Fine tuning of CpG spatial distribution with DNA origami for improved therapeutic cancer vaccination

Abstract

Multivalent presentation of ligands often enhances receptor activation and downstream signaling. DNA origami offers precise nanoscale spacing of ligands, a potentially useful feature for therapeutic nanoparticles. Here we introduce a square-block DNA origami platform to explore the importance of spacing of CpG oligonucleotides, which engage Toll-like receptors and thereby act as danger signals for dendritic cells. Through in vitro cell-culture studies and in vivo tumor-treatment models, we demonstrate that square blocks induce Th1 immune polarization when CpG is spaced at 3.5 nm. We observe that this DNA origami vaccine enhances DC activation, antigen cross-presentation, CD8 T cell activation, Th1-polarized CD4 activation and NK cell activation. The vaccine also synergizes effectively with anti-PD-L1 for improved cancer immunotherapy in melanoma and lymphoma models and induced long-term T cell memories. Our results suggest that DNA origami may serve as an advanced vaccine platform for controlling adjuvant spacing and co-delivering antigens.

Innate Immune Stimulation Using 3D Wireframe DNA Origami

“…While nucleic acid nanodevices have been applied to various therapeutic areas, their immunostimulatory properties have been explored to a lesser degree. Such fundamental understanding of NANP immunological properties is important to inform the design of follow-on in vivo studies using CpG overhangs (e.g., Zeng et al, bioRxiv, and Oktay et al, bioRxiv), to further explore prophylactic and therapeutic potential of these nanomaterials. , By establishing a deeper understanding of the baseline immunostimulatory properties of unmodified wireframe NANPs and the relative impacts of various NANP design parameters on DNA nanoparticle-mediated tunable TLR9 activation, we can work toward enabling the design of DNA nanostructures with specific immunostimulatory profiles for targeted biological outcomes.…”

origamiFISH allows universal, label-free, single molecule visualization of DNA origami nanodevices across biological samples

“…We first implemented origamiFISH in RAW264.7 macrophage cells, a widely utilized cell line within the DNA origami field with high DN uptake capacity (Kern et al, 2021; Liu et al, 2020; Maezawa et al, 2020; Zeng et al, 2022). Following our origamiFISH protocol, DNs appear as bright, distinct fluorescent puncta, or “spots”, within each cell ( Fig.…”

A Synthetic Biology Approach for Vaccine Candidate Design against Delta Strain of SARS-CoV-2 Revealed Disruption of Favored Codon Pair as a Better Strategy over Using Rare Codons

“…Regarding the role of spacing between CpGs, it is demonstrated that when CpG is present in pairs, the DC stimulation is enhanced, and CD8 T cells are highly activated [ 103 ]. In the present study, in the native construct, no CpG dimer was present, while 04, 09, and 06 CpG dimers were present in constructs 1, 2, and 3.…”

“…In the present study, in the native construct, no CpG dimer was present, while 04, 09, and 06 CpG dimers were present in constructs 1, 2, and 3. More CpGs in the sequence lead to increased IL10 and IL12 secretion [ 103 ]; thus highest IL10 and IL12 secretion will be there with construct 2.…”