Pembrolizumab plus Chemotherapy in Advanced Endometrial Cancer.

BACKGROUND: Standard first-line chemotherapy for endometrial cancer is paclitaxel plus carboplatin. The benefit of adding pembrolizumab to chemotherapy remains unclear. METHODS: In this double-blind, placebo-controlled, randomized, phase 3 trial, we assigned 816 patients with measurable disease (stage III or IVA) or stage IVB or recurrent endometrial cancer in a 1:1 ratio to receive pembrolizumab or placebo along with combination therapy with paclitaxel plus carboplatin. The administration of pembrolizumab or placebo was planned in 6 cycles every 3 weeks, followed by up to 14 maintenance cycles every 6 weeks. The patients were stratified into two cohorts according to whether they had mismatch repair-deficient (dMMR) or mismatch repair-proficient (pMMR) disease. Previous adjuvant chemotherapy was permitted if the treatment-free interval was at least 12 months. The primary outcome was progression-free survival in the two cohorts. Interim analyses were scheduled to be triggered after the occurrence of at least 84 events of death or progression in the dMMR cohort and at least 196 events in the pMMR cohort. RESULTS: In the 12-month analysis, Kaplan-Meier estimates of progression-free survival in the dMMR cohort were 74% in the pembrolizumab group and 38% in the placebo group (hazard ratio for progression or death, 0.30; 95% confidence interval [CI], 0.19 to 0.48; P<0.001), a 70% difference in relative risk. In the pMMR cohort, median progression-free survival was 13.1 months with pembrolizumab and 8.7 months with placebo (hazard ratio, 0.54; 95% CI, 0.41 to 0.71; P<0.001). Adverse events were as expected for pembrolizumab and combination chemotherapy. CONCLUSIONS: In patients with advanced or recurrent endometrial cancer, the addition of pembrolizumab to standard chemotherapy resulted in significantly longer progression-free survival than with chemotherapy alone. (Funded by the National Cancer Institute and others; NRG-GY018 ClinicalTrials.gov number, NCT03914612.).

Fluorescent and Bioluminescent Reporter Mouse-Adapted Ebola Viruses Maintain Pathogenicity and Can Be Visualized in Vivo.

Ebola virus (EBOV) causes lethal disease in humans but not in mice. Here, we generated recombinant mouse-adapted (MA) EBOVs, including 1 based on the previously reported serially adapted strain (rMA-EBOV), along with single-reporter rMA-EBOVs expressing either fluorescent (ZsGreen1 [ZsG]) or bioluminescent (nano-luciferase [nLuc]) reporters, and dual-reporter rMA-EBOVs expressing both ZsG and nLuc. No detriment to viral growth in vitro was seen with inclusion of MA-associated mutations or reporter proteins. In CD-1 mice, infection with MA-EBOV, rMA-EBOV, and single-reporter rMA-EBOVs conferred 100% lethality; infection with dual-reporter rMA-EBOV resulted in 73% lethality. Bioluminescent signal from rMA-EBOV expressing nLuc was detected in vivo and ex vivo using the IVIS Spectrum CT. Fluorescent signal from rMA-EBOV expressing ZsG was detected in situ using handheld blue-light transillumination and ex vivo through epi-illumination with the IVIS Spectrum CT. These data support the use of reporter MA-EBOV for studies of Ebola virus in animal disease models.

Characterization of humoral responses to Nipah virus infection in the Syrian Hamster model of disease.

Nipah virus (NiV) is a highly pathogenic paramyxovirus. The Syrian hamster model recapitulates key features of human NiV disease and is a critical tool for evaluating antivirals and vaccines. Here we describe longitudinal humoral immune responses in NiV-infected Syrian hamsters. Samples were obtained 1-28 days after infection and analyzed by ELISA, neutralization, and Fc-mediated effector function assays. NiV infection elicited robust antibody responses against the nucleoprotein and attachment glycoprotein. Levels of neutralizing antibodies were modest and only detectable in surviving animals. Fc-mediated effector functions were mostly observed in nucleoprotein-targeting antibodies. Antibody levels and activities positively correlated with challenge dose.

Metabolomic identification of predictive and early biomarkers of cisplatin-induced acute kidney injury in adult head and neck cancer patients.

AIM: Cisplatin causes acute kidney injury (AKI) in approximately one third of patients. Serum creatinine and urinary output are poor markers of cisplatin-induced AKI. Metabolomics was utilized to identify predictive or early diagnostic biomarkers of cisplatin-induced AKI. METHODS: Thirty-one adult head and neck cancer patients receiving cisplatin (dose ≥70 mg/m2 ) were recruited for metabolomics analysis. Urine and serum samples were collected prior to cisplatin (pre), 24-48 h after cisplatin (24-48 h) and 5-14 days (post) after cisplatin. Based on serum creatinine concentrations measured at the post timepoint, 11/31 patients were classified with clinical AKI. Untargeted metabolomics was performed using liquid chromatography-mass spectrometry (LC-MS). RESULTS: Metabolic discrimination was observed between "AKI" patients and "no AKI" patients at all timepoints. Urinary glycine, hippuric acid sulfate, 3-hydroxydecanedioc acid and suberate were significantly different between AKI patients and no AKI patients prior to cisplatin infusion. Urinary glycine and hippuric acid sulfate were lower (-2.22-fold and -8.85-fold), whereas 3-hydroxydecanedioc acid and suberate were higher (3.62-fold and 1.91-fold) in AKI patients relative to no AKI patients. Several urine and serum metabolites were found to be altered 24-48 h following cisplatin infusion, particularly metabolites involved with mitochondrial energetics. CONCLUSIONS: We propose glycine, hippuric acid sulfate, 3-hydroxydecanedioc acid and suberate as predictive biomarkers of predisposition to cisplatin-induced AKI. Metabolites indicative of mitochondrial dysfunction may serve as early markers of subclinical AKI.

ARTISTRY-7: phase III trial of nemvaleukin alfa plus pembrolizumab vs chemotherapy for platinum-resistant ovarian cancer.

Standard single-agent nonplatinum chemotherapy provides only modest benefit in a small proportion of patients with platinum-resistant/-refractory ovarian cancer, with objective response rates of 6-20% and progression-free survival of ≈3-4 months. Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel cytokine designed to capture and expand the therapeutic potential of high-dose interleukin-2 (IL-2) while mitigating its associated toxicity issues. Nemvaleukin preferentially activates cytotoxic CD8+ T cells and natural killer cells with minimal, non-dose-dependent effects on CD4+ regulatory T cells. The global, randomized, open-label, phase III ARTISTRY-7 trial will compare efficacy and safety of nemvaleukin plus pembrolizumab with chemotherapy in patients with platinum-resistant ovarian cancer. The primary end point is investigator-assessed progression-free survival. Clinical Trial Registration: GOG-3063; ENGOT-OV68; NCT05092360 (ClinicalTrials.gov).

In many patients with ovarian cancer who are treated with platinum-based chemotherapy, the tumor comes back after a few months and fails to respond to repeated treatment. This type of disease is called platinum-resistant ovarian cancer (PROC). Researchers are searching for new medicines to help more patients with PROC. One treatment approach that has shown promise in different cancers is called immunotherapy. These medicines work by helping the body's immune system attack cancer cells. One of the immunotherapies being studied is called nemvaleukin. It is designed to trigger specific immune responses that may result in the immune system attacking cancer cells while potentially avoiding other immune responses that can block the attack or cause certain unwanted side effects. Nemvaleukin is being studied in a variety of cancer types. In a worldwide clinical trial called ARTISTRY-7, researchers are investigating how nemvaleukin works in patients with PROC when given with another immunotherapy called pembrolizumab. Patients who participate in this trial will be randomly assigned to one of four treatment groups: the combination of nemvaleukin and pembrolizumab, nemvaleukin by itself, pembrolizumab by itself, or a type of chemotherapy selected by the treating physician. The main purpose of ARTISTRY-7 is to understand whether the combination of nemvaleukin and pembrolizumab helps patients with PROC live longer without their cancer getting worse. At the time of this writing, ARTISTRY-7 is open for new patients to join.

Correction: Integrating transcriptomic network reconstruction and eQTL analyses reveals mechanistic connections between genomic architecture and Brassica rapa development.

[This corrects the article DOI: 10.1371/journal.pgen.1008367.].

Lassa Virus Replicon Particle Vaccine Protects Strain 13/N Guinea Pigs Against Challenge With Geographically and Genetically Diverse Viral Strains.

Lassa virus (LASV) causes mild to severe hemorrhagic fever disease in humans. Strain 13/N guinea pigs are highly susceptible to infection with LASV strain Josiah (clade IV), providing a critical model system for therapeutics and vaccine development. To develop additional models of disease, we detail the clinical course in guinea pigs infected with 5 geographically and genetically diverse LASV strains. Two of the developed models (LASV clades II and III) were then used to evaluate efficacy of a virus replicon particle vaccine against heterologous LASV challenge, demonstrating complete protection against clinical disease after a single vaccination dose.

Adavosertib plus gemcitabine for platinum-resistant or platinum-refractory recurrent ovarian cancer: a double-blind, randomised, placebo-controlled, phase 2 trial.

BACKGROUND: The Wee1 (WEE1hu) inhibitor adavosertib and gemcitabine have shown preclinical synergy and promising activity in early phase clinical trials. We aimed to determine the efficacy of this combination in patients with ovarian cancer. METHODS: In this double-blind, randomised, placebo-controlled, phase 2 trial, women with measurable recurrent platinum-resistant or platinum-refractory high-grade serous ovarian cancer were recruited from 11 academic centres in the USA and Canada. Women were eligible if they were aged 18 years or older, had an Eastern Cooperative Oncology Group performance status of 0-2, a life expectancy of more than 3 months, and normal organ and marrow function. Women with ovarian cancer of non-high-grade serous histology were eligible for enrolment in a non-randomised exploratory cohort. Eligible participants with high-grade serous ovarian cancer were randomly assigned (2:1), using block randomisation (block size of three and six) and no stratification, to receive intravenous gemcitabine (1000 mg/m2 on days 1, 8, and 15) with either oral adavosertib (175 mg) or identical placebo once daily on days 1, 2, 8, 9, 15, and 16, in 28-day cycles until disease progression or unacceptable toxicity. Patients and the team caring for each patient were masked to treatment assignment. The primary endpoint was progression-free survival. The safety and efficacy analysis population comprised all patients who received at least one dose of treatment. The trial is registered with ClinicalTrials.gov, NCT02151292, and is closed to accrual. FINDINGS: Between Sept 22, 2014, and May 30, 2018, 124 women were enrolled, of whom 99 had high-grade serous ovarian cancer and were randomly assigned to adavosertib plus gemcitabine (65 [66%]) or placebo plus gemcitabine (34 [34%]). 25 women with non-high-grade serous ovarian cancer were enrolled in the exploratory cohort. After randomisation, five patients with high-grade serous ovarian cancer were found to be ineligible (four in the experimental group and one in the control group) and did not receive treatment. Median age for all treated patients (n=119) was 62 years (IQR 54-67). Progression-free survival was longer with adavosertib plus gemcitabine (median 4·6 months [95% CI 3·6-6·4] with adavosertib plus gemcitabine vs 3·0 months [1·8-3·8] with placebo plus gemcitabine; hazard ratio 0·55 [95% CI 0·35-0·90]; log-rank p=0·015). The most frequent grade 3 or worse adverse events were haematological (neutropenia in 38 [62%] of 61 participants in the adavosertib plus gemcitabine group vs ten [30%] of 33 in the placebo plus gemcitabine group; thrombocytopenia in 19 [31%] of 61 in the adavosertib plus gemcitabine group vs two [6%] of 33 in the placebo plus gemcitabine group). There were no treatment-related deaths; two patients (one in each group in the high-grade serous ovarian cancer cohort) died while on study medication (from sepsis in the experimental group and from disease progression in the control group). INTERPRETATION: The observed clinical efficacy of a Wee1 inhibitor combined with gemcitabine supports ongoing assessment of DNA damage response drugs in high-grade serous ovarian cancer, a TP53-mutated tumour type with high replication stress. This therapeutic approach might be applicable to other tumour types with high replication stress; larger confirmatory studies are required. FUNDING: US National Cancer Institute Cancer Therapy Evaluation Program, Ontario Institute for Cancer Research, US Department of Defense, Princess Margaret Cancer Foundation, and AstraZeneca.

The influence of adjuvant chemotherapy dose intensity on overall survival in resected colon cancer: a multicentered retrospective analysis.

BACKGROUND: Colorectal cancer remains the second leading cause of cancer death in North America. Fluorouracil and oxaliplatin based adjuvant chemotherapy for resected colon cancer (CC) reduces cancer recurrence, but also causes significant toxicity requiring dose reductions. The effect of dose intensity on survival outcomes is not fully understood and strengthening the evidence supports informed decision making between patients and oncologists. METHODS: Patients treated with adjuvant chemotherapy, between 2006 and 2011, for resected colon cancer at four Canadian academic cancer centers were retrospectively analyzed. All patients must have received oxaliplatin with either capecitabine (CAPOX) or 5-FU (FOLFOX). Dose intensity (DI) was calculated as total delivered dose of an individual chemotherapy agent divided by the cumulative intended dose of that agent. The influence of DI on overall survival was examined. RESULTS: Five hundred thirty-one patients with high-risk stage II or stage III resected CC were eligible and included in the analysis. FOLFOX was the most common regimen (69.6%) with 29.7% of patients receiving CAPOX and 0.7% receiving both therapies. Median follow-up was 36.7 months. The median DI for 5-FU and capecitabine was 100% and 100% with 13.6% and 9.8% of patients receiving ≤ 80% DI, respectively. The median DI of oxaliplatin was 70% with 56.8% of patients receiving ≤ 80% DI. A DI of > 80% for each chemotherapy component was associated with a significant improvement in overall survival compared to those with a DI of ≤ 80% (5-FU HR = 0.23, 95% CI = 0.08-0.65, p = 0.006; capecitabine HR = 0.56, 95% CI = 0.33-0.94, p = 0.026; oxaliplatin HR = 0.52, 95% CI = 0.33-0.82, p = 0.005). Patients with T2 and/or N2 disease with an oxaliplatin DI > 80% had a trend towards improved survival (HR = 0.62, 95% CI = 0.38-1.02, p = 0.06). CONCLUSIONS: In resected CC an adjuvant chemotherapy DI of > 80%, of each chemotherapy agent, is associated with improved overall survival.

Patient self-reporting of tolerability using PRO-CTCAE in a randomized double-blind, placebo-controlled phase II trial comparing gemcitabine in combination with adavosertib or placebo in patients with platinum resistant or refractory epithelial ovarian carcinoma.

BACKGROUND: A double-blind, randomized, placebo-controlled, phase 2 trial assessed gemcitabine in combination with the wee1 inhibitor adavosertib or placebo in platinum resistant or refractory high grade serous ovarian cancer (HGSOC), demonstrating improved progression free and overall survival favouring the adavosertib/gemcitabine arm. An exploratory objective of the study included the PRO-CTCAE assessment, to capture self-reporting of frequency, severity and/or interference of symptomatic adverse events (syAEs). METHODS: PRO-CTCAE items at baseline, days 1 and 15 of each cycle and off treatment, were completed in two centres, with the objective of characterizing syAEs in the first three months of therapy. The maximum post-baseline score proportion for each syAE was tabulated per patient. The 12-week area under the curve (AUC12w) as a measure of syAE over-time and incremental AUC12w (iAUC12w) for adjustment to baseline syAEs. RESULTS: Sixty-one patients were approached for PRO-CTCAE surveys and 55 were evaluable. Among patients with HGSOC, 28 received gemcitabine/adavosertib (arm A) and 19 gemcitabine/placebo (arm B). Survey completion rates were high. The proportion of participants with positive (≥1) PRO-CTCAE scores was higher for difficulty swallowing with gemcitabine/adavosertib (arm A 35.7% vs arm B 5.3%, p = 0.02). The high score (≥3) syAEs showed more frequent diarrhea with gemcitabine/adavosertib (arm A 25% vs arm B 0%, p = 0.03). The proportions of worsening syAEs over time were higher in patients receiving gemcitabine/adavosertib for difficulty swallowing (arm A 35.7% vs arm B 5.3%; p = 0.03) and fatigue severity (arm A 71.43% vs arm B 42.1%; p = 0.04). CONCLUSIONS: The longitudinal assessment of patient self-reported tolerability showed greater difficulty swallowing and fatigue severity in patients receiving gemcitabine/adavosertib, compared to gemcitabine/placebo. PRO-CTCAE provides complementary and objective assessment of drug tolerability from a patient's perspective.

Integrating transcriptomic network reconstruction and eQTL analyses reveals mechanistic connections between genomic architecture and Brassica rapa development.

Plant developmental dynamics can be heritable, genetically correlated with fitness and yield, and undergo selection. Therefore, characterizing the mechanistic connections between the genetic architecture governing plant development and the resulting ontogenetic dynamics of plants in field settings is critically important for agricultural production and evolutionary ecology. We use hierarchical Bayesian Function-Valued Trait (FVT) models to estimate Brassica rapa growth curves throughout ontogeny, across two treatments, and in two growing seasons. We find genetic variation for plasticity of growth rates and final sizes, but not the inflection point (transition from accelerating to decelerating growth) of growth curves. There are trade-offs between growth rate and duration, indicating that selection for maximum yields at early harvest dates may come at the expense of late harvest yields and vice versa. We generate eigengene modules and determine which are co-expressed with FVT traits using a Weighted Gene Co-expression Analysis. Independently, we seed a Mutual Rank co-expression network model with FVT traits to identify specific genes and gene networks related to FVT. GO-analyses of eigengene modules indicate roles for actin/cytoskeletal genes, herbivore resistance/wounding responses, and cell division, while MR networks demonstrate a close association between metabolic regulation and plant growth. We determine that combining FVT Quantitative Trait Loci (QTL) and MR genes/WGCNA eigengene expression profiles better characterizes phenotypic variation than any single data type (i.e. QTL, gene, or eigengene alone). Our network analysis allows us to employ a targeted eQTL analysis, which we use to identify regulatory hotspots for FVT. We examine cis vs. trans eQTL that mechanistically link FVT QTL with structural trait variation. Colocalization of FVT, gene, and eigengene eQTL provide strong evidence for candidate genes influencing plant height. The study is the first to explore eQTL for FVT, and specifically do so in agroecologically relevant field settings.

Large-effect flowering time mutations reveal conditionally adaptive paths through fitness landscapes in Arabidopsis thaliana.

Contrary to previous assumptions that most mutations are deleterious, there is increasing evidence for persistence of large-effect mutations in natural populations. A possible explanation for these observations is that mutant phenotypes and fitness may depend upon the specific environmental conditions to which a mutant is exposed. Here, we tested this hypothesis by growing large-effect flowering time mutants of Arabidopsis thaliana in multiple field sites and seasons to quantify their fitness effects in realistic natural conditions. By constructing environment-specific fitness landscapes based on flowering time and branching architecture, we observed that a subset of mutations increased fitness, but only in specific environments. These mutations increased fitness via different paths: through shifting flowering time, branching, or both. Branching was under stronger selection, but flowering time was more genetically variable, pointing to the importance of indirect selection on mutations through their pleiotropic effects on multiple phenotypes. Finally, mutations in hub genes with greater connectedness in their regulatory networks had greater effects on both phenotypes and fitness. Together, these findings indicate that large-effect mutations may persist in populations because they influence traits that are adaptive only under specific environmental conditions. Understanding their evolutionary dynamics therefore requires measuring their effects in multiple natural environments.

Effective in vitro inactivation of SARS-CoV-2 by commercially available mouthwashes.

Infectious SARS-CoV-2 can be recovered from the oral cavities and saliva of COVID-19 patients with potential implications for disease transmission. Reducing viral load in patient saliva using antiviral mouthwashes may therefore have a role as a control measure in limiting virus spread, particularly in dental settings. Here, the efficacy of SARS-CoV-2 inactivation by seven commercially available mouthwashes with a range of active ingredients were evaluated in vitro. We demonstrate ≥4.1 to ≥5.5 log10 reduction in SARS-CoV-2 titre following a 1 min treatment with commercially available mouthwashes containing 0.01-0.02 % stabilised hypochlorous acid or 0.58 % povidone iodine, and non-specialist mouthwashes with both alcohol-based and alcohol-free formulations designed for home use. In contrast, products containing 1.5 % hydrogen peroxide or 0.2 % chlorhexidine gluconate were ineffective against SARS-CoV-2 in these tests. This study contributes to the growing body of evidence surrounding virucidal efficacy of mouthwashes/oral rinses against SARS-CoV-2, and has important applications in reducing risk associated with aerosol generating procedures in dentistry and potentially for infection control more widely.

Fluorescent Crimean-Congo hemorrhagic fever virus illuminates tissue tropism patterns and identifies early mononuclear phagocytic cell targets in Ifnar-/- mice.

Crimean-Congo hemorrhagic fever virus (CCHFV, order Bunyavirales, family Nairoviridae, genus Orthonairovirus) is the tick-borne etiological agent of Crimean-Congo hemorrhagic fever (CCHF) in humans. Animals are generally susceptible to CCHFV infection but refractory to disease. Small animal models are limited to interferon-deficient mice, that develop acute fatal disease following infection. Here, using a ZsGreen1- (ZsG) expressing reporter virus (CCHFV/ZsG), we examine tissue tropism and dissemination of virus in interferon-α/ß receptor knock-out (Ifnar-/-) mice. We demonstrate that CCHFV/ZsG retains in vivo pathogenicity comparable to wild-type virus. Interestingly, despite high levels of viral RNA in all organs assessed, 2 distribution patterns of infection were observed by both fluorescence and immunohistochemistry (IHC), corresponding to the permissiveness of organ tissues. To further investigate viral dissemination and to temporally define cellular targets of CCHFV in vivo, mice were serially euthanized at different stages of disease. Flow cytometry was used to characterize CCHFV-associated alterations in hematopoietic cell populations and to classify infected cells in the blood, lymph node, spleen, and liver. ZsG signal indicated that mononuclear phagocytic cells in the lymphatic tissues were early targets of infection; in late-stage infection, overall, the highest levels of signal were detected in the liver, and ZsG was found in both antigen-presenting and lymphocyte cell populations.

Characterization of patients with long-term responses to rucaparib treatment in recurrent ovarian cancer.

OBJECTIVE: To describe molecular and clinical characteristics of patients with high-grade recurrent ovarian carcinoma (HGOC) who had long-term responses to the poly(ADP-ribose) polymerase (PARP) inhibitor rucaparib. METHODS: This post hoc analysis pooled patients from Study 10 (NCT01482715; Parts 2A and 2B; n = 54) and ARIEL2 (NCT01891344; Parts 1 and 2; n = 491). Patients with investigator-assessed complete or partial response per RECIST were classified based on duration of response (DOR): long (≥1 year), intermediate (6 months to <1 year), or short (<6 months). Next-generation sequencing was used to detect deleterious mutations and loss of heterozygosity (LOH) in tumors. RESULTS: Overall, 25.3% (138/545) of enrolled patients were responders. Of these, 27.5% (38/138) had long-term responses; 28.3% (39/138) were intermediate- and 34.8% (48/138) were short-term responders. Most of the long-term responders harbored a BRCA1 or BRCA2 (BRCA) mutation (71.1%, 27/38), and BRCA structural variants were most frequent among long-term responders (14.8%; 4/27). Responders with HGOC harboring a BRCA structural variant (n = 5) had significantly longer DOR than patients with other mutation types (n = 81; median not reached vs 0.62 years; HR, 0.21; 95% CI, 0.10-0.43; unadjusted p = 0.014). Among responders with BRCA wild-type HGOC, most long- and intermediate-term responders had high genome-wide LOH: 81.8% (9/11) and 76.9% (10/13), respectively, including 7 with deleterious RAD51C, RAD51D, or CDK12 mutations. CONCLUSION: Among patients who responded to rucaparib, a substantial proportion achieved responses lasting ≥1 year. These analyses demonstrate the relationship between DOR to PARP inhibitor treatment and molecular characteristics in HGOC, such as presence of reversion-resistant BRCA structural variants.

Inhibition of Nipah Virus by Defective Interfering Particles.

The error-prone nature of RNA-dependent RNA polymerases drives the diversity of RNA virus populations. Arising within this diversity is a subset of defective viral genomes that retain replication competency, termed defective interfering (DI) genomes. These defects are caused by aberrant viral polymerase reinitiation on the same viral RNA template (deletion DI species) or the nascent RNA strand (copyback DI species). DI genomes have previously been shown to alter the dynamics of a viral population by interfering with normal virus replication and/or by stimulating the innate immune response. In this study, we investigated the ability of artificially produced DI genomes to inhibit Nipah virus (NiV), a highly pathogenic biosafety level 4 paramyxovirus. High multiplicity of infection passaging of both NiV clinical isolates and recombinant NiV in Vero cells generated an extensive DI population from which individual DIs were identified using next-generation sequencing techniques. Assays were established to generate and purify both naturally occurring and in silico-designed DIs as fully encapsidated, infectious virus-like particles termed defective interfering particles (DIPs). We demonstrate that several of these NiV DIP candidates reduced NiV titers by up to 4 logs in vitro. These data represent a proof-of-principle that a therapeutic application of DIPs to combat NiV infections may be an alternative source of antiviral control for this disease.

In Situ Imaging of Fluorescent Nipah Virus Respiratory and Neurological Tissue Tropism in the Syrian Hamster Model.

Using a recombinant Nipah virus expressing a fluorescent protein (ZsG), we visualized virus tropism in the Syrian hamster model. We found that anatomical localization of fluorescence correlated to clinical signs; signal was primarily visualized in the respiratory tract in animals with acute-onset terminal disease, whereas central nervous system localization was seen in animals that succumbed with delayed disease onset. While polymerase chain reaction (PCR) detection corresponded well to ZsG signal, virus was only isolated from some lung, brain, liver, and kidney samples that were ZsG and/or PCR positive, and only from animals euthanized on or before 15 days post infection.

Alterations in Blood Chemistry Levels Associated With Nipah Virus Disease in the Syrian Hamster Model.

Nipah virus (NiV; family Paramyxoviridae, genus Henipavirus) infection can cause severe respiratory and neurological disease in humans. The pathophysiology of disease is not fully understood, and it may vary by presentation and clinical course. In this study, we investigate changes in blood chemistry in NiV-infected Syrian hamsters that survived or succumbed to disease. Increased sodium and magnesium and decreased albumin and lactate levels were detected in animals euthanized with severe clinical disease compared with mock-infected controls. When subjects were grouped by clinical syndrome, additional trends were discernable, highlighting changes associated with either respiratory or neurological disease.

Griffithsin Inhibits Nipah Virus Entry and Fusion and Can Protect Syrian Golden Hamsters From Lethal Nipah Virus Challenge.

Nipah virus (NiV) is a highly pathogenic zoonotic paramyxovirus that causes fatal encephalitis and respiratory disease in humans. There is currently no approved therapeutic for human use against NiV infection. Griffithsin (GRFT) is high-mannose oligosaccharide binding lectin that has shown in vivo broad-spectrum activity against viruses, including severe acute respiratory syndrome coronavirus, human immunodeficiency virus 1, hepatitis C virus, and Japanese encephalitis virus. In this study, we evaluated the in vitro antiviral activities of GRFT and its synthetic trimeric tandemer (3mG) against NiV and other viruses from 4 virus families. The 3mG had comparatively greater potency than GRFT against NiV due to its enhanced ability to block NiV glycoprotein-induced syncytia formation. Our initial in vivo prophylactic evaluation of an oxidation-resistant GRFT (Q-GRFT) showed significant protection against lethal NiV challenge in Syrian golden hamsters. Our results warrant further development of Q-GRFT and 3mG as potential NiV therapeutics.

Evaluation of a Single-Dose Nucleoside-Modified Messenger RNA Vaccine Encoding Hendra Virus-Soluble Glycoprotein Against Lethal Nipah virus Challenge in Syrian Hamsters.

In the absence of approved vaccines and therapeutics for use in humans, Nipah virus (NiV) continues to cause fatal outbreaks of encephalitis and respiratory disease in Bangladesh and India on a near-annual basis. We determined that a single dose of a lipid nanoparticle nucleoside-modified messenger RNA vaccine encoding the soluble Hendra virus glycoprotein protected up to 70% of Syrian hamsters from lethal NiV challenge, despite animals having suboptimally primed immune responses before challenge. These data provide a foundation from which to optimize future messenger RNA vaccination studies against NiV and other highly pathogenic viruses.