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DNA vaccines represent a promising technology that uses DNA to encode the antigen(s) of interest, instead of inoculating with attenuated or inactivated microbes or isolated antigens. The cells containing DNA vaccines express the antigen and present it to the recipient's immune system. DNA vaccines have many potential advantages. No unsafe unfectious agents are involved and they can induce both humoral and cytotoxic T cell responses, even without replication. There is a potential for encoding multiple immunogenic epitopes with the purpose of raising protection against several diseases by a single vaccine. DNA vaccines may be manufactured quickly and easily, and they are relatively stable. Therefore, for clinical trials, the U.S. FDA (Food and Drug Administration) has provided manufacturers with guidance on toxicology studies. Among these recommended studies are repeated-dose toxicology, biodistribution, and integration analyses.
A Hantaan virus DNA vaccine has been tested in vivo for immunogenicity, and got a satisfied result [5, 6, 11]. Thus, it provides a very good perspective for preventing Hemorrhagic fever with renal syndrome (HFRS). HFRS, caused by Hantaan virus (family Bunyaviridae, genus Hantavirus), is a rodent-borne zoonosis widely distributed over China, particularly in the northeast part of China. It is characterized by a period of fever, hemorrhagic manifestations and renal impairment. As of now, there is no effective treatment.
In this study, we constructed a Hantaan virus DNA vaccine containing an S antigen gene fragment coding Hantavirus strain 76-118 nucleocapsid protein (NP) and observed the kinetics of the fusion protein generated following intramuscular delivery of pEGFP/S in mice and examined the persistence of the plasmid in several organs (liver, lung, kidney, spleen, brain and local muscle) we hope the study will conduce to the research of DNA vaccine pharmacokinetics and HFRS pathogenic mechanism[9].
In Vivo Kinetics and Biodistribution of a Hantaan Virus DNA Vaccine after Intramuscular Injection in Mice
- Received Date: 30 September 2009
- Accepted Date: 08 March 2010
Abstract: To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine, pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGFP. In this report, we provide evidence that pEGFP/S was distributed and persistently expressed for more than 60 days in several organs after inoculation. Our findings suggest that the persistent immune responses induced by a Hantaan virus DNA vaccine are likely due to the plasmid pEGFP/S deposited in vivo, which acts as a booster immunization.