High Level of Memory Killer Cells Correlates With Better Melanoma Survival Rate

Investigators from the Karolinska Institutet in Sweden and the University of Copenhagen in Denmark have identified how immune T cells, called tissue-resident memory cells, are formed. They found that high levels of the memory killer cells in cancer tissue may correlate with a better survival rate for individuals with melanoma.¹

Credit: freshidea - stock.adobe.com

According to the researchers, the tissue-resident memory cells are formed locally in the skin, as well as other tissues, protecting against infections that the cells have previously encountered. Some of the cells express proteins that enable them to kill infected cells, calling them memory killer cells.¹

“We don’t know so much about how and why memory killer cells are formed in the skin and what it means for [those with] cancer,” Yenan Bryceson, PhD, from the Department of Medicine (Huddinge) at the Karolinska Institutet, said in a statement. “Finding out how these cells develop enables us to contribute to the development of more efficacious immunotherapy for diseases like melanoma.”¹

These cells may also contribute to inflammatory skin disorders and involvement in the body’s immune response to a variety of cancers. The memory killer cells have also been shown to respond to immunotherapy, which is normally administered as a complement to other cancer treatments.¹

Study investigators aimed to determine the development of the memory killer cells in the skin. They isolated T cells from the skin and blood of individual who were healthy and volunteered, using advanced techniques to examine gene activity and expression of a variety of proteins.¹

Investigators were able to identify T cells in the blood that had the potential to develop into memory killer cells within the skin or other tissues. After investigators excluded specific genes, they were also able to determine which genes were required for memory killer cells in the tissue.¹

Furthermore, they also studied tumor samples from individuals with melanoma and found that those with a higher rate of survival also had a larger number of epidermal memory killer cells.¹

“We’ve been able to identify several factors that control the formation of memory killer cells, which play an important part in maintaining a healthy skin,” Liv Eidsmo, PhD, a dermatologist and professor at the University of Copenhagen in Denmark, said in the statement. “There’s a fine balance between effective protection against tumors and infections in the skin and contribution to inflammatory diseases like vitiligo and psoriasis.”¹

Investigators intend to use their findings to optimize the immunotherapy-induced T cell response, which could help make these therapies better at eliminating cancer cells in tissues.¹ According to the CDC, there were a total of 77,230 new cases of melanoma reported in the United Statas in 2020, with 8214 individuals who died of melanoma.²

References

1. Memory killer cells can improve survival for melanoma patients. New release. EurekAlert. June 2, 2023. Accessed June 16, 2023. https://www.eurekalert.org/news-releases/991188
2. U.S. Cancer Statistics Working Group. U.S. Cancer Statistics Data Visualizations Tool. US Department of Health and Human Services, Centers for Disease Control, and Prevention and National Cancer Institute. Updated June 2023. Accessed June 16, 2023. https://www.cdc.gov/cancer/dataviz