Rapid-response RNA-fluorescence in situ hybridization (FISH) assay platform for coronavirus antiviral high-throughput screening.

Over the past 25 years, the global community has faced challenges posed by three distinct outbreaks of coronaviruses including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The identification of a novel alphacoronavirus canine CoV (CCoV-HuPn2018) in human patients in Malaysia underscores the potential for crossover infections to humans. The threat of the ever-evolving nature of viral infections as well as the lingering health and socioeconomic effects of the recent SARS-CoV-2 pandemic emphasize the urgent need for advanced antiviral drug screening tools that can be quickly implemented to strengthen preparedness and preventive measures against future outbreaks.

Pyrimidine Azepine Targets the Complex and Displays Multistage Antimalarial Activity.

Malaria control and elimination efforts would benefit from the identification and validation of new malaria chemotherapeutics. Recently, a transgenic line was used to perform a series of high-throughput in vitro screens for new antimalarials acting against the parasite sexual stages. The screens identified pyrimidine azepine chemotypes with potent activity.

Identification of Potent, Broad-Spectrum Coronavirus Main Protease Inhibitors for Pandemic Preparedness.

The COVID-19 pandemic highlights the ongoing risk of zoonotic transmission of coronaviruses to global health. To prepare for future pandemics, it is essential to develop effective antivirals targeting a broad range of coronaviruses. Targeting the essential and clinically validated coronavirus main protease (M), we constructed a structurally diverse M panel by clustering all known coronavirus sequences by M active site sequence similarity.

Establishment of human post-vaccination SARS-CoV-2 standard reference sera.

There is a critical need to understand the effectiveness of serum elicited by different SARS-CoV-2 vaccines against SARS-CoV-2 variants. We describe the generation of reference reagents comprised of post-vaccination sera from recipients of different primary vaccines with or without different vaccine booster regimens in order to allow standardized characterization of SARS-CoV-2 neutralization in vitro. We prepared and pooled serum obtained from donors who received a either primary vaccine series alone, or a vaccination strategy that included primary and boosted immunization using available SARS-CoV-2 mRNA vaccines (BNT162b2, Pfizer and mRNA-1273, Moderna), replication-incompetent adenovirus type 26 vaccine (Ad26.

Nonspecific membrane bilayer perturbations by ivermectin underlie SARS-CoV-2 activity.

Since it was proposed as a potential host-directed antiviral agent for SARS-CoV-2, the antiparasitic drug ivermectin has been investigated thoroughly in clinical trials, which have provided insufficient support for its clinical efficacy. To examine the potential for ivermectin to be repurposed as an antiviral agent, we therefore undertook a series of preclinical studies. Consistent with early reports, ivermectin decreased SARS-CoV-2 viral burden in models at low micromolar concentrations, five- to ten-fold higher than the reported toxic clinical concentration.

Quantitative Bioactivity Signatures of Dietary Supplements and Natural Products.

Dietary supplements and natural products are often marketed as safe and effective alternatives to conventional drugs, but their safety and efficacy are not well regulated. To address the lack of scientific data in these areas, we assembled a collection of Dietary Supplements and Natural Products (DSNP), as well as Traditional Chinese Medicinal (TCM) plant extracts. These collections were then profiled in a series of high-throughput screening assays, including a liver cytochrome p450 enzyme panel, CAR/PXR signaling pathways, and P-glycoprotein (P-gp) transporter assay activities.

Small molecule antiviral compound collection (SMACC): A comprehensive, highly curated database to support the discovery of broad-spectrum antiviral drug molecules.

Diseases caused by new viruses cost thousands if not millions of human lives and trillions of dollars. We have identified, collected, curated, and integrated all chemogenomics data from ChEMBL for 13 emerging viruses that hold the greatest potential threat to global human health. By identifying and solving several challenges related to data annotation accuracy, we developed a highly curated and thoroughly annotated database of compounds tested in both phenotypic and target-based assays for these viruses that we dubbed SMACC (Small Molecule Antiviral Compound Collection).

Novel Transmission-Blocking Antimalarials Identified by High-Throughput Screening of Plasmodium berghei Ookluc.

Safe and effective malaria transmission-blocking chemotherapeutics would allow a community-level approach to malaria control and eradication efforts by targeting the mosquito sexual stage of the parasite life cycle. However, only a single drug, primaquine, is currently approved for use in reducing transmission, and drug toxicity limits its widespread implementation. To address this limitation in antimalarial chemotherapeutics, we used a recently developed transgenic Plasmodium berghei line, Ookluc, to perform a series of high-throughput screens for compounds that inhibit parasite fertilization, the initial step of parasite development within the mosquito.

A Plasmodium falciparum RING Finger E3 Ubiquitin Ligase Modifies the Roles of PfMDR1 and PfCRT in Parasite Drug Responses.

Protein ubiquitination is an important posttranslational regulation mechanism that mediates development and modifies parasite responses to antimalarial drugs. Although mutations in several parasite ubiquitination enzymes have been linked to increased drug tolerance, the molecular mechanisms by which ubiquitination pathways mediate these parasite responses remain largely unknown. Here, we investigate the roles of a Plasmodium falciparum ring finger ubiquitin ligase (PfRFUL) in parasite development and in responses to antimalarial drugs.

A humanized nanobody phage display library yields potent binders of SARS CoV-2 spike.

Neutralizing antibodies targeting the SARS-CoV-2 spike protein have shown a great preventative/therapeutic potential. Here, we report a rapid and efficient strategy for the development and design of SARS-CoV-2 neutralizing humanized nanobody constructs with sub-nanomolar affinities and nanomolar potencies. CryoEM-based structural analysis of the nanobodies in complex with spike revealed two distinct binding modes.

Small Molecule Antiviral Compound Collection (SMACC): a database to support the discovery of broad-spectrum antiviral drug molecules.

Diseases caused by new viruses costs thousands if not millions of human lives and trillions of dollars in damage to the global economy. Despite the rapid development of vaccines for SARS-CoV-2, the lack of small molecule antiviral drugs that work against multiple viral families (broad-spectrum antivirals; BSAs) has left the entire world’s human population vulnerable to the infection between the beginning of the outbreak and the widespread availability of vaccines. Developing BSAs is an attractive, yet challenging, approach that could prevent the next, inevitable, viral outbreak from becoming a global catastrophe.

Allosteric Binders of ACE2 Are Promising Anti-SARS-CoV-2 Agents.

The COVID-19 pandemic has had enormous health, economic, and social consequences. Vaccines have been successful in reducing rates of infection and hospitalization, but there is still a need for acute treatment of the disease. We investigate whether compounds that bind the human angiotensin-converting enzyme 2 (ACE2) protein can decrease SARS-CoV-2 replication without impacting ACE2's natural enzymatic function.

Allosteric binders of ACE2 are promising anti-SARS-CoV-2 agents.

The COVID-19 pandemic has had enormous health, economic, and social consequences. Vaccines have been successful in reducing rates of infection and hospitalization, but there is still a need for an acute treatment for the disease. We investigate whether compounds that bind the human ACE2 protein can interrupt SARS-CoV-2 replication without damaging ACE2’s natural enzymatic function.

A platform of assays for the discovery of anti-Zika small-molecules with activity in a 3D-bioprinted outer-blood-retina model.

The global health emergency posed by the outbreak of Zika virus (ZIKV), an arthropod-borne flavivirus causing severe neonatal neurological conditions, has subsided, but there continues to be transmission of ZIKV in endemic regions. As such, there is still a medical need for discovering and developing therapeutical interventions against ZIKV. To identify small-molecule compounds that inhibit ZIKV disease and transmission, we screened multiple small-molecule collections, mostly derived from natural products, for their ability to inhibit wild-type ZIKV.

A humanized nanobody phage display library yields potent binders of SARS CoV-2 spike.

Neutralizing antibodies targeting the SARS-CoV-2 spike protein have shown a great preventative/therapeutic potential. Here, we report a rapid and efficient strategy for the development and design of SARS-CoV-2 neutralizing humanized nanobody constructs with sub-nanomolar affinities and nanomolar potencies. CryoEM-based structural analysis of the nanobodies in complex with spike revealed two distinct binding modes.

Deep learning identifies synergistic drug combinations for treating COVID-19.

Effective treatments for COVID-19 are urgently needed. However, discovering single-agent therapies with activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been challenging. Combination therapies play an important role in antiviral therapies, due to their improved efficacy and reduced toxicity.

Drug Repurposing Screen for Compounds Inhibiting the Cytopathic Effect of SARS-CoV-2.

Drug repurposing is a rapid approach to identify therapeutics for the treatment of emerging infectious diseases such as COVID-19. To address the urgent need for treatment options, we carried out a quantitative high-throughput screen using a SARS-CoV-2 cytopathic assay with a compound collection of 8,810 approved and investigational drugs, mechanism-based bioactive compounds, and natural products. Three hundred and nineteen compounds with anti-SARS-CoV-2 activities were identified and confirmed, including 91 approved drugs and 49 investigational drugs.

Application of niclosamide and analogs as small molecule inhibitors of Zika virus and SARS-CoV-2 infection.

Zika virus has emerged as a potential threat to human health globally. A previous drug repurposing screen identified the approved anthelminthic drug niclosamide as a small molecule inhibitor of Zika virus infection. However, as antihelminthic drugs are generally designed to have low absorption when dosed orally, the very limited bioavailability of niclosamide will likely hinder its potential direct repurposing as an antiviral medication.

Identification and Profiling of a Novel Diazaspiro[3.4]octane Chemical Series Active against Multiple Stages of the Human Malaria Parasite and Optimization Efforts.

A novel diazaspiro[3.4]octane series was identified from a whole-cell high-throughput screening campaign. Hits displayed activity against multiple stages of the parasite lifecycle, which together with a novel sp-rich scaffold provided an attractive starting point for a hit-to-lead medicinal chemistry optimization and biological profiling program.

Chemoprotective antimalarials identified through quantitative high-throughput screening of Plasmodium blood and liver stage parasites.

The spread of Plasmodium falciparum parasites resistant to most first-line antimalarials creates an imperative to enrich the drug discovery pipeline, preferably with curative compounds that can also act prophylactically. We report a phenotypic quantitative high-throughput screen (qHTS), based on concentration-response curves, which was designed to identify compounds active against Plasmodium liver and asexual blood stage parasites. Our qHTS screened over 450,000 compounds, tested across a range of 5 to 11 concentrations, for activity against Plasmodium falciparum asexual blood stages.

Modulation of Triple Artemisinin-Based Combination Therapy Pharmacodynamics by Genotype.

The first-line treatments for uncomplicated malaria are artemisinin-based combination therapies (ACTs), consisting of an artemisinin derivative combined with a longer acting partner drug. However, the spread of with decreased susceptibility to artemisinin and partner drugs presents a significant challenge to malaria control efforts. To stem the spread of drug resistant parasites, novel chemotherapeutic strategies are being evaluated, including the implementation of triple artemisinin-based combination therapies (TACTs).

Synergistic and Antagonistic Drug Combinations against SARS-CoV-2.

Antiviral drug development for coronavirus disease 2019 (COVID-19) is occurring at an unprecedented pace, yet there are still limited therapeutic options for treating this disease. We hypothesized that combining drugs with independent mechanisms of action could result in synergy against SARS-CoV-2, thus generating better antiviral efficacy. Using in silico approaches, we prioritized 73 combinations of 32 drugs with potential activity against SARS-CoV-2 and then tested them in vitro.

Targeting ACE2-RBD Interaction as a Platform for COVID-19 Therapeutics: Development and Drug-Repurposing Screen of an AlphaLISA Proximity Assay.

The COVID-19 pandemic, caused by SARS-CoV-2, is a pressing public health emergency garnering a rapid response from scientists across the globe. Host cell invasion is initiated through direct binding of the viral spike protein to the host receptor angiotensin-converting enzyme 2 (ACE2). Disrupting the spike protein-ACE2 interaction is a potential therapeutic target for treating COVID-19.

Therapeutic candidates for the Zika virus identified by a high-throughput screen for Zika protease inhibitors.

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors.

Drug Repurposing Screen for Compounds Inhibiting the Cytopathic Effect of SARS-CoV-2.

Drug repurposing is a rapid approach to identifying therapeutics for the treatment of emerging infectious diseases such as COVID-19. To address the urgent need for treatment options, we carried out a quantitative high-throughput screen using a SARS-CoV-2 cytopathic assay with a compound collection of 8,810 approved and investigational drugs, mechanism-based bioactive compounds, and natural products. Three hundred and nineteen compounds with anti-SARS-CoV-2 activities were identified and confirmed, including 91 approved drug and 49 investigational drugs.