Adjuvant compositions

Abstract

The present invention provides methods and compositions for the stimulation of immune responses. In particular, the invention provides methods and compositions for enhancing an immune response to one or more antigens. Compositions and methods of the invention are useful for the treatment and/or prevention of microbial infections, such as infections caused by bacteria, viruses, fungi, and parasites, as well as the treatment and/or prevention of cancer and malignant diseases. Compositions and methods of the invention include one or more antigens/immunogens together with an adjuvant formulation comprising an emulsion delivery system in combination with one or more immunostimulatory compounds (e.g., a compound that stimulates the innate immune system (e.g., a toll-like receptor antagonist (e.g., synthetic oligodeoxynucleotides (ODN)))) that enhance immune responses to the one or more antigens/immunogens when administered to a subject. Compositions and methods of the invention find use in, among other things, clinical (e.g. therapeutic and preventative medicine (e.g., vaccination)) and research applications.

What is claimed is: 
     
         1 . An adjuvant composition for modulating an immune response to an antigen administered to a host, the composition comprising:
 (a) a nanoemulsion adjuvant; and (b) at least one immunostimulatory compound.   
     
     
         2 . The adjuvant composition of  claim 1 , wherein the immunostimulatory compound is a compound that stimulates the innate immune system. 
     
     
         3 . The adjuvant composition of  claim 2 , wherein the immunostimulatory compound is a toll-like receptor antagonist. 
     
     
         4 . The adjuvant composition of  claim 1 , wherein the immunostimulatory compound is a synthetic oligodeoxynucleotide (ODN). 
     
     
         5 . The adjuvant composition of  claim 4 , wherein the synthetic ODN contains a CpG motif. 
     
     
         6 . The adjuvant composition of  claim 1 , wherein the immunostimulatory compound is a saponin. 
     
     
         7 . The adjuvant composition of  claim 6 , wherein the saponin is a triterpene glycoside saponin. 
     
     
         8 . The adjuvant composition of  claim 7 , wherein the triterpene glycoside saponin is QS-21. 
     
     
         9 . An immunogenic composition for eliciting an immune response in a subject comprising:
 (a) one or more antigens; (b) a nanoemulsion adjuvant; and (c) at least one immunostimulatory compound.   
     
     
         10 . The immunogenic composition of  claim 9 , wherein the one or more antigens are selected from an inactivated microbial pathogen, an isolated and/or recombinant peptide, an isolated and/or recombinant protein, a glycoprotein, a lipoprotein, a glycopeptide, a lipopeptide, a toxoid, a carbohydrate, and a tumor-specific antigen. 
     
     
         11 . The immunogenic composition of  claim 9 , wherein the nanoemulsion comprises oil, water, an organic solvent, a cationic surfactant, and an nonionic surfactant. 
     
     
         12 . The immunogenic composition of  claim 9 , wherein the immunostimulatory compound is a toll-like receptor antagonist. 
     
     
         13 . The immunogenic composition of  claim 9 , wherein the immunostimulatory compound is a synthetic oligodeoxynucleotide (ODN). 
     
     
         14 . The immunogenic composition of  claim 13 , wherein the synthetic ODN contains a CpG motif. 
     
     
         15 . The immunogenic composition of  claim 9 , wherein the immunostimulatory compound is a saponin. 
     
     
         16 . The immunogenic composition of  claim 15 , wherein the saponin is a triterpene glycoside saponin. 
     
     
         17 . The adjuvant composition of  claim 16 , wherein the triterpene glycoside saponin is QS-21. 
     
     
         18 . A method of generating an immune response in a subject comprising administering to the subject an immunogenic composition comprising:
 (a) one or more antigens; (b) a nanoemulsion adjuvant; and (c) at least one immunostimulatory compound.   
     
     
         19 . The method of  claim 18 , wherein the immune response is greater than the immune response generated in a subject administered a composition containing the one or more antigens and only the nanoemulsion adjuvant, and/or is greater than the immune response generated in a subject administered a composition containing the one or more antigens and only the immunostimulatory compound. 
     
     
         20 . The method of  claim 19 , wherein the immune response is synergistically greater.