Evaluation of transgene expression characteristics and DNA vaccination against melanoma metastasis of an intravenously injected ternary complex with biodegradable dendrigraft poly-L-lysine in mice

Abstract

We developed a biocompatible splenic vector for a DNA vaccine against melanoma. The splenic vector is a ternary complex composed of plasmid DNA (pDNA), biodegradable dendrigraft poly-L-lysine (DGL), and c-polyglutamic acid (c-PGA), the selective uptake of which by the spleen has already been demonstrated. The ternary complex containing pDNA encoding luciferase (pCMV-Luc) exhibited stronger luciferase activity for RAW264.7 mouse macrophage-like cells than naked pCMV-Luc. Although the ternary complex exhibited strong luciferase activity in the spleen after its tail vein injection, luciferase activity in the liver and spleen was significantly decreased by a pretreatment with clodronate liposomes, which depleted macrophages in the liver and spleen. These results indicate that the ternary complex is mainly transfected in macrophages and is a suitable formulation for DNA vaccination. We applied the ternary complex to a pUb-M melanoma DNA vaccine. The ternary complex containing pUb-M suppressed the growth of melanoma and lung metastasis by B16-F10 mouse melanoma cells. We also examined the acute and liver toxicities of the pUb-M ternary complex at an excess pDNA dose in mice. All mice survived the injection of the excess amount of the ternary complex. Liver toxicity was negligible in mice injected with the excess amount of the ternary complex. In conclusion, we herein confirmed that the ternary complex was mainly transfected into macrophages in the spleen after its tail vein injection. We also showed the prevention of melanoma metastasis by the DNA vaccine and the safety of the ternary complex.

Suitable Promoter for DNA Vaccination Using a pDNA Ternary Complex

“…Actually, pre-administration of clodronate liposomes decreased gene expression of γ-PGA coated complexes in the spleen. This result indicated that γ-PGA coated complexes were partly taken by the macrophages in the spleen [23]. Matsuo K. et al have also reported that γ-PGA coated nanoparticles efficiently delivered entrapped antigenic proteins into DCs and presented antigens to DCs via major histocompatibility complex class I and II molecules [24].…”

Serum-Resistant Ternary DNA Polyplexes for Suicide Gene Therapy of Uterine Leiomyoma

“…Their in vivo instability, however, poses a fundamental challenge to the field [ 50 , 51 ]. The inclusion of polyanionic component to DNA/cationic peptide complexes may prevent a serum-mediated inhibition of transfection, both in vitro and in vivo [ 39 , 40 , 46 ]. In this study biodegradable cystine-cross-linked-poly-L glutamic acid was added to the pDNA/arginine-histidine-cysteine-rich peptide-based polyplexes.…”

“…Kurosaki et al reported that, after intravenous injection, γ-polyglutamic acid-coated cationic complexes of DNA and poly-L-arginine or poly-L-lysine showed high gene expression in the spleen [ 44 ]. Kodama et al demonstrated that after γ-PGA-coated dendrigraft poly-L-lysine-based polyplexes were intravenously injected into mice, they displayed high transfection efficiency (mainly in the spleen) and negligible liver toxicity [ 45 , 46 ]. Importantly, DNA vaccination using the ternary vehicles suppressed the growth of melanoma and lung metastasis in mice by activating the systemic immunity, proving the efficiency and safety of ternary PGA-coated polypeptide complexes for clinical gene therapy [ 46 ].…”

Recent Advances in DNA Vaccines against Lung Cancer: A Mini Review

“…Up to now, various nanoparticles have been applied to deliver DNA-based vaccines and promote antitumor immune responses, including polymeric nanoparticles, liposomes, silica nanoparticles, bisphosphonate-modified calcium phosphate nanoparticles, gold nanoparticles, virus nanoparticles, and carbon nanotubes [ 72 , 73 , 74 ]. Liposomes are one of the well-recognized nanoparticle vaccine delivery platforms, which are easy to construct by altering the composition, surface of lipid, and other important properties [ 75 , 76 , 77 ]. Liposomes can not only augment the immunogenicity of special antigens for cancer DNA vaccines, but they also improve the therapeutic efficacy.…”