Publications by authors named "Trottein F"

Article Synopsis
  • Aging significantly impacts the severity and recovery from acute viral pneumonia, particularly in the context of COVID-19 as studied in hamsters.
  • Researchers utilized advanced metagenomics and metabolomics to explore the gut microbiota changes in young and aged hamsters, finding distinct age-related differences in gut health that correlate with disease outcomes.
  • The study highlights specific metabolites and bacterial changes linked to disease severity in older hamsters, suggesting that targeted microbiome interventions could improve management of pneumonia in elderly patients.
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  • Neutrophil subsets with regulatory properties are often seen as harmful to immune responses against tumors and infections, but new findings suggest otherwise in cases of severe viral respiratory infections (VRI).
  • A significant population of neutrophils expressing programmed death-ligand 1 (PD-L1) was identified in humans and mice with VRI, exhibiting strong regulatory functions but diminished antimicrobial capabilities.
  • Depleting these PD-L1 neutrophils or blocking their function during VRI led to worse outcomes, indicating that they play a crucial role in managing inflammation and could be potential targets for future treatments.
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Introduction: The COVID-19 pandemic caused by the SARS-CoV-2 virus has underscored the urgent necessity for the development of antiviral compounds that can effectively target coronaviruses. In this study, we present the first evidence of the antiviral efficacy of hyperforin, a major metabolite of St. John's wort, for which safety and bioavailability in humans have already been established.

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Bacterial-viral co-infections are frequent, but their reciprocal effects are not well understood. Here, we examined the effect Bordetella pertussis infection and the role of pertussis toxin (PT) on influenza A virus (IAV) infection and disease. In C57BL/6J mice, prior nasal administration of virulent B.

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The gut-lung axis is critical during viral respiratory infections such as influenza. Gut dysbiosis during infection translates into a massive drop of microbially produced short-chain fatty acids (SCFAs). Among them, butyrate is important during influenza suggesting that microbiome-based therapeutics targeting butyrate might hold promises.

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The gut-to-lung axis is critical during respiratory infections, including influenza A virus (IAV) infection. In the present study, we used high-resolution shotgun metagenomics and targeted metabolomic analysis to characterize influenza-associated changes in the composition and metabolism of the mouse gut microbiota. We observed several taxonomic-level changes on day (D)7 post-infection, including a marked reduction in the abundance of members of the and families, and an increase in the abundance of .

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Background: Cerebral malaria (CM) is a fatal neuroinflammatory syndrome caused (in humans) by the protozoa Plasmodium (P.) falciparum. Glial cell activation is one of the mechanisms that contributes to neuroinflammation in CM.

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Smoking is the main risk factor for many lung diseases including chronic obstructive pulmonary disease. Cigarette smoke (CS) contains carcinogenic and reactive oxygen species that favor DNA mutations and perturb the homeostasis and environment of cells. CS induces lung cell senescence resulting in a stable proliferation arrest and a senescence-associated secretory phenotype.

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The age-related decline in immunity reduces the effectiveness of vaccines in older adults. Immunosenescence is associated with chronic, low-grade inflammation, and the accumulation of senescent cells. The latter express Bcl-2 family members (providing resistance to cell death) and exhibit a pro-inflammatory, senescence-associated secretory phenotype (SASP).

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Article Synopsis
  • Recent research links loss of gonadotropin-releasing hormone (GnRH) to cognitive decline, suggesting a similar mechanism may underlie neurological symptoms in post-COVID patients.
  • Investigations revealed persistent low testosterone levels in some men post-COVID could indicate hypothalamic impact, connecting hormonal changes to cognitive issues.
  • Dysfunction of GnRH neurons and certain brain cells due to SARS-CoV-2 could lead to reproductive, metabolic, and mental health problems, potentially increasing risks for neurological disorders across all ages.
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Pneumococcal conjugate vaccines offer an excellent safety profile and high protection against the serotypes comprised in the vaccine. However, inclusion of protein antigens fromcombined with potent adjuvants and a suitable delivery system are expected to both extend protection to serotype strains not represented in the formulation and stimulate a broader immune response, thus more effective in young children, elderly, and immunocompromised populations. Along this line, nanoparticle (NP) delivery systems can enhance the immunogenicity of antigens by protecting them from degradation and increasing their uptake by antigen-presenting cells, as well as offering co-delivery with adjuvants.

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Older age is one of the strongest risk factors for severe COVID-19. In this study, we determined whether age-associated cellular senescence contributes to the severity of experimental COVID-19. Aged golden hamsters accumulate senescent cells in the lungs, and the senolytic drug ABT-263, a BCL-2 inhibitor, depletes these cells at baseline and during SARS-CoV-2 infection.

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Article Synopsis
  • The gut microbiota plays a crucial role in metabolic dysfunction, making it a target for new treatments focused on restoring its balance.
  • Two specific strains of gut microbiota were found to have anti-obesity effects by promoting the secretion of a hormone that helps regulate appetite and fat storage in obese mice.
  • These strains not only reduced inflammation in fat tissues but also improved lipid and bile acid metabolism, highlighting their potential as live biotherapeutics for metabolic disease treatment and prevention.
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  • Inflammation is a vital immune response to harm but can become excessive, contributing to various diseases and is not completely understood at the molecular level.
  • The glycoprotein CD44 helps cells take up metals like copper, which, when present in mitochondria of inflammatory macrophages, plays a crucial role in their metabolic and epigenetic changes.
  • Targeting mitochondrial copper with the compound LCC-12 can reduce inflammation and alter macrophage behavior, suggesting a promising new therapeutic approach for managing inflammation and enhancing immune responses.
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Progression of tuberculosis is tightly linked to a disordered immune balance, resulting in inability of the host to restrict intracellular bacterial replication and its subsequent dissemination. The immune response is mainly characterized by an orchestrated recruitment of inflammatory cells secreting cytokines. This response results from the activation of innate immunity receptors that trigger downstream intracellular signaling pathways involving adaptor proteins such as the TIR-containing adaptor protein (Tirap).

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Coronavirus disease 2019 (COVID-19, caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2)) is primarily a respiratory illness. However, various extrapulmonary manifestations have been reported in patients with severe forms of COVID-19. Notably, SARS-CoV-2 was shown to directly trigger white adipose tissue (WAT) dysfunction, which in turn drives insulin resistance, dyslipidemia, and other adverse outcomes in patients with COVID-19.

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The accumulation of senescent cells in tissues is a key process of aging and age-related diseases, including lung diseases such as chronic obstructive pulmonary disease, lung fibrosis, or cancer. In recent years, the spectrum of respiratory diseases associated with cellular senescence has been broadened, in particular acute viral pulmonary infections, foremost among which is coronavirus disease 2019 (COVID19), which is particularly severe in the elderly or in subjects with comorbidities. Influenza virus infection, which strikes more severely at the extreme ages of life, is also associated with severe pulmonary senescence.

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Obese patients with non-alcoholic steatohepatitis (NASH) are prone to severe forms of COVID-19. There is an urgent need for new treatments that lower the severity of COVID-19 in this vulnerable population. To better replicate the human context, we set up a diet-induced model of obesity associated with dyslipidemia and NASH in the golden hamster (known to be a relevant preclinical model of COVID-19).

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Obese patientss with nonalcoholic steatohepatitis (NASH) are particularly prone to developing severe forms of coronavirus disease 19 (COVID-19). The gut-to-lung axis is critical during viral infections of the respiratory tract, and a change in the gut microbiota's composition might have a critical role in disease severity. Here, we investigated the consequences of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the gut microbiota in the context of obesity and NASH.

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The development of anti-infectives against a large range of AB-like toxin-producing bacteria includes the identification of compounds disrupting toxin transport through both the endolysosomal and retrograde pathways. Here, we performed a high-throughput screening of compounds blocking Rac1 proteasomal degradation triggered by the Cytotoxic Necrotizing Factor-1 (CNF1) toxin, which was followed by orthogonal screens against two toxins that hijack the endolysosomal (diphtheria toxin) or retrograde (Shiga-like toxin 1) pathways to intoxicate cells. This led to the identification of the molecule C910 that induces the enlargement of EEA1-positive early endosomes associated with sorting defects of CNF1 and Shiga toxins to their trafficking pathways.

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Non-conventional T cells, such as γδ T and invariant natural killer T (iNKT) cells, are emerging players in fighting cancer. Alpha-galactosylceramide (α-GalCer) is used as an exogenous ligand to activate iNKT cells. Human cells don't have a direct pathway producing α-GalCer, which, however, can be produced by bacteria.

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Drug repurposing has the advantage of shortening regulatory preclinical development steps. Here, we screened a library of drug compounds, already registered in one or several geographical areas, to identify those exhibiting antiviral activity against SARS-CoV-2 with relevant potency. Of the 1,942 compounds tested, 21 exhibited a substantial antiviral activity in Vero-81 cells.

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The expanding knowledge on the systemic influence of the human microbiome suggests that fecal samples are underexploited sources of new beneficial strains for extra-intestinal health. We have recently shown that acetate, a main circulating microbiota-derived molecule, reduces the deleterious effects of pulmonary and enteric serovar Typhimurium bacterial post-influenza superinfections. Considering the beneficial and broad effects of acetate, we intended to isolate a commensal strain, producing acetate and potentially exploitable in the context of respiratory infections.

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Article Synopsis
  • Short-chain fatty acids (SCFAs), particularly acetate, play a critical role in enhancing immune responses by activating macrophages in the lungs to fight bacterial infections.
  • The study reveals that acetate influences macrophage behavior through changes in gene expression, metabolic processes, and boosts nitric oxide production, which is essential for their bactericidal activity.
  • Notably, acetate's effects are linked to the NLRP3 inflammasome and HIF-1α activation via enhanced glycolysis, rather than through traditional receptor pathways or metabolism enzymes.
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