Researchers Discover T-Cell That Fights Melanoma

A T-cell usually associated with allergies and asthma may be effective in fighting melanoma, according to the results of a recent study.

Tumor immunology—the study of the immune system’s interactions with cancer cells—is a growing field of study. A T-cell usually associated with allergies and asthma may be effective in fighting melanoma, according to findings published online on July 8, 2012, in Nature Medicine. Researchers at Brigham and Women’s Hospital in Boston discovered that expression of interleukin-9, a cell-signaling molecule in immune cells, hinders melanoma tumor growth.

The 2 lead researchers, Thomas S. Kupper, MD, and Rahul Purwar, PhD, studied mice to investigate which immune T-cells can fight melanoma. They originally hypothesized that T helper cell 17 (T_H17), a newly discovered T-cell, would not effectively hinder melanoma tumor growth. However, when they ran an experiment in mice lacking T_H17, they were surprised to discover that melanoma tumor growth was still inhibited. They isolated T helper cell 9 (T_H9) and linked it to resistance to melanoma. Further, they found that T_H9 only inhibits tumor growth in the presence of mast cells.

Thus far, the cytokine interleukin-9, produced by T_H9 cells, has only been associated with asthma and allergies; this study was the first to link T_H9 with melanoma tumor suppression. Other cytokines have been used with varying degrees of success to treat melanoma.

Although the researchers used mice in their study, they also confirmed that T_H9 cells are present in human blood and skin. In addition, they found that patients with various types of cancer, including melanoma and lung cancer, had lower-than-normal T_H9 concentrations—a finding never before reported in human cancer research.

Now the researchers are working to determine if other T-cells can become T_H9 cells.

Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.