Liedl A, Grießing J, Kretzmann JA, Dietz H.

J Am Chem Soc. 2023 Mar 8;145(9):4946-4950. doi: 10.1021/jacs.2c12733. Epub 2023 Feb 24.

ABSTRACT

DNA origami enables the creation of complex 3D shapes from genetic material. Future uses could include the delivery of genetic instructions to cells, but nuclear import remains a major barrier to gene delivery due to the impermeability of the nuclear membrane. Here we realize active nuclear import of DNA origami objects in dividing and chemically arrested mammalian cells. We developed a custom DNA origami single-strand scaffold featuring a mammalian-cell expressible reporter gene (mCherry) and multiple Simian virus 40 (SV40) derived DNA nuclear targeting sequences (DTS). Inclusion of the DTS within DNA origami rescued gene expression in arrested cells, indicating that active transport into the nucleus occurs. Our work successfully adapts mechanisms known from viruses to promote the cellular expression of genetic instructions encoded within DNA origami objects.

PMID:36828394 | PMC:PMC9999407 | DOI:10.1021/jacs.2c12733

Kretzmann JA, Liedl A, Monferrer A, Mykhailiuk V, Beerkens S, Dietz H.

Nat Commun. 2023 Feb 23;14(1):1017. doi: 10.1038/s41467-023-36601-1.

ABSTRACT

DNA origami may enable more versatile gene delivery applications through its ability to create custom nanoscale objects with specific targeting, cell-invading, and intracellular effector functionalities. Toward this goal here we describe the expression of genes folded in DNA origami objects delivered to mammalian cells. Genes readily express from custom-sequence single-strand scaffolds folded within DNA origami objects, provided that the objects can denature in the cell. We demonstrate enhanced gene expression efficiency by including and tuning multiple functional sequences and structures, including virus-inspired inverted-terminal repeat-like (ITR) hairpin motifs upstream or flanking the expression cassette. We describe gene-encoding DNA origami bricks that assemble into multimeric objects to enable stoichiometrically controlled co-delivery and expression of multiple genes in the same cells. Our work provides a framework for exploiting DNA origami for gene delivery applications.

PMID:36823187 | PMC:PMC9950468 | DOI:10.1038/s41467-023-36601-1

Monferrer A, Kretzmann JA, Sigl C, Sapelza P, Liedl A, Wittmann B, Dietz H.

ACS Nano. 2022 Nov 2. doi: 10.1021/acsnano.1c11328. Online ahead of print.

ABSTRACT

Effective broadband antiviral platforms that can act on existing viruses and viruses yet to emerge are not available, creating a need to explore treatment strategies beyond the trodden paths. Here, we report virus-encapsulating DNA origami shells that achieve broadband virus trapping properties by exploiting avidity and a widespread background affinity of viruses to heparan sulfate proteoglycans (HSPG). With a calibrated density of heparin and heparan sulfate (HS) derivatives crafted to the interior of DNA origami shells, we could encapsulate adeno, adeno-associated, chikungunya, dengue, human papilloma, noro, polio, rubella, and SARS-CoV-2 viruses or virus-like particles, in one and the same HS-functionalized shell system. Additional virus-type-specific binders were not needed for the trapping. Depending on the relative dimensions of shell to virus particles, multiple virus particles may be trapped per shell, and multiple shells can cover the surface of clusters of virus particles. The steric occlusion provided by the heparan sulfate-coated DNA origami shells can prevent viruses from further interactions with receptors, possibly including those found on cell surfaces.

PMID:36323320 | DOI:10.1021/acsnano.1c11328

da Costa KAS, Del Rosario JMM, Ferrari M, Vishwanath S, Asbach B, Kinsley R, Wagner R, Heeney JL, Carnell GW, Temperton NJ.

Vaccines (Basel). 2022 Sep 14;10(9):1520. doi: 10.3390/vaccines10091520.

ABSTRACT

To better understand how inhibition of the influenza neuraminidase (NA) protein contributes to protection against influenza, we produced lentiviral vectors pseudotyped with an avian H11 hemagglutinin (HA) and the NA of all influenza A (N1-N9) subtypes and influenza B (B/Victoria and B/Yamagata). These NA viral pseudotypes (PV) possess stable NA activity and can be utilized as target antigens in in vitro assays to assess vaccine immunogenicity. Employing these NA PV, we developed an enzyme-linked lectin assay (pELLA) for routine serology to measure neuraminidase inhibition (NI) titers of reference antisera, monoclonal antibodies and post-vaccination sera with various influenza antigens. We also show that the pELLA is more sensitive than the commercially available NA-Fluor™ in detecting NA inhibition in these samples. Our studies may lead to establishing the protective NA titer that contributes to NA-based immunity. This will aid in the design of superior, longer lasting and more broadly protective vaccines that can be employed together with HA-targeted vaccines in a pre-pandemic approach.

PMID:36146598 | PMC:PMC9571397 | DOI:10.3390/vaccines10091520