Within all of our bodies there is a special type of “super” immune cell that holds enormous potential. Unlike regular immune cells that can only attack one cancer at a time, these “super” immune cells have the ability to target many types of cancers at once. These specialized cells are known as invariant natural killer T cells or iNKT cells for short. Unfortunately, there are relatively few of these cells normally present in the body.

However, in a CIRM-funded study, Dr. Lily Yang and her team of researchers at UCLA have found a way to produce iNKT cells from human blood stem cells. They were then able to test these iNKT cells on mice with both human bone marrow and human cancers. These mice either had multiple melanoma, a type of blood cancer, or melanoma, a solid tumor cancer. The researchers then studied what happened to mice’s immune system, cancers, and engineered iNKT cells after they had integrated into the bone marrow.

The results were remarkable. The team found that the blood stem cells now differentiated normally into iNKT cells, producing iNKT cells for the rest of the animal’s life, which was generally about a year. Mice without the engineered stem cell transplants had undetectable levels of iNKT cells while those that received the engineered cells had iNKT cells make up as much as 60% of the total immune system cells. The team also found that the engineered iNKT cells were able to suppress tumor growth in both multiple myeloma and melanoma.

Dr. Yang, in a press release by UCLA health, discussed the significance of the results in this animal model and the enormous potential this could have for cancer patients.

“What’s really exciting is that we can give this treatment just once and it increases the number of iNKT cells to levels that can fight cancer for the lifetime of the animals.” said Yang.

In the same press release, Dr. Yang continued to highlight the study’s importance by saying that,

“One advantage of this approach is that it’s a one-time cell therapy that can provide patients with a lifelong supply of iNKT cells.”

Researchers mentioned that they could control total iNKT cell make up in the immune system depending on how they engineered the blood stem cells. However, more research is needed to determine how these engineered iNKT cells might be useful for treating cancer in humans and evaluating any long-term side effects associated with an increased number of these cells.

The full results of this study were published in the journal Cell Stem Cell.