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Biology subjects

tenOever, B.

Publications and source records attributed to tenOever, B..

8 recordsLinked to original sources

IFNγ-Driven Inflammatory Responses in the Nasal Mucosa Drive Influenza Virus Shedding and Transmission

What determines host infectiousness during influenza A virus (IAV) infection remains a fundamental unanswered question in virology. While upper respiratory tract (URT) replication is necessary for transmission, its insufficient to explain host-to-host variation in contagiousness. Using the infant mouse model of influenza transmission, we show that viruses containing H3 hemagglutinin shed at higher levels than non-H3-containing viruses, despite comparable URT replication. H3-containing virus infection was associated with higher URT inflammation, characterized by increased cytokine production, immune cell recruitment, and mucus hypersecretion, which directly correlated with shedding efficiency. Transcriptomic profiling identified enrichment of interferon-stimulated gene programs, with a dominant interferon gamma (IFN{gamma}) signature during H3 infections. Functional studies demonstrated that IFN{gamma} deficiency reduced mucus production, shedding, and transmission, whereas IFN{gamma} supplementation restored these phenotypes. Together, these findings identify IFN{gamma}-driven mucosal inflammation key host determinant of influenza infectiousness, reframing contagiousness as a consequence of host inflammatory clearance rather than viral replication alone.

microbiology↗

SARS-CoV-2 Airway Infection Results in Time-dependent Sensory Abnormalities in a Hamster Model

Despite being largely confined to the airways, SARS-CoV-2 infection has been associated with sensory abnormalities that manifest in both acute and long-lasting phenotypes. To gain insight on the molecular basis of these sensory abnormalities, we used the golden hamster infection model to characterize the effects of SARS-CoV-2 versus Influenza A virus (IAV) infection on the sensory nervous system. Efforts to detect the presence of virus in the cervical/thoracic spinal cord and dorsal root ganglia (DRGs) demonstrated detectable levels of SARS-CoV-2 by quantitative PCR and RNAscope uniquely within the first 24 hours of infection. SARS-CoV-2-infected hamsters demonstrated mechanical hypersensitivity during acute infection; intriguingly, this hypersensitivity was milder, but prolonged when compared to IAV-infected hamsters. RNA sequencing (RNA-seq) of thoracic DRGs from acute infection revealed predominantly neuron-biased signaling perturbations in SARS-CoV-2-infected animals as opposed to type I interferon signaling in tissue derived from IAV-infected animals. RNA-seq of 31dpi thoracic DRGs from SARS-CoV-2-infected animals highlighted a uniquely neuropathic transcriptomic landscape, which was consistent with substantial SARS-CoV-2-specific mechanical hypersensitivity at 28dpi. Ontology analysis of 1, 4, and 30dpi RNA-seq revealed novel targets for pain management, such as ILF3. Meta-analysis of all SARS-CoV-2 RNA-seq timepoints against preclinical pain model datasets highlighted both conserved and unique pro-nociceptive gene expression changes following infection. Overall, this work elucidates novel transcriptomic signatures triggered by SARS-CoV-2 that may underlie both short- and long-term sensory abnormalities while also highlighting several therapeutic targets for alleviation of infection-induced hypersensitivity. One Sentence SummarySARS-CoV-2 infection results in an interferon-associated transcriptional response in sensory tissues underlying time-dependent hypersensitivity.

neuroscience↗

SARS-CoV-2 infection results in lasting and systemic perturbations post recovery

SARS-CoV-2 has been found capable of inducing prolonged pathologies collectively referred to as Long-COVID. To better understand this biology, we compared the short- and long-term systemic responses in the golden hamster following either SARS-CoV-2 or influenza A virus (IAV) infection. While SARS-CoV-2 exceeded IAV in its capacity to cause injury to the lung and kidney, the most significant changes were observed in the olfactory bulb (OB) and olfactory epithelium (OE) where inflammation was visible beyond one month post SARS-CoV-2 infection. Despite a lack of detectable virus, OB/OE demonstrated microglial and T cell activation, proinflammatory cytokine production, and interferon responses that correlated with behavioral changes. These findings could be corroborated through sequencing of individuals who recovered from COVID-19, as sustained inflammation in OB/OE tissue remained evident months beyond disease resolution. These data highlight a molecular mechanism for persistent COVID-19 symptomology and characterize a small animal model to develop future therapeutics.

microbiology↗

Nipah virus Bangladesh infection elicits organ-specific innate and inflammatory responses in the marmoset model

The common marmoset (Callithrix jacchus) is increasingly recognized as an ideal non-human primate (NHP) at high-biocontainment due to its smaller size and relative ease of handling. Here, we evaluated the susceptibility and pathogenesis of Nipah virus Bangladesh strain (NiVB) infection in marmosets at biosafety level 4. Infection via the intranasal and intratracheal route resulted in fatal disease in all four infected marmosets. Three developed pulmonary edema and hemorrhage as well as multi-focal hemorrhagic lymphadenopathy, while one recapitulated neurologic clinical symptoms and cardiomyopathy on gross pathology. Organ-specific innate and inflammatory responses were characterized by RNA-seq in six different tissues from infected and control marmosets. Notably, a unique transcriptome was revealed in the brainstem of the marmoset exhibiting neurological symptoms. Our results provide a more comprehensive understanding of NiV pathogenesis in an accessible and novel NHP model, closely reflecting clinical disease as observed in NiV patients.

microbiology↗

Zinc-embedded fabrics inactivate SARS-CoV-2 and influenza A virus

Infections with respiratory viruses can spread via liquid droplets and aerosols, and cause diseases such as influenza and COVID-19. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of respiratory droplets containing these viruses. However, influenza A viruses and coronaviruses are stable for hours on various materials, which makes frequent and correct disposal of these PPE important. Metal ions embedded into PPE may inactivate respiratory viruses, but confounding factors such as absorption of viruses make measuring and optimizing the inactivation characteristics difficult. Here we used polyamide 6.6 (PA66) fibers that had zinc ions embedded during the polymerisation process and systematically investigated if these fibers can absorb and inactivate pandemic SARS-CoV-2 and influenza A virus H1N1. We find that these viruses are readily absorbed by PA66 fabrics and inactivated by zinc ions embedded into this fabric. The inactivation rate (pfu{middle dot}gram-1{middle dot}min-1) exceeds the number of active virus particles expelled by a cough and supports a wide range of viral loads. Moreover, we found that the zinc content and the virus inactivating property of the fabric remain stable over 50 standardized washes. Overall, these results provide new insight into the development of "pathogen-free" PPE and better protection against RNA virus spread.

microbiology↗

Common genetic variation in humans impacts in vitro susceptibility to SARS-CoV-2 infection

The host response to SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, demonstrates significant inter-individual variability. In addition to showing more disease in males, the elderly, and individuals with underlying co-morbidities, SARS-CoV-2 can seemingly render healthy individuals with profound clinical complications. We hypothesize that, in addition to viral load and host antibody repertoire, host genetic variants also impact vulnerability to infection. Here we apply human induced pluripotent stem cell (hiPSC)-based models and CRISPR-engineering to explore the host genetics of SARS-CoV-2. We demonstrate that a single nucleotide polymorphism (rs4702), common in the population at large, and located in the 3UTR of the protease FURIN, impacts alveolar and neuron infection by SARS-CoV-2 in vitro. Thus, we provide a proof-of-principle finding that common genetic variation can impact viral infection, and thus contribute to clinical heterogeneity in SARS-CoV-2. Ongoing genetic studies will help to better identify high-risk individuals, predict clinical complications, and facilitate the discovery of drugs that might treat disease.

cell biology↗

An inability to maintain the ribonucleoprotein genomic structure is responsible for host detection of negative-sense RNA viruses

Cellular biology has a uniformity not shared amongst viruses. This is perhaps best exemplified by negative-sense RNA viruses that encode their genetic material as a ribonucleoprotein complex composed of genome, RNA-dependent RNA polymerase, and the nucleoprotein. Here we demonstrate that limiting nucleoprotein availability not only universally culminates in a replicative catastrophe for negative-sense RNA viruses, but it results in the production of aberrant genomic material and induction of the interferon-based host defenses. This dynamic illustrates the tremendous stress imposed on negative-sense RNA viruses during replication as genomic products accumulate in an environment that requires an increasing demand on nucleoprotein availability. We show that limiting NP by RNA interference or drug targeting blocks replication and primes neighboring cells through the production of interferon. Together, these results demonstrate that the nucleoprotein represents the Achilles heel of the entire phylum of negative-sense RNA viruses. Here we establish this principle for a diverse collection of human pathogens and propose that the nucleoprotein should be a primary target for the development of future antiviral drugs. HIGHLIGHTSO_LILimited levels of NP result in production of defective viral genomes C_LIO_LIDefective viral genomes and viral antagonists are key determinants of the host antiviral response C_LIO_LIThe host response and defective viral genome generation further exasperate NP availability C_LIO_LINP is an optimal drug target for the whole phylum of negative-sense RNA viruses C_LI

microbiology↗

Engineering an RNA-based tissue-specific platform for genetic editing through use of a miRNA-enabled Cas12a

The capacity to edit genomes using CRISPR-Cas systems holds immense potential for countless genetic-based diseases. However, one significant impediment preventing broad therapeutic utilization is in vivo delivery. While genetic editing at a single cell level in vitro can be achieved with high efficiency, the capacity to utilize these same biologic tools in a desired tissue in vivo remains challenging. Non-integrating RNA virus-based vectors constitute efficient platforms for transgene expression and surpass several barriers to in vivo delivery. However, the broad tissue tropism of viral vectors raises the concern for off-target effects. Moreover, prolonged expression of the Cas proteins, regardless of delivery method, can accumulate aberrant RNAs leading to unwanted immunological responses. In an effort to circumvent these shortcomings, here we describe a versatile RNA virus-based technology that can achieve cell-specific activity and self-inactivation by combining host microRNA (miRNA) biology with the CRISPR-Cas12a RNA-guided nuclease. Exploiting the RNase activity of Cas12a, we generated a vector that self-inactivates upon delivery of Cas12a and an accompanying CRISPR RNA (crRNA). Furthermore, we show that maturation of the crRNA can be made dependent on cell-specific miRNAs, which confers cell-specificity. We demonstrate that this genetic editing circuit delivers diminished yet sufficient levels of Cas12a to achieve effective genome editing whilst inducing a minimal immunological response. It can also function in a cell-specific manner thereby facilitating in vivo editing and mitigating the risk of unwanted, off-target effects.

bioengineering↗