A cousin of herpes might just help us fight cancer. Scientists have engineered a protein derived from a herpesvirus in monkeys that could enhance the immune system’s potency against cancer.
Researchers at the University of Michigan detailed their work on the protein in a paper published last month. In experiments with mice, the protein prolonged the life of cancer-fighting T cells, leading to reduced tumor growth. The findings point to a novel way that we can further strengthen immune-related cancer treatments, the researchers say.
The protein comes from herpesvirus saimiri, named after the squirrel monkeys (all members of the genus Saimiri) that the virus primarily infects. The researchers had identified the virus as carrying proteins that activate certain pathways in T cells—the immune system’s frontline soldiers against infections and cancers—that extended their survivability. They ultimately engineered a modified version of one particular protein from the virus, called tyrosine kinase interacting protein (TIP). They hoped their version of TIP could bind to a protein in T cells that would stimulate the production of other proteins called STAT that could then boost the T cells’ longevity and cancer-killing potential.
As expected, the protein increased levels of STAT (specifically the protein STAT5) in T cells in a Petri dish. They then tested the protein on mice with melanoma and lymphoma. The T cells of treated mice lived longer and killed tumor cells more effectively, resulting in reduced cancer growth, the researchers found.
“Our findings demonstrate that signaling pathways can be rewired in T cells to sustain their function in solid tumors,” the researchers wrote in the paper, published in Science Immunology.
In recent years, scientists have developed a class of treatments that ramp up the immune system’s natural ability to recognize and attack cancers, which is broadly known as immunotherapy. So the U-M scientists believe that their protein could be used in combination with existing immunotherapies to keep T cells in tip-top cancer-bashing shape. More broadly, they believe that other organisms or their genes can be tweaked to modify our immune cells to make them better at fighting cancers.
The team’s protein is still experimental, so it will take plenty more research to know whether it can be safely and effectively used in people. But it may not take too long for other herpesviruses to contribute to cancer treatment. Several research teams have developed modified versions of the herpes simplex 1 virus (the primary cause of cold sores) to directly eradicate tumors. Some of these treatments have already begun to be tested in people, and have shown promise in early clinical trials so far.
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