Scientists have developed a new type of cancer vaccine that shows promise in eradicating leukemia in mice. This technology can reprogram cancer cells into immune cells, teaching the immune system how to fight off disease.
Our immune system always defeats cancer by fighting it squarely. But rather than fight this vile disease fairly, it uses various deceptive tricks to evade detection. Immunotherapy, a new treatment that involves boosting the immune system to fight cancer, has shown very promising early results.
One of the most common forms of immunotherapy works by removing T cells from patients, programming them to recognize specific cancer antigens, and releasing them in the body to hunt down cancer with those antigens. To do. The problem is that it requires a certain amount of guesswork in determining which antigen is most useful for each patient.
So for a new study, scientists at the Stanford University School of Medicine have developed a method to teach T cells to recognize a wider range of antigens, making a patient’s immune system more likely to attack cancer. . The secret is to transform cancer cells into macrophages. Macrophages are a type of antigen presenting cell (APC) that tells T cells what to look for.
“We hypothesized that cancer cells reprogrammed into macrophage cells could stimulate T cells because these APCs carry all the antigens of the original cancer cells.” said Ravi Majeti, senior author of the study.
To test this idea, the researchers induced mouse leukemic cells to convert to APCs. And sure enough, the control mice were successful in curing the cancer. Even better, vaccine strategies appeared to work long-term to prevent disease recurrence.
“When we first saw data showing that leukemia disappeared in mice with a functioning immune system, we were blown away,” said Majeti. “We couldn’t believe it worked so well. In addition, we showed that the immune system remembered what these cells taught us.” When we reintroduced the cancer, they still had a strong immune response that protected them.”
The team then tested the technique in mice bearing three types of solid tumors: fibrosarcoma, breast cancer and bone cancer. The results were not as effective as in leukemia, but still showed a positive effect.
And finally, the researchers performed experiments with cells taken from human patients. Sure enough, her APCs derived from human leukemia cells seem to have successfully taught her T cells from the same patient what to look for. This suggests that the method may eventually be applied to humans, but more work needs to be done.
“We showed that reprogrammed tumor cells lead to a persistent and systemic attack on cancer in mice, and that immune cells in human patients can exhibit similar responses,” said Majeti. said Mr. “In the future, we may be able to take tumor cells, convert them to APCs, and give them back to patients as therapeutic cancer vaccines. We may be able to transform enough cells to activate the immune system against cancer without taking it out, and it’s science fiction at this point, but that’s the direction we’re interested in. .”
A study was published in a journal cancer detection.
Source: Stanford Medicine
