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Worwa, G.

Publications and source records attributed to Worwa, G..

3 recordsLinked to original sources

Modeling Risk Group 4 virus infection and antiviral treatment in microfluidic lung organ-on-chips in maximum containment laboratories

Development of candidate countermeasures against human pathogens frequently includes nonhuman animal experimentation. Preclinical animal pathogen exposure studies are conducted to model diseases and accumulate preliminary and hypothetically translatable data to inform and justify the design of clinical trial evaluation of countermeasure safety and efficacy. In addition to frequent ethical critiques, challenges associated with animal experimentation include considerable resources needed to achieve statistical power and robustness, replicability and reproducibility concerns, potentially compromised objectivity through lack of blinding, fundamental species-specific biological differences, and risk of unpredictable pathogen adaptation to the experimental animal. Recent U.S. and U.K. government initiatives aim to reduce animal experimentation by complementing or potentially replacing them with new approach methodologies (NAMs), i.e., increasingly sophisticated in silico, in chemico, and in vitro approaches. We piloted development of one type of NAM, organ-on-chips (OOCs), in the highly challenging environment of a maximum (biosafety level 4) containment laboratory. Using a Risk Group 4 virus, Nipah virus (NiV), and two types of lung OOCs seeded with human or porcine cells, we demonstrated the recapitulation of key features of NiV lung infection, including viral infection, replication, and translocation, that are associated with proinflammatory cytokine secretion, immune cell recruitment, and disruption of the air-liquid interface barrier. We reproduced the known anti-NiV activity of remdesivir and evaluated that of another potential antiviral, zotatifin. Our results pave the way for similar applications of advanced microphysiological systems for modeling infections caused by high-consequence viruses.

microbiology↗

Delivery of defective interfering RNA antivirals to the lungs using hyperbranched poly(beta-amino ester) nanoparticles

Hyperbranched poly(beta-amino ester) (hPBAE) nanoparticles represent a promising platform for nucleic acid delivery, particularly to the lungs. In this study, we evaluate the potential of hPBAE nanoparticles to deliver defective interfering RNA (diRNA) antivirals targeting betacoronaviruses under a range of formulations and storage conditions. hPBAE-diRNA nanoparticles demonstrated efficient cellular uptake of functional diRNA across diverse cell types, conferred protection against nuclease-mediated degradation, and exhibited low in vitro cytotoxicity. In vivo, these nanoparticles enabled effective delivery of functional diRNA to the lungs of golden hamsters without inducing adverse physiological effects. Collectively, these findings support hPBAE nanoparticles as a safe and effective platform for diRNA delivery for the treatment of respiratory viral infections. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=66 SRC="FIGDIR/small/721911v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@2fc386org.highwire.dtl.DTLVardef@1cda4f9org.highwire.dtl.DTLVardef@9f61borg.highwire.dtl.DTLVardef@1fc8461_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract.C_FLOATNO Defective interfering RNA was mixed with hyperbranched poly(beta-amino ester) nanoparticles and delivered to cells in vitro and to golden hamsters in vivo, to measure toxicity and the replication potential of the RNA. C_FIG

microbiology↗

A 667-nucleotide sequence in the SARS-CoV-2 nsp15 coding region promotes genome encapsidation

Coronavirus genome encapsidation depends on cis-acting RNA elements that interact with viral structural proteins. While such packaging signals have been characterized in several coronaviruses, their definition in SARS-CoV-2 remains incomplete. Using synthetic defective SARS-CoV-2 genomes, we identify a 667-nucleotide region within the nsp15 coding sequence that preferentially binds SARS-CoV-2 nucleoprotein and enhances the accumulation of defective viral genomes both in vitro and in vivo. Sequential and targeted deletion analyses further delineate candidate RNA secondary structures within this region that contribute to this enrichment. These structures show similarity to elements within the putative packaging signal of SARS-CoV but are not conserved across other coronaviruses. Together, these findings support the presence of a structured RNA element within nsp15 that contributes to SARS-CoV-2 genome encapsidation and provide a framework for further structural and functional dissection of coronavirus packaging signals. IMPORTANCEThis study identifies a 667-nt region within the SARS-CoV-2 nsp15 coding sequence that binds nucleoprotein and promotes accumulation of defective viral genomes, revealing a previously unrecognized contributor to genome encapsidation. Mapping of candidate RNA structures within this region links SARS-CoV-2 packaging activity to conserved structural features observed in SARS-CoV, while highlighting key differences from other coronaviruses. These findings refine understanding of cis-acting packaging signals in SARS-CoV-2 and provide a foundation for further structural and functional analysis of coronavirus genome encapsidation. O_FIG O_LINKSMALLFIG WIDTH=177 HEIGHT=200 SRC="FIGDIR/small/721935v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@1b64611org.highwire.dtl.DTLVardef@1b21b7borg.highwire.dtl.DTLVardef@2a68b5org.highwire.dtl.DTLVardef@405fe1_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGRAPHICAL ABSTRACTC_FLOATNO A part of the nsp15 coding sequence of SARS-CoV-2 promotes efficient transmission of defective viral genomes in vitro and in vivo. Using a sequential deletion library and targeted deletions within this region we identify RNA structures that may function as packaging signals. C_FIG

microbiology↗