Production of antigenic protein

PURPOSE: To transform a host cell following incorporating it with a DNA transport medium containing part or the whole of HBV genome followed by proliferating the recombinant host cell so as to intend the maintenance, expression and replication of the genetically genuine strain of the HBV genome or its fraction. CONSTITUTION: A DNA transport medium consisting of a plasmid having a nucleotide sequence encoding a protein composed of hepatitis B surface antigen sequence and the sequence lying just before the above sequence and having 174 amino acid on the end, or an immunologically active peptide component of the above protein, but virtually free from a nucleotide sequence encoding hepatitis B nuclear antigen, is provided. A host cell is transformed by the above medium followed by selecting a host cell strain capable of maintaining, replicating and expressing the above medium and then proliferating the selected host cell under conditions suitable for the proliferation. Thereby, the nucleotide sequence encoding at least part of hepatitis B surface antigen and the preceding sequence containing the 174 amino acid on the end can be maintained, replicated and expressed. COPYRIGHT: (C)1990,JPO