Scientists at the Texas A&M Health Science Centre Institute of Biosciences & Technology, in collaboration with researchers from the University of Massachusetts Medical School Immunotherapy, are studying how to kill cancer cells using light. If successful, current cancer immunotherapies will vastly improve and side effects would be reduced.

“Although neuroscientists have been using light to stimulate neurons for years, this is the first time the technique, called optogenetics, has been used in the immune system,” said Yubin Zhou, assistant professor at the Centre for Translational Cancer Research at the Texas A&M Health Science Centre Institute of Biosciences & Technology. “Neuroscientists have learned a lot about brain circuits using the technique, and now researchers in many other fields are giving it a try.”

According to the study, neuroscientists modify cells to produce proteins from light-sensitive microbes, which allows nerve cells to send or stop sending nerve impulses upon exposure to a specific colour of light. However, unlike neurons, the immune cells do not communicate via electrical impulses and these are found deep in the body, moving around constantly.

Nevertheless, Zhou was able to combine optogenetic approaches with nanotechnology called optogenetic immunomodulation. Through this, the research team can finally control immune cells to kill tumour cells.

Researchers genetically engineered immune cells to make the calcium gate-controlling protein sensitive to light. The calcium gates open once these are exposed to blue light, and calcium flow is greater if they are exposed to more light.

When a tumour was injected with the nanoparticles and the engineered immune cells, the calcium channels opened, making the immune response more efficient in killing cancer cells.

This new method only activates the dendritic cell or T-cell in one body part at a time. So, this greatly decreases the side effects as compared to what other cancer treatment options cause. This can also be turned on and off, making it more convenient.

“Other scientists will likely use the technique to help them study immune, heart and other types of cells that use calcium to perform their tasks,” Zhou adds. “It’s quite a cool technology. With these tools, we can now not only answer fundamental questions of science that we never could before but also translate it into the clinic for disease intervention.”