Norovirus and Sapovirus antigens
Immunogenic compositions that elicit immune responses against Norovirus and Sapovirus antigens are described. In particular, the invention relates to polynucleotides encoding one or more capsid proteins or other immunogenic viral polypeptides from one or more strains of Norovirus and/or Sapovirus, coexpression of such immunogenic viral polypeptides with adjuvants, and methods of using the polynucleotides in applications including immunization and production of immunogenic viral polypeptides and viral-like particles (VLPs). Methods for producing Norovirus- or Sapovirus-derived multiple epitope fusion antigens or polyproteins and immunogenic compositions comprising one or more immunogenic polypeptides, polynucleotides, VLPs, and/or adjuvants are also described. The immunogenic compositions of the invention may also contain antigens other than Norovirus or Sapovirus antigens, including antigens that can be used in immunization against pathogens that cause diarrheal diseases, such as antigens derived from rotavirus.
1. A method for producing viral-like particles (VLPs), the method comprising:
a) transforming a host cell with an expression vector comprising a recombinant polynucleotide comprising the nucleotide sequence of SEQ ID NO:2;
b) culturing the transformed host cell under conditions whereby capsid proteins are expressed and assembled into VLPs.
2. The method of claim 1 , further comprising transforming said host cell one or more sequences encoding a structural protein from a Norovirus or Sapovirus.
3. The method of claim 1 , wherein said expression vector further comprises one or more ORF1- and/or ORF3-encoding sequences from a Norovirus or Sapovirus.
4. The method of claim 1 , further comprising transforming the host cell with an additional expression vector comprising a sequence encoding an adjuvant.
5. The method of claim 4 , wherein said adjuvant is a detoxified mutant of an E. coli heat-labile toxin (LT) selected from the group consisting of LT-K63 and LT-R72.
6. The method of claim 1 , wherein the host cell is a yeast or insect cell.
7. The method of claim 1 , wherein the expression vector is an alphavirus vector.