Pcv2 immunogenic compositions and methods of producing such compositions

Abstract

An improved method for recovering the protein expressed by open reading frame 2 from porcine circovirus type 2 is provided. The method generally involves the steps of transfecting recombinant virus containing open reading frame 2 coding sequences into cells contained in growth media, causing the virus to express open reading frame 2, and recovering the expressed protein in the supernate. This recovery should take place beginning approximately 5 days after infection of the cells in order to permit sufficient quantities of recombinant protein to be expressed and secreted from the cell into the growth media. Such methods avoid costly and time-consuming extraction procedures required to separate and recover the recombinant protein from within the cells.

1 . An immunogenic composition comprising an effective amount of recombinant PCV2 ORF2 protein, wherein said immunogenic composition is effective for lessening the severity of clinical symptoms associated with a PCV2 infection after a single dose thereof. 
     
     
         2 . The immunogenic composition of  claim 1 , wherein said PCV2 ORF2 protein is selected from the group consisting of:
 i) a polypeptide comprising a sequence selected from the group consisting of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 9, SEQ ID NO: 10, and SEQ ID NO: 11;   ii) any polypeptide that is at least 90% homologous to the polypeptide of i);   iii) a polypeptide that is encoded by a DNA comprising the sequence of SEQ ID NO: 3or SEQ ID NO: 4; and   iv) any polypeptide that is encoded by a polynucleotide that is at least 90% homologous to the polynucleotide of v).   
     
     
         3 . The immunogenic composition of  claim 1 , wherein said composition further comprises an inactivated viral vector. 
     
     
         4 . The immunogenic composition of  claim 3 , wherein said inactivated viral vector is a recombinant baculovirus coding for the PCV2 ORF2 protein. 
     
     
         5 . The immunogenic composition of  claim 1 , wherein said composition further comprises an additional component selected from the group consisting of cell culture supernate, BEI, sodium thiosulfate, carriers, adjuvants, media, viral inactivators, diluents, isotonic agents, immunomodulatory agents, antibiotics, and combinations thereof. 
     
     
         6 . The immunogenic composition of  claim 5 , wherein said adjuvant is selected from the group consisting of acrylic acid, methacrylic acid, and any polymer thereof. 
     
     
         7 . The immunogenic composition of  claim 6 , wherein said adjuvant is a polymer of an acrylic or methacrylic acid and wherein said polymer is cross-linked with polyalkenyl ethers of sugars or polyalcohols. 
     
     
         8 . The immunogenic composition of  claim 1 , wherein said composition further comprises a carbomer. 
     
     
         9 . The immunogenic composition of  claim 8 , wherein said carbomer is present in an amount of about 500 μg to about 5 mg carbomer per dose. 
     
     
         10 . The immunogenic composition of  claim 1 , wherein said composition further comprises a pharmaceutical acceptable salt. 
     
     
         11 . The immunogenic composition of  claim 1 , wherein said immunogenic composition comprises 4-400 μg of recombinant PCV2 ORF2 protein. 
     
     
         12 . The immunogenic composition of  claim 1 , wherein said immunogenic composition is a vaccine. 
     
     
         13 . The immunogenic composition of  claim 1 , wherein the clinical symptoms are selected from the group consisting of lung lesions, nasal shedding, cough, diarrhea, and combinations thereof. 
     
     
         14 . The immunogenic composition of  claim 1 , wherein said 1 dose of said immunogenic composition is formulated to have a volume of at least 1 ml. 
     
     
         15 . The immunogenic composition of  claim 1 , wherein said dose of said composition is retained in a container. 
     
     
         16 . A method of reducing the severity of or the incidence of clinical symptoms of PCV2 infection in a pig after a single dose of an immunogenic composition comprising the step of:
 administering said immunogenic composition to said pig, wherein said immunogenic composition comprises an effective amount of recombinant PCV2 ORF2 protein.   
     
     
         17 . The method of  claim 16 , wherein said clinical symptoms are selected from the group consisting of lung lesions, nasal shedding, cough, diarrhea, and combinations thereof. 
     
     
         18 . The method of  claim 16 , wherein said administration occurs when said pig is about 3 weeks of age. 
     
     
         19 . The method of  claim 16 , wherein said immunogenic composition is administered intramuscularly, subcutaneously, intranasally, orally, or any combination thereof. 
     
     
         20 . The method of  claim 16 , wherein said effective amount of recombinant PCV2 ORF2 is at least 4 μg. 
     
     
         21 . An immunogenic composition comprising at least 2 μg of recombinant PCV2 ORF2 protein, wherein said immunogenic composition is effective for lessening the severity of clinical symptoms associated with a PCV2 infection.