A DNA nanorobot targeted release aTIGIT improves the immunosuppressive state and synergizes the anti-tumor effect of aPD-1

Abstract

Abstract Immune checkpoint inhibitor (ICIs) therapies have become the prominent breakthrough in the treatment of hepatocellular carcinoma (HCC). Dual blockade of TIGIT and PD-1 have promising results achieving synergistic antitumor effects for ICI-resistant HCC. However, immune-related adverse events (irAEs) and immune cell depletion in tumor microenvironment affect the clinical use of ICIs therapies. DNA nanobots have shown excellent potential as targeted release drug delivery systems in vivo. Here, using DNA origami we constructed an autonomous DNA robot to transport TIGIT antibodies to tumor site. The Pb (2+) dependent DNAzyme GR5 was used to achieve the aTIGIT free-loaded in DNA cargoes. The nucleolin-targeting aptamer serves both as a targeting domain and as a molecular trigger for the open of the DNA cargoes in tumor microenvironment. The CpG oligodeoxynucleotides (ODNs) responsible for immunostimulatory in tumor site by activation of TLR9, producing high-level secretion of various pro-inflammatory cytokines including tumor necrosis factor (TNF)-R, interleukin (IL)-6, and IL-12. DNA gel electrophoresis and TEM showing the structure of the nanobots. FRET efficiency verified the open of the cargoes regulated by nucleolin aptamer. Confocol microscopy showing the targeting of the nanobots to nucleolin-positive HCC cells. Cy5-modified oligonucleotides were conjugated to aTIGIT and the UV-Vis spectrometry results showed that aTIGIT was free-loaded and protected by the DNA cargoes. Tumor-bearing mouse model will be established to evaluate the synergistic antitumor effect of the DNA nanobots for aPD-1 in vivo. Our DNA nanorobot provide a safe and high efficient immunostimulatory delivery system for ICIs therapies.