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At least 235 records · Page 13

Evaluation of the Deletion of the African Swine Fever Virus Gene O174L from the Genome of the Georgia Isolate

African swine fever virus (ASFV) is a structurally complex, double-stranded DNA virus, which causes African swine fever (ASF), a contagious disease affecting swine. ASF is currently affecting pork production in a large geographical region, including Eurasia and the Caribbean. ASFV has a large genome, which harbors more than 160 genes, but most of these genes’ functions have not been experimentally characterized. One of these genes is the O174L gene which has been experimentally shown to function as a small DNA polymerase. Here, we demonstrate that the deletion of the O174L gene from the genome of the virulent strain ASFV Georgia2010 (ASFV-G) does not significantly affect virus replication in vitro or in vivo. A recombinant virus, having deleted the O174L gene, ASFV-G-ΔO174L, was developed to study the effect of the O174L protein in replication in swine macrophages cultures in vitro and disease production when inoculated in pigs. The results demonstrated that ASFV-G-ΔO174L has similar replication kinetics to parental ASFV-G in swine macrophage cultures. In addition, animals intramuscularly inoculated with 10 2 HAD 50 of ASFV-G-ΔO174L presented a clinical form of the disease that is indistinguishable from that induced by the parental virulent strain ASFV-G. All animals developed a lethal disease, being euthanized around day 7 post-infection. Therefore, although O174L is a well-characterized DNA polymerase, its function is apparently not critical for the process of virus replication, both in vitro and in vivo, or for disease production in domestic pigs.

59 BASIC BIOLOGICAL SCIENCES↗

Evidence that Maackia amurensis seed lectin (MASL) exerts pleiotropic actions on oral squamous cells with potential to inhibit SARS-CoV-2 infection and COVID-19 disease progression

COVID-19 was declared an international public health emergency in January, and a pandemic in March of 2020. There are over 125 million confirmed COVID-19 cases that have caused over 2.7 million deaths worldwide as of March 2021. COVID-19 is caused by the SARS-CoV-2 virus. SARS-CoV-2 presents a surface “spike” protein that binds to the ACE2 receptor to infect host cells. In addition to the respiratory tract, SARS-Cov-2 can also infect cells of the oral mucosa, which also express the ACE2 receptor. The spike and ACE2 proteins are highly glycosylated with sialic acid modifications that direct viral-host interactions and infection. Maackia amurensis seed lectin (MASL) has a strong affinity for sialic acid modified proteins and can be used as an antiviral agent. Here, we report that MASL targets the ACE2 receptor, decreases ACE2 expression and glycosylation, suppresses binding of the SARS-CoV-2 spike protein, and decreases expression of inflammatory mediators by oral epithelial cells that cause ARDS in COVID-19 patients. In addition, we report that MASL also inhibits SARS-CoV-2 infection of kidney epithelial cells in culture. This work identifies MASL as an agent with potential to inhibit SARS-CoV-2 infection and COVID-19 related inflammatory syndromes.

60 APPLIED LIFE SCIENCES↗

Convergent use of phosphatidic acid for hepatitis C virus and SARS-CoV-2 replication organelle formation

Double membrane vesicles (DMVs) serve as replication organelles of plus-strand RNA viruses such as hepatitis C virus (HCV) and SARS-CoV-2. Viral DMVs are morphologically analogous to DMVs formed during autophagy, but lipids driving their biogenesis are largely unknown. Here we show that production of the lipid phosphatidic acid (PA) by acylglycerolphosphate acyltransferase (AGPAT) 1 and 2 in the ER is important for DMV biogenesis in viral replication and autophagy. Using DMVs in HCV-replicating cells as model, we found that AGPATs are recruited to and critically contribute to HCV and SARS-CoV-2 replication and proper DMV formation. An intracellular PA sensor accumulated at viral DMV formation sites, consistent with elevated levels of PA in fractions of purified DMVs analyzed by lipidomics. Apart from AGPATs, PA is generated by alternative pathways and their pharmacological inhibition also impaired HCV and SARS-CoV-2 replication as well as formation of autophagosome-like DMVs. These data identify PA as host cell lipid involved in proper replication organelle formation by HCV and SARS-CoV-2, two phylogenetically disparate viruses causing very different diseases, i.e. chronic liver disease and COVID-19, respectively. Host-targeting therapy aiming at PA synthesis pathways might be suitable to attenuate replication of these viruses.

60 APPLIED LIFE SCIENCES↗

Multiplex detection and identification of viral, bacterial, and protozoan pathogens in human blood and plasma using an expanded high-density resequencing microarray platform

Introduction: Nucleic acid tests for blood donor screening have improved the safety of the blood supply; however, increasing numbers of emerging pathogen tests are burdensome. Multiplex testing platforms are a potential solution. Methods: The Blood Borne Pathogen Resequencing Microarray Expanded (BBP-RMAv.2) can perform multiplex detection and identification of 80 viruses, bacteria and parasites. This study evaluated pathogen detection in human blood or plasma. Samples spiked with selected pathogens, each with one of 6 viruses, 2 bacteria and 5 protozoans were tested on this platform. The nucleic acids were extracted, amplified using multiplexed sets of primers, and hybridized to a microarray. The reported sequences were aligned to a database to identify the pathogen. To directly compare the microarray to an emerging molecular approach, the amplified nucleic acids were also submitted to nanopore next generation sequencing (NGS). Results: The BBP-RMAv.2 detected viral pathogens at a concentration as low as 100 copies/ml and a range of concentrations from 1,000 to 100,000 copies/ml for all the spiked pathogens. Coded specimens were identified correctly demonstrating the effectiveness of the platform. The nanopore sequencing correctly identified most samples and the results of the two platforms were compared. Discussion: These results indicated that the BBP-RMAv.2 could be employed for multiplex detection with potential for use in blood safety or disease diagnosis. The NGS was nearly as effective at identifying pathogens in blood and performed better than BBP-RMAv.2 at identifying pathogen-negative samples.

59 BASIC BIOLOGICAL SCIENCES↗

Simultaneous gentamicin-mediated damage and Atoh1 overexpression promotes hair cell regeneration in the neonatal mouse utricle

Highlights: • Type I hair cells were the primary target of gentamicin. • Simultaneous induction of gentamicin and Atoh1 promoted hair cell generation. • Type II-like hair cells regenerated in the striola via direct transdifferentiation. • Type I/II hair cells generated in the ectopic region in mitotic and non-mitotic way. • Mitosis enhanced type I hair cell production. Loss of hair cells from vestibular epithelium results in balance dysfunction. The current therapeutic regimen for vestibular diseases is limited. Upon injury or Atoh1 overexpression, hair cell replacement occurs rapidly in the mammalian utricle, suggesting a promising approach to induce vestibular hair cell regeneration. In this study, we applied simultaneous gentamicin-mediated hair cell ablation and Atoh1 overexpression to induce neonatal utricular hair cell formation in vitro. We confirmed that type I hair cells were the primary targets of gentamicin. Furthermore, injury and Atoh1 overexpression promoted hair cell regeneration in a timely and efficient manner through robust viral transfection. Hair cells regenerated with type II characteristics in the striola and type I/II characteristics in non-sensory regions. Rare EdU{sup +}/myosin7a{sup +} cells in sensory regions and robust EdU{sup +}/myosin7a{sup +} signals in ectopic regions indicate that transdifferentiation of supporting cells in situ, and mitosis and differentiation of non-sensory epithelial cells in ectopic regions, are sources of regenerative hair cells. Distinct regeneration patterns in in situ and ectopic regions suggested robust plasticity of vestibular non-sensory epithelium, generating more developed hair cell subtypes and thus providing a promising stem cell-like source of hair cells. These findings suggest that simultaneously causing injury and overexpressing Atoh1 promotes hair cell regeneration efficacy and maturity, thus expanding the understanding of ectopic plasticity in neonatal vestibular organs.

60 APPLIED LIFE SCIENCES↗

A deep learning approach to real-time HIV outbreak detection using genetic data

Pathogen genomic sequence data are increasingly made available for epidemiological monitoring. A main interest is to identify and assess the potential of infectious disease outbreaks. While popular methods to analyze sequence data often involve phylogenetic tree inference, they are vulnerable to errors from recombination and impose a high computational cost, making it difficult to obtain real-time results when the number of sequences is in or above the thousands. Here, we propose an alternative strategy to outbreak detection using genomic data based on deep learning methods developed for image classification. The key idea is to use a pairwise genetic distance matrix calculated from viral sequences as an image, and develop convolutional neutral network (CNN) models to classify areas of the images that show signatures of active outbreak, leading to identification of subsets of sequences taken from an active outbreak. We showed that our method is efficient in finding HIV-1 outbreaks with R0 ≥ 2.5, and overall a specificity exceeding 98% and sensitivity better than 92%. We validated our approach using data from HIV-1 CRF01 in Europe, containing both endemic sequences and a well-known dual outbreak in intravenous drug users. Our model accurately identified known outbreak sequences in the background of slower spreading HIV. Importantly, we detected both outbreaks early on, before they were over, implying that had this method been applied in real-time as data became available, one would have been able to intervene and possibly prevent the extent of these outbreaks. This approach is scalable to processing hundreds of thousands of sequences, making it useful for current and future real-time epidemiological investigations, including public health monitoring using large databases and especially for rapid outbreak identification.

59 BASIC BIOLOGICAL SCIENCES↗

Torque Teno Sus Virus 1: A Potential Surrogate Pathogen to Study Pig-Transmitted Transboundary Animal Diseases

Understanding the epidemiology and transmission dynamics of transboundary animal diseases (TADs) among wild pigs (Sus scrofa) will aid in preventing the introduction or containment of TADs among wild populations. Given the challenges associated with studying TADs in free-ranging populations, a surrogate pathogen system may predict how pathogens may circulate and be maintained within wild free-ranging swine populations, how they may spill over into domestic populations, and how management actions may impact transmission. We assessed the suitability of Torque teno sus virus 1 (TTSuV1) to serve as a surrogate pathogen for molecular epidemiological studies in wild pigs by investigating the prevalence, persistence, correlation with host health status and genetic variability at two study areas: Archbold’s Buck Island Ranch in Florida and Savannah River Site in South Carolina. We then conducted a molecular epidemiological case study within Archbold’s Buck Island Ranch site to determine how analysis of this pathogen could inform transmission dynamics of a directly transmitted virus. Prevalence was high in both study areas (40%, n = 190), and phylogenetic analyses revealed high levels of genetic variability within and between study areas. Our case study showed that pairwise host relatedness and geographic distance were highly correlated to pairwise viral genetic similarity. Molecular epidemiological analyses revealed a distinct pattern of direct transmission from pig to pig occurring within and between family groups. Our results suggest that TTSuV1 is highly suitable for molecular epidemiological analyses and will be useful for future studies of transmission dynamics in wild free-ranging pigs.

60 APPLIED LIFE SCIENCES↗

Simultaneous and Staggered Foot-and-Mouth Disease Virus Coinfection of Cattle

Foot-and-mouth disease (FMD) field studies have suggested the occurrence of simultaneous infection of individual hosts by multiple virus strains; however, the pathogenesis of foot-and-mouth disease virus (FMDV) coinfections is largely unknown. In the current study, cattle were experimentally exposed to two FMDV strains of different serotypes (O and A). One cohort was simultaneously infected with both viruses, while additional cohorts were initially infected with FMDV A and subsequently superinfected with FMDV O after 21 or 35 days. Coinfections were confirmed during acute infection, with both viruses concurrently detected in blood, lesions, and secretions. Staggered exposures resulted in overlapping infections as convalescent animals with persistent subclinical FMDV infection were superinfected with a heterologous virus. Staggering virus exposure by 21 days conferred clinical protection in six of eight cattle, which were subclinically infected following the heterologous virus exposure. This effect was transient, as all animals superinfected at 35 days post-initial infection developed fulminant FMD. The majority of cattle maintained persistent infection with one of the two viruses while clearing the other. Analysis of viral genomes confirmed interserotypic recombination events within 10 days in the upper respiratory tract of five superinfected animals from which the dominant genomes contained the capsid coding regions of the O virus and nonstructural coding regions of the A virus. In contrast, there were no dominant recombinant genomes detected in samples from simultaneously coinfected cattle. These findings inculpate persistently infected carriers as potential FMDV mixing vessels in which novel strains may rapidly emerge through superinfection and recombination.

59 BASIC BIOLOGICAL SCIENCES↗

Antiviral discovery using sparse datasets by integrating experiments, molecular simulations, and machine learning

Computational methods have demonstrated success in identifying virucidal agents, effectively contributing to the discovery of novel virucidal molecules. In this study, we developed a machine learning (ML) model, trained on a small dataset, to predict inhibitors of human enterovirus 71 (EV71), a pathological agent that causes severe disease in children and immunocompromised adults. Despite the dataset’s limitation, comprising of only 36 compounds tested, our ML framework demonstrated significant predictive capability. Notably, experimental validation revealed that five out of the eight compounds predicted by our model from the Chinese cosmetic material list exhibited virucidal activity. The inhibitor effects displayed by the main active compounds were further confirmed by molecular dynamics simulation. This underscores the potential of our AI-driven approach to bypass data constraints in identifying active molecules against viral pathogens.

60 APPLIED LIFE SCIENCES↗

Different Pathogenesis of CCR5-Using Primary HIV-1 Isolates from Non-Switch and Switch Virus Patients in Human Lymphoid Tissue Ex Vivo

CCR5-utilizing HIV-1 variants (R5) typically transmit infection and dominate its early stages, whereas emergence of CXCR4-using (X4 or R5X4) HIV-1 is often associated with disease progression. However, such a switch in co-receptor usage can only be detected in approximately onehalf of HIV-infected patients (switch virus patients), and progression to immunodeficiency may also occur in patients without detectable switch in co-receptor usage (non-switch virus patients). Here, we used a system of ex vivo-infected tonsillar tissue to compare the pathogenesis of sequential primary R5 HIV-1 isolates from the switch and non-switch patients. Inoculation of ex vivo tissue with these R5 isolates resulted in viral replication and CCR5(+)CD4(+) T cell depletion. The levels of such depletion by HIV-1 isolated from non-switch virus patients were significantly higher than those by R5 HIV-1 isolates from switch virus patients. T cell depletion seemed to be controlled by viral factors and did not significantly vary between tissues from different donors. In contrast, viral replication did not correlate with the switch status of the patients; in tissues fiom different donors it varied 30-fold and seemed to be controlled by a combination of viral and tissue factors. Nevertheless, replication-level hierarchy among sequential isolates remained constant in tissues from various donors. Viral load in vivo was higher in switch virus patients compared to non-switch virus patients. The high cytopathogenicity of CCR5(+)CD4(+) T cells by R5 HIV-1 isolates from non-switch virus patients may explain the steady decline of CD4(+) T cells in the absence of CXCR4 using virus; elimination of target cells by these isolates may limit their own replication in vivo.

Iarlsson, Ingrid↗

Deletion of CD2-Like (CD2v) and C-Type Lectin-Like (EP153R) Genes from African Swine Fever Virus Georgia-Δ9GL Abrogates Its Effectiveness as an Experimental Vaccine

African swine fever virus (ASFV) is currently the most dreaded infectious disease affecting the global swine production industry. There is no commercial vaccine available, making the culling of infected animals the current solution to control outbreaks. Effective experimental vaccines have been developed by deleting virus genes associated with virulence. Deletion of the ASFV 9GL gene (Δ9GL) has resulted in the attenuation of different ASFV strains, although the degree of attenuation varies across isolates. Here, we investigated the possibility of the increased safety of the experimental vaccine strain ASFV-G-Δ9GL by deleting two additional virus genes involved in pathogenesis, CD2v, a CD2 like viral encoded gene from the EP402R open reading frame (ORF), and C-type lectin-like viral gene, encoded from the EP153R ORF. Two new recombinant viruses were developed, ASFV-G-Δ9GL/ΔCD2v and ASFV-G-Δ9GL/ΔCD2v/ΔEP153R, harboring two and three gene deletions, respectively. ASFV-G-Δ9GL/ΔCD2v/ΔEP153R, but not ASFV-G-Δ9GL/ΔCD2v, had a decreased ability to replicate in vitro in swine macrophage cultures when compared with parental ASFV-G-Δ9GL. Importantly, ASFV-G-Δ9GL/ΔCD2v and ASFV-G-Δ9GL/ΔCD2v/ΔEP153R induced almost undetectable viremia levels when inoculated into domestic pigs and failed to protect them against challenge with parental virulent ASFV-Georgia, while ASFV-G-Δ9GL offered robust protection during challenge. Therefore, the deletion of CD2-like and C-type lectin-like genes significantly decreased the protective potential of ASFV-G-Δ9GL as a vaccine candidate. This study constitutes an example of the unpredictability of genetic manipulation involving the simultaneous deletion of multiple genes from the ASFV genome.

59 BASIC BIOLOGICAL SCIENCES↗

Enhancement of biological control agents for use against forest insect pests and diseases through biotechnology

Research and development efforts in our research group are focused on the generation of more efficacious biological control agents through the techniques of biotechnology for use against forest insect pests and diseases. Effective biological controls for the gypsy moth and for tree fungal wilt pathogens are under development. The successful use of Gypchek, a formulation of the Lymantria dispar nuclear polyhedrosis virus (LdNPV), in gypsy moth control programs has generated considerable interest in that agent. As a consequence of its specificity, LdPNV has negligible adverse ecological impacts compared to most gypsy moth control agents. However, LdNPV is not competitive with other control agents in terms of cost and efficacy. We are investigating several parameters of LdNPV replication and polyhedra production in order to enhance viral potency and efficacy thus mitigating the current disadvantages of LdNPV for gypsy moth control, and have identified LdNPV variants that will facilitate these efforts. Tree endophytic bacteria that synthesize antifungal compounds were identified and an antibiotic compound from one of these bacteria was characterized. The feasibility of developing tree endophytes as biological control agents for tree vascular fungal pathogens is being investigated.

Slavicek, James M.↗

Can N95 Respirators Be Reused after Disinfection? How Many Times?

The coronavirus disease 2019 (COVID-19) pandemic has led to a major shortage of N95 respirators, which are essential for protecting healthcare professionals and the general public who may come into contact with the virus. Thus, it is essential to determine how we can reuse respirators and other personal protective equipment in these urgent times. We investigated multiple commonly used disinfection schemes on media with particle filtration efficiency of 95%. Heating was recently found to inactivate the virus in solution within 5 min at 70 °C and is among the most scalable, user-friendly methods for viral disinfection. We found that heat (≤85 °C) under various humidities (≤100% relative humidity, RH) was the most promising, nondestructive method for the preservation of filtration properties in meltblown fabrics as well as N95-grade respirators. At 85 °C, 30% RH, we were able to perform 50 cycles of heat treatment without significant changes in the filtration efficiency. At low humidity or dry conditions, temperatures up to 100 °C were not found to alter the filtration efficiency significantly within 20 cycles of treatment. Ultraviolet (UV) irradiation was a secondary choice, which was able to withstand 10 cycles of treatment and showed small degradation by 20 cycles. However, UV can potentially impact the material strength and subsequent sealing of respirators. Finally, treatments involving liquids and vapors require caution, as steam, alcohol, and household bleach all may lead to degradation of the filtration efficiency, leaving the user vulnerable to the viral aerosols.

60 APPLIED LIFE SCIENCES↗

Detection of significant antiviral drug effects on COVID-19 with reasonable sample sizes in randomized controlled trials: A modeling study

Development of an effective antiviral drug for Coronavirus Disease 2019 (COVID-19) is a global health priority. Although several candidate drugs have been identified through in vitro and in vivo models, consistent and compelling evidence from clinical studies is limited. The lack of evidence from clinical trials may stem in part from the imperfect design of the trials. We investigated how clinical trials for antivirals need to be designed, especially focusing on the sample size in randomized controlled trials. A modeling study was conducted to help understand the reasons behind inconsistent clinical trial findings and to design better clinical trials. We first analyzed longitudinal viral load data for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) without antiviral treatment by use of a within-host virus dynamics model. The fitted viral load was categorized into 3 different groups by a clustering approach. Comparison of the estimated parameters showed that the 3 distinct groups were characterized by different virus decay rates (p-value < 0.001). The mean decay rates were 1.17 d -1 (95% CI: 1.06 to 1.27 d -1 ), 0.777 d -1 (0.716 to 0.838 d -1 ), and 0.450 d -1 (0.378 to 0.522 d -1 ) for the 3 groups, respectively. Such heterogeneity in virus dynamics could be a confounding variable if it is associated with treatment allocation in compassionate use programs (i.e., observational studies). Subsequently, we mimicked randomized controlled trials of antivirals by simulation. An antiviral effect causing a 95% to 99% reduction in viral replication was added to the model. To be realistic, we assumed that randomization and treatment are initiated with some time lag after symptom onset. Using the duration of virus shedding as an outcome, the sample size to detect a statistically significant mean difference between the treatment and placebo groups (1:1 allocation) was 13,603 and 11,670 (when the antiviral effect was 95% and 99%, respectively) per group if all patients are enrolled regardless of timing of randomization. The sample size was reduced to 584 and 458 (when the antiviral effect was 95% and 99%, respectively) if only patients who are treated within 1 day of symptom onset are enrolled. We confirmed the sample size was similarly reduced when using cumulative viral load in log scale as an outcome. We used a conventional virus dynamics model, which may not fully reflect the detailed mechanisms of viral dynamics of SARS-CoV-2. The model needs to be calibrated in terms of both parameter settings and model structure, which would yield more reliable sample size calculation. In this study, we found that estimated association in observational studies can be biased due to large heterogeneity in viral dynamics among infected individuals, and statistically significant effect in randomized controlled trials may be difficult to be detected due to small sample size. The sample size can be dramatically reduced by recruiting patients immediately after developing symptoms. We believe this is the first study investigated the study design of clinical trials for antiviral treatment using the viral dynamics model.

60 APPLIED LIFE SCIENCES↗

Enhancing Biopreparedness through a Model System to Understand the Molecular Mechanisms that Lead to Pathogenesis and Disease Transmission: NW-BRaVE

The science of biopreparedness to counter biological threats hinges on understanding the fundamental principles and molecular mechanisms that lead to pathogenesis and disease transmission. Our vision to address this challenge is to create a powerful and user-friendly platform to elucidate the fundamental principles of how molecular interactions drive pathogen-host relationships and host shifts. We will enable groundbreaking discoveries by integrating a wide range of structural, genomics, proteomics, and other advanced omics measurements, along with evolutionary and artificial intelligence predictions. To make sure the system is applicable to real-world problems, we will develop it in the context of a tractable model system, the small, abundant, and accessible photosynthetic cyanobacteria and their constantly co-adapting viral pathogens, cyanophages. This model will maintain the system’s applicability to real-world problems and techniques, but the overall focus will be on elucidating general principles of detecting, assessing, and surveilling molecular interaction, adaptation, and coevolution that are system agnostic and therefore extensible to other viral-host interactions. Our overall objectives are to (1) identify the molecular complexes that comprise the cyanobacteria redox macromolecular subsystem and how they dynamically change with bacteriophage infection in situ, using cryo-electron tomography; (2) profile regulatory changes during infection using proteomics, multiomics, and experimental validation, and integrate the data with in situ structures; (3) use genomics and metagenomics to determine environmental and population factors across time scales that impact the interactions between marine cyanobacteria and their cyanophage parasites, predicting the evolutionary origins of in situ structural and functional interactions, convergence and coevolution; and (4) develop a data integration and transformation platform that facilitates the integration of in situ, proteomic, and evolutionary measurements of molecular interactions to surveil diverse hosts and parasites in various environmental contexts. These objectives address Focus Area 2 Reveal Molecular Interactions Across Biological Scales for Design of Targeted Interventions. Our powerful and user-friendly platform will enhance connections between the often-siloed fields of structure, molecular phenotype, and evolutionary genomics that are key to biopreparedness, but in need of integration (Figure 1). We will build an integrated navigation tool to facilitate the effective use of globally distributed experimental data for integrated analysis and predictive modeling. The project will develop, implement, and test a platform to assess host-pathogen molecular interactions, adaptation to hosts and host shifts, and coevolution between hosts and pathogens, successfully impacting the research community by revolutionizing abilities to study any host-pathogen interaction, encourage diverse community contributions, and gain fundamental insights into how proteins adapt to new contexts. This ability will be critical for designing early interventions to address future threats. We will build surveillance training capability, aiming for a fair and equitable response to future pandemics and biothreats.

59 BASIC BIOLOGICAL SCIENCES↗

MEMS reagent and sample handling procedure: Feasibility of viral antibody detection by passive immune agglutination

An attempt was made to develop a test requiring no preadsorption steps for the assessment of antibodies to rubella and mumps viruses using the passive immune agglutination (PIA) method. Both rubella and mumps antigens and antibodies were prepared. Direct PIA tests, using rubella antigen-coated beads, and indirect PIA tests, using rubella antibody-coated beads, were investigated. Attempts, using either method, were unsuccessful. Serum interference along with nonspecific agglutination of beads by the rubella antigen resulted in no specific response under the test conditions investigated. A new, highly sensitive approach, the enzyme immunoassay (EIA) test system, is recommended to overcome the nonspecificity. This system is a logical outgrowth of some of the solid phase work done on MEMS and represents the next generation tests system that can be directly applied to early disease detection and monitoring.

Bailey, G. D.↗

How lipidomics can transform our understanding of virus infections

Traditionally, lipids have been thought of as molecules that provide structure and energy, but their functional relevance in disease mechanisms is increasingly clear, and with advancements in mass spectrometry technologies, lipidomics analyses is a tool gaining recognition. Beyond the utility of lipoprotein and fatty acid profiles in clinical diagnosis and chemotaxonomic identifications, respectively, lipidomics analysis that combines knowledge across disciplines and can resolve exact lipid structures has the potential to advance clinical diagnoses and associated treatment, differentiate pathogen types (e.g., virus vs. bacterial vs. fungal), detect natural vs lab-grown viruses, and perhaps distinguish a pathogen from a benign biological agent (i.e., threat potential). As new viruses emerge and localized outbreaks expand, lipidomics will accelerate our understanding of viral infections and aid in maximizing the discovery of novel biomarkers of pathogenicity and host response.

59 BASIC BIOLOGICAL SCIENCES↗

Nebulized delivery of a broadly neutralizing SARS-CoV-2 RBD-specific nanobody prevents clinical, virological, and pathological disease in a Syrian hamster model of COVID-19

There remains an unmet need for globally deployable, low-cost therapeutics for the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Previously, we reported on the isolation and in vitro characterization of a potent single-domain nanobody, NIH-CoVnb-112, specific for the receptor-binding domain (RBD) of SARS-CoV-2. Here, we report on the molecular basis for the observed broad in vitro neutralization capability of NIH-CoVnb-112 against variant SARS-CoV-2 pseudoviruses. The structure of NIH-CoVnb-112 bound to SARS-CoV-2 RBD reveals a large contact surface area overlapping the angiotensin converting enzyme 2 (ACE2) binding site, which is largely unencumbered by the common RBD mutations. In an in vivo pilot study, we demonstrate effective reductions in weight loss, viral burden, and lung pathology in a Syrian hamster model of COVID-19 following nebulized delivery of NIH-CoVnb-112. These findings support the further development of NIH-CoVnb-112 as a potential adjunct preventative therapeutic for the treatment of SARS-CoV-2 infection.

60 APPLIED LIFE SCIENCES↗