- Researchers discover a new type of T-Cell Receptor (TCR) that identifies and destroys most human cancer types, without affecting healthy cells.
- It increases the prospect of “one-size-fits-all” cancer treatment.
The traditional method of treating cancer involves surgery, chemotherapy, and radiation therapy. Targeted therapies — in which drugs activate by specific molecular changes and target cancer cells — have also evolved over the last 20 years.
However, in the past few years, the ‘5th pillar’ of cancer treatment has emerged. It is called immunotherapy; it involves strengthening the immune system of a patient to attack tumors.
One of the most promising immunotherapies is T-cell therapy, where immune cells are removed, altered, and returned to the patient’s blood. These modified cells then search and destroy cancer cells.
The most commonly used therapy, called CAR-T, is personalized for every patient. But it has not been proved successful for many types (and majority) of cancers.
Recently, researchers at Cardiff University in the United Kingdom found a new type of T-Cell Receptor (TCR) that identifies and destroys most human cancer types, without affecting healthy cells.
How Does It Work?
The TCR identifies a molecule present in the body’s normal cells and on the surface of various cancer cells. It can also distinguish between cancerous cells and healthy ones, destroying only the former.
Traditional T-cells scan other cells’ surface to find abnormal protein and remove cancerous cells. They, however, do not notice cells containing ‘usual’ proteins.
The scanning system identifies human leukocyte antigen (HLA), which are cell-surface proteins responsible for the regulation of the immune system in humans. But since HLA greatly varies between people, scientists haven’t been able to create a single T-cell-based therapy that can target most cancer cells.
In this study, researchers presented a unique TCR that identifies several cancer types using a single HLA-like molecule named MR1, which does not vary between individuals.
Reference: Nature Immunology | DOI:10.1038/s41590-019-0578-8 | Cardiff University
They tested the new TCR in mice bearing a human immune system and human cancer. It successfully killed blood, lung, ovarian, breast, prostate, skin, lung, kidney, colon, bone, and cervical cancer cells, without harming healthy cells.
In addition to destroying a patient’s own cancer cells, this new TCR could also kill other patients’ cancer cells, irrespective of their HLA type.
Finding a TCR with such a wide range of cancer specificity is a significant milestone. It increases the prospect of “one-size-fits-all” cancer treatment. A few years ago, nobody would have believed that this could be possible.
What’s Next?
Researchers are currently investigating the molecular mechanism through which the TCR differentiates between cancerous cells and healthy cells. They are also conducting various tests to ensure that T-cells modified with this new TCR identify cancer cells only.
Read: Suppressing Growth Of Cancer Cells By Starving Them
If everything goes according to the plan, the trial in patients will most probably begin by the end of this year. Even then, there will be numerous challenges ahead, and it will take several years before this new therapy comes into the market.
