Immune system T-cells are more able to destroy skin cancer cells when a T-cell regulator called SLAMF6 is missing, a new study in eLife shows.
Immunotherapies, which boost the immune system's ability to destroy cancer cells, have become an important type of cancer treatment, but they are only successful for about half of patients treated with them. The new study in mice suggests that immunotherapies that turn off SLAMF6 might add an option that could be used alone or in combination with other immunotherapies to treat cancer more effectively.
"There is a real need to find new targets for immunotherapies," says lead author Emma Hajaj, an MD-PhD candidate at the Sharett Institute of Oncology at Hadassah Hebrew University Hospital, Jerusalem, Israel. "We thought that SLAMF6, which is a receptor found on all T-cells, was a good candidate for immunotherapy, but more thorough research was needed to confirm this."
To investigate this further, Hajaj and her colleagues created a mouse model that enabled the team to understand the role of SLAMF6 in melanoma treatment. They found that tumours in mice treated with SLAMF6-lacking T-cells shrunk faster and stayed smaller than tumours in mice treated with typical T-cells.
Additionally, they saw that the expression of a gene called LAG-3 increased in the SLAMF6-lacking cells, possibly to make up for the loss of the regulator. Combining SLAMF6-lacking T-cells with an antibody that blocks LAG-3 also increased their tumour-shrinking effect.
"The results from our study show that the absence of SLAMF6 unleashes powerful anti-tumour T-cells, which extended survival in our mouse model," explains senior author Michal Lotem, Head of the Center for Melanoma and Cancer Immunotherapy at Hadassah Hebrew University Hospital. "These findings may have important implications for cancer immunotherapy and could lead to the development of new melanoma treatments that turn off SLAMF6."
The paper 'SLAMF6 deficiency augments tumor killing and skews towards an effector phenotype revealing it as a novel T cell checkpoint' can be freely accessed online at https://doi.org/10.7554/eLife.52539. Contents, including text, figures and data, are free to reuse under a CC BY 4.0 license.
This study will be included in eLife's upcoming Special Issue: 'Discovery and Translation of Cancer Immunology'. To be alerted as new papers are published, follow #eLifeCancerImmunology on Twitter.
Emily Packer, Senior Press Officer
eLife is a non-profit organisation inspired by research funders and led by scientists. Our mission is to help scientists accelerate discovery by operating a platform for research communication that encourages and recognises the most responsible behaviours in science. We publish important research in all areas of the life and biomedical sciences, including Human Biology and Medicine, and Immunology and Inflammation, which is selected and evaluated by working scientists and made freely available online without delay. eLife also invests in innovation through open-source tool development to accelerate research communication and discovery. Our work is guided by the communities we serve. eLife is supported by the Howard Hughes Medical Institute, the Max Planck Society, the Wellcome Trust and the Knut and Alice Wallenberg Foundation. Learn more at https://elifesciences.org/about.
To read the latest Human Biology and Medicine research published in eLife, see https://elifesciences.org/subjects/human-biology-medicine.
And for the latest in Immunology and Inflammation, see https://elifesciences.org/subjects/immunology-inflammation.
Dr. Miriam and Sheldon G Adelson Medical Research Foundation, Fred Lovejoy Resident Research Fund Awards, International Development Research Centre, Canadian Institutes of Health Research, Melanoma Research Alliance, Israel Science Foundation, Azrieli Foundation, Deutsche Forschungsgemeinschaft, Rosetrees Trust, Perlstein family fund