LED Light Approach Harnesses Immune System for Cancer Attack

Using the immune system to launch an attack on cancer cells has been an increasingly popular approach to fighting the disease. Immunotherapy drugs bolster the immune system and can lead to less cell toxicity compared with older treatments.

In a new study published by Nature Communications, investigators discovered a way to use light and optics to guide immune cells towards cancer.

Immunotherapy techniques stimulate T cells to attack cancer rather than attacking the cells directly. Numerous types of immunotherapies are being used in a clinical setting or are being developed, including checkpoint inhibitors and CAR T cell therapy.

Since the immune system is complex, sometimes these treatments can cause the immune system to overreact or underreact, according to the study. Additionally, cancer cells can disguise themselves from T cells and can even suppress the immune system in the surrounding areas.

The only solution to an immune system that underreacts is to flood the body with more T cells, which can often result in toxicity and organ shutdown, the authors wrote.

The current study explored how to overcome immunosuppression in cancer.

The authors conducted a biological study to understand and create light-sensitive molecules that can escort T cells towards cancerous tumors. They found that the channelrhodopsin (CatCh) molecule can be introduced through a virus and can control T cell response, according to the study.

The authors also conducted an engineering experiment to develop an LED chip for in vivo testing in mouse models of melanoma. The mice wore a battery pack that sent signals to the LED chip. This allowed the investigators to light up the cancer and improve the function of T cells.

The light-controlled method was found to increase the efficacy of the immune system, which nearly killed all melanoma cells without toxic side effects, according to the study. This suggests that it may be able to treat superficial cancers in humans as well, the authors noted.

In the future, the investigators plan to determine whether this LED method could be used to treat cancers inside the body, rather than just on the surface of the skin.

With the goal of improving cancer care, researchers look to immunotherapy, but less than half of patients treated with immunotherapy respond. However, patients who respond to the therapy often have dramatic improvements, according to the study.

The authors noted that their LED approach is meant to be used in addition to immunotherapy to increase safety and efficacy. This method may also allow physicians to see if a treatment is reaching its target immediately, rather than waiting for imaging scans, according to the study.

"The beauty of our approach is that it's highly flexible, non-toxic, and focused on activating T cells to do their jobs," concluded lead study author Minsoo Kim, PhD.