[Construction and immunological analysis of a combined multi-epitope vaccine against EGFR/HER2]

A recombinant plasmid pET28a-HBcAg-delta n was constructed, in which three mimic B-epitopes of HER family were inserted into the truncated HBc vector. The fusion protein expressed was purified and used to immunize BALB/c mice to induce antibody against the epitopes. Three mimic epitope genes were inserted into the sequences of amino acid residues 78 and 79 of HBcAg by overlap PCR. The PCR product was then cloned into pET28a to construct recombinant expression plasmid which was transformed to E. coli BL21 (DE3) and induced by IPTG. After purification, the fused protein designed HBHE was used to immunize BALB/c mice to detect humoral immunoresponse. The recombinant plasmid was successfully constructed by DNA sequencing analysis. A fusion protein with correct molecular mass was expressed and confirmed by SDS-PAGE. High titre antibody was elicited in the mice immunized with HBHE by indirect ELISA and Western blotting. The HBc particle vector containing three B-epitopes of HER family had been successfully prepared, purified and high titre antibody against HBHE was detected. All these data are helpful in further research of the broad-spectrum anti-tumour effect of combine polypeptide epi-position vaccine of EGFR and HER2.