Peripheral T cell expansion predicts tumour infiltration and clinical response

Immune expansion behind cancer drugs’ effects

31 August 2020

Checkpoint-blocking immunotherapy against cancer may work through the proliferation of particular immune cells in the bloodstream that then infiltrate tumours and the surrounding tissue.

Cancer immunotherapy harnesses the body’s immune system in the fight against cancer. But much remains unknown about the mechanisms of some immunotherapies.

Now, scientists at Genentech, a Roche subsidiary, have looked at the origin, behaviour and fate of T cells from 14 patients.

They found evidence that cancer-killing T cells in tumours shared a common clonal origin with those in neighbouring healthy cells and the circulating blood. The more these clonal cells proliferated, the better patients did in response to checkpoint-blocking immunotherapy.

The findings suggest that checkpoint inhibitors work by enhancing the supply and activity of non-exhausted T cells from the bloodstream.

Diagnostic tests that profile those cells could help to identify patients most likely to benefit from immunotherapy drugs.

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References

1. Nature 579, 274–278 (2020). doi: 10.1038/s41586-020-2056-8