Immunogenic composition
An immunogenic composition includes as an effective ingredient an antigen-adjuvant microparticle complex containing an antigen encapsulated in an adjuvant microparticle composed of an amphiphilic polymer(s) whose hydrophobic segment is a poly(hydroxy acid), or a particle composed of the antigen-adjuvant microparticle complex associated together, can induce a high immune response against the antigen even with a small amount of the antigen and a small number of doses, so that the immunogenic composition is useful as a vaccine effective for therapy and prophylaxis of infectious diseases, cancer and the like.
1. A method comprising administering an effective amount of an immunogenic composition comprising an antigen-adjuvant microparticle complex containing an antigen encapsulated in an adjuvant microparticle composed of an amphiphilic graft copolymer(s) comprising a poly(hydroxyl acid) as a hydrophobic graft segment and a polysaccharide as a hydrophilic backbone segment, wherein the number of poly(hydroxyl acid) graft chains of the amphiphilic graft copolymer is 2 to 50, to a living body, and
inducing an immune response in the living body.
2. The method according to claim 1 , comprising as an effective ingredient a particle composed of said antigen-adjuvant microparticle complex associated together.
3. The method according to claim 1 , wherein said adjuvant microparticle has a hydrophilic portion in the inside thereof, said hydrophilic portion being composed of a hydrophilic segment of said amphiphilic polymer, and has an outer layer composed of a hydrophobic portion constituted by said hydrophobic segment of said amphiphilic polymer.
4. The method according to claim 1 , wherein said polysaccharide is dextran.
5. The method according to claim 1 , wherein said poly(hydroxy acid) is a poly(lactic-co-glycolic acid).
6. The method according to claim 1 , further comprising a surface modifier bound to said poly(hydroxy acid) of said adjuvant microparticle.
7. The method according to claim 1 , wherein the average particle size of said antigen-adjuvant microparticle complex or said particle composed of said antigen-adjuvant microparticle complex associated together is 0.1 to 50 μm.
8. The method according to claim 1 , further comprising an immune-activating substance as an effective ingredient.
9. The method according to claim 8 , wherein said immune-activating substance is a nucleic acid.
10. The method according to claim 8 , wherein said immune-activating substance is CpG.
11. The method according to claim 9 , wherein said immune-activating substance is CpG.
12. The method according to claim 2 , wherein said adjuvant microparticle has a hydrophilic portion in the inside thereof, said hydrophilic portion being composed of a hydrophilic segment of said amphiphilic polymer, and has an outer layer composed of a hydrophobic portion constituted by said hydrophobic segment of said amphiphilic polymer.
13. The method according to claim 2 , wherein said poly(hydroxy acid) is a poly(lactic-co-glycolic acid).
14. The method according to claim 3 , wherein said poly(hydroxy acid) is a poly(lactic-co-glycolic acid).
15. The method according to claim 4 , wherein said poly(hydroxy acid) is a poly(lactic-co-glycolic acid).
16. The method according to claim 2 , further comprising a surface modifier bound to said poly(hydroxy acid) of said adjuvant microparticle.
17. The method according to claim 3 , further comprising a surface modifier bound to said poly(hydroxy acid) of said adjuvant microparticle.
18. The method according to claim 1 , wherein said inducing the immune response is vaccination or prevention in a living body of infectious diseases or cancer.
19. A method of inducing an immune response in a cell comprising applying an effective amount of composition comprising an antigen-adjuvant microparticle complex containing an antigen encapsulated in an adjuvant microparticle composed of an amphiphilic graft copolymer(s) comprising a poly(hydroxyl acid) as a hydrophobic graft segment and a polysaccharide as a hydrophilic backbone segment, wherein the number of poly(hydroxyl acid) graft chains of the amphiphilic graft copolymer is 2 to 50, to a living body.