Figure 1. Construction of DNA vaccines pCTLA4-E7E6 and pE7E6.

HPV16 E7 gene was fused with E6 gene. The fusion gene was optimized with human biased codons. (A) Mutation introduced into HPV16 E7 and E6 to disrupt transformation activity are labeled in the schema. ²⁴C, ²⁶E and ⁹¹C of E7 and ⁶³C and ¹⁰⁶C of E6 (arrows) were mutated to glycine. (B) pE7E6 was constructed by cloning the modified E7E6 fusion gene into pVAX1 vector at Kpn I and Not I restriction sites. pCTLA4-E7E6 encodes the signal peptide and extracellular domains of CTLA4, the hinge and Fc region of human IgG1, and the E7E6 fusion gene.