Publications by authors named "Prevost J"

Background: Effectiveness of disease-modifying treatment (DMT) in people affected by primary progressive multiple sclerosis (PPMS) is limited. Whether specific subgroups may benefit more from DMT in a real-world setting remains unclear. Our aim was to investigate the potential effect of DMT on disability worsening among patients with PPMS stratified by different disability trajectories.

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The nucleoprotein (NP) of type A influenza virus (IAV) is highly conserved across all virus strains, making it an attractive candidate antigen for universal vaccines. While various studies have explored NP-induced mucosal immunity, here we interrogated the mechanistic differences between intramuscular (IM) and intranasal (IN) delivery of a recombinant adenovirus carrying NP fused with a bifunctional CD40 ligand. Despite being less effective than IM delivery in inducing systemic cellular immune responses and antibody-dependent cellular cytotoxicity (ADCC), IN immunization elicited superior antigen-specific recall humoral and cellular response in the nasal associated lymphoid tissue (NALT) of the upper respiratory tract, the initial site of immune recognition and elimination of inhaled pathogens.

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Background And Objectives: Women with multiple sclerosis (MS) are at risk of disease reactivation in the early postpartum period. Ocrelizumab (OCR) is an anti-CD20 therapy highly effective at reducing MS disease activity. Data remain limited regarding use of disease-modifying therapies (DMTs), including OCR, and disease activity during peripregnancy periods.

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Article Synopsis
  • HIV-1 envelope glycoprotein (Env) structure affects the immune response, with "closed" forms evading certain antibodies while "open" forms are vulnerable to others.
  • Infected CD4+ T cells show that downmodulation of CD4 occurs before HIV-1 mRNA expression, and these cells mainly express "closed" Envs, resistant to non-neutralizing antibodies (nnAbs).
  • The study challenges the effectiveness of nnAbs in targeting productively infected cells for HIV-1 treatment, as attempts with nnAbs did not reduce viral replication in humanized mouse models.
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The majority of naturally elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs) because they are unable to recognize the Env trimer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have the potential to eliminate HIV-1-infected cells by antibody-dependent cellular cytotoxicity (ADCC) provided that Env is present on the cell surface in its "open" conformation. This is because most nnAbs recognize epitopes that become accessible only after Env interaction with CD4 and the exposure of epitopes that are normally occluded in the closed trimer.

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While historically confined to endemic areas, Monkeypox virus (MPXV) infection has increasingly garnered international attention due to sporadic outbreaks in non-endemic countries in the last two decades and its potential for human-to-human transmission. In 2022, a multi-country outbreak of mpox disease was declared by the World Health Organization (WHO) and nearly 100 000 mpox cases have been reported since the beginning of this pandemic. The clade II variant of the virus appears to be responsible for the vast majority of these infections.

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Unlabelled: CD4-mimetics (CD4mcs) are small molecule compounds that mimic the interaction of the CD4 receptor with HIV-1 envelope glycoproteins (Env). Env from primary viruses normally samples a "closed" conformation that occludes epitopes recognized by CD4-induced (CD4i) non-neutralizing antibodies (nnAbs). CD4mcs induce conformational changes on Env resulting in the exposure of these otherwise inaccessible epitopes.

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The HIV-1 envelope glycoprotein (Env) is expressed at the surface of infected cells and as such can be targeted by non-neutralizing antibodies (nnAbs) that mediate antibody-dependent cellular cytotoxicity (ADCC). Previous single-molecule Förster resonance energy transfer (smFRET) studies demonstrated that Env from clinical isolates predominantly adopt a "closed" conformation (State 1), which is resistant to nnAbs. After interacting with the cellular receptor CD4, the conformational equilibrium of Env shifts toward States 2 and 3, exposing the coreceptor binding site (CoRBS) and permitting binding of antibodies targeting this site.

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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds the receptor angiotensin converting enzyme 2 (ACE2) and drives virus-host membrane fusion through refolding of its S2 domain. Whereas the S1 domain contains high sequence variability, the S2 domain is conserved and is a promising pan-betacoronavirus vaccine target. We applied cryo-electron tomography to capture intermediates of S2 refolding and understand inhibition by antibodies to the S2 stem-helix.

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Background: Comparisons between cladribine and other potent immunotherapies for multiple sclerosis (MS) are lacking.

Objectives: To compare the effectiveness of cladribine against fingolimod, natalizumab, ocrelizumab and alemtuzumab in relapsing-remitting MS.

Methods: Patients with relapsing-remitting MS treated with cladribine, fingolimod, natalizumab, ocrelizumab or alemtuzumab were identified in the global MSBase cohort and two additional UK centres.

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Background: First-line standard-of-care for unresectable, pleural mesothelioma (PM) changed with the phase 3 CheckMate 743 study results, showing that nivolumab plus ipilimumab (Nivo + Ipi) significantly extended overall survival (OS) versus platinum + pemetrexed chemotherapy for PM (median OS 18.1 versus 14.1 months; hazard ratio: 0.

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The majority of naturally-elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs), because they are unable to recognize the Env timer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have the potential to eliminate HIV-1-infected cells by Antibody-Dependent Cellular Cytotoxicity (ADCC) provided that Env is present on the cell surface in its "open" conformation. This is because most nnAbs recognize epitopes that become accessible only after Env interaction with CD4 and the exposure of epitopes that are normally occluded in the closed trimer.

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CD4-mimetics (CD4mcs) are small molecule compounds that mimic the interaction of the CD4 receptor with HIV-1 envelope glycoproteins (Env). Env from primary viruses normally samples a "closed" conformation which occludes epitopes recognized by CD4-induced (CD4i) non-neutralizing antibodies (nnAbs). CD4mcs induce conformational changes on Env resulting in the exposure of these otherwise inaccessible epitopes.

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Article Synopsis
  • - The study analyzes plasma samples from 318 COVID-19 patients to understand how RNAemia, delayed antibody responses, and inflammation affect patient outcomes, revealing four distinct patient clusters based on severity and survival probability.
  • - Critically ill patients were categorized into good prognosis and high-fatality clusters, while non-critical survivors were divided into high and low early antibody responders, each showing different patterns in antibody development and inflammation.
  • - The findings indicate that high-fatality patients have specific genomic signatures linked to severe COVID-19, and both critical and non-critical patients with delayed antibody responses exhibit persistent interferon (IFN) activity, suggesting that high IFN levels might hinder the body's ability to build effective immunity.
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Deleterious effects of exercise close to bedtime could be due to increased physiological arousal that can be detected during sleep using sleep spectral analysis. Resistance and endurance exercises have different effects on cortisol release that may lead them to impact sleep spectral signatures differently. The present study aimed to investigate the effects of two types of evening exercise on sleep architecture, sleep spectral parameters and salivary cortisol.

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Article Synopsis
  • The study aims to identify predictors of treatment switching in patients with relapsing-remitting MS using data from multiple national registries.
  • A total of 269,822 treatment episodes from 110,326 patients were analyzed, focusing on those who started disease-modifying treatments during their RRMS phase.
  • Key findings indicate that higher disability scores (EDSS), being female, and older age increase the likelihood of treatment switching, with certain DMTs initiated between 2007 and 2012 showing even higher rates of switching.
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Aim: To evaluate the real-world comparative effectiveness and the cost-effectiveness, from a UK National Health Service perspective, of natalizumab versus fingolimod in patients with rapidly evolving severe relapsing-remitting multiple sclerosis (RES-RRMS).

Methods: Real-world data from the MSBase Registry were obtained for patients with RES-RRMS who were previously either naive to disease-modifying therapies or had been treated with interferon-based therapies, glatiramer acetate, dimethyl fumarate, or teriflunomide (collectively known as BRACETD). Matched cohorts were selected by 3-way multinomial propensity score matching, and the annualized relapse rate (ARR) and 6-month-confirmed disability worsening (CDW6M) and improvement (CDI6M) were compared between treatment groups.

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Background: Chronic inflammation persists in some people living with human immunodeficiency virus (HIV) during antiretroviral therapy and is associated with premature aging. The glycoprotein 120 (gp120) subunit of HIV-1 envelope sheds and can be detected in plasma, showing immunomodulatory properties even in the absence of detectable viremia. We evaluated whether plasma soluble gp120 (sgp120) and a family of gp120-specific anti-cluster A antibodies, linked to CD4 depletion in vitro, contribute to chronic inflammation, immune dysfunction, and subclinical cardiovascular disease in participants of the Canadian HIV and Aging Cohort Study with undetectable viremia.

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The HIV-1 entry inhibitor temsavir prevents the viral receptor CD4 (cluster of differentiation 4) from interacting with the envelope glycoprotein (Env) and blocks its conformational changes. To do this, temsavir relies on the presence of a residue with small side chain at position 375 in Env and is unable to neutralize viral strains like CRF01_AE carrying His375. Here we investigate the mechanism of temsavir resistance and show that residue 375 is not the sole determinant of resistance.

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Article Synopsis
  • This study investigates the relationship between environmental factors and progressive-onset multiple sclerosis (POMS) compared to relapse-onset multiple sclerosis (ROMS), aiming to better understand the causes of POMS.
  • Data is drawn from two major studies, including a sample of 155 POMS, 204 ROMS, and 558 controls, ensuring that the POMS sample is representative of the broader Australian POMS population.
  • The research addresses various methodological challenges, such as biases and differences between POMS and controls, and will present findings on the associations in future publications.
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Background: Chronic inflammation persists in some people living with HIV (PLWH), even during antiretroviral therapy (ART) and is associated with premature aging. The gp120 subunit of the HIV-1 envelope glycoprotein can shed from viral and cellular membranes and can be detected in plasma and tissues, showing immunomodulatory properties even in the absence of detectable viremia. We evaluated whether plasmatic soluble gp120 (sgp120) and a family of gp120-specific anti-cluster A antibodies, which were previously linked to CD4 depletion , could contribute to chronic inflammation, immune dysfunction, and sub-clinical cardiovascular disease in participants of the Canadian HIV and Aging cohort (CHACS) with undetectable viremia.

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HIV-1 evades antibody-dependent cellular cytotoxicity (ADCC) responses not only by controlling Env conformation and quantity at the cell surface but also by altering NK cell activation via the downmodulation of several ligands of activating and co-activating NK cell receptors. The signaling lymphocyte activation molecule (SLAM) family of receptors, which includes NTB-A and 2B4, act as co-activating receptors to sustain NK cell activation and cytotoxic responses. These receptors cooperate with CD16 (FcγRIII) and other activating receptors to trigger NK cell effector functions.

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Article Synopsis
  • The study investigates geographical differences in the risk of secondary progressive multiple sclerosis (SPMS) and how these may be influenced by factors like latitude and treatment types.
  • It utilizes data from a global patient registry, focusing on relapsing-remitting multiple sclerosis patients and factors such as age, sex, and treatment efficacy.
  • The research analyzes data from over 51,000 patients across 27 countries to establish patterns in the progression from relapsing-remitting to secondary progressive phases of the disease.
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Article Synopsis
  • The study highlights the risk of increased disease activity after stopping natalizumab, emphasizing the need for effective alternative therapies to manage relapsing-remitting multiple sclerosis (RRMS).
  • It compares the effectiveness of switching to three disease-modifying therapies—dimethyl fumarate, fingolimod, and ocrelizumab—following natalizumab discontinuation among RRMS patients.
  • The analysis included data from 1386 patients and focused on outcomes like annualized relapse rate and time to first relapse, revealing important insights into treatment persistence and effectiveness for managing disease after discontinuing natalizumab.
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