Biology subjects

Siridechadilok, B.

Publications and source records attributed to Siridechadilok, B..

4 recordsLinked to original sources

bioRxiv2026

Disrupting IFIT1-STAT2 viral evasion synergy yields live-attenuated flavivirus with enhanced immune priming

Diverse human viruses deploy a common immune-evasion strategy: viral 2-O-methylation coupled with STAT2 antagonism. Yet the importance of this coupling and whether targeting the coupled functions offers benefits in vaccine development, remains unknown. Using deep mutational scanning of the dengue NS5 protein, we discovered that the two immune-evasion functions work synergistically to cripple interferon signaling. Disrupting this synergy exposes a reciprocal regulatory relationship between the host proteins IFIT1 and STAT2 that controls both viral restriction and immune cell activation. Dengue viruses with mutations that disrupt the synergy are potently attenuated yet trigger antigen-presenting cell activation that exceeds a licensed dengue vaccine benchmark. Our results establish a generalizable principle: targeting synergies between viral immune evasion mechanisms can simultaneously achieve maximal viral attenuation and innate immune priming. This work provides a rational design framework for developing high-performance vaccines against many human viruses that exploit the IFIT1-STAT2 axis. TeaserBreaking synergistic viral immune evasion unlocks potent innate immunity for next-generation live-attenuated vaccines.

microbiology↗

bioRxiv2025

Mechanism of neuroinvasion and interferon response in human choroid plexus organoids during Japanese encephalitis virus infection

Orthoflaviviruses are medically important arthropod-borne pathogens that cause a significant global disease burden. Some of these viruses can cause neurological infections, requiring a clear understanding of how they enter the central nervous system (CNS). The choroid plexus (ChP) is a cerebrospinal fluid (CSF)-producing tissue residing in the brain ventricles. The ChP forms a blood-CSF barrier, which acts as a crucial peripheral-CNS interface and a physical defense against neuroinvasive pathogens. While this tissue is increasingly recognized as a potential entry site for hematogenous pathogens, how orthoflaviviruses overcome the blood-CSF barrier and the corresponding intrinsic immune response in a human model remains critically undefined. This study aimed to investigate the potential of the ChP to serve as a neuroinvasive site for orthoflaviviruses. ChP organoids (ChPOs) derived from human inducible pluripotent stem cells were established and determined for susceptibility to a panel of orthoflaviviruses, namely Japanese encephalitis virus (JEV), Zika virus (ZIKV), and Dengue virus (DENV). These viruses exhibited differential susceptibility to ChPOs, with the pathogenic JEV strain being the most infective. Transcriptomic analysis of ChPOs confirmed a robust interferon (IFN) response to JEV infection. Functional studies further demonstrated that antiviral defenses are crucial for controlling virus infection, and that type I IFN responses are superior to the epithelial-restricted type III IFN responses. Critically, despite the productive release of JEV into the CSF-like fluid within the ChP lumen, selective barrier integrity was maintained, confirming a nondestructive transcellular neuroinvasion mechanism across the blood-CSF barrier. This study highlights a valuable in vitro platform and its potential for studying virus neuroinvasion at the blood-CSF barrier.

microbiology↗

bioRxiv2023

Functional analysis of flavivirus replicase by deep mutational scanning of dengue NS5

Flavivirus NS5 is multi-functional viral protein that play critical roles in virus replication, evolution, and immune antagonism against the hosts. Its error-prone replicase activity copies viral RNA for progeny virus particles and shapes virus evolution. Its methyltransferase activity and STAT2-targeting activity compromise type-I interferon signalling, dampening protective immune response during infection. It interacts with several host factors to shape the host-cell environment for virus replication. Thus, NS5 represents a critical target for both vaccine and antiviral drug development. Here, we performed deep mutational scanning (DMS) on the NS5 of dengue virus serotype 2 in mammalian cells. In combination with available structural and biochemical data, the comprehensive single amino-acid mutational data corroborated key residues and interactions involved in enzymatic functions of the replicase and suggested potential plasticity in NS5 guanylyl transferase. Strikingly, we identified that a set of strictly conserved residues in the motifs lining the replicase active site could tolerate mutations, suggesting additional roles of the priming loop in viral RNA synthesis and possible strategies to modulate the error rate of viral replicase activity through active-site engineering. Our DMS dataset and NS5 libraries could provide a framework and a resource to investigate molecular, evolutionary, and immunological aspects of NS5 functions, with relevance to vaccine and antiviral drug development.

microbiology↗

bioRxiv2020

Potent programmable antiviral against dengue virus in primary human cells by Cas13b RNP with short spacer and delivery by virus-like particle

With sequencing as a standard frontline protocol to identify emerging viruses such zika virus and SARS-CoV2, direct utilization of sequence data to program antivirals against the viruses could accelerate drug development to treat their infections. CRISPR-Cas effectors are promising candidates that could be programmed to inactivate viral genetic material based on sequence data but several challenges such as delivery and design of effective crRNA need to be addressed to realize practical use. Here, we showed that virus-like particle (VLP) could deliver PspCas13b-crRNA ribonucleoprotein (RNP) in nanomolar range to efficiently suppress dengue virus infection in primary human target cells. Shortening spacer length could significantly enhance RNA-targeting efficiency of PspCas13b in mammalian cells compared to the natural length of 30 nucleotides without compromising multiplex targeting by a crRNA array. Our results demonstrate the potentials of applying PspCas13b RNP to suppress RNA virus infection, with implications in targeting host RNA as well.

microbiology↗