LOS ANGELES, CA (Catholic Online) - While these cells naturally occur in small numbers, it's hoped injecting large quantities back into a patient could turbo-charge the immune system.

Researchers at the RIKEN Research Centre for Allergy and Immunology have announced their success in creating cancer-specific, immune system cells called killer T lymphocytes. Researchers reprogrammed T lymphocytes specialized in killing a certain type of cancer, into another type of cell called induced pluripotent stem cells, or iPS cells.

These iPS cells then generated the cancer-specific T lymphocytes. These lymphocytes regenerated from iPS cells could potentially serve as cancer therapy in the future.

Killer T lymphocytes in previous studies produced in lab conditions using conventional methods proved to be inefficient in killing cancer cells, due to their very short life-span, which limits their use as treatment for cancer.

Japanese researchers led by Hiroshi Kawamoto then reprogrammed mature human killer T lymphocytes into iPS cells and then investigated how these cells differentiate.

The team induced killer T lymphocytes specific for a certain type of skin cancer to reprogram into iPS cells by exposing the lymphocytes to the "Yamanaka factors," a group of compounds that induce cells to revert back to a non-specialized, stage.

The iPS cells obtained were then grown in the lab and induced to differentiate into killer T lymphocytes again. This new batch of T lymphocytes was shown to be specific for the same type of skin cancer as the original lymphocytes.

They maintained the genetic reorganization, enabling them to express the cancer-specific receptor on their surface. The new T lymphocytes were also shown to be active and to produce an anti-tumor compound.

"We have succeeded in the expansion of antigen-specific T cells by making iPS cells and differentiating them back into functional T cells," Kawamoto says.

"The next step will be to test whether these T cells can selectively kill tumor cells but not other cells in the body. If they do, these cells might be directly injected into patients for therapy. This could be realized in the not-so-distant future."

Dr Dusko Ilic, Senior Lecturer in Stem Cell Science, King's College London, is optimistic of this new branch of research. "The study tackled a novel, quite interesting approach to cell based therapy, something that we do not usually hear about," Ilic says.

"Although this approach requires further verification and a lot of work needs to be done before we can think about clinical trials, the initial data are promising.

"This pioneering work definitely provides a strong foundation to build and expand our knowledge about new opportunities in cell based therapy and personalized medicine."