遺伝子銃による生体への遺伝子導入 : 原虫感染症に対するDNAワクチン及びサイトカイン遺伝子治療への応用

The particle-mediated method for gene delivery with a gene gun utilizes a shock wave to accelerate DNA-coated gold particles into target cells or tissues. This gene delivery method is effective in various somatic tissues in vitro and in vivo. We have, herein, applied this gene delivery system to DNA vaccine and cytokine gene therapy for protozoan parasite infections. We used cDNA encoding 47 kDa of Plasmodium falciparum serine repeat antigen (SERA) that is a vaccine candidate antigen and did SERA DNA immunization with mice using gene gun. Significant SERA-specific antibodies (Abs) were observed by SERA DNA immunization. Furthermore, these Ab responses were enhanced and regulated by coinoculation of cytokine expression plasmid. For other application, we examined the effects of in vivo IL-12 gene treatment on the course of infection with obligate protozoa, Trypanosoma cruzi. Transfer with IL-12 expression plasmid in vivo regulated systemic immune responses and furthermore this treatment controlled the progression of experimental trypanosomiasis. Therefore, this gene gun approach may be a useful for DNA vaccine and gene therapy in a wide spectrum of diseases other than the protozoan parasite infection.