Type Of Media：バイオ工学系専門誌
Publication/Magazine/Media：日経バイオテク
Naked mRNA vaccine induces immunity in primates, iCONM lab head Uchida and colleagues confirm.
Summary:
The research group led by Satoshi Uchida (Professor, Tokyo Medical and Dental University), belonging to R&D Theme 2, confirmed the immune-inducing effects of a naked mRNA vaccine against the novel coronavirus (SARS-CoV-2) in mice and primates, without using lipid nanoparticles (LNP). This study was published on April 3, 2024, in the journal Molecular Therapy.
Conventional mRNA vaccines utilize LNPs to effectively deliver the mRNA to immune cells and enhance the immune response, but side effects such as fever and swelling have been reported. Therefore, the research group developed a naked mRNA vaccine that can be administered directly to the skin without LNPs. Using a jet injector, they administered mRNA coding for a model antigen to mice, confirming antibody production effects comparable to those of LNPs. They also successfully induced CD4-positive and CD8-positive T cells.
In mice that were administered SARS-CoV-2, those that had previously received the naked mRNA vaccine showed significantly lower viral loads in the lungs and reduced pneumonia symptoms. Additionally, efficacy was demonstrated in macaques without significant side effects. Although the naked mRNA remained at the injection site, it was observed that antigen-presenting cells migrated to the lymph nodes, which is believed to contribute to the vaccine's effect.
It is also suggested that the temporary inflammation caused by the jet injector may have functioned as a "physical adjuvant," enhancing the immune response by attracting lymphocytes.
http://bio.nikkeibp.co.jp/atcl/news/p1/24/04/04/11769/
http://doi.org/10.1016/j.ymthe.2024.03.022
