In a study published online in the journal Nature Communications researchers have discovered a way to use light to guide the immune system to attack tumour cells, thus giving a fresh boost to immunotherapy for cancer treatments.
"Method is similar to sending light on a spy mission"
The optical control was sufficient to allow the immune system in mice with melanoma on the ears, to nearly wipe out the melanoma with no toxic side effects. Lead author Minsoo Kim, Professor at University of Rochester Medical Centre in New York said the method is similar to "sending light on a spy mission to track down cancer cells". Immunotherapy, which is different from radiation or chemotherapy - instead of directly killing cancer cells, tells the immune system to act in certain ways by stimulating T cells to attack the disease.
Aggressive tumors also suppress the immune system
According to Kim, the problem, is that immunotherapy can cause the immune system to overreact or underreact. Also, cancer cells being evasive may hide from killer T-cells. Also, keeping T cells out, aggressive tumors also suppress the immune system in the areas surrounding the malignancy (called the microenvironment). Currently the only way to modify, if the immune system under-reacts, is to pump more T cells into the body. But this often unleashes a storm of toxicities that can shut down a patient's organs.
Channelrhodopsin a molecule active in algae was found light sensitive
Kim's team focused on overcoming the immunesuppressive environment that cancer creates. The researchers found that channelrhodopsin (CatCh), a molecule active in algae and is light sensitive, could be introduced to the immune system via a virus and activated to control the T- cell response to cancer. The researchers tested in mice an LED chip which could eventually be implanted in humans. The optical control allowed the immune system to nearly wipe out the melanoma with no toxic side effects, the study reported.