In vivo monitoring of DNA vaccine gene expression using firefly luciferase as a naked DNA.
The administration of naked DNA into animals is increasing as a research tool to develop DNA vaccine. To monitor the distribution and duration of gene expression of a DNA vaccine in living organisms, we used the naked DNA encoding firefly luciferase (Fluc) as an imaging reporter gene, and evaluated in vivo bioluminescent images in a murine model. We observed bioluminescence at the injection site and at inguinal lymph node from 10h to 24h post-injection when DNA vaccine encoding Fluc (pcDNA3.1-Fluc) was injected into the bilateral posterior flanks in mice. Fluc gene expressions at injection sites and unilateral posterior flank inguinal lymph node were also confirmed by RT-PCR. However, when pcDNA3.1-Fluc was injected into the mid-dorsum bioluminescent signals were observed at the injection site for up to 14 days post-injection, but no bioluminescent signals were detected in inguinal lymph nodes. Concurrent mRNA expressions of Fluc gene at injection sites but not at inguinal lymph nodes were confirmed by RT-PCR. These findings suggest that optical imaging using Fluc could be useful for monitoring the location, intensity and duration of gene expression of naked DNA vaccines in living animals non-invasively and repetitively.
Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.
Yong Hyun
YH
Jeon
Yun
Y
Choi
Joo Hyun
JH
Kang
June-Key
JK
Chung
Yong Jin
YJ
Lee
Chul Woo
CW
Kim
Jae Min
JM
Jeong
Dong Soo
DS
Lee
Myung Chul
MC
Lee
D000818:Animals; D005260:Female; D015870:Gene Expression; D017930:Genes, Reporter; D007091:Image Processing, Computer-Assisted; D049409:Luciferases, Firefly / Q000032:analysis* / Q000235:genetics; D008163:Luminescent Measurements; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology*
D012333:RNA, Messenger; D019444:Vaccines, DNA; D049409:Luciferases, Firefly