New cancer vaccine molecules clump together to stay on target
Current cancer treatments take time, can harm healthy cells and have mixed results. Ideally, fighting cancer would be as simple as a vaccine, and scientists are taking steps towards that goal. Now, researchers at EPFL have developed a way to make vaccine molecules bigger, so they don’t disperse in the blood stream before reaching their target.
The idea behind cancer vaccines sounds simple enough. They’re made up of antigens not been seen by the immune system before, called neoantigens, that are tuned to the type of tumor that a patient has. These are then injected into a patient’s bloodstream, where the drug molecules travel to the lymph nodes and enter the dendritic cells. There, the neoantigens are presented to immune cells, which then go out and hunt for the corresponding cancer in the body.
In practice though, things aren’t that easy. There are so many variations of antigens that it can be hard to tell which ones specifically will work for a given patient. And even then, these neoantigens are so small that they often disperse through blood vessels before ever reaching the lymph nodes, reducing their effectiveness.
The EPFL researchers tackled the second problem with the new work. The team developed a way to chemically bind the different components of the vaccine together. The end result is a structure that’s too large to pass through the walls of blood vessels, ensuring that the vaccine reaches the lymph nodes. Once inside the dendritic cells, the components are designed to break apart again, presenting the neoantigens to T cells and triggering the desired immune response.
The team tested the technique on mice, and found that their T cells responded well with the correct antigens, and provided protective immunity against cancer. The method could eventually be put to work in conjunction with other immunotherapy techniques to improve responses, and potentially reduce the chance of relapse.
As for the other part of the problem, the researchers have also founded a startup called PepGene, which is aiming to develop an algorithm to identify antigens for different tumor types. Hopefully, this allows for better cancer vaccines to be developed.
“This new vaccine, combined with a highly advanced analysis of each patient’s neoantigens, should allow cancer patients’ immune systems to be activated in a personalized and safe way,” says Li Tang, lead researcher on the study. “Since these neoantigens aren’t present in healthy cells, accurate identification will allow us to target tumor cells very precisely, without any toxicity in healthy tissue.”
The research was published in the journal ACS Central Science.