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Viruses have evolved countless mechanisms to subvert and impair the host innate immune response. Measles virus (MeV), an enveloped, non-segmented, negative-strand RNA virus, alters the interferon response through different mechanisms, yet no viral protein has been described as directly targeting mitochondria. Among the crucial mitochondrial enzymes, 5'-aminolevulinate synthase (ALAS) is an enzyme that catalyzes the first step in heme biosynthesis, generating 5'-aminolevulinate from glycine and succinyl-CoA. In this work, we demonstrate that MeV impairs the mitochondrial network through the V protein, which antagonizes the mitochondrial enzyme ALAS1 and sequesters it to the cytosol. This re-localization of ALAS1 leads to a decrease in mitochondrial volume and impairment of its metabolic potential, a phenomenon not observed in MeV deficient for the V gene. This perturbation of the mitochondrial dynamics demonstrated both in culture and in infected IFNAR-/- hCD46 transgenic mice, causes the release of mitochondrial double-stranded DNA (mtDNA) in the cytosol. By performing subcellular fractionation post infection, we demonstrate that the most significant source of DNA in the cytosol is of mitochondrial origin. Released mtDNA is then recognized and transcribed by the DNA-dependent RNA polymerase III. The resulting double-stranded RNA intermediates will be captured by RIG-I, ultimately initiating type I interferon production. Deep sequencing analysis of cytosolic mtDNA editing divulged an APOBEC3A signature, primarily analyzed in the 5'TpCpG context. Finally, in a negative feedback loop, APOBEC3A an interferon inducible enzyme will orchestrate the catabolism of mitochondrial DNA, decrease cellular inflammation, and dampen the innate immune response.
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Interferones , Mitocondrias , Ratones , Animales , Mitocondrias/metabolismo , Virus del Sarampión , 5-Aminolevulinato Sintetasa/genética , 5-Aminolevulinato Sintetasa/metabolismo , ADN MitocondrialRESUMEN
OBJECTIVES: Sexual dysfunction has wide-ranging impacts on the person's functioning and quality of life, being associated with higher severity of psychiatric illnesses and poor therapeutic response. Given the paucity of data on this topic in bipolar disorder (BD), we investigated sexual functioning among males and females with BD and healthy controls (HCs) as well as whether illness severity markers and subthreshold mood symptoms were associated with sexual dysfunctions in BD patients. METHODS: The study included 80 BD outpatients and 70 HCs. Sexual functioning was evaluated using the validated, gender-specific Changes in Sexual Functioning Questionnaire (CSFQ-14). RESULTS: BD patients had a significantly poorer sexual functioning than HCs (p < 0.00001). The odds of sexual dysfunction doubled given a one-unit increase in the number of suicide attempts (adjusted OR = 2.01, 95% CI:1.23-3.55; p < 0.01) and increased by 60% for every additional hospitalization (p < 0.05). Greater illness duration was associated with arousal/orgasmic (p < 0.05) and overall sexual dysfunctions (p < 0.01). BD patients with more mixed or (hypo)manic episodes had a lower likelihood of libido loss and arousal/orgasmic disturbances (p < 0.01), respectively. Higher levels of subthreshold depressive symptoms increased by 20% the odds of sexual interest/frequency dysfunctions (p < 0.05), and up to 60% regarding orgasmic disturbances (p < 0.01). CONCLUSIONS: Sexual functioning may be a useful proxy of illness severity as well as a relevant dimension to more deeply characterize BD patients. Further studies are warranted to replicate our findings, to evaluate temporal associations between sexual dysfunctions and illness severity across the BD mood and treatment spectrums and to explore neurobiological underpinnings of these associations.
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Trastorno Bipolar , Trastorno Bipolar/psicología , Costo de Enfermedad , Femenino , Voluntarios Sanos , Humanos , Masculino , Gravedad del Paciente , Calidad de VidaRESUMEN
HIV-1 successfully establishes long-term infection in its target cells despite viral cytotoxic effects. We have recently shown that cell metabolism is an important factor driving CD4+ T cell susceptibility to HIV-1 and the survival of infected cells. We show here that expression of antiapoptotic clone 11 (AAC-11), an antiapoptotic factor upregulated in many cancers, increased with progressive CD4+ T cell memory differentiation in association with the expression of cell cycle, activation, and metabolism genes and was correlated with susceptibility to HIV-1 infection. Synthetic peptides based on the LZ domain sequence of AAC-11, responsible for its interaction with molecular partners, were previously shown to be cytotoxic to cancer cells. Here, we observed that these peptides also blocked HIV-1 infection by inducing the death of HIV-1-susceptible primary CD4+ T cells across all T cell subsets. The peptides targeted metabolically active cells and had the greatest effect on effector and transitional CD4+ T cell memory subsets. Our results suggest that the AAC-11 survival pathway is potentially involved in the survival of HIV-1-infectible cells and provide proof of principle that some cellular characteristics can be targeted to eliminate the cells offering the best conditions to sustain HIV-1 replication.IMPORTANCE Although antiretroviral treatment efficiently blocks HIV multiplication, it cannot eliminate cells already carrying integrated proviruses. In the search for an HIV cure, the identification of new potential targets to selectively eliminate infected cells is of the outmost importance. We show here that peptides derived from antiapoptotic clone 11 (AAC-11), whose expression levels correlated with susceptibility to HIV-1 infection of CD4+ T cells, induced cytotoxicity in CD4+ T cells showing the highest levels of activation and metabolic activity, conditions known to favor HIV-1 infection. Accordingly, CD4+ T cells that survived the cytotoxic action of the AAC-11 peptides were resistant to HIV-1 replication. Our results identify a new potential molecular pathway to target HIV-1 infection.
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Proteínas Reguladoras de la Apoptosis/farmacología , Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/fisiología , Memoria Inmunológica/efectos de los fármacos , Proteínas Nucleares/farmacología , Péptidos/farmacología , Replicación Viral/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/química , Linfocitos T CD4-Positivos/patología , Linfocitos T CD4-Positivos/virología , Susceptibilidad a Enfermedades , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/patología , Humanos , Proteínas Nucleares/química , Péptidos/química , Dominios Proteicos , Replicación Viral/inmunologíaRESUMEN
[This corrects the article DOI: 10.1371/journal.ppat.1007945.].
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Metabolically quiescent pathogens can persist in a viable non-replicating state for months or even years. For certain infectious diseases, such as tuberculosis, cryptococcosis, histoplasmosis, latent infection is a corollary of this dormant state, which has the risk for reactivation and clinical disease. During murine cryptococcosis and macrophage uptake, stress and host immunity induce Cryptococcus neoformans heterogeneity with the generation of a sub-population of yeasts that manifests a phenotype compatible with dormancy (low stress response, latency of growth). In this subpopulation, mitochondrial transcriptional activity is regulated and this phenotype has been considered as a hallmark of quiescence in stem cells. Based on these findings, we worked to reproduce this phenotype in vitro and then standardize the experimental conditions to consistently generate this dormancy in C. neoformans. We found that incubation of stationary phase yeasts (STAT) in nutriment limited conditions and hypoxia for 8 days (8D-HYPOx) was able to produced cells that mimic the phenotype obtained in vivo. In these conditions, mortality and/or apoptosis occurred in less than 5% of the yeasts compared to 30-40% of apoptotic or dead yeasts upon incubation in normoxia (8D-NORMOx). Yeasts in 8D-HYPOx harbored a lower stress response, delayed growth and less that 1% of culturability on agar plates, suggesting that these yeasts are viable but non culturable cells (VBNC). These VBNC were able to reactivate in the presence of pantothenic acid, a vitamin that is known to be involved in quorum sensing and a precursor of acetyl-CoA. Global metabolism of 8D-HYPOx cells showed some specific requirements and was globally shut down compared to 8D-NORMOx and STAT conditions. Mitochondrial analyses showed that the mitochondrial mass increased with mitochondria mostly depolarized in 8D-HYPOx compared to 8D-NORMox, with increased expression of mitochondrial genes. Proteomic and transcriptomic analyses of 8D-HYPOx revealed that the number of secreted proteins and transcripts detected also decreased compared to 8D-NORMOx and STAT, and the proteome, secretome and transcriptome harbored specific profiles that are engaged as soon as four days of incubation. Importantly, acetyl-CoA and the fatty acid pathway involving mitochondria are required for the generation and viability maintenance of VBNC. Altogether, these data show that we were able to generate for the first time VBNC phenotype in C. neoformans. This VBNC state is associated with a specific metabolism that should be further studied to understand dormancy/quiescence in this yeast.
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Cryptococcus neoformans/fisiología , Cryptococcus neoformans/patogenicidad , Animales , Criptococosis/microbiología , Cryptococcus neoformans/genética , Medios de Cultivo , Ácidos Grasos/metabolismo , Proteínas Fúngicas/metabolismo , Humanos , Ratones , Viabilidad Microbiana , Mitocondrias/genética , Mitocondrias/metabolismo , Oxígeno/metabolismo , Ácido Pantoténico/farmacología , Fenotipo , TranscriptomaRESUMEN
BACKGROUND: Comparing the composition of microbial communities among groups of interest (e.g., patients vs healthy individuals) is a central aspect in microbiome research. It typically involves sequencing, data processing, statistical analysis and graphical display. Such an analysis is normally obtained by using a set of different applications that require specific expertise for installation, data processing and in some cases, programming skills. RESULTS: Here, we present SHAMAN, an interactive web application we developed in order to facilitate the use of (i) a bioinformatic workflow for metataxonomic analysis, (ii) a reliable statistical modelling and (iii) to provide the largest panel of interactive visualizations among the applications that are currently available. SHAMAN is specifically designed for non-expert users. A strong benefit is to use an integrated version of the different analytic steps underlying a proper metagenomic analysis. The application is freely accessible at http://shaman.pasteur.fr/ , and may also work as a standalone application with a Docker container (aghozlane/shaman), conda and R. The source code is written in R and is available at https://github.com/aghozlane/shaman . Using two different datasets (a mock community sequencing and a published 16S rRNA metagenomic data), we illustrate the strengths of SHAMAN in quickly performing a complete metataxonomic analysis. CONCLUSIONS: With SHAMAN, we aim at providing the scientific community with a platform that simplifies reproducible quantitative analysis of metagenomic data.
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Clasificación , Internet , Metagenómica/métodos , Programas Informáticos , Estadística como Asunto , Interfaz Usuario-Computador , Líquidos Corporales/microbiología , Preescolar , Heces/microbiología , Humanos , Metagenoma , Microbiota , ARN Ribosómico 16S/genética , Flujo de TrabajoRESUMEN
OBJECTIVES: Diagnosis and management of bipolar disorder (BD) are limited by the absence of available biomarkers. Allostatic load (AL) represents the strain that stress, including the effects of acute phases and inter-episode chronic mood instability, exerts on interconnected biological systems. This study aimed to operationalize an AL index and explore whether it could be relevant to better characterize BD patients with and without emotional hyper-reactivity particularly those at higher risk of immune-cardiometabolic dysregulation and functional impairment. METHODS: Levels of biomarkers of chronic inflammation (hsCRP and albumin), cardiovascular (systolic/diastolic blood pressure) and metabolic functions (fasting glucose, glycosylated hemoglobin, total cholesterol, LDL, HDL, and triglycerides) were measured in 1072 adult BD outpatients. Patients were classified in two groups (with/without emotional hyper-reactivity) assessed by the Multidimensional Assessment of Thymic States scale. An Allostatic Load Index for BD (BALLI), comprising six biomarkers, was constructed using data-driven biomarker selection. RESULTS: BALLI showed 81.1% accuracy with good sensitivity (81%) and specificity (81.2%) for characterizing BD patients presenting emotional hyper-reactivity, elevated risk of inflammation (increased hsCRP, hypoalbuminemia) and cardiometabolic disturbances (hypertension, hyperglycemia, and hypertriglyceridemia). Patients classified by the BALLI as presenting emotional hyper-reactivity had significantly lower global and cognitive functioning than those without emotional hyper-reactivity (P < .0001). CONCLUSIONS: A multidimensional approach based on a simple AL score (eg, BALLI) and dimensions of behavior (eg, emotional hyper-reactivity) alongside mood is clinically relevant. AL index could be a useful tool to detect multisystemic physiological dysregulations in BD patients with/without emotional hyper-reactivity particularly those at higher risk of immune-cardiometabolic disturbances and functional impairment.
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Alostasis , Trastorno Bipolar , Adulto , Afecto , Trastorno Bipolar/complicaciones , Proteína C-Reactiva , Hemoglobina Glucada , HumanosRESUMEN
Listeria monocytogenes is responsible for gastroenteritis in healthy individuals and for a severe invasive disease in immunocompromised patients. Among the three identified L. monocytogenes evolutionary lineages, lineage I strains are overrepresented in epidemic listeriosis outbreaks, but the mechanisms underlying the higher virulence potential of strains of this lineage remain elusive. Here, we demonstrate that Listeriolysin S (LLS), a virulence factor only present in a subset of lineage I strains, is a bacteriocin highly expressed in the intestine of orally infected mice that alters the host intestinal microbiota and promotes intestinal colonization by L. monocytogenes, as well as deeper organ infection. To our knowledge, these results therefore identify LLS as the first bacteriocin described in L. monocytogenes and associate modulation of host microbiota by L. monocytogenes epidemic strains to increased virulence.
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Bacteriocinas/metabolismo , Microbioma Gastrointestinal , Listeria monocytogenes/fisiología , Listeriosis/microbiología , Animales , Epidemias , Femenino , Interacciones Huésped-Patógeno , Humanos , Listeria monocytogenes/patogenicidad , Listeriosis/epidemiología , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Viabilidad Microbiana , VirulenciaRESUMEN
Chromatin regulates the selectivity of retroviral integration into the genome of infected cells. At the nucleosome level, both histones and DNA structure are involved in this regulation. We propose a strategy that allows to specifically study a single factor: the DNA distortion induced by the nucleosome. This strategy relies on mimicking this distortion using DNA minicircles (MCs) having a fixed rotational orientation of DNA curvature, coupled with atomic-resolution modeling. Contrasting MCs with linear DNA fragments having identical sequences enabled us to analyze the impact of DNA distortion on the efficiency and selectivity of integration. We observed a global enhancement of HIV-1 integration in MCs and an enrichment of integration sites in the outward-facing DNA major grooves. Both of these changes are favored by LEDGF/p75, revealing a new, histone-independent role of this integration cofactor. PFV integration is also enhanced in MCs, but is not associated with a periodic redistribution of integration sites, thus highlighting its distinct catalytic properties. MCs help to separate the roles of target DNA structure, histone modifications and integrase (IN) cofactors during retroviral integration and to reveal IN-specific regulation mechanisms.
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ADN Circular/química , ADN Viral/química , Conformación de Ácido Nucleico , Retroviridae/fisiología , Integración Viral , Biblioteca de Genes , Integrasa de VIH/metabolismo , VIH-1/fisiología , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Modelos Moleculares , Nucleosomas/metabolismoRESUMEN
MOTIVATION: With the continued improvement of requisite mass spectrometers and UHPLC systems, Hydrogen/Deuterium eXchange Mass Spectrometry (HDX-MS) workflows are rapidly evolving towards the investigation of more challenging biological systems, including large protein complexes and membrane proteins. The analysis of such extensive systems results in very large HDX-MS datasets for which specific analysis tools are required to speed up data validation and interpretation. RESULTS: We introduce a web application and a new R-package named 'MEMHDX' to help users analyze, validate and visualize large HDX-MS datasets. MEMHDX is composed of two elements. A statistical tool aids in the validation of the results by applying a mixed-effects model for each peptide, in each experimental condition, and at each time point, taking into account the time dependency of the HDX reaction and number of independent replicates. Two adjusted P-values are generated per peptide, one for the 'Change in dynamics' and one for the 'Magnitude of ΔD', and are used to classify the data by means of a 'Logit' representation. A user-friendly interface developed with Shiny by RStudio facilitates the use of the package. This interactive tool allows the user to easily and rapidly validate, visualize and compare the relative deuterium incorporation on the amino acid sequence and 3D structure, providing both spatial and temporal information. AVAILABILITY AND IMPLEMENTATION: MEMHDX is freely available as a web tool at the project home page http://memhdx.c3bi.pasteur.fr CONTACT: marie-agnes.dillies@pasteur.fr or sebastien.brier@pasteur.frSupplementary information: Supplementary data is available at Bioinformatics online.
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Deuterio , Hidrógeno , Conjuntos de Datos como Asunto , Medición de Intercambio de Deuterio , Espectrometría de Masas , Programas InformáticosRESUMEN
Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) worldwide, causing over 150 million clinical cases annually. There is currently no specific treatment addressing the asymptomatic carriage in the gut of UPEC before they initiate UTIs. This study investigates the efficacy of virulent bacteriophages to decrease carriage of gut pathogens. Three virulent bacteriophages infecting an antibiotic-resistant UPEC strain were isolated and characterized both in vitro and in vivo. A new experimental murine model of gut carriage of E. coli was elaborated and the impact of virulent bacteriophages on colonization levels and microbiota diversity was assessed. A single dose of a cocktail of the three bacteriophages led to a sharp decrease in E. coli levels throughout the gut. We also observed that microbiota diversity was much less affected by bacteriophages than by antibiotics. Therefore, virulent bacteriophages can efficiently target UPEC strains residing in the gut, with potentially profound public health and economic impacts. These results open a new area with the possibility to manipulate specifically the microbiota using virulent bacteriophages, which could have broad applications in many gut-related disorders/diseases and beyond.
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Antibacterianos/farmacología , Bacteriófagos/fisiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/virología , Microbioma Gastrointestinal , Animales , Bacteriófagos/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/fisiología , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/virología , Femenino , Tracto Gastrointestinal/microbiología , Humanos , Ratones , Ratones Endogámicos BALB C , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/microbiología , Infecciones Urinarias/virologíaAsunto(s)
Trastorno Bipolar/clasificación , Trastorno Bipolar/fisiopatología , Enfermedades Cardiovasculares/fisiopatología , Disfunción Cognitiva/fisiopatología , Emociones/fisiología , Adulto , Trastorno Bipolar/complicaciones , Análisis por Conglomerados , Disfunción Cognitiva/etiología , Estudios Transversales , Femenino , Humanos , Aprendizaje Automático , Masculino , Persona de Mediana Edad , Inducción de Remisión , Riesgo , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: The induction of de novo CD8 + T-cell responses is essential for protective antiviral immunity, but this process is often impaired in people with HIV-1 (PWH). We investigated the extent to which the immune competence of naive CD8 + T cells, a key determinant of priming efficacy, could be preserved or restored in PWH via long-term antiretroviral therapy (ART). METHODS: We used flow cytometry, molecular analyses of gene transcription and telomere length, and a fully validated priming assay to characterize naive CD8 + T cells ex vivo and evaluate the induction of antigen-specific effector/memory CD8 + T cells in vitro , comparing age-matched healthy uninfected donors (HUDs), PWH on ART, and natural HIV-1 controllers (HICs). RESULTS: We found that naive CD8 + T cells were numerically reduced and exhibited a trend toward shorter telomere lengths in PWH on ART compared with HUDs and HICs. These features associated with impaired priming efficacy. However, we also found that naive CD8 + T cells were fully equipped proliferatively and transcriptionally in PWH on ART, enabling the generation of antigen-specific effector/memory CD8 + T cells with functional and phenotypic attributes comparable to those primed from HUDs. CONCLUSION: Our data suggest that naive CD8 + T cells in PWH on ART are intrinsically capable of generating functionally and phenotypically intact effector/memory CD8 + T cells in response to antigen, despite evidence of senescence and an overall numerical reduction that compromises priming efficacy relative to HUDs and HICs.
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Infecciones por VIH , Seropositividad para VIH , VIH-1 , Humanos , Infecciones por VIH/tratamiento farmacológico , Linfocitos T CD8-positivosRESUMEN
Drug-recalcitrant infections are a leading global-health concern. Bacterial cells benefit from phenotypic variation, which can suggest effective antimicrobial strategies. However, probing phenotypic variation entails spatiotemporal analysis of individual cells that is technically challenging, and hard to integrate into drug discovery. In this work, we develop a multi-condition microfluidic platform suitable for imaging two-dimensional growth of bacterial cells during transitions between separate environmental conditions. With this platform, we implement a dynamic single-cell screening for pheno-tuning compounds, which induce a phenotypic change and decrease cell-to-cell variation, aiming to undermine the entire bacterial population and make it more vulnerable to other drugs. We apply this strategy to mycobacteria, as tuberculosis poses a major public-health threat. Our lead compound impairs Mycobacterium tuberculosis via a peculiar mode of action and enhances other anti-tubercular drugs. This work proves that harnessing phenotypic variation represents a successful approach to tackle pathogens that are increasingly difficult to treat.
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Antituberculosos , Mycobacterium tuberculosis , Análisis de la Célula Individual , Tuberculosis , Mycobacterium tuberculosis/efectos de los fármacos , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Análisis de la Célula Individual/métodos , Tuberculosis/tratamiento farmacológico , Tuberculosis/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Microfluídica/métodos , Fenotipo , Descubrimiento de Drogas/métodos , Sinergismo FarmacológicoRESUMEN
Arthropod-borne viruses (arboviruses) pose a significant global health threat and are primarily transmitted by mosquitoes. In Cambodia, there are currently 290 recorded mosquito species, with at least 17 of them considered potential vectors of arboviruses to humans. Effective surveillance of virome profiles in mosquitoes from Cambodia is vital, as it could help prevent and control arbovirus diseases in a country where epidemics occur frequently. The objective of this study was to identify and characterize the viral diversity in mosquitoes collected during a one-year longitudinal study conducted in various habitats across Cambodia. For this purpose, we used a metatranscriptomics approach and detected the presence of chikungunya virus in the collected mosquitoes. Additionally, we identified viruses categorized into 26 taxa, including those known to harbor arboviruses such as Flaviviridae and Orthomyxoviridae, along with a group of viruses not yet taxonomically identified and provisionally named "unclassified viruses". Interestingly, the taxa detected varied in abundance and composition depending on the mosquito genus, with no significant influence of the collection season. Furthermore, most of the identified viruses were either closely related to viruses found exclusively in insects or represented new viruses belonging to the Rhabdoviridae and Birnaviridae families. The transmission capabilities of these novel viruses to vertebrates remain unknown.
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Birnaviridae , Culicidae , Humanos , Animales , Cambodia/epidemiología , Estudios Longitudinales , Mosquitos VectoresRESUMEN
The diversity and circulation of arboviruses are not much studied in Madagascar. The fact is that arboviral emergences are rarely detected. The existing surveillance system primarily relies on serological detection and records only a few human infections annually. The city of Mahajanga, however, experienced a confirmed dengue fever epidemic in 2020 and 2021. This study aimed to characterize and analyze the virome of mosquitoes collected in Mahajanga, near patients with dengue-like syndromes to detect known and unknown viruses as well as investigate the factors contributing to the relative low circulation of arboviruses in the area. A total of 4280 mosquitoes representing at least 12 species from the Aedes, Anopheles, and Culex genera were collected during the dry and the rainy seasons from three sites, following an urbanization gradient. The virome analysis of 2192 female mosquitoes identified a diverse range of viral families and genera and revealed different patterns that are signatures of the influence of the mosquito genus or the season of collection on the composition and abundance of the virome. Despite the absence of known human or veterinary arboviruses, the identification and characterization of viral families, genera, and species in the mosquito virome contribute to our understanding of viral ecology and diversity within mosquito populations in Madagascar. This study serves as a foundation for ongoing surveillance efforts and provides a basis for the development of preventive strategies against various mosquito-borne viral diseases, including known arboviruses.
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Recently, an intestinal dysbiotic microbiota with enrichment in oral cavity bacteria has been described in colorectal cancer (CRC) patients. Here, we characterize and investigate one of these oral pathobionts, the Gram-positive anaerobic coccus Parvimonas micra. We identified two phylotypes (A and B) exhibiting different phenotypes and adhesion capabilities. We observed a strong association of phylotype A with CRC, with its higher abundance in feces and in tumoral tissue compared with the normal homologous colonic mucosa, which was associated with a distinct methylation status of patients. By developing an in vitro hypoxic co-culture system of human primary colonic cells with anaerobic bacteria, we show that P. micra phylotype A alters the DNA methylation profile promoters of key tumor-suppressor genes, oncogenes, and genes involved in epithelial-mesenchymal transition. In colonic mucosa of CRC patients carrying P. micra phylotype A, we found similar DNA methylation alterations, together with significant enrichment of differentially expressed genes in pathways involved in inflammation, cell adhesion, and regulation of actin cytoskeleton, providing evidence of P. micra's possible role in the carcinogenic process.
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Neoplasias Colorrectales , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/genética , Firmicutes/genética , Bacterias , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/microbiologíaRESUMEN
BACKGROUND: CD8+ T cells equipped with a full arsenal of antiviral effector functions are critical for effective immune control of HIV-1. It has nonetheless remained unclear how best to elicit such potent cellular immune responses in the context of immunotherapy or vaccination. HIV-2 has been associated with milder disease manifestations and more commonly elicits functionally replete virus-specific CD8+ T cell responses compared with HIV-1. We aimed to learn from this immunological dichotomy and to develop informed strategies that could enhance the induction of robust CD8+ T cell responses against HIV-1. METHODS: We developed an unbiased in vitro system to compare the de novo induction of antigen-specific CD8+ T cell responses after exposure to HIV-1 or HIV-2. The functional properties of primed CD8+ T cells were assessed using flow cytometry and molecular analyses of gene transcription. FINDINGS: HIV-2 primed functionally optimal antigen-specific CD8+ T cells with enhanced survival properties more effectively than HIV-1. This superior induction process was dependent on type I interferons (IFNs) and could be mimicked via the adjuvant delivery of cyclic GMP-AMP (cGAMP), a known agonist of the stimulator of interferon genes (STING). CD8+ T cells elicited in the presence of cGAMP were polyfunctional and highly sensitive to antigen stimulation, even after priming from people living with HIV-1. INTERPRETATION: HIV-2 primes CD8+ T cells with potent antiviral functionality by activating the cyclic GMP-AMP synthase (cGAS)/STING pathway, which results in the production of type I IFNs. This process may be amenable to therapeutic development via the use of cGAMP or other STING agonists to bolster CD8+ T cell-mediated immunity against HIV-1. FUNDING: This work was funded by INSERM, the Institut Curie, and the University of Bordeaux (Senior IdEx Chair) and by grants from Sidaction (17-1-AAE-11097, 17-1-FJC-11199, VIH2016126002, 20-2-AEQ-12822-2, and 22-2-AEQ-13411), the Agence Nationale de la Recherche sur le SIDA (ECTZ36691, ECTZ25472, ECTZ71745, and ECTZ118797), and the Fondation pour la Recherche Médicale (EQ U202103012774). D.A.P. was supported by a Wellcome Trust Senior Investigator Award (100326/Z/12/Z).
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Infecciones por VIH , Interferón Tipo I , Humanos , Interferón Tipo I/metabolismo , Linfocitos T CD8-positivos , Interferones/metabolismo , Adyuvantes InmunológicosRESUMEN
It is becoming increasingly obvious that glycophosphatidylinositol (GPI)-anchored proteins (GAPs) play a prominent role in fungi, a full understanding of GAPs is however lacking especially for the human opportunistic fungus Cryptococcus neoformans. Using online GPI prediction tools, GAPs were identified and subsequently a mutant library for these GAP-encoding genes was developed and a publicly available knock out (KO) mutant library was used. In total, 41 overexpression and 34 KO mutants, representing 47 unique genes, were analyzed. From the analysis of the two libraries, two main gene candidates, a mannoprotein 88 (MP88) (CNAG_00776) and an uncharacterized protein (CNAG_00137) were further investigated by constructing additional independent mutant strains. The CNAG_00776 mutant showed an impaired growth upon plasma membrane stress and significant decreased phagocytosis. The CNAG_00137 mutant showed impaired growth during cell wall stress or increased temperature and significant decreased phagocytosis. By performing a large genetic screen of GAPs in the genome of the human fungal pathogen C. neoformans, we identified two candidate GAP genes involved in C. neoformans/host interaction and stress response. Further research into these two genes could potentially result in new targets for antfungals, treatment strategies or vaccines to manage C. neoformans disease.
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Criptococosis , Cryptococcus neoformans , Humanos , Glicosilfosfatidilinositoles/metabolismo , Cryptococcus neoformans/genética , Cryptococcus neoformans/metabolismo , Pared Celular/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Membrana Celular/metabolismo , Criptococosis/metabolismoRESUMEN
Virus-specific CD8+ T cells play a central role in HIV-1 natural controllers to maintain suppressed viremia in the absence of antiretroviral therapy. These cells display a memory program that confers them stemness properties, high survival, polyfunctionality, proliferative capacity, metabolic plasticity, and antiviral potential. The development and maintenance of such qualities by memory CD8+ T cells appear crucial to achieving natural HIV-1 control. Here, we show that targeting the signaling pathways Wnt/transcription factor T cell factor 1 (Wnt/TCF-1) and mTORC through GSK3 inhibition to reprogram HIV-specific CD8+ T cells from noncontrollers promoted functional capacities associated with natural control of infection. Features of such reprogrammed cells included enrichment in TCF-1+ less-differentiated subsets, a superior response to antigen, enhanced survival, polyfunctionality, metabolic plasticity, less mTORC1 dependency, an improved response to γ-chain cytokines, and a stronger HIV-suppressive capacity. Thus, such CD8+ T cell reprogramming, combined with other available immunomodulators, might represent a promising strategy for adoptive cell therapy in the search for an HIV-1 cure.