How a Lowly Immune Cell Helps the Immune System Fight Cancer

New research reveals that long-underestimated neutrophils play key role in determining success of cancer immunotherapy

An illustration of a large, white immune cell surrounded by smaller red blood cells
A new study has revealed the important role of neutrophils in the success of immunotherapy in treating cancer. Image: Dr_Microbe/iStock/Getty Images Plus

At a glance:

  • Immune cells called neutrophils can affect the success of immunotherapy in treating cancer.
  • Neutrophil type is critical to treatment response because some neutrophils promote tumor growth while others combat cancer cells.
  • Tumors that respond well to immunotherapy contain more cancer-combating neutrophils.
  • The findings, based on work in mice and analysis of outcomes in patients with cancer, suggest that researchers may be able to manipulate neutrophils to make cancer therapies more effective.

Cancer immunotherapies that recruit a patient’s own immune system to destroy tumors have transformed the treatment of many types of cancer. Yet these therapies do not elicit universally good treatment responses. Why they work in some patients but not in others has remained somewhat of a mystery and an ongoing clinical challenge.

A new study, published March 30 in Cell, led by researchers at Harvard Medical School, the University of Geneva, and Ludwig Cancer Research, sheds light on this very question by exploring how the immune system differs based on response to immune therapy.

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The work, based on research in mice, included an analysis of outcomes in patients with cancer and shows that immune cells called neutrophils play a key role in immunotherapy success.

The scientists discovered that neutrophils have different molecular identities: Some promote tumor growth, while others combat cancer cells, and it is these cancer-combating neutrophils that were more abundant in tumors that responded well to immunotherapy.

The study illuminates a fundamental aspect of how the immune system responds to cancer.

If affirmed in further studies, the findings could form the basis of new treatments that target neutrophils to boost immune response against tumors and make immunotherapy more effective.

“We wanted to understand what is special about an immune system that successfully attacks a tumor, as compared to one that doesn’t — which is hugely important, because it could lead to new strategies to trigger successful therapy,” said Allon Klein, associate professor of systems biology in the Blavatnik Institute at HMS and co-senior author on the paper.

Elucidating immune system differences, the research team said, is critical to optimizing cancer treatment.