Nucleic acid construct encoding a processing component derived from the N-terminal region of the hepatitis virus ORF2, and an antigenic polypeptide

A method for enhancing, in an animal, an immune response to a viral capsid polypeptide, said method comprising administering to said animal an effective amount of a composition comprising a nucleic acid construct encoding a fusion protein comprising a processing component and said capsid polypeptide wherein said processing component is encoded by a sequence of nucleotides substantially as set forth in SEQ ID NO:

• 5 or SEQ ID NO:
• 6 or a functional derivative, variant, part or homologue thereof and provides heterogenous processing of said capsid protein and a resulting enhancement of the immune response thereto.

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding a processing peptide which enhances an immune response to an antigenic polypeptide of interest in a host when said nucleic acid molecule is expressed in a host cell as a fusion protein comprising the processing peptide and the antigenic polypeptide.

An isolated nucleic acid molecule comprising a sequence of nucleotides encoding a processing peptide which provides heterogeneous processing of an antigenic polypeptide of interest when said nucleic acid molecule is expressed in a host cell as a fusion protein comprising the processing peptide and the antigenic polypeptide.

An isolated nucleic acid construct comprising a sequence of nucleotides encoding a fusion protein comprising a processing component and at least one antigenic component, said processing component comprising a sequence of amino acids substantially as set forth in SEQ ID NO:

• 2 or SEQ ID NO:
• 3 wherein said processing component provides heterogenous processing of the antigenic polypeptide component when the nucleic acid construct is expressed in a host cell and a resulting in enhancement of the immune response to the antigenic polypeptide.