Posted on 22 January 2020
Reprogramming a patient’s T cells to target cancer-specific proteins is an approach that has seen a significant upsurge in recent years. Such treatments are in use, but face the problem of heterogeneity: different types of cancer in different individuals vary drastically in the proteins they express. Thus, new T cells must be generated specifically for each patient, and there are many cancers for which T cell therapies have not yet been developed.
The solution to this problem would be a T cell able to recognise a wide range of different cancers. Remarkably, this is what research published in Nature Immunology appears to have identified. The T cell was able to recognise cells from a wide range of cancers, while ignoring non-cancer cells. This was thanks to a new T cell receptor that recognises MR1, a protein that shows little variation between individuals, making it an attractive target for a universal immunotherapy.
Intriguingly, MR1 is present on cancer and regular cells alike, yet the T cells remained specific to cancer cells. Determining exactly how the T cells make this distinction will require further effort. Additionally, results of the experiments performed in mice are not guaranteed to translate well to humans. This research nevertheless has huge potential implications for cancer treatment, as it would in many cases remove the need to develop T cell therapies on and individual basis.
“We hope this new TCR may provide us with a different route to target and destroy a wide range of cancers in all individuals,” said Professor Andrew Sewell, lead author on the study.
“Current TCR-based therapies can only be used in a minority of patients with a minority of cancers.
“Cancer-targeting via MR1-restricted T-cells is an exciting new frontier – it raises the prospect of a ‘one-size-fits-all’ cancer treatment; a single type of T-cell that could be capable of destroying many different types of cancers across the population.
“Previously nobody believed this could be possible.”https://www.cardiff.ac.uk/news/view/1749599-discovery-of-new-t-cell-raises-prospect-of-universal-cancer-therapy
Genome-wide CRISPR–Cas9 screening reveals ubiquitous T cell cancer targeting via the monomorphic MHC class I-related protein MR1: https://doi.org/10.1038/s41590-019-0578-8