A recent study conducted by a group of Penn researchers revealed that a specific combination of a protein and immune cells could shrink cancerous tumors.
School of Medicine postdoctoral fellow Chrystal Paulos and professor Carl June recently published a study in the Science Translational Medicine journal. In it, they reported that when a cell, Th17, was stimulated with a particular protein, it shrank human tumors implanted in a mouse model.
Human immune cell Th17 is known to help the body fight infection. However, excessive amounts of the cell have been linked to such diseases as multiple sclerosis and Crohn’s disease.
The key to developing a new way to treat cancer or any other autoimmune disease is to use Th17’s disease-fighting capability while leaving its disease-causing aspects inactivated, according to the study. In this case, the protein ICOS stimulates Th17 to expand the immune cells to large numbers so they can fight cancerous cells.
Paulos and June plan to use their findings to develop new ways of conducting adoptive T-cell transfer therapy, a therapy for cancer patients in which immune cells are extracted from the patient, expanded in a laboratory and engineered with a certain molecule that would allow them to kill cancer cells when injected back into the patient’s body.
Paulos explained that one could “polarize” immune cells, also known as T-cells, grown with the protein ICOS using bioengineering techniques to direct an immune response to attack specific tumor cells.
“This can become broader,” she said. “Theoretically, we can make any tumor-specific T-cell to kill any kind of tumor.”
Penn Med staff scientist and co-author of the study Carmine Carpenito called these findings a foray into “boutique science,” or personalized medicine in which one could engineer T-cells to target any cancer, specific to any individual.
“For example, you could obtain tumor-specific tissue of ovarian cancer, genetically engineer a T-cell immune response and put that back into the patient’s body to fight the cancer,” he said.
According to Carpenito, the key to developing a diverse immune response that can attack any cancer cell is investigating the ICOS protein.
Previous studies often used a different protein, CD28, to stimulate the growth of Th17 immune cells. The results of this study came as a surprise in translational medicine, as ICOS was identified as having a stronger response in its ability to grow and target cancerous tumors.
Immunotherapy options, like the ones the Penn study aims to develop, are a growing treatment option in cancer medicine. Earlier this year, the Food and Drug Administration introduced its first immunotherapy treatment by approving Provenge, a treatment geared toward advanced prostate cancer in men.
Provenge operates much like the treatment Paulos and June hope to develop. According to an FDA press release, each dose of Provenge is made by obtaining a patient’s immune cells from his blood. The immune cells are then exposed to a protein found in most prostate cancers. The patient’s own cells are returned to his body to treat the cancer.
After the approval of Provenge, the FDA began looking into immunotherapy applications not only for cancer, but also for asthma and allergies.
Paulos and Carpenito are now enrolling participants for clinical trial testing in which their findings will be tested on a small group of individuals, probably those suffering from ovarian cancer and mesothelioma, a condition most commonly brought on by interactions with asbestos.
Both researchers hope to develop their findings into a practical future treatment for patients. “Our study just became its own monster and grew and grew,” Carpenito said. “Hopefully it’ll keep growing.”
