News - 07 Nov `18Research update: BH4 controls growth of killer T-cells

New

Scientists have uncovered a new way to curb autoimmunity — including vitiligo. A molecule recognized as essential for many functions in neurobiology is now identified as a natural "killer T-cell" controller, thereby pawing way to completely new therapies.

It's probably a good time for a recap that begins with some introspection.

RECAP

Autoimmune diseases result from an overactive or misdirected immune system. There are more than 80 types of autoimmune disease, and these arise because the immune system attacks healthy tissue, mistaking it for a threat.

"Killer" T-cells are our main defence against viruses and tumours. As a major part of the adaptive immune system, T-cells scan the intracellular environment to target and destroy intruders.

In vitiligo, for reasons yet unclear, T-cells attack and destroy healthy melanocytes that produce color, thereby creating white patches on the skin.

DISCOVERY

A well-known molecule called tetrahydrobiopterin (BH4) was found to have a previously unknown role: it helps to control the growth of "killer" T cells in the immune system.

What is particularly interesting, is that the discovery concerns the control of T cell growth — as opposed to the cells' activation — when T-cells go nuts for unknown reasons and rage onto healthy cells.

It seems that T cells need BH4 to help them regulate iron and produce energy. By dialing down the amount of BH4, researchers can block T-cell proliferation in autoimmune diseases. The researchers tested some BH4 blockers on mouse models of allergies and autoimmune diseases. The experimental drugs "calmed" auto-aggressive T-cells and stopped inflammation.

The beauty of the new approach is that instead of targeting a single cytokine or class of T cells, researchers can halt proliferation in all disease-related T cells.

HIGH HOPES

The finding should lead to a wide variety of medical uses, ranging from controlling autoimmune diseases, asthma, or allergies to having a new way to trigger anticancer immunity. It may take a while — but hey — we're getting there!

ABOUT

The leaders of the study are researchers at the Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA) in Vienna and others at the Boston Children's Hospital in Massachusetts. The journal Nature published the findings today, on November 7, 2018.

      FAQOther Questions

      • How long does it take to treat vitiligo?

        Treatment results will vary by person and type of vitiligo. The rule of thumb is that you will need to allow at least 3 to 6 months before you begin to see results from any trea...

      • Vitiligo and hearing loss: any connection?

        In short, NO. Recent research shows no relationship between a degree of skin depigmentation and hearing loss severity in vitiligo patients. The results of this study showed tha...

      • What tests should be done?

        A well-trained dermatologist should be able to diagnose vitiligo and distinguish it from contact leukoderma or more than twenty other conditions with similar skin appearance bas...