Biology subjects

Lash, B.

Publications and source records attributed to Lash, B..

3 recordsLinked to original sources

bioRxiv2026

In vitro-reconstituted Drosophila Arc capsids deliver gene editors to dystrophic muscle

The intracellular delivery of therapeutic macromolecules remains a major challenge in biomedicine. Here we reconstitute the Drosophila melanogaster Arc1 (dArc1) retroelement-derived capsid entirely from purified recombinant protein components and in vitro transcribed RNA, creating a fully defined, cell-free assembled protein nanoparticle system. Through affinity engineering of the dArc1 RNA-binding domain, we enable efficient encapsulation of mRNA payloads and Cas9 ribonucleoproteins. Unexpectedly, we discover that dArc1 capsids bind mammalian cells through a direct interaction with the surface receptor SORCS2. Leveraging this interaction, we show that intramuscular injection of dArc1 capsids carrying Cas9 gene editors achieves up to 18% exon skipping and restores dystrophin expression in muscle fibers of mdx mice, a model of Duchenne muscular dystrophy. Enhanced delivery efficiency in regenerating and dystrophic muscle correlates with upregulated SORCS2 expression, supporting our finding that SORCS2 facilitates cellular uptake of dArc1 capsids. This work demonstrates the potential of in vitro-assembled protein nanoparticles for delivery of molecular cargoes.

molecular biology↗

bioRxiv2024

ViRNN: A Deep Learning Model for Viral Host Prediction

Viral outbreaks are on the rise in the world, with the current outbreak of COVID-19 being among one of the worst thus far. Many of these outbreaks were the result of zoonotic transfer between species, and thus understanding and predicting the host of a virus is very important. With the rise of sequencing technologies it is becoming increasingly easy to sequence the full genomes of viruses, databases of publicly available viral genomes are widely available. We utilize a convolutional and recurrent neural network architecture (ViRNN) to predict the hosts for the Coronaviridae family (Coronaviruses) amongst the eleven most common hosts of this family. Our architecture performed with an overall accuracy of 90.55% on our test dataset, with a micro-average AUC-PR of 0.97. Performance was variable per host. ViRNN outperformed previously published methods like k-nearest neighbors and support vector machines, as well as previously published deep learning based methods. Saliency maps based on integrated gradients revealed a number of proteins in the viral genome that may be important interactions determining viral infection in hosts. Overall, this method provides an adaptable classifier capable of predicting host species from viral genomic sequence with high accuracy.

genetics↗

bioRxiv2019

Modification of primary amines to higher order amines reduces in vivo hematological and immunotoxicity of cationic nanocarriers through TLR4 and complement pathways

For decades, cationic polymer nanoparticles have been investigated for nucleic acid delivery. Despite promising in vitro transfection results, most formulations have failed to translate into the clinic due to significant in vivo toxicity - especially when delivered intravenously. To address this significant problem, we investigated the detailed mechanisms that govern the complex in vivo systemic toxicity response to common polymeric nanoparticles. We determined that the toxicity response is material dependent. For branched polyethylenimine (bPEI) nanoparticles - toxicity is a function of multiple pathophysiological responses - triggering of innate immune sensors, induction of hepatic toxicity, and significant alteration of hematological properties. In contrast, for chitosan-based nanoparticles - systemic toxicity is primarily driven through innate immune activation. We further identified that modification of primary amines to secondary and tertiary amines using the small molecule imidazole-acetic-acid (IAA) ameliorates in vivo toxicity from both nanocarriers by different, material-specific mechanisms related to Toll-like receptor 4 activation (for bPEI) and complement activation driven neutrophil infiltration (for chitosan), respectively. Our results provide a detailed roadmap for evaluating in vivo toxicity of nanocarriers and identifies potential opportunities to reduce toxicity for eventual clinical translation.\n\nGraphical Abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC=\"FIGDIR/small/647305v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (27K):\norg.highwire.dtl.DTLVardef@63c7a7org.highwire.dtl.DTLVardef@c8ac52org.highwire.dtl.DTLVardef@a9589dorg.highwire.dtl.DTLVardef@1f8ec62_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗