Distribution And Safety Studies Of IBV DNA Vaccine And DNA/Cationic Liposome Complex

With the development of DNA vaccine, scientists paid more attention to the distribution and safety studies of DNA vaccines.This research provided scientific datas for the applying of IBV DNA vaccine and DNA/Catiomc liposome complex.In order to evaluate the distribution and safety of IBV DNA vaccine and DNA/Cationic liposome complex which were constructed and prepared in our lab, DNA vaccine was injected into 7-day-old health chickens via i.m. administration and DNA/Cationic liposome complex was injected via i.m. administration and intranasal or in eyes administration respectively at the same time. Blood and different tissue samples were collected for distribution and integration studies by PCR method. In toxicity studies, DNA/Cationic liposome complex was administered by i.m. administration and intranasal or in eyes administration to 1-day-old health chickens, 7-day-old health chickens was injected by repeated intramuscular dose for a week, five times as many as common dose(hyper-dose) was injected via i.m. administration at the same time. Mortality and clinical signs were observed and any deviations from normal were recorded during this experiment, at 48h after injection and 30-day-old, hematology, blood chemistry and histopathology were analyzed.Results of distribution studies showed that three plasmid DNA can be detected both in blood and different tissues at 24h after injection which indicated that IBV DNA vaccine and DNA/Cationic liposome complex can rapidly distribute in vivo within 24h, it can persist in various tissues and blood up to 90 days. At 120d after injection, plasmid DNA can't be detected in blood and plasmid pIBVS1 can't be detected both in blood and tissues in all test groups. In DNA vaccine group, Plasmid pIBVM, pIBVN only can be detected from heart, lung, kidney, thymus and muscles of injected site; intramuscularly DNA/Cationic liposome complex can be detected from heart, spleen, lung, kidney and muscles of injected site; DNA/Cationic liposome complex injected by intranasal or in eyes administration can be detected from all test tissues besides heart and liver.