Development of a DNA Vaccine for Melanoma Metastasis by Inhalation Based on an Analysis of Transgene Expression Characteristics of Naked pDNA and a Ternary Complex in Mouse Lung Tissues

Abstract

The present study investigated a pulmonary delivery system of plasmid DNA (pDNA) and its application to melanoma DNA vaccines. pCMV-Luc, pEGFP-C1, and pZsGreen were used as a model pDNA to evaluate transfection efficacy after inhalation in mice. Naked pDNA and a ternary complex, consisting of pDNA, dendrigraft poly-l-lysine (DGL), and γ-polyglutamic acid (γ-PGA), both showed strong gene expression in the lungs after inhalation. The transgene expression was detected in alveolar macrophage-rich sites by observation using multi-color deep imaging. On the basis of these results, we used pUb-M, which expresses melanoma-related antigens (ubiquitinated murine melanoma gp100 and tyrosinase-related protein 2 (TRP2) peptide epitopes), as DNA vaccine for melanoma. The inhalation of naked pUb-M and its ternary complex significantly inhibited the metastasis of B16-F10 cells, a melanoma cell line, in mice. The levels of the inflammatory cytokines, such as TNF-α, IFN-γ, and IL-6, which enhance Th1 responses, were higher with the pUb-M ternary complex than with naked pUb-M and pEGFP-C1 ternary complex as control. In conclusion, we clarified that the inhalation of naked pDNA as well as its ternary complex are a useful technique for cancer vaccination.

A novel concept for treatment and vaccination against Covid‐19 with an inhaled chitosan‐coated DNA vaccine encoding a secreted spike protein portion

“…A study by Kodama et al, reveals the practicality of this route by using the luciferase gene to show gene expression in lung tissue by fluorescene intensty 19 . This study revealed that high levels of inhaled DNA vaccine expression can occur in lung tissue as seen by the increase in fluorsecence in lung samples, and in microscopic lung sections 19 . These results indicate that high levels of protein expression may be generated by inhaled DNA for competitive antagonism against coronavirus.…”

“…19 This study revealed that high levels of inhaled DNA vaccine expression can occur in lung tissue as seen by the increase in fluorsecence in lung samples, and in microscopic lung sections. 19 These results indicate that high levels of protein expression may be generated by inhaled DNA for competitive antagonism against coronavirus. A large dose of inhaled chitosan DNA construct or multiple doses can easily be given when symptoms first appear when there is a lower viral load early in infection.…”

“…Currently, there are few studies available using a DNA vaccine by the respiratory route for treatment. A study by Kodama et al, reveals the practicality of this route by using the luciferase gene to show gene expression in lung tissue by fluorescene intensty 19 . This study revealed that high levels of inhaled DNA vaccine expression can occur in lung tissue as seen by the increase in fluorsecence in lung samples, and in microscopic lung sections 19 .…”

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

“…Luciferase activities in the liver and spleen were measured as described above. In vivo imaging was observed as previously reported (Kodama et al., 2020 ).…”

“…A promising strategy to markedly enhance DNA vaccine efficacy is the targeting of a DNA vaccine to APCs (Wang et al, 2011). We previously reported that a ternary complex with DGL containing pUb-M suppressed the lung metastasis of B16-F10 after its pulmonary administration (Kodama et al, 2020). Pulmonary administration is expected to become an appropriate route to extend vaccination coverage because of its more convenient administration and lower risks than routes using needles.…”