Biology subjects

Hwang, W. Y.

Publications and source records attributed to Hwang, W. Y..

4 recordsLinked to original sources

bioRxiv2026

De novo design of a safe and potent respiratory syncytial virus immuno-focusing antigen

Respiratory syncytial virus (RSV) remains the leading cause of severe respiratory infections in infants, the elderly, and the immunocompromised. Although stabilized full-length pre-fusion (pre-F) protein vaccines are promising, enhanced respiratory disease (ERD) remains a critical safety concern. Here, we used artificial intelligence to design a de novo immuno-focused antigen that structurally preserves the RSV F head region containing critical neutralising epitopes-- site O, II and V-while replacing the non-neutralising stem with a computationally designed scaffold to minimise immunopathological risk. The lead candidate, aRF6, elicited robust protective immunity against RSV in mice and similar immunogenicity in non-human primates without detectable toxicity. Importantly, in stringent ERD-promoting models, aRF6 induced minimal pulmonary pathology and markedly attenuated Th2-biased cytokine responses, outperforming formalin-inactivated RSV and full-length-stabilized pre-F. The results of cryoelectron microscopy confirmed that the aRF6 structure precisely matched the computational predictions. These results demonstrated that computationally designed de novo immuno-focused antigens can yield safe and effective RSV vaccines, thereby providing a rational framework for next-generation vaccine development.

microbiology↗

bioRxiv2026

Disruption of the hypothalamic orexin system links SARS-CoV-2 infection to persistent cortical neuronal pathology

Long COVID frequently presents with persistent neurological symptoms, including cognitive impairment, fatigue, and sleep disturbances; however, its underlying mechanisms remain unclear. Here, we show that SARS-CoV-2 infection induces lasting cortical neuronal injury and hypothalamic orexin (hypocretin) dysfunction in vivo. In K18-hACE2 and wild-type BALB/c mice, viral RNA persisted in the brain and coincided with focal loss of Neuronal Nuclei (NeuN)-positive cortical neurones beyond acute infection. SARS-CoV-2, but not the influenza A virus, triggered rapid and sustained suppression of hypothalamic orexin expression, defining a virus-specific neuropathological signature. Considering the downregulation of orexin and focal cortical NeuN expression, we showed that augmenting orexin signalling using recombinant orexin-A/B restored NeuN expression in vitro and in vivo. Overall, these findings identify the orexin system as a selective neural vulnerability to SARS-CoV-2 and define orexinergic circuit disruption as a mechanistic axis underlying the neurological manifestations of Long COVID.

microbiology↗

bioRxiv2025

Liquid-liquid phase separation mediated immune evasion of RSV against OAS-RNase L pathway

Respiratory syncytial virus (RSV) infection is the major cause of severe respiratory illnesses in infants and older adults. RSV forms phase-separated biomolecular condensates called inclusion bodies (IBs), which serve as hubs for viral replication. However, the contribution of IBs to host immune response evasion remains elusive. We report that RSV IBs protect viral RNA from the 2'-5' oligoadenylate synthetase (OAS)-RNase L pathway, a critical antiviral defense mechanism that cleaves viral and cellular RNAs. RSV infection did not activate the OAS-RNase L pathway, and ectopically activated RNase L did not suppress viral replication. In RSV-infected cells, double-stranded RNA (dsRNA) was efficiently sequestered within liquid-liquid phase separation (LLPS)-mediated IBs, rendering its detection challenging. LLPS perturbation caused dsRNA release from IBs into the cytosol. dsRNA extracted from infected cells, which lacked LLPS shielding, triggered OAS-RNase L pathway activation. Thus, LLPS-driven IBs structurally sequester viral RNA, facilitating RSV to evade RNase-dependent genomic RNA degradation mediated by the OAS-RNase L antiviral pathway.

microbiology↗

bioRxiv2021

Kap-β2/Transportin mediates β-catenin nuclear transport in Wnt signaling

Wnt signaling is essential for many aspects of embryonic development including the formation of the primary embryonic axis. In addition, excessive Wnt signaling drives multiple diseases including cancer highlighting its importance for disease pathogenesis. {beta}-catenin is a key effector in this pathway that translocates into the nucleus and activates Wnt responsive genes. However, due to our lack of understanding of {beta}-catenin nuclear transport, therapeutic modulation of Wnt signaling has been challenging. Here, we took an unconventional approach to address this long-standing question by exploiting a heterologous model system, the budding yeast Saccharomyces cerevisiae, which contains a conserved nuclear transport machinery. In contrast to prior work, we demonstrate that {beta}-catenin accumulates in the nucleus in a Ran dependent manner, suggesting the use of a nuclear transport receptor (NTR). Indeed, a systematic and conditional inhibition of NTRs revealed that only Kap104, the orthologue of Kap-{beta}2/Transportin-1 (TNPO1), was required for {beta}-catenin nuclear import. We further demonstrate direct binding between TNPO1 and {beta}-catenin that is mediated by a conserved amino acid sequence that resembles a PY NLS. Finally, using Xenopus secondary axis and TCF/LEF reporter assays, we demonstrate that our results in yeast can be directly translated to vertebrates. By elucidating the NLS in {beta}-catenin and its cognate NTR, our study provides new therapeutic targets for a host of human diseases caused by excessive Wnt signaling. Indeed, we demonstrate that a small chimeric peptide designed to target TNPO1 can reduce Wnt signaling as a first step towards therapeutics.

developmental biology↗