A series of papers published Wednesday in the journal Nature show how the immune system can fight off cancer, and how that discovery could usher in new vaccines to stimulate that process to become more efficient. It’s the latest advance in personalized medicine — tailoring a treatment to the unique genetic profile of the patient.
One of the jobs of the immune system is to patrol the body looking for foreign invaders that are then disposed of. When tumor cells arise, they are often “marked for death” because they have special molecules on the surface called antigens. The immune system recognizes these antigens and then destroys the tumor cell.
But cancer cells can be crafty. Some of them are able to hide from the immune system because they produce chemicals that can shut the immune response down. The chemicals disable a component of the immune system called T cells.
So scientists designed a vaccine to block the activity of those disabling chemicals. This allows the T cells to rev into gear and destroy the tumor cells. A vaccine has to be created for each individual because everyone’s cancer cells are different.
"The concept is that, if we engage the immune system to attack the cancer, the immune system has the ability to remember, it has memory," Antoni Ribas, Professor of Medicine and director of the Tumor Immunology Program at the Johnson Cancer Center at UCLA, told Sputnik. Ribas was one of the doctors who carried out some of the cancer vaccine experiments. "That would lead to a long-lasting response, which is the feature that's important."
In one experiment, mice with an advanced form of muscle cancer were given a vaccine tailored to their specific tumor type. Astonishingly, the immune systems of the animals responded by obliterating the cancer in 90% of the mice that were treated.
“This is proof that personalized cancer vaccines can be very powerful and need to be applied to human cancers now”, said Dr. Robert Schreiber of the Washington University School of Medicine, one of the lead authors of the study.
As knowledge of what makes the immune system tick continues to improve, the effectiveness of using the body’s own defenses to fight cancer is likely to make treatment outcomes better.
