGS-004, was evaluated in a multicenter Phase 2 trial. The treatment regiment consisted of four intradermal doses, administered monthly in combination with anti-retroviral therapy (ART) followed by a well-controlled structured treatment interruption (STI). The immunotherapy consisted of monocyte-derived DC co-electroporated with CD40L in vitro transcribed (IVT) RNA along with amplified IVT RNA encoding for 4 HIV-1 antigens (GAG, NEF, REV and VPR).

Survivin is a member of the inhibitor of apoptosis protein family and its over-expression has been reported in many cancer types such as melanoma, colon, brain, breast, and ovarian cancers making it a promising target for immunotherapy. DPX-Survivac is a Survivin multi-epitope vaccine that covers a broad range of HLA haplotypes (HLA-A1, A2, A3, A24, B7). The adjuvanted water free depot vaccine is designed to specifically induce CD8+ T cells. In a Phase I study in ovarian cancer patients (n=18), we aimed to evaluate one dose level of the vaccine (0.5 mL) without cyclophosphamide (Cohort A) and two dose levels (0.1 mL and 0.5 mL) combined with oral low dose cyclophosphamide as an immune modulator (Cohorts B and C). Using multiparametric flow cytometry, we measured the ex-vivo frequency, phenotype and function of Regulatory T cells (CD25+FoxP3+Ki67+) and Survivin-specific CD4 and CD8 T cells. Our data shows that cohort C preferentially mounted survivin-specific CD8 T cells which significantly peaked at one month following the third vaccination (study day 70) and persisted until at least day 126 post-vaccination. This polyfunctional T cell response was endowed with cytotoxic and proliferative functions as measured by the expression of IL-2, IFNγ, TNFα, Granzyme B and CD107a. The immune responses identified in this cohort functionally diversified over time and were distributed within the Effector memory (CD45RA-CD27-), Central Memory (CD45RA-CD27+) and Late Differentiated CD8 T cell pool (CD45RA+CD27-). Of note, polyfunctional CD4 helper responses directed against tetanus toxoid and Survivin were induced by DPX-Survivac and possibly contributed to the maintenance of the CD8 T cell response. Taken together, the data presented herein shows that DPX-Survivac induced durable polyfunctional CD4 helper and CD8 T cells providing a strong rationale for combining the targeted immune therapy with immune modulation using metronomic cyclophosphamide. Citation Format: Yoav Peretz, Dominike Sauvé, Dominic Gagnon, Salim Ahmed Khan, Geneviève Lévesque, Nathalie Saha, Gilbert Croteau, Valérie Hébert, Karyne Savard, Bader Yassine Diab, Jean-Francois Poulin, Claire Landry, Mohan Karkada, Marc Mansour. Immune profiling of patients vaccinated with the survivin targeted therapeutic vaccine DPX-Survivac demonstrates durable polyfunctional CD4+ and CD8+ T cells in ovarian cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT411. doi:10.1158/1538-7445.AM2014-CT411