DNA Vaccines Delivered By Microneedle and Tattoo Gun Induce Protective Immune Responses to Hla-A2.1 Restricted CRPV E1 and HPV16e7 Epitopes in HLA-A2.1 Transgenic Rabbits

How to cite this article Hu J, Bounds CE, Budgeon LR, Cladel NM, Balogh K and Christensen ND. DNA Vaccines Delivered By Microneedle and Tattoo Gun Induce Protective Immune Responses to Hla-A2.1 Restricted CRPV E1 and HPV16e7 Epitopes in HLA-A2.1 Transgenic Rabbits. SM Vaccine Vaccin. 2016; 2(1): 1017. OPEN ACCESS Gene gun delivery of DNA vaccines has proven to be effective for protective and therapeutic immunization in various animal models. However, gene gun vaccine components are expensive, and maintenance and repairs for the gene gun are costly. Two novel delivery methods – the tattoo gun and microneedle have been reported promising for DNA vaccination. Tattoo gun allows for direct application of the DNA vaccine to the skin followed by electronic stimulation, and microneedle is noninvasive and generates minimal pain in the host. However, these two delivery systems have not been tested in the rabbit model before. In the current study, we performed experiments comparing these three vaccination strategies using two HLA-A2.1 restricted epitope DNA vaccines (HPV16E7/82-90 and CRPVE1ep1-5 epitope), which have been previously shown to generate robust protective immunity via gene gun delivery. In the first study, we compared gene gun with tattoo gun side by side using the HPV16E7/82-90 DNA vaccine. Comparative protection was found in these two methods. In the second experiment, we compared microneedle with tattoo gun delivery using the CRPVE1ep1-5 epitope DNA vaccine. DNA vaccination by both tattoo gun and microneedle resulted in significantly smaller tumors when compared with those of the control group [P<0.05, one way ANOVA analysis]. In vivo killing assay demonstrated that animals immunized via both microneedle and tattoo gun showed increased specific killing to the epitope presenting cells. These data indicate that DNA vaccination via microneedle and tattoo gun is simple, useful, and costeffective alternative to the gene gun and produces comparable results. Introduction