Richard Liang 18’

Skin cancer melanomas develop from melanocytes, or pigment-containing cells, and cause discoloration in various parts of the body. Patients with melanomas are also likely to develop an autoimmune disease known as vitiligo, in which the body’s immune system attacks melanocytes. This results in a patchy loss of pigmentation.

Recently, in a study led by Mary Jo Turk from the Department of Microbiology and Immunology of Geisel School of Medicine at Dartmouth, the cells responsible for vitiligo have been linked to antitumor immunity. Tissue-resident memory T cells (TRM) were discovered to permanently reside in vitiligo-affected skin, where they actively kill healthy melanocytes, with the potential to develop into cancerous melanoma cells. Previously, T cells that fought against cancer were thought to only reside in immune organs like the spleen and lymph nodes, entering tumors via the blood. However, the results of this study indicate otherwise.

Mice models with vitiligo were used to test whether TRM cells were able to respond to melanoma cells.  Flow cytometry, a type of laser-based cell analysis, was used to observe the effects of administering melanoma cells to tissue with TRM cells. As expected, the TRM cells quickly responded by attacking the melanoma cells that were present in the mice tissue.

From the results of this study, it can be inferred that TRM cells can be used to bolster immunity against skin melanomas. Since these cells can be administered in various regions of the skin, they can also be used to stop metastatic melanoma in other organs. Further research is required to test the efficacy and long-term effects of this type of treatment in human tissue. With initial experiments showing promising results, these TRM cells could be the key to future cancer therapies.

References

1. B. T. Malik, et al., Resident memory T cells in the skin mediate durable immunity to melanoma. Science Immunology. 2, (2017), eaam6346 DOI: 10.1126/sciimmunol.aam6346
2. https://upload.wikimedia.org/wikipedia/commons/thumb/7/75/Vitiligo2.JPG/1280px-Vitiligo2.JPG