Leukemia cells can be killed off by training a person’s immune system with the use of gene therapy, University of Pennsylvania doctors have demonstrated.
Doctors gutted and reconstructed a disabled form of HIV-1 by selecting DNA from humans, mice and cows, a virus that infects woodchucks, and one that infects cows.
The virus infects T-cells, a white blood cell that fights viruses and tumors, and alters the T-cells to reproduce chimeric antigen receptors, The New York Times reports.
Chimeric antigen receptors, also known as CARS, are protein complexes that transform the cells into “serial killers.”
The T-cells recognize cancer, attack it, multiply, and continue to live on after the eradication of the cancer, patrolling the body to defend against remission.
Doctors first tried the experimental treatment on William Ludwig, then a 65-year-old retired corrections officer from Bridgeton, NJ., reports The NY Times.
Researchers passed Ludwig’s blood through a machine that removed about a billion T-cells before putting the blood back into his veins.
The removed T-cells were introduced to the HIV virus, which infected and genetically transformed Ludwig’s T-cells, and then frozen temporarily.
After chemotherapy to deplete any remaining T-cells that may have impeded the growth of the altered ones, the new T-cells were infused back into Ludwig’s blood.
Dr. Carl June, head of the research team, explains that, “The patient then becomes a bioreactor,” The NY Times reports.
After 10 days, as the T-cells reproduced, Ludwig began shaking with chills, his temperature soared, and his blood pressure dropped dangerously.
The T-cells were producing chemicals called cytokines that caused flulike symptoms.
After several weeks, the symptoms disappeared, along with the leukemia. Ludwig’s doctors estimated that the treatment had killed two pounds of cancer cells in his blood, reports The NY Times.
Seeing as only a year has passed since the operation, Ludwig’s doctors cannot say that he is cured, but even Dr. June admits that he and his colleagues were astounded by the results.
Although reconstructed HIV has been used to treat other diseases, never before has it been used to treat cancer.
“I have my life back,” Ludwig said, adding that he feels wonderful, and is even walking through all 18 holes of golf, The NY Times reports.
Since Ludwig, two other patients have been treated. One experienced full remission.
When the other developed chills and fever, another hospital treated him with steroids, and may have disrupted the T-cells’ activity.
Doctors also noted that his leukemia may have been too advanced. Still, he experienced partial remission, reports The NY Times.
Experts said the results marked a giant leap in molecular biology. Other cancers may also be vulnerable to the new treatment.
