A New Immune Cell Discovered by Chance That Kills Most Cancer Cell Types

A new type of immune system cell that kills most cancers was discovered in a finding potentially heralding a major breakthrough. The study appeared on 20 January 2020 in Nature Immulogy .

Cardiff University researchers in the UK found a completely new T-cell type while searching for bacteria-fighting immune cells in Welsh blood-bank samples.

The new immune cell ignores healthy cells while attaching to most human cancers like a hook; its previously unidentified receptor is carried by this cell.

Laboratory studies showed cells equipped with the new receptor killed lung, skin, blood, colon, breast, bone, prostate, ovarian, kidney, and cervical cancer.

Lead author and Cardiff University School of Medicine expert in T cells Professor Andrew Sewell said finding a cell with potent anticancer properties and raising universal treatment possibilities was “a big deal” .

“This is a chance discovery; nobody knew this cell existed,” Prof. Sewell said.

“Our finding raises the prospect of a ‘one size fit all’ cancer treatment, one T-cell type effective against many cancers. Previously, nobody believed this possible.”

This raises whether some people have natural immune protection against cancer. Authors stress this may be possible very rarely. This rare T-cell receptor may be absent or inactive in many people.

Treatments modifying immune cells to fight particular cancers, immunotherapies , already exist, such asCAR-T cell therapy, but currently mainly help certain leukemia-lymphoma forms and remain weak against the solid organ tumors making up most cancers.

Called CAR-T and TCR-T (T Cell Receptor) therapies, these collect patient immune cells and modify them to lock onto molecules on cancer-cell surfaces.

Cells are expanded into millions and reinjected into the bloodstream.

CAR-T now treats certain leukemias and lymphomas but not most solid cancers. TCR-T may work elsewhere, but must bind HLA molecules that vary widely between people.

The new T cell instead binds a molecule unchanged between humans, MR1 , on cancer cells. These cells were therefore named MR1T-cells .

This suggests treatment could address most cancers and allow future specialized “immune cell banks” for cancer therapy.

Injected into mice carrying human cancer and a human immune system, the cells produced “encouraging” cancer-clearing results.

Skin cancer patients' T cells modified to express the receptor killed not just their own cancer cells but other patients' cancer cells in the laboratory.

Prof. Sewell said a good team is developing the potential therapy, and progress may now be rapid. Human clinical trialsin terminally ill patients could begin by November 2020 if further laboratory safety tests succeed.

Cardiff hematology head Professor Oliver Ottmann, who administers CAR-T, said: “This new T-cell therapy has enormous potential to overcome current CAR-T limitations. It targets more than a few cancer types.”

Conclusion

A new T cell, very rare and not present in everyone, reacts rapidly to most cancers in preclinical laboratory-animal tests, an unexpected finding. It was discovered partly by chance while seeking bacteria-fighting T cells in Welsh blood-bank samples. It may surpass CAR-T, considered the peak of cellular immunotherapy; if all goes well, human trials could begin in late 2020. Further work must clarify how these cells recognize and kill cancer while not responding to healthy cells.