Lipid Nanoparticle Formulation Increases Efficiency of DNA-Vectored Vaccines/Immunoprophylaxis in Animals Including Transchromosomic Bovines

Abstract

The use of nucleic acid as a drug substance for vaccines and other gene-based medicines continues to evolve. Here, we have used a technology originally developed for mRNA in vivo delivery to enhance the immunogenicity of DNA vaccines. We demonstrate that neutralizing antibodies produced in rabbits and nonhuman primates injected with lipid nanoparticle (LNP)-formulated Andes virus or Zika virus DNA vaccines are elevated over unformulated vaccine. Using a plasmid encoding an anti-poxvirus monoclonal antibody (as a reporter of protein expression), we showed that improved immunogenicity is likely due to increased in vivo DNA delivery, resulting in more target protein. Specifically, after four days, up to 30 ng/mL of functional monoclonal antibody were detected in the serum of rabbits injected with the LNP-formulated DNA. We pragmatically applied the technology to the production of human neutralizing antibodies in a transchromosomic (Tc) bovine for use as a passive immunoprophylactic. Production of neutralizing antibody was increased by >10-fold while utilizing 10 times less DNA in the Tc bovine. This work provides a proof-of-concept that LNP formulation of DNA vaccines can be used to produce more potent active vaccines, passive countermeasures (e.g., Tc bovine), and as a means to produce more potent DnA-launched immunotherapies. It is now possible to rapidly determine the genomic sequence of emerging infectious disease threats, even before the microbe has been isolated. That is, nonspecific amplification and sequencing of nucleic acid can be performed when virus is difficult to propagate and/or in samples where viable virus no longer exists. This genomic information can then be used to design and synthesize candidate nucleic acid-based vaccines. The vaccines can be used as active vaccines, or as passive vaccines to produce antibody-based medical countermeasures. In order to increase the potency of plasmid DNA vaccines, we have explored the possibility of formulating the DNA using lipid nanoparticles (LNPs). The microbes targeted in this research include Andes virus (ANDV) and Zika virus (ZIKV). ANDV is a South American, New World hantavirus and member of the Family Hantaviridae, Order Bunyavirales. The enveloped virion contains a single stranded, tripartite, negative sense RNA genome. The three segments, S, M, and L, encode the nucleocapsid protein (N), the envelope glycoproteins (G n /G c), and the RNA-dependent RNA polymerase, respectively. ANDV is rodent-borne and causes a severe disease referred to as hantavirus pulmonary syndrome (HPS) in humans. ANDV is the only hantavirus known to transmit person-to-person. The case fatality rate of this virus is >35% even in modern intensive care units. There are no vaccines or drugs approved to prevent or treat HPS 1 .

COVID-19 phase 4 vaccine candidates, effectiveness on SARS-CoV-2 variants, neutralizing antibody, rare side effects, traditional and nano-based vaccine platforms: a review

“…Nanocarriers protect and shield the DNA vaccine from degradation by DNases and other enzymes (Cai et al 2018). Liposomes or lipid nanoparticles, polymers, chitosan-based, functionalized silica nanoparticles can be employed in DNA vaccine delivery systems, as revealed in various animal experiments (Mucker et al 2020;Tatlow et al 2020;Theobald 2020;Zhao et al 2013;Zhao et al 2021). The alternative ways to increase the efficiency of DNA vaccine delivery could be the addition of adjuvants and applying a transcutaneous microneedle delivery system.…”

DNA Based Vaccine Expressing SARS-CoV-2 Spike-CD40L Fusion Protein Confers Protection Against Challenge in a Syrian Hamster Model

“…One potential avenue for improvement is through the use of alternative immunization devices, such as jet injectors, electroporation and gene-guns, all of which have been shown to improve the uptake of DNA vaccines and their subsequent efficacy relative to needle injection (61,62). Another promising strategy is encapsulating the DNA vaccines in nanoparticles, which can improve DNA uptake, protect DNA from DNase degradation and act as an vaccine adjuvant (63)(64)(65)(66). The successful usage of lipid-nanoparticle formulated RNA vaccines against SARS-CoV-2 lends credence to their use as a DNA vaccine delivery vector (67).…”

Pandemic Preparedness Against Influenza: DNA Vaccine for Rapid Relief

“…DNA vaccines against influenza have been in development since the 1990's with promising data in pre-clinical models, but the reduced efficacy often observed in larger animals and humans has hampered progression to clinical application (17). New formulations such as lipid nanoparticles (32,33), viral vector formulations (34,35), and gene delivery methods (36) have increased vaccine efficacy, and a naked DNA vaccine from Inovio against SARS-CoV-2 just entered Phase 3 clinical testing (37).…”