Algal based edible vaccines

Abstract

The present invention provides edible vaccines comprising transgenic microalgae expressing at least one exogenous antigen or an intervening organism comprising the transgenic microalgae. The antigen expressing microalgae are used for oral delivery of the antigen to a target organism in its intact and functional form. The exogenous antigen, expressed in the microalgae, is characterized by exerting at least one immunogenic response in the subject consuming the vaccine.

1 . An edible vaccine comprising a transgenic eukaryotic microalga, the transgenic microalga comprising an expression cassette comprising at least one polynucleotide encoding an exogenous antigen, wherein the encoded exogenous antigen is localized within a subcellular compartment of the microalga cell, wherein the subcellular compartment is selected from the group consisting of endoplasmic reticulum, Golgi system, lysosome, and peroxisome. 
     
     
         2 . The edible vaccine of  claim 1 , wherein the subcellular compartment of the transgenic microalga is the cell endoplasmic reticulum (ER), and wherein the expression cassette further comprises a polynucleotide encoding an ER targeting peptide. 
     
     
         3 . The edible vaccine of  claim 1 , wherein the encoded exogenous antigen induces an immune response in a target subject consuming said vaccine against a disease caused by a pathogen. 
     
     
         4 . The edible vaccine of  claim 3 , wherein the vaccine comprises an intervening organism that ingested the transgenic microalgae. 
     
     
         5 . The edible vaccine of  claim 3 , wherein the antigen is from a pathogen that causes a disease in a target subject selected from the group consisting of a fish and a poultry subject. 
     
     
         6 . The edible vaccine of  claim 5 , wherein the target subject is a fish and the pathogen is selected from the group consisting of  Streptococcus iniae, Streptococcus agalactiae, Betanodavirus,  and infectious salmon anemia virus. 
     
     
         7 . The edible vaccine of  claim 5 , wherein the target subject is a poultry subject and the pathogen is  Salmonella enterica.    
     
     
         8 . The edible vaccine of  claim 1 , wherein the microalga is a marine alga. 
     
     
         9 . The edible vaccine of  claim 1 , wherein the microalga is selected from the group consisting of  Phaeodactylum tricornutum, Dunaliella  spp.,  Nannochloropsis  spp.,  Nannochloris  spp.,  Tetraselmis  spp.,  Isochrysis galbana; Pavlova  spp.;  Amphiprora hyaline; Chaetoceros muelleri;  and  Neochloris oleoabundans.    
     
     
         10 . An edible composition comprising the edible vaccine of  claim 1 , further comprising edible diluents, excipients or carriers. 
     
     
         11 . An edible composition comprising the edible vaccine of  claim 4 , further comprising edible diluents, excipients or carriers. 
     
     
         12 . A method for oral delivery of an antigen to a subject in need thereof, the method comprising orally administering to the subject an effective amount of the vaccine of  claim 1 . 
     
     
         13 . A method for oral delivery of an antigen to a target animal subject, the method comprising the steps of:
 (a) orally administering to an intervening organism an effective amount of of the vaccine of  claim 1 ; and
 (b) orally administering to the target animal subject an effective amount of the intervening organism that has ingested the transgenic microalga. 
   
     
     
         14 . An edible vaccine comprising a transgenic eukaryotic microalga, the transgenic microalga comprising an expression cassette comprising at least one polynucleotide encoding an exogenous antigen further comprising a polynucleotide encoding a vacuolar targeting peptide having an amino acid sequence at least 90% homologous to the amino acid sequence set forth in any one of SEQ ID NO:1 and SEQ ID NO:9, wherein the encoded exogenous antigen is localized within the vacuole of the microalga cell, and wherein said encoded exogenous antigen induces an immune response in a target subject consuming said vaccine against a disease caused by a pathogen. 
     
     
         15 . The edible vaccine of  claim 14 , wherein the vaccine comprises an intervening organism that ingested the transgenic microalgae. 
     
     
         16 . The edible vaccine of  claim 14 , wherein the antigen is from a pathogen that causes a disease in a target subject selected from the group consisting of a fish and a poultry subject. 
     
     
         17 . An edible composition comprising the edible vaccine of  claim 14 , further comprising edible diluents, excipients or carriers. 
     
     
         18 . An edible composition comprising the edible vaccine of  claim 15 , further comprising edible diluents, excipients or carriers. 
     
     
         19 . A method for oral delivery of an antigen to a subject in need thereof, the method comprising orally administering to the subject an effective amount of the vaccine of  claim 14 . 
     
     
         20 . A method for oral delivery of an antigen to a target animal subject, the method comprising the steps of:
 (a) orally administering to an intervening organism an effective amount of of the vaccine of  claim 14 ; and   (b) orally administering to the target animal subject an effective amount of the intervening organism that has ingested the transgenic microalga.