Major Step Forwards For Vaccine Against Cervical Cancer

Cervical cancer is caused by a virus. The vaccines against cervical cancer induce an immune response to proteins from this virus, rendering it harmless. Laboratory animals which had already developed a tumour, could be treated with a vaccination.

Human papillomavirus (HPV) is the virus responsible for cervical cancer. More than one hundred types of the virus are known. Some of these are high-risk types of HPV, which can convert healthy cells into cancer cells. Proteins E6 and E7 from the virus are responsible for this and are an ideal target for treatment because they only occur in malignant cells. The vaccine developed by Bungener, induces a specific immune response against these two proteins.

To test the vaccine, Bungener administered two different vaccines to mice. The 'recombinant Semliki Forest virus' and virosomes from the flu virus. The 'recombinant Semliki Forest virus' induces the production of proteins E6 and E7. The virosomes from the flu virus contain the E7 protein.

Both vaccines induced an immune response in mice against these proteins. During the immune response, the animals produce cytotoxic T-lymphocytes that are specific for E6 and E7 and prevent the tumour from growing further. Even mice that already had a tumour could be treated with a vaccination of the 'recombinant Semliki Forest virus'.

Bungener also investigated the mechanism underlying the vaccinations by using model proteins in 'recombinant Semliki Forest virus' and in the virosomes.

The research was funded by the Netherlands Organisation for Scientific Research.