Exosome-targeted dna vaccine

Abstract

In order to further increase antigenicity to provide a DNA vaccine which is clinically usable in humans, the inventors of the present invention focused on exosomes, which are garnering attention as tools for DDS, and discovered that an exosome expressing a fusion antigen of an exosome (extracellular microparticle)-constituent protein and a vaccine antigen has excellent cytotoxic T-cell inducibility. Consequently, the present invention provides a nucleic acid constituent including a nucleic acid sequence coding for an exosome marker protein and a nucleic acid sequence coding for a vaccine antigen.

1 . A nucleic acid construct comprising a nucleic acid sequence encoding an exosome marker protein and a nucleic acid sequence encoding a vaccine antigen. 
     
     
         2 . The nucleic acid construct of  claim 1 , wherein the exosome marker protein is a protein that is present in a membrane of an exosome. 
     
     
         3 . The nucleic acid construct of  claim 1 , wherein the exosome marker protein belongs to the tetraspanin family. 
     
     
         4 . The nucleic acid construct of  claim 1 , wherein the exosome marker protein is selected from the group consisting of CD63, CD81, CD9, CD31, HLA-G, TSG101, Rab5b, and ALIX. 
     
     
         5 . The nucleic acid construct of  claim 1 , wherein the exosome marker protein is selected from the group consisting of CD63, CD81, and CD9. 
     
     
         6 . The nucleic acid construct of  claim 1 , wherein the antigen is selected from a cancer antigen and a viral antigen. 
     
     
         7 . The nucleic acid construct of  claim 1 , which is a plasmid DNA. 
     
     
         8 . A DNA vaccine comprising the nucleic acid construct of  claim 1 . 
     
     
         9 . The DNA vaccine of  claim 8  for improving Th1-type immunity induction. 
     
     
         10 . The DNA vaccine of  claim 9 , characterized in targeting cancer or a viral disease. 
     
     
         11 . A protein in a form of a vaccine antigen protein fused with an exosome marker protein. 
     
     
         12 . An exosome comprising a vaccine antigen protein and an exosome marker protein in a fused form. 
     
     
         13 . An immune response enhancer comprising the nucleic acid construct of  claim 1 . 
     
     
         14 . A composition for enhancing a T cell response comprising the protein of  claim 11 . 
     
     
         15 . A cytotoxic agent comprising the exosome of  claim 12 . 
     
     
         16 . A medicament comprising one of: (a) a nucleic acid construct comprising a nucleic acid sequence encoding an exosome marker protein and a nucleic acid sequence encoding a vaccine antigen; (b) a protein in a form of a vaccine antigen protein fused with an exosome marker protein; or (c) an exosome comprising a vaccine antigen protein and an exosome marker protein in a fused form. 
     
     
         17 . A medicament for treating or preventing cancer, comprising the medicament of  claim 16 . 
     
     
         18 . A method of enhancing an immune response in a subject, comprising administering to the subject an effective amount of a composition that comprises at least one of: (a) a nucleic acid construct comprising a nucleic acid sequence encoding an exosome marker protein and a nucleic acid sequence encoding a vaccine antigen; (b) a protein in a form of a vaccine antigen protein fused with an exosome marker protein; and (c) an exosome comprising a vaccine antigen protein and an exosome marker protein in a fused form. 
     
     
         19 . A method of enhancing a T cell response, comprising administering to a subject an effective amount of a composition that comprises at least one of: (a) a nucleic acid construct comprising a nucleic acid sequence encoding an exosome marker protein and a nucleic acid sequence encoding a vaccine antigen: (b) a protein in a form of a vaccine antigen protein fused with an exosome marker protein; and (c) an exosome comprising a vaccine antigen protein and an exosome marker protein in a fused form. 
     
     
         20 . A method of treating or preventing cancer, comprising administering to a subject an effective amount of a composition that comprises at least one of: (a) a nucleic acid construct comprising a nucleic acid sequence encoding an exosome marker protein and a nucleic acid sequence encoding a vaccine antigen: (b) a protein in a form of a vaccine antigen protein fused with an exosome marker protein; and (c) an exosome comprising a vaccine antigen protein and an exosome marker protein in a fused form. 
     
     
         21 . A composition for improving immunogenicity of a vaccine DNA, comprising a nucleic acid sequence encoding an exosome marker protein. 
     
     
         22 . The composition of  claim 21 , wherein the exosome marker protein is a protein that is present in a membrane of an exosome. 
     
     
         23 . The composition of  claim 21 , wherein the exosome marker protein belongs to the tetraspanin family. 
     
     
         24 . The composition of  claim 21 , wherein the exosome marker protein is selected from the group consisting of CD63, CD81, CD9, CD31, HLA-G, TSG101, Rab5b, and ALIX. 
     
     
         25 . The composition of  claim 21 , wherein the exosome marker protein is selected from the group consisting of CD63, CD81, and CD9. 
     
     
         26 . The composition of  claim 21 , wherein an antigen contained in the vaccine DNA is selected from a cancer antigen and a viral antigen. 
     
     
         27 . The composition of  claim 21 , wherein the vaccine DNA is a plasmid DNA.