Gene expression vaccine

Abstract

An effective prophylactic mucosal gene expression vaccine (GXV), made up of a cocktail of at least 4 different plasmid DNAs encoding corresponding RSV antigens, coacervated with chitosan to formulate nanospheres. In a murine model of RSV infection, intranasal administration with GXV results in significant induction of RSV-specific antibodies, nasal IgA antibodies, cytotoxic T lymphocytes, and IFN-γ production in the lung and splenocytes. A single dose of GXV induces a drastic reduction of viral titers.

Description

[0001] This application claims priority from U.S. Ser. No. 60 / 325,573, filed Sept. 28, 2001.FIELD OF THE INVENTION [0002] The invention relates generally to gene expression vaccines. More specifically, the invention relates to gene expression vaccines that can be administered intra-nasally or orally. BACKGROUND [0003] The respiratory syncytial virus (RSV) is the most common cause of viral lower respiratory tract infections in infants and children, affecting about 4 million children globally and leading to about 100,000 hospitalizations and 4,500 deaths per annum in the United States alone. RSV infection is associated with recurrent episodes of bronchiolitis, bronchial obstruction and exacerbation of asthma in children. Incidence of RSV infection-induced bronchiolitis has been increasing. There is no effective prophylaxis available against RSV infection. Previous attempts to develop a vaccine using a formalin-inactivated RSV vaccine not only failed but also exacerbated the disease wh...

AI Technical Summary

Benefits of technology

[0008] The present invention provides gene expression vaccine (GXV) comprising a cocktail of plasmid DNAs encoding corresponding RSV antigens in the form of chitosan nanospheres. In a first embodiment, the cocktail contains a combination comprising the F, G and at least one of the M, M2, SH, NS1, NS2, N, and P RSV antigens. In an alternative embodiment, the cocktail is a combination comprising the M2 and at least one of the F, G, M, SH, NS1, NS2, N, and P RSV antigens. In a further alternative embodiment, the cocktail contains a combination comprising the F, G, M2 and at least one of the M, SH, NS1, NS2, N, and P RSV antigens: The GXV is safe and effective against RSV, significantly attenuates pulmonary inflammation induced by RSV infection, and can be administered intra-nasally or orally. Not to be limited by theory, and although the precise cellular and molecular mechanisms for the effectiveness of GXV remain to be investigated, it is likely that the route, the combination of immunogenic antigens, and / or the conjugation with chitosan contribute to its effectiveness.

[0017] In a further embodiment, the vaccine induces increases in specific IgG titers, nasal IgA titers, and enhances IFN-γ production in both lung as well as spleen tissues.

Problems solved by technology

There is no effective prophylaxis available against RSV infection.

Previous attempts to develop a vaccine using a formalin-inactivated RSV vaccine not only failed but also exacerbated the disease when subsequent RSV infection occurred.

Further, development of therapy against RSV has been limited by the short incubation period.

However, the quantity of DNA used per unit bodymass and the route chosen might make these vaccines unsuitable for human use.

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