Image by: James Heilman, MD, via Wikimedia commons
Blockade of interleukin (IL)-15 signalling may have the potential to produce long-lasting correction in vitiligo, new research suggests.
Published in Science Translational Medicine (July 18, 2018; 10(450):eaam7710), the paper describes how investigators found resident memory T cells (TRM) in the vitiligo lesions of humans and mice. This phenotype of cells is involved in rapid, localized protection against reinfection by viruses in the skin and mucosa, so the researchers suspected the TRM cells might be playing a role in the return of pigment loss after treatment of vitiligo.
These TRM cells were found to express a subunit of the IL-15 receptor, so investigators tried treating mice with established vitiligo with an antibody that targets IL-15 signalling.
The anti-IL-15 treatment resulted in reversal of depigmentation in the mice. In particular, short-term treatment inhibited the TRMs ability to produce interferon-gamma, and long-term treatment depleted the TRM from the skin lesions. Overall, short-term anti-IL-15 treatment provided durable repigmentation when administered systemically or locally in the skin of the mice.
“Patients are a huge motivation for what we research,” said senior author Dr. John E. Harris in a press release. “Ultimately, we want to give vitiligo patients treatments that last a long time.”
Dr. Harris is an associate professor of dermatology and director of the University of Massachusetts Medical School Vitiligo Clinic and Research Center, in Worcester, Mass.
The next step will be to explore the potential for targeting IL-15 in human vitiligo patients.
“We are working with the Immune Tolerance Network, an NIH [National Institutes of Health]-supported national funding agency formed to conduct mechanistic studies that address immune tolerance in humans, to develop a clinical trial to determine whether targeting T cells could represent a viable therapeutic strategy for vitiligo patients,” Dr. Harris said.