Vaccination with human papillomavirus type 16-derived peptides using a tattoo device.

Tattooing has been shown to be very efficient at inducing immunity by vaccination with DNA vaccines. In this study, we examined the usability of tattooing for delivery of peptide vaccines. We compared tattooing with subcutaneous (s.c.) needle injection using peptides derived from human papillomavirus type 16 (HPV16) proteins. We observed that higher peptide-specific immune responses were elicited after vaccination with the simple peptides (E7(44-62) and E7(49-57)) and keyhole limpet hemocyanin-(KLH)-conjugated peptides (E7(49-57), L2(18-38) and L2(108-120)) with a tattoo device compared to s.c. inoculation. The administration of the synthetic oligonucleotide containing immunostimulatory CpG motifs (ODN1826) enhanced the immune responses developed after s.c. injection of some peptides (E7(44-62), KLH-conjugated L2(18-38) and L2(108-120)) to levels close to or even comparable to those after tattoo delivery of identical peptides with ODN1826. The highest efficacy of tattooing was observed in combination with ODN1826 for the vaccination with the less immunogenic E6(48-57) peptide and KLH-conjugated and non-conjugated E7(49-57) peptides which form the visible aggregates that could negatively influence the development of immune responses after s.c. injection but probably not after tattooing. In summary, we first evidenced that tattoo administration of peptide vaccines that might be useful in some cases efficiently induced both humoral and cell-mediated immune responses.

Experimental therapy of HPV16 induced tumors with IL12 expressed by recombinant vaccinia virus in mice.

Recombinant vaccinia viruses derived from strain Praha, clone P13, and strain MVA were used for intratumoral delivery and expression of IL12 genes in tumors induced by HPV16 E6+E7 oncogenes in mice. Intratumoral injection of 10(3) PFU of P13-IL12 virus resulted in an increase of intra-tumoral IL12 on days 6-13, while only low levels of IL12 were found in sera. After the inoculation of 10(6) PFU of MVA-IL12, the same levels of IL12 were found as in animals injected with control virus. The intratumoral inoculation of 10(3) PFU P13-IL12 resulted in only approximately 30% of the tumors being virus positive, which was a consequence of reduced multiplication of the recombinant virus in vivo. The number of virus-positive tumors was not increased by repeated inoculations on three consecutive days. Intratumoral therapy with a dose of 10(3) PFU of P13-IL12 slowed down the growth of TC1 tumors, but never caused their regression. When local P13-IL12 treatment was combined with antigen-specific, DNA-vaccination therapy, no synergy between the two treatments was observed. The treatment with IL12-expressing virus retarded tumor growth to some degree, but did not change the number of regressing tumors. The highest efficacy of intra-tumoral P13-IL12 therapy was observed when the TC-1/A9 cell subline, with downregulated MHC class I expression, was used. TC-1/A9 tumors are less refractory to treatment with 10(3) P13-IL12/EL than are parental TC-1 cells.