Preclinical development of highly effective and safe DNA vaccines directed against XXXX E6 and E7.

@entity5 @entity1457 @entity189 @entity379 @entity1799 @entity1082 @entity116
To allow vaccination irrespective of HLA type, DNA vaccines encoding full-length antigens are required. However, here, we demonstrate that the immunogenicity of DNA vaccines encoding the full-length @entity1082 ) @entity1799 E7 and E6 proteins is highly reduced compared to vaccines encoding only the immunodominant epitope. Furthermore, the low remaining immunogenicity is essentially lost for both E7 and E6 when a nononcogenic "gene-shuffled" variant is utilized. To address these issues, we tested whether alterations in transgene design can restore the immunogenicity of full-length and gene-shuffled DNA vaccines. Remarkably, genetic fusion of E7 with @entity116 toxin fragment C (TTFC) resulted in a dramatic increase in immunogenicity both for the full-length and the gene-shuffled version of E7. Moreover, the TTFC fusion vaccines were more immunogenic than a vaccine encoding a fusion of E7 and mycobacterial @entity1457 protein-70, which has recently been tested in a clinical trial. Interestingly, vaccination with these TTFC fusion vaccines also resulted in extremely persistent T-cell responses. The E7-specific CD8(+) T cells induced by TTFC fusion vaccines were functional in terms of @entity379 production, formation of immunological memory, in vivo cytolytic activity and @entity5 eradication. Finally, we show that genetic fusion with TTFC also improves the immunogenicity of a gene-shuffled E6 DNA vaccine. These data demonstrate that genetic fusion with @entity116 toxin fragment C can dramatically improve the immunogenicity of full-length and gene-shuffled DNA vaccines. The DNA fusion vaccines developed here will be evaluated for the treatment of @entity189 in future studies.
