For years scientists have tried to beat back glioblastoma using immunotherapy, a process that turns the body’s own immune system against the deadly cancer but with very little success. Finally, however, a new study published in Nature, researchers claim to have discovered a way to improve the outcome of immunotherapy among glioblastoma patients.
“For a while immunotherapies including dendritic cell-based therapy have been considered promising for combating brain cancer. However, our study shows that it is possible to significantly improve their clinical impact among patients with this terrible disease,” said Duane A. Mitchell, M.D., Ph.D., director of the Brain Tumor Immunotherapy Program at the University of Florida in Gainesville and co-lead author of the study.
Normally specialized immune cells called dendritic cells capture microorganisms and migrate to the lymph nodes where they prepare immune weapons like T cells, to fight off the invaders. They have, therefore, been used for immunotherapy against a variety of tumor types, including brain tumours. These cells are drawn from patients and then injected back into them after they have been ‘doctored’ to express antigens from the tumor to create a vaccine. Inside the patient, the injected dendritic cells activate T cells, which are not only capable of battling the tumor buts also can prevent it from returning via an immune memory response.
Would increasing dendritic cell migration to lymph nodes improve the efficacy of the vaccine? To find out Dr. Mitchell and his team administered a tetanus booster shot on a random group of glioblastoma patients before injecting them with the dendritic cell vaccine. The purpose of the booster was to set off an inflammatory response at the vaccination site and thereby prep the immune system for a larger battle. Another group of patients received their own native dendritic cells instead of a tetanus shot before being treated with the dendritic cell vaccine.
The results showed that a shot of tetanus booster prior to the injection of the vaccine not only increased the migration of dendritic cells to lymph nodes but also had a significant effect on clinical outcomes. The booster patients lived more than 36.6 months after diagnosis compared to an average of 18.5 months in those who received dendritic cells alone.