Scientists have discovered a new "killer immune
cell" that could be used as a "universal" cancer cure.
Researchers at Cardiff University discovered a
"T-cell" found in human blood that recognises and kills many types of
cancer while ignoring healthy cells. The researchers suggest the cell could be
used to develop a "one-size-fits-all" cancer treatment.
T-cell therapies for cancer – where immune cells are
removed, modified and returned to the patient’s blood to seek and destroy
cancer cells – are the latest paradigm in cancer treatments. The most widely
used is known as CAR-T and is personalised to each patient. However, it only
targets a limited number of cancers and has not been successful for solid
tumours, which make up the majority of cancers.
Immune cell that destroys most types of cancer discovered,
and scientists are hopeful it could be used to develop a
But scientists have now discovered T-cells equipped with a
new type of T-cell receptor (TCR) which can distinguish between healthy and
diseased cells – only killing only the cancerous ones, Metri UK reports.
Professor Andrew Sewell, lead author on the study from Cardiff
University’s School of Medicine, said it was "highly unusual" to find
a TCR with such broad cancer specificity and this raised the prospect of
universal cancer therapy.
He added: "We hope this new TCR may provide us with a
different route to target and destroy a wide range of cancers in all
individuals.
"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."
Conventional T-cells scan the surface of other cells to find
anomalies and eliminate cancerous cells, but ignore cells that contain only
"normal" proteins. The scanning recognises small parts of cellular
proteins that are bound to cell-surface molecules called human leukocyte
antigen (HLA), allowing killer T-cells to see what is occurring inside cells by
scanning their surface. But the study, published in Nature Immunology,
describes a unique TCR that can recognise many types of cancer via a single
HLA-like molecule called MR1. Unlike HLA, MR1 is does not vary in the human
population – meaning it is a hugely attractive new target for immunotherapies.
In the lab, T-cells equipped with the new TCR were shown to
kill lung, skin, blood, colon, breast, bone, prostate, ovarian, kidney and
cervical cancer cells, while ignoring healthy cells.
To test the therapeutic potential of these cells in vivo,
the researchers injected T-cells able to recognise MR1 into mice bearing human
cancer and with a human immune system.
Scientists say this showed encouraging cancer-clearing,
comparable to the now NHS-approved CAR-T therapy in a similar animal model.
They were also able to demonstrate that T-cells of melanoma
patients modified to express this new TCR could destroy not only the patient’s
own cancer cells, but also other patients’ cancer cells in the laboratory,
regardless of the patient’s HLA type.
The researchers are now experimenting to determine the
precise molecular mechanism by which the new TCR distinguishes between healthy
cells and cancer. They hope to trial the new approach in patients towards the
end of the year.
