Cancer research breakthrough in Israel

“We found a protein mechanism that puts a brake on the immune system, and we were able to remove it so that the immune system worked again,” Prof. Carmit Levy from Tel Aviv University (TAU) announced to the press.

Levy co-authored the study with Prof. Yaron Carmi and PhD student Avishai Maliah, also from TAU, along with other researchers from Massachusetts and Israel.

In their peer-reviewed study published in Nature Communications, the researchers explained how they identified a protein that prevented the immune system from attacking cancerous growths, but that they had discovered a way to reverse the process.

The surprise discovery of the protein and its ability to attack tumors – even in types of cancer considered resistant to prevailing forms of immunotherapy – has made headlines in yet another potential breakthrough for Israeli scientists.

"It all happened by coincidence,” Prof. Levy explained. “My lab studies both cancer and the effects of ultraviolet (UV) radiation from the sun on our skin and body – both of which are known to suppress the immune system. Cancer suppresses approaching immune cells and solar radiation suppresses the skin's immune system. While in most cases, we cancer researchers worldwide focus on the tumor and look for mechanisms by which cancer inhibits the immune system, here we proposed a different approach: investigating how UV exposure suppresses the immune system and applying our findings to cancer. The discovery of a mechanism that inhibits the immune system opens new paths for innovative therapies."

She added: "With this idea in mind, I asked my colleague Prof. Yaron Carmi, a global expert on the immune system, to join the study. Avishai Maliah, an MD/PhD candidate in my lab, led the project. The first stage was a comprehensive investigation of changes in the skin induced by exposure to UV, using a mouse model. Avishai examined the behavior of dozens of proteins post-UV exposure, and surprisingly discovered a significant rise in the level of a relatively unexplored protein called Ly6a. This unexpected finding led us to investigate further, to understand the protein function and whether it is involved in the immune suppression process."

Once they had discovered Ly6a’s possible impact on immune cells, Prof. Yaron Carmi called Levy even though it was almost midnight. She recalled, “He was so excited and told me, ‘I’ve never seen something like this in my whole career.’”

Maliah explained, "We found that after exposure to UV radiation, the immune system's T cells – that play a critical role in fighting cancer – begin to express high levels of the protein Ly6a. We suspected that Ly6a serves as a brake through which UV inhibits the immune system, and that by releasing this brake, optimal activation of the immune system might be resumed."

Carmi expressed hope for the future of cancer treatment, saying, "Immunotherapy has revolutionized the treatment of cancer. However, about 50% of the patients do not respond to the currently prevailing treatment – the protein PD1. We discovered a new protein, Ly6a, and found that its antibody eradicated tumors in our model animals – even those resistant to PD1 therapy. At present we are working to translate our findings into a drug for human cancer patients, hoping to offer an effective new treatment."