Expression of protective antigens in transgenic chloroplasts and the production of improved vaccines

Abstract

Vaccines for conferring immunity in mammals to infective pathogens are provided, as well as vectors and methods for plastid transformation of plants to produce protective antigens and vaccines for oral delivery. The invention further provides transformed plastids having the ability to survive selection in both the light and the dark, at different developmental stages by using genes coding for two different enzymes capable of detoxifying the same selectable marker, driven by regulatory signals that are functional in proplastids as well as in mature chloroplasts. The invention utilizes antibiotic-free selectable markers to provide edible vaccines for conferring immunity to a mammal against Bacillus anthracis , as well as Yersina pestis . The vaccines are operative by parenteral administration as well. The invention also extends to the transformed plants, plant parts, and seeds and progeny thereof. The invention is applicable to monocot and dicot plants.

1 . An orally-administrable vaccine composition for conferring immunity to  Bacillus anthracis  to a mammal, said vaccine comprising plant material comprising anthrax protective antigen. 
     
     
         2 . The vaccine composition of  claim 1 , wherein said plant material comprises a plant plastid genome having a polynucleotide sequence encoding for anthrax protective antigen. 
     
     
         3 . The vaccine composition of  claim 1 , wherein said plant material comprises a plurality of plant cells homoplasmic with respect to plant plastids transformed to express anthrax protective antigen. 
     
     
         4 . The vaccine composition of  claim 1 , wherein said vaccine composition is heat-stable. 
     
     
         5 . A process for vaccinating a mammal against  Bacillus anthracis  comprising feeding to said mammal an effective amount of the vaccine composition of  claim 1 . 
     
     
         6 . (canceled) 
     
     
         7 . A plant cell homoplasmic with respect to plastids transformed to express anthrax protective antigen. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . An orally-administrable vaccine composition for conferring immunity to  Yershina pestis  to a mammal, said vaccine comprising plant material comprising V and F1 antigens of  Y. pestis.    
     
     
         14 . The vaccine composition of  claim 13 , wherein said plant material comprises a plant plastid genome having a genetic sequence encoding for V and F1 antigens of  Y. pestis.    
     
     
         15 . The vaccine composition of  claim 13 , wherein said plant material comprises a plurality of plant cells homoplasmic with respect to plant plastids transformed to express V and F1 antigens of  Y. pestis.    
     
     
         16 . The vaccine composition of  claim 13 , wherein said vaccine composition is heat-stable. 
     
     
         17 . A process for vaccinating a mammal against  Yershina pestis  comprising feeding to said mammal an effective amount of the vaccine composition of  claim 13 . 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . The composition of  claim 1 , wherein said vaccine is free of both anthrax edema factor and anthrax lethal factor.