Biology subjects

Vu, T. Q.

Publications and source records attributed to Vu, T. Q..

5 recordsLinked to original sources

bioRxiv2025

DNA-Directed Assembly of Multivalent Lipid Nanoparticles for Targeted T Cell Gene Delivery

Lipid nanoparticles (LNPs) are a powerful emerging tool for in vivo T cell engineering with applications ranging from B cell lymphomas to other cancers and autoimmune diseases. Key challenges in designing these therapeutics include achieving both precise cell targeting and efficient mRNA translation. While single-targeted LNPs have been extensively studied, bispecific LNPs have only been briefly explored. Engagement of multiple T cell receptors offers the opportunity for enhanced mRNA delivery, expression, and T cell targeting. Here, a DNA-tethering method enables rapid modification of lipid nanoparticles with commercial antibodies. Using this strategy, we evaluated a variety of bispecific LNPs for targeted mRNA delivery to T cells both in vitro and in vivo. We identify bispecific formulations that improve targeting and subsequent transfection of T cells in vitro and in vivo relative to monotargeted LNPs. Additionally, we find that targeting molecules can alter LNP biodistribution to the spleen and liver. This fast and efficient approach to assembling antibody-targeted LNPs should enable high-throughput screening of diverse antibody combinations for improved specificity and efficiency of in vivo gene delivery. Significance StatementA major challenge in in vivo gene delivery is achieving both precise targeting and efficient mRNA translation. Multitargeted LNPs offer a potential solution to this challenge; however, their rapid assembly remains difficult, necessitating the development of new methods to construct and evaluate targeted LNPs. Here, we use a DNA-tethering method to enable rapid antibody modification of LNPs and evaluate bispecific formulations for targeted T cell mRNA delivery in vitro and in vivo. We find bispecific LNPs improve T cell targeting and expression compared to single-targeted particles. To the best of our knowledge, this study represents the first systematic screening and comparison of bispecific LNPs. Our method provides a modular approach for identifying effective antibody combinations to enhance in vivo gene delivery that can be customized for different undruggable diseases.

immunology↗

bioRxiv2022

Enhancing functionalized liposome avidity to cells via lipid phase separation

The addition of both cell-targeting moieties and polyethylene glycol (PEG) to nanoparticle (NP) drug delivery systems is a standard approach to improve the biodistribution, specificity, and uptake of therapeutic cargo. The spatial presentation of these molecules affects avidity of the NP to target cells in part through an interplay between the local ligand concentration and the steric hindrance imposed by PEG molecules. Here, we show that lipid phase separation in nanoparticles can modulate liposome avidity by changing the proximity of PEG and targeting protein molecules on a nanoparticle surface. Using lipid-anchored nickelnitrilotriacetic acid (Ni-NTA) as a model ligand, we demonstrate that the attachment of lipid anchored Ni-NTA and PEG molecules to distinct lipid domains in nanoparticles can enhance liposome binding to cancer cells by increasing ligand clustering and reducing steric hindrance. We then use this technique to enhance the binding of RGD-modified liposomes, which can bind to integrins overexpressed on many cancer cells. These results demonstrate the potential of lipid phase separation to modulate the spatial presentation of targeting and shielding molecules on nanocarriers, offering a powerful tool to enhance the efficacy of NP drug delivery systems.

bioengineering↗

bioRxiv2022

Hydrophobic mismatch drives self-organization of designer proteins into synthetic membranes

The extent to which membrane biophysical properties, such as hydrophobic thickness, can drive membrane protein organization remains unknown. Inspired by this question, we used de novo protein design, molecular dynamic simulations, and cell-free systems to elucidate how membrane-protein hydrophobic mismatch affects protein integration and organization in synthetic lipid membranes. We found that membranes must deform to accommodate membrane-protein hydrophobic mismatch, which reduces the expression and co-translational insertion of membrane proteins into synthetic membranes. We used this principle to sort proteins both between and within membranes, thereby achieving one-pot assembly of vesicles with distinct functions and controlled split-protein assembly, respectively. Our results shed light on protein organization in biological membranes and provide a framework to self-organizing membrane-based materials with new functions.

synthetic biology↗

bioRxiv2019

Barcoding biological reactions with DNA-functionalized vesicles

Targeted vesicle fusion is a promising approach to selectively control interactions between vesicle compartments and would enable the initiation of biological reactions in complex aqueous environments. Here, we explore how two features of vesicle membranes, DNA tethers and phase-segregated membranes, promote fusion between specific vesicle populations. We show that membrane phase-segregation provides an energetic driver for membrane fusion that increases the efficiency of DNA-mediated fusion events. Using this system, we show that orthogonality provided by DNA tethers allows us to direct fusion and delivery of DNA cargo to specific vesicle populations. We then demonstrate that vesicle fusion between DNA-tethered vesicles can be used to initiate in vitro protein expression that leads to the synthesis of model soluble and membrane proteins. The ability to engineer orthogonal fusion events between DNA-tethered vesicles will provide a new strategy to control the spatio-temporal dynamics of cell-free reactions, expanding opportunities to engineer artificial cellular systems.

synthetic biology↗

bioRxiv2019

HER2 Cancer Protrusion Growth Signaling Regulated by Unhindered, Localized Filopodial Dynamics

Protrusions are plasma membrane extensions that are found in almost every cell in the human body. Cancer cell filopodial and lamellipodial protrusions play key roles in the integral processes of cell motility and signaling underlying tumor invasion and metastasis. HER2 (ErbB-2) is overexpressed in diverse types of tumors and regulates PI3K-pathway-mediated protrusion growth. It is known that HER2 resides at breast cancer cell protrusions, but how protrusion-based HER2 spatiotemporal dynamics shape cancer signaling is unclear. Here, we study how HER2 location and motion regulate protrusion signaling and growth using quantitative spatio-temporal molecular imaging approaches. Our data highlight morphologically-segregated features of filopodial and lamellipodial protrusions, in in vitro 2D breast cancer cells and in vivo intact breast tumor. Functional-segregation parallels morphological-segregation, as HER2 and its activated downstream pAKT-PI3K signaling remain spatially-localized at protrusions, provoking new protrusion growth proximal to sites of HER2 activation. HER2 in SKBR3 breast cancer cell filopodia exhibits fast, linearly-directed motion that is distinct from lamellipodia and non-protrusion subcellular regions ([~]3-4 times greater diffusion constant, rapid speeds of 2-3 um2/s). Surprisingly, filopodial HER2 motion is passive, requiring no active energy sources. Moreover, while HER2 motion in lamellipodia and non-protrusion regions show hindered diffusion typical of membrane proteins, HER2 diffuses freely within filopodia. We conclude that HER2 activation, propagation, and functional protrusion growth is a local process in which filopodia have evolved to exploit Brownian thermal fluctuations within a barrier-free nanostructure to transduce rapid signaling. These results support the importance of developing filopodia and other protrusion-targeted strategies for cancer.

cancer biology↗