As scientists work hard to make groundbreaking discoveries, they sometimes find themselves encountering questions they're unable to answer. This was the case with recent discoveries made by researchers when they studied the results of a leukemia cancer treatment. Here's what they found.
The treatment, named CAR T cell therapy, involves a process in which scientists take virus-battling white blood cells - called "T cells" - out of the patient's blood and genetically engineer them to fight cancer cells. After this process is completed, the modified cells are then reinserted into the patient's circulation. The patient's cancers cells are called "B cells," which the patient's T cells are taught to recognize and destroy. By the end of the treatment, a patient should have no B cells, meaning the cancer cells would be gone from their bodies. But the aftermath of this process recently left researchers with a puzzling mystery...
The interesting issue that baffled researchers was what they discovered had happened to the modified T cells that had initially been given to the now cured patients. These T cells actually contained two different subsets of cells: the first is known as CD8 cells, suspected to be the type to actually take on the cancer cells; the other subset is called CD4 cells, which can be considered the "helpers" of CD8 cells. The CD8 cells did their job well - exactly as scientists had hoped - and defeated every B cell in the body. However, the phenomenon that took scientists by surprise was that the CD8 cells, which remained in the blood after the treatment, had unexpectedly turned into CD4 cells. When examined by investigators, those cells proved to be able to kill B cells in the laboratory! The CD4 cells became the cancer-killers, or "at least guardians that can keep the tumor cells at bay and undetectable in the patient for years," explained Dr. DiPersio, head of the oncology division at Washington University in St. Louis.
The biggest question that lingers from this study is why the CD4 cells remain in the patients' circulation. Could they possibly stay there with no B cells to attack? Or are they there to take on cancer cells that keep trying to come back? Guess we can only hope that more research will bring more answers to these ongoing questions. Stay tuned.