Targeting DNA-LNPs to Endothelial Cells Improves Expression Magnitude, Duration, and Specificity

Abstract

DNA-lipid nanoparticles (DNA-LNPs) loaded with inhibitors of the cGAS-STING pathway enable safe and effective delivery of DNA in vivo . However, unmodified LNPs primarily accumulate in the liver. Herein, we report the first instances of extrahepatic DNA-LNP targeting, focused on delivery to endothelial cells, as they play a central role in myriad diseases, such as pulmonary hypertension and stroke. DNA-LNPs conjugated to antibodies against PECAM-1 or VCAM-1 target the endothelium of the lungs and brain/spleen, respectively. These LNPs drive robust transgene expression in their target organs, with greater magnitude and duration than untargeted LNPs. Organ specificity of PECAM-targeted expression increases markedly over two weeks, as off-target liver expression declines to undetectable levels. This improvement in organ-specificity of expression is further improved by replacing full-length antibodies with Fab fragments, resulting in a markedly higher lung-to-liver expression ratio than mAb mRNA-LNPs. Single-cell expression analysis reveals the mechanism underlying the improvements in organ-specificity: target organ expression is dominated by long-lived endothelial cells, while off-target liver expression is in non-endothelial cells with shorter half-lives. Collectively, these studies demonstrate that targeted DNA-LNPs achieve high levels of organ- and cell-type-specific transgene expression and thus provide a therapeutic platform for dozens of endothelial-centric diseases.

Table of contents: Attaching antibodies against endothelial cell surface proteins redirects the delivery and expression of DNA-lipid nanoparticles to organs of interest. Our targeted nanoparticles enable organ-selective DNA expression in the endothelium of the lungs, brain, or spleen, providing a therapeutic platform for dozens of endothelial-centric diseases.