Tiny nanoparticles, far smaller than the width of a human hair, might help the body’s own immune system fight tumors, a new study shows. In experiments with mice, the nanoparticle-based therapy not only wiped out the original targeted breast cancer tumors, but metastases in other parts of the body as well. Human clinical trials with the new therapy could begin within the next several months, researchers say.
The search for drugs that spur the immune system to fight tumors is one of the hottest fields in cancer research. Immune sentries, known as T cells, are normally on the prowl for suspicious looking targets, such as bacterial invaders and potential tumor cells. If they recognize one, they sound the alarm, inducing other immune cells to mount a larger response. However, the T cells’ alarm can be muted by so-called immune checkpoints, other proteins on the surface of normal cells that tamp down the immune response to prevent harmful autoimmune reaction to normal tissue. Tumor cells often over express these checkpoint molecules, putting the brakes on the immune system’s search and destroy work.
To overcome that problem, pharmaceutical companies have developed a number of different antibody proteins that block these overexpressed checkpoint molecules and enable the immune system to target tumors. In cases where there are lots of T cells in the vicinity of a tumor, or where tumor cells have undergone large numbers of mutations, which creates additional targets for immune sentries, T cells will signal a full-fledged immune response to the cancer. Such cancer immunotherapy can add extra years to patients’ lives.
Service, R. F. (5 de January de 2017). Science mag. Obtenido de http://www.sciencemag.org/news/2017/01/nanoparticles-awaken-immune-cells-fight-cancer