Engineered retroviruses map ligand-receptor interactions

Precision-Guided Stealth Missiles in Biomedicine: Biological Carrier-Mediated Nanomedicine Hitchhiking Strategy

Nanodrug delivery systems (NDDS) have demonstrated broad application prospects in disease treatment, prevention, and diagnosis due to several advantages, including functionalization capability, high drug-loading capacity, drug stability protection, and the enhanced permeability and retention (EPR) effect. However, their clinical translation still faces multiple challenges, including rapid clearance by the reticuloendothelial system (RES), poor targeting specificity, and insufficient efficiency in crossing biological barriers. To address these limitations, researchers have developed the biological carrier-mediated nanomedicine hitchhiking strategy (BCM-NHS), which leverages circulating cells, proteins, or bacteria as natural "mobile carriers" to enhance drug delivery. This approach enables nanocarriers to inherit the intrinsic biological properties, endowing them with immune evasion, prolonged circulation, dynamic targeting, biocompatibility, biodegradability, and naturally optimized biological interfaces. Here, a systematic overview of the BCM-NHS is provided. First, the review delves into the methods of nanoparticles (NPs) binding and immobilization, encompassing both the surface-attachment-mediated "backpack" strategy and the encapsulation-based "Trojan horse" strategy. Second, the classification of biological carriers, including both cell-based and non-cell-based carriers, is elucidated. Third, the physical properties and release mechanisms of these nanomaterials are thoroughly described. Finally, the latest applications of BCM-NHS in therapeutic and diagnostic contexts across various disease models including tumor, ischemic stroke, and pneumonia are highlighted.

Trojan Horse-Like Vehicles for CRISPR-Cas Delivery: Engineering Extracellular Vesicles and Virus-Like Particles for Precision Gene Editing in Cystic Fibrosis

The advent of genome editing has kindled the hope to cure previously uncurable, life-threatening genetic diseases. However, whether this promise can be ultimately fulfilled depends on how efficiently gene editing agents can be delivered to therapeutically relevant cells. Over time, viruses have evolved into sophisticated, versatile, and biocompatible nanomachines that can be engineered to shuttle payloads to specific cell types. Despite the advances in safety and selectivity, the long-term expression of gene editing agents sustained by viral vectors remains a cause for concern. Cell-derived vesicles (CDVs) are gaining traction as elegant alternatives. CDVs encompass extracellular vesicles (EVs), a diverse set of intrinsically biocompatible and low-immunogenic membranous nanoparticles, and virus-like particles (VLPs), bioparticles with virus-like scaffold and envelope structures, but devoid of genetic material. Both EVs and VLPs can efficiently deliver ribonucleoprotein cargo to the target cell cytoplasm, ensuring that the editing machinery is only transiently active in the cell and thereby increasing its safety. In this review, we explore the natural diversity of CDVs and their potential as delivery vectors for the clustered regularly interspaced short palindromic repeats (CRISPR) machinery. We illustrate different strategies for the optimization of CDV cargo loading and retargeting, highlighting the versatility and tunability of these vehicles. Nonetheless, the lack of robust and standardized protocols for CDV production, purification, and quality assessment still hinders their widespread adoption to further CRISPR-based therapies as advanced "living drugs." We believe that a collective, multifaceted effort is urgently needed to address these critical issues and unlock the full potential of genome-editing technologies to yield safe, easy-to-manufacture, and pharmacologically well-defined therapies. Finally, we discuss the current clinical landscape of lung-directed gene therapies for cystic fibrosis and explore how CDVs could drive significant breakthroughs in in vivo gene editing for this disease.

Illuminating T cell-dendritic cell interactions in vivo by FlAsHing antigens

Delineating the complex network of interactions between antigen-specific T cells and antigen presenting cells (APCs) is crucial for effective precision therapies against cancer, chronic infections, and autoimmunity. However, the existing arsenal for examining antigen-specific T cell interactions is restricted to a select few antigen-T cell receptor pairs, with limited in situ utility. This lack of versatility is largely due to the disruptive effects of reagents on the immune synapse, which hinder real-time monitoring of antigen-specific interactions. To address this limitation, we have developed a novel and versatile immune monitoring strategy by adding a short cysteine-rich tag to antigenic peptides that emits fluorescence upon binding to thiol-reactive biarsenical hairpin compounds. Our findings demonstrate the specificity and durability of the novel antigen-targeting probes during dynamic immune monitoring in vitro and in vivo. This strategy opens new avenues for biological validation of T-cell receptors with newly identified epitopes by revealing the behavior of previously unrecognized antigen-receptor pairs, expanding our understanding of T cell responses.

Illuminating T cell-dendritic cell interactions in vivo by FlAsHing antigens

Delineating the complex network of interactions between antigen-specific T cells and antigen presenting cells (APCs) is crucial for effective precision therapies against cancer, chronic infections, and autoimmunity. However, the existing arsenal for examining antigen-specific T cell interactions is restricted to a select few antigen-T cell receptor pairs, with limited in situ utility. This lack of versatility is largely due to the disruptive effects of reagents on the immune synapse, which hinder real-time monitoring of antigen-specific interactions. To address this limitation, we have developed a novel and versatile immune monitoring strategy by adding a short cysteine-rich tag to antigenic peptides that emits fluorescence upon binding to thiol-reactive biarsenical hairpin compounds. Our findings demonstrate the specificity and durability of the novel antigen-targeting probes during dynamic immune monitoring in vitro and in vivo. This strategy opens new avenues for biological validation of T-cell receptors with newly identified epitopes by revealing the behavior of previously unrecognized antigen-receptor pairs, expanding our understanding of T cell responses.

Illuminating T cell-dendritic cell interactions in vivo by FlAsHing antigens

Delineating the complex network of interactions between antigen-specific T cells and antigen presenting cells (APCs) is crucial for effective precision therapies against cancer, chronic infections, and autoimmunity. However, the existing arsenal for examining antigen-specific T cell interactions is restricted to a select few antigen-T cell receptor pairs, with limited in situ utility. This lack of versatility is largely due to the disruptive effects of reagents on the immune synapse, which hinder real-time monitoring of antigen-specific interactions. To address this limitation, we have developed a novel and versatile immune monitoring strategy by adding a short cysteine-rich tag to antigenic peptides that emits fluorescence upon binding to thiol-reactive biarsenical hairpin compounds. Our findings demonstrate the specificity and durability of the novel antigen-targeting probes during dynamic immune monitoring in vitro and in vivo. This strategy opens new avenues for biological validation of T-cell receptors with newly identified epitopes by revealing the behavior of previously unrecognized antigen-receptor pairs, expanding our understanding of T cell responses.

Cell type-specific delivery by modular envelope design

The delivery of genetic cargo remains one of the largest obstacles to the successful translation of experimental therapies, in large part due to the absence of targetable delivery vectors. Enveloped delivery modalities use viral envelope proteins, which determine tropism and induce membrane fusion. Here we develop DIRECTED (Delivery to Intended REcipient Cells Through Envelope Design), a modular platform that consists of separate fusion and targeting components. To achieve high modularity and programmable cell type specificity, we develop multiple strategies to recruit or immobilize antibodies on the viral envelope, including a chimeric antibody binding protein and a SNAP-tag enabling the use of antibodies or other proteins as targeting molecules. Moreover, we show that fusogens from multiple viral families are compatible with DIRECTED and that DIRECTED components can target multiple delivery chassis (e.g., lentivirus and MMLV gag) to specific cell types, including primary human T cells in PBMCs and whole blood.