Lee, T.-K. | Search bioRxiv

bioRxiv2025

Enhanced Neutralization of Japanese Encephalitis Virus Using an Engineered VL Double-Domain

Japanese encephalitis virus (JEV) is an emerging virus responsible for thousands of deaths in Asia; however, an effective treatment has not yet been discovered. JEV envelope (E) proteins play important roles in viral survival and infection. In this study, we isolated scFv- and VL-targeting E proteins using phage display biopanning. The isolated VL was engineered to form VL double domains to increase its neutralization activity. Several candidates showed binding abilities, whereas only the DE2 VL double-domain treatment showed neutralizing activity against JEV. DE2 was also highly specific to JEV and did not bind to other flaviviruses. Immunocytochemistry results showed that DE2 was co-localized with the endosome 4 h post-infection. Thus, the mechanism of DE2 neutralization involves blocking the E protein from fusing with the endosomal membrane, resulting in the unrelease of the viral genome into the cytoplasm. Docking analysis showed that DE2 was bound to three domains, especially DIII, of the JEV E protein. In contrast, other scFv that were unable to bind to DIII showed no or low neutralizing activity. DE2 was also predicted to neutralize all the JEV genotypes. In conclusion, a combined in vitro and in silico study showed the high potential of DE2 to neutralize JEV infections, which may be applied in future therapeutic systems. ImportanceJapanese encephalitis virus (JEV) is a serious mosquito-borne disease that causes brain infections and deaths across Asia. However, there is still no specific treatment once infection occurs. In this study, we developed a new type of antibody fragment, called a VL double-domain, that can block the virus. Among several candidates, DE2 showed a strong ability to stop JEV from infecting cells, while others could bind to the virus but did not block infection. Our findings reveal that DE2 works by attaching to a key region of the virus, preventing it from releasing its genetic material. Moreover, DE2 is predicted to work against all known JEV strains, highlighting its potential as a universal treatment option. This research provides an important step toward developing new antiviral therapies for JEV and possibly for other viruses with similar infection mechanisms.

microbiology↗

bioRxiv2023

Hybrid Neural Networks of the Olfactory Learning Center in the Drosophila Brain

Biological signal encoding is shaped by the underlying neural circuitry. In Drosophila melanogaster, the mushroom body (MB) houses thousands of Kenyon cells (KCs) that process olfactory signals from hundreds of projection neurons (PNs). Previous studies debated the connectivity between PNs and KCs (random vs. structured). Our multiscale analysis of electron microscopic data revealed a hybrid network with diverse synaptic connection preferences and input divergence across different KC classes. Using MB connectome data, our simulation model, validated via functional imaging, accurately predicted distinct chemical sensitivities in the major KC classes. The model suggests that the hybrid network excels in detecting food odors while maintaining precise odor discrimination in different KC classes. These findings underscore the computational advantages of this hybrid network.

neuroscience↗

bioRxiv2018

Visualization of axonal protein allocation in Drosophila with whole brain localization microscopy

Long-term memory (LTM) formation requires learning-induced protein synthesis in specific neurons and synapses within a neural circuit. Precisely how neural activity allocates new proteins to specific synaptic ensembles, however, remains unknown. We developed a deep-tissue super-resolution imaging tool suitable for single-molecule localization in intact adult Drosophila brain, and focused on the axonal protein allocation in mushroom body (MB), a central neuronal structure involved in olfactory memory formation. We found that insufficient training suppresses LTM formation by inducing the synthesis of vesicular monoamine transporter (VMAT) proteins within a dorsal paired medial (DPM) neuron, which innervates all axonal lobes of the MB. Surprisingly, using our localization microscopy, we found that these learning-induced proteins are distributed only in a subset of DPM axons in specific sectors along the MB lobes. This neural architecture suggests that sector-specific modulation of neural activity from MB neurons gates consolidation of early transient memory into LTM.

neuroscience↗