Publications by authors named "Marnix van Loock"

Prophylactic drugs against dengue are currently under development. In this study, we explored how such prophylactic approaches might affect dengue cases in four communes of Nha Trang City, Vietnam. A community level dengue transmission survey indicated high levels of previous exposure to dengue (89.

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Article Synopsis
  • Dengue fever poses a major health and economic challenge in (sub)tropical regions, with no antiviral treatments currently available.
  • JNJ-A07 has been shown to be effective against various dengue virus genotypes by targeting the viral non-structural protein 4B (NS4B) and disrupting important interactions needed for viral replication.
  • This research clarifies how JNJ-A07 and a similar compound, NITD-688, inhibit the formation of vesicle packets crucial for dengue virus RNA replication, offering new insights into potential antiviral strategies.
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Dengue is a global public health threat, with about half of the world's population at risk of contracting this mosquito-borne viral disease. Climate change, urbanization, and global travel accelerate the spread of dengue virus (DENV) to new areas, including southern parts of Europe and the US. Currently, no dengue-specific small-molecule antiviral for prophylaxis or treatment is available.

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The recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) posed a major threat to global health. Although the World Health Organization ended the public health emergency status, antiviral drugs are needed to address new variants of SARS-CoV-2 and future pandemics. To identify novel broad-spectrum coronavirus drugs, we developed a high-content imaging platform compatible with high-throughput screening.

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In the absence of any approved dengue-specific treatment, the discovery and development of a novel small-molecule antiviral for the prevention or treatment of dengue are critical. We previously reported the identification of a novel series of 3-acyl-indole derivatives as potent and pan-serotype dengue virus inhibitors. We herein describe our optimization efforts toward preclinical candidates and with improved pan-serotype coverage (EC's against the four DENV serotypes ranging from 0.

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Background: Dengue is a growing global health threat with no specific antiviral drugs available for treatment or prophylaxis. This first-in-human, double-blind, randomized, placebo-controlled study aimed to examine the safety, tolerability, and pharmacokinetics of increasing single and multiple oral doses of JNJ-1802, a pan-serotype dengue antiviral small molecule.

Methods: Eligible healthy participants (18-55 years of age) were randomized to receive oral JNJ-1802 in fasted conditions as (1) single doses (50-1200 mg; n = 29) or placebo (n = 10); or (2) once-daily doses (50-560 mg for 10 consecutive days or 400 mg for 31 days; n = 38) or placebo (n = 9).

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The ongoing COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is partly under control by vaccination. However, highly potent and safe antiviral drugs for SARS-CoV-2 are still needed to avoid development of severe COVID-19. We report the discovery of a small molecule, Z-Tyr-Ala-CHN, which was identified in a cell-based antiviral screen.

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Dengue virus (DENV) causes repeated outbreaks of disease in endemic areas, with patterns of local transmission strongly influenced by seasonality, importation via human movement, immunity, and vector control efforts. An understanding of how each of these interacts to enable endemic transmission (continual circulation of local virus strains) is largely unknown. There are times of the year when no cases are reported, often for extended periods of time, perhaps wrongly implying the successful eradication of a local strain from that area.

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Dengue is a major health threat and the number of symptomatic infections caused by the four dengue serotypes is estimated to be 96 million with annually around 10,000 deaths. However, no antiviral drugs are available for the treatment or prophylaxis of dengue. We recently described the interaction between non-structural proteins NS3 and NS4B as a promising target for the development of pan-serotype dengue virus (DENV) inhibitors.

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While progress has been made in fighting diseases disproportionally affecting underserved populations, unmet medical needs persist for many neglected tropical diseases. The World Health Organization has encouraged strong public-private partnerships to address this issue and several public and private organizations have set an example in the past showing a strong commitment to combat these diseases. Pharmaceutical companies are contributing in different ways to address the imbalance in research efforts.

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In continuation of our efforts of finding novel nucleoside inhibitors for the treatment of viral diseases, we initiated a discovery research program aimed at identifying novel nucleos(t)ide inhibitors for emerging diseases like Dengue and Chikungunya. Based on the previously reported 2'-spiro-oxetane uridine derivatives active against Hepatitis C Virus (HCV), we envisaged its sulfur analogue as an interesting congener both from a synthetic as well as biological point of view. Surprisingly, we found the 2'-spirothietane uridine derivatives not only to be active against HCV and Dengue virus (DENV), viruses belonging to the flavivirus family, but also to demonstrate activity against alphaviruses like Chikungunya virus (CHIKV) and Sindbis virus (SINV).

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Article Synopsis
  • - Dengue virus (DENV) infections, prevalent in tropical areas, lead to significant health issues, with over 400 million infections annually and around 20,000 deaths, underscoring the need for better understanding of immune responses during infection.
  • - A study was conducted on individuals infected with the DENV-1 strain 45AZ5, revealing a strong immune response characterized by distinct antibodies (IgA, IgM, IgG) and specific delays in antibody production, providing insights into the timing and nature of the body's response.
  • - The research utilized RNA sequencing to identify key gene expression patterns that correlate with the onset of virus replication and adaptive immunity, highlighting important immunological features of primary DENV-1 infections that could
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  • The study explores the effectiveness of combining different rapid diagnostic tests (RDTs) to determine dengue virus (DENV) immune status at the point of care, simplifying the diagnostic process.
  • The research involved analyzing serum from dengue patients in Indonesia and Vietnam to correlate rapid test outcomes with laboratory results, revealing a high accuracy in identifying primary and post-primary infections.
  • The findings suggest that using a combination of NS1, IgM, and IgG RDTs can accurately estimate a patient’s DENV immune status, potentially enhancing diagnosis in clinical settings where laboratory access is limited.
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Although vaccines are currently used to control the coronavirus disease 2019 (COVID-19) pandemic, treatment options are urgently needed for those who cannot be vaccinated and for future outbreaks involving new severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) strains or coronaviruses not covered by current vaccines. Thus far, few existing antivirals are known to be effective against SARS-CoV-2 and clinically successful against COVID-19. As part of an immediate response to the COVID-19 pandemic, a high-throughput, high content imaging-based SARS-CoV-2 infection assay was developed in VeroE6 African green monkey kidney epithelial cells expressing a stable enhanced green fluorescent protein (VeroE6-eGFP cells) and was used to screen a library of 5676 compounds that passed Phase 1 clinical trials.

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  • Dengue virus causes about 96 million infections each year, leading to illnesses like dengue fever, and there are currently no medicines to fight it.
  • A new powerful drug called JNJ-A07 can block the dengue virus very effectively by stopping two important virus proteins from working together.
  • Testing in mice showed that JNJ-A07 can quickly reduce the amount of virus in the body, and researchers are now working on a similar version of this drug.
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Background: Targeting interventions to areas that have recently experienced cases of disease is one strategy to contain outbreaks of infectious disease. Such case-area targeted interventions (CATI) have become an increasingly popular approach for dengue control but there is little evidence to suggest how precisely targeted or how recent cases need to be, to mount an effective response. The growing interest in the development of prophylactic and therapeutic drugs for dengue has also given new relevance for CATI strategies to interrupt transmission or deliver early treatment.

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Although vaccination campaigns are currently being rolled out to prevent coronavirus disease (COVID-19), antivirals will remain an important adjunct to vaccination. Antivirals against coronaviruses do not exist, hence global drug repurposing efforts have been carried out to identify agents that may provide clinical benefit to patients with COVID-19. Itraconazole, an antifungal agent, has been reported to have activity against animal coronaviruses.

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Objectives: Given the high need and the absence of specific antivirals for treatment of COVID-19 (the disease caused by severe acute respiratory syndrome-associated coronavirus-2 [SARS-CoV-2]), human immunodeficiency virus (HIV) protease inhibitors are being considered as therapeutic alternatives.

Methods: Prezcobix/Rezolsta is a fixed-dose combination of 800 mg of the HIV protease inhibitor darunavir (DRV) and 150 mg cobicistat, a CYP3A4 inhibitor, which is indicated in combination with other antiretroviral agents for the treatment of HIV infection. There are currently no definitive data on the safety and efficacy of DRV/cobicistat for the treatment of COVID-19.

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Dengue fever is the most widespread of the human arbovirus diseases, with approximately one third of the world's population at risk of infection. Dengue viruses are members of the genus Flavivirus (family Flaviviridae) and, antigenically, they separate as four closely related serotypes (1-4) that share 60-75% amino acid homology. This genetic diversity complicates the process of antiviral drug discovery.

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Dengue is the most important mosquito-borne viral disease in the world, representing a major unmet medical need and a growing public health concern. The disease imposes a heavy burden to the affected individuals, to the health care systems, and to the economies of endemic countries. Vector control is the most widespread tool to curb dengue epidemics, but has been insufficient.

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Dengue is the most important mosquito-transmitted viral disease and a major global health concern. Over the last decade, dengue virus (DENV) drug discovery and development has intensified, however, this has not resulted in approved DENV-specific antiviral treatments yet. DENV and hepatitis C virus (HCV) belong to the same Flaviviridae family and, in contrast to DENV, antiviral treatments for HCV have been licensed.

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Human cytomegalovirus (HCMV) is a betaherpesvirus which rarely presents problems in healthy individuals, yet may result in severe morbidity in immunocompromised patients and in immune-naïve neonates. HCMV has a large 235 kb genome with a coding capacity of at least 165 open reading frames (ORFs). This large genome allows complex gene regulation resulting in different sets of transcripts during lytic and latent infection.

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Human cytomegalovirus, a member of the herpesvirus family, can cause significant morbidity and mortality in immune compromised patients resulting from either primary lytic infection or reactivation from latency. Latent infection is associated with a restricted viral transcription programme compared to lytic infection which consists of defined protein coding RNAs but also includes a number of virally encoded microRNAs (miRNAs). One of these, miR-UL112-1, is known to target the major lytic IE72 transcript but, to date, a functional role for miR-UL112-1 during latent infection has not been shown.

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