Experimental vaccine against cervical cancer successfully tested

Cervical cancer vaccine successfully tested on mice

According to health experts, around 4,500 women in Germany contract cervical cancer each year. Researchers have now developed a therapeutic vaccine designed to combat human papillomavirus (HPV) -related cancer. This has already been achieved in animal experiments.

One of the most common cancers in women

Cervical cancer is the third most common cancer in women worldwide, reports the German Cancer Research Center (DKFZ) in a recent release. In Germany alone, around 4,540 women fall ill with it, reports the German Cancer Society on its portal. DKFZ scientists have developed a therapeutic vaccine designed to combat human papillomavirus (HPV) -related cancer. This has already been achieved in mice. The aim is to develop a vaccine for people who are already ill and therefore no longer benefit from a vaccine.

Human papillomavirus can cause cervical cancer. Researchers have now successfully tested an experimental vaccine against this cancer in mice. (Image: Dr. Kateryna / fotolia.com)

Human papillomaviruses

Cervical cancer is usually caused by human papillomavirus (HPV), which infects the mucosal cells and proliferate uncontrollably.

In addition, HPV infection can lead to anal cancer and oropharyngeal cancers.

To protect against the carcinogenic viruses vaccines are available that prevent infection.

However, this HPV vaccine does not work in people who have already come into contact with the virus.

In addition, the HPV vaccination rates are low.

Although the Standing Vaccination Commission (STIKO) has been recommending the HPV vaccine for girls for years - and now also for boys - in Germany less than half of the 17-year-old girls are vaccinated against HPV.

Therapeutic vaccine for the treatment of cancer patients

"Our goal is to develop a therapeutic vaccine that can treat people who already have HPV infection and possibly even HPV-related cancer or precancerous lesions," said Angelika Riemer from the DKFZ.

"A therapeutic vaccine stimulates the immune system to target and kill infected or degenerate cells."

According to the information, at the time of vaccination, one of the most important differences between vaccination and therapeutic vaccination is: the former only works if it is already given before an infection.

By contrast, a therapeutic vaccination can treat existing infections and their consequences.

Another difference between vaccination and therapeutic vaccination is the response of the immune system: after a vaccination, the body produces antibodies that protect it from future infection with the appropriate pathogen.

On the other hand, a therapeutic vaccine causes cytotoxic T cells to get on the scene. These immune cells are able to recognize tiny molecular structures of the papillomavirus, called epitopes, on the surface of infected cells or cancer cells and thereby kill the cells identified as suspicious.

In half of the vaccinated animals the tumors disappeared completely

Riemer and her colleagues have already shown in mice that their experimental therapeutic vaccine is effective against HPV-related cancers.

Their results were published in the journal "OncoImmunology".

"In half of the vaccinated mice, the tumors disappeared completely," says the DKFZ researcher.

As stated in the communication, the vaccine contains as its key component the epitopes that also carry the HPV-induced tumor on its surface.

These protein structures are transported to the lymph nodes after vaccination. "This is especially efficient in triggering an immune response, because it contains all the immune cells that are needed for a defensive reaction," Riemer explained.

Decisive in this case are the cytotoxic T cells. If they come in contact with the epitopes from the vaccine, this is the signal for them to scan the rest of the body for cells that also carry these recognition molecules.

If they then encounter cancer cells carrying these HPV epitopes on the surface, the cytotoxic T cells kill them.

Effectiveness must be even better

Currently, the therapeutic vaccine against cervical cancer and other HPV-related cancers is still in the pre-clinical development phase. To be able to use it in the future with humans, there are still some hurdles to overcome.

"The effectiveness of the vaccine must be even better," said Riemer.

From the development of therapeutic vaccines against other cancers, it is known that a vaccine sometimes works better if it contains different recognition molecules.

"In our first experiment on mice, it was the other way round," says Riemer. It may be better for HPV tumors to use only one, but a really good recognition molecule. But only further investigations can show that. "(Ad)