Prof. Li Tang and his colleagues at the École Polytechnique de Lausanne have been working for several years to create a powerful, yet highly targeted immunotherapy treatment that attacks tumors without being too harmful to the rest of the body.
Boost the immune system
Immunotherapies have been used for over 20 years against cancer. They help strengthen or restore the immune system’s ability to fight cancer. These are chemicals, including proteins such as antibodies and cytokines, made or modified in the laboratory, that are injected into the patient’s body.
When a doctor prescribes this type of treatment for a patient, it is given to them intravenously and it spreads everywhere, not just where the tumor or metastases are., explains Li Tang.
While these substances activate immune cells (including lymphocytes or T cells) and help them fight tumors, they also spread throughout the body and
damage healthy tissue.
Most of the immunotherapies developed in the preclinical phase are shown to be very powerful in the fight against cancer. But they cannot be used on patients, because they are too dangerous for the rest of the body., continues Professor Tang.
For this reason, current immunotherapies are less intense and therefore less effective against cancer so as not to harm the rest of the body.
The goal of the Swiss team was therefore to develop a powerful immunotherapy, necessary to fight cancer cells, which is activated only when the chemicals that compose it come into contact with cancerous tissue.
” We got there thanks to the interdisciplinarity of the laboratory: a mixture of chemistry and immunoengineering. “
The chemistry of cancer
Researchers already knew that the chemical environment of cancer cells was different from the rest of the body.
For example, the pH, or acidity, is lower, just as the interior of the cancer cell is characterized by a chemical reduced state., says bioengineer Yu Zhao.
Using this knowledge, Yu Zhao built an envelope of polymers that surrounds the drug protein so that it can travel to the tumor without spreading its toxicity into healthy tissues and organs.
I first developed stimuli-sensitive chemical bonds that attach to the surface of protein molecules, like little hooks. To these bonds I added polymers which are very long molecules and hooked them to the bonds of proteins. They completely cover the surface of the protein and act as a shield, explains Yu Zhao.
Then, as soon as the protein shield comes in contact with the cancerous tissue,
the chemical environment of the latter takes care of the rest of the operations.
“In the tumor, the chemical reaction breaks the bonds on the surface of the protein, and then the polymer shell also comes off. The protein can then unleash its full power and activate lymphocytes called to fight cancer only in the tumor tissue. “
This work took years of testing in order to arrive at the right chemical combination and the right dosage.
It will take several years and significant funding for this technology to be potentially used in the treatment of cancer., concludes Professor Tang.
Details of this work are published in the journal Sscience Advances (New window) (in English)