Researchers at Dartmouth College's Norris Cotton Cancer Center published a study about how they discovered unique immune cells. These are deemed as resident memory T cells and are the ones that battle melanoma.

They observed that patients with melanoma, who develop vitiligio, have a good prognosis. Vitiligo is an autoimmune skin condition that works against normal healthy melanocytes and causes the loss of skin pigmentation in blotches.

MedicalXpress reported that the team studied mouse models of melanoma and vitiligo and found that resident memory T cells permanently reside in vitiligo-affected skin. These kill melanoma cells.

Resident memory T cells were already known to prevent skin viral infection. However, it was not known until now that they could fight tumors.

The research study was led by Mary Jo Turk, PhD. They sought to understand why patients diagnosed with metastatic melanoma and developed vitiligo during the course of their treatment were able to survive longer.

The study showed for the first time that resident memory T cells are generated in response to a tumor, naturally as a result of autoimmune vilitigo, and play a significant role in protecting patients against future tumors. Their paper will be published in the next issue of the journal "Science Immunology."

The findings are surprising since T cells that fight cancer were previously thought to reside only in immune organs such as the spleen, lymph nodes and blood while tumors enter from the blood. The study challenge old notions by demonstrating that tumor-killing T cells are already in the skin, where they can rapidly respond and fight melanoma cells.

EurekAlert noted that these current studies are still limited to mice. Nonetheless, the presence of similar cells may explain why human patients with vitiligo are well-protected against melanoma and are able to survive longer.

The team is planning to find these cells in human patients. The generation of these types of cells is expected to be the goal of future cancer therapies.