Heidi Ledford in Nature:
Researchers in both academia and industry are turning to immune-suppressing cells to clamp down on autoimmune disorders, and the effort is building to a fever pitch. On 24 July, pharmaceutical firm Eli Lilly of Indianapolis, Indiana, announced that it would pay up to US$400 million to support the development of a drug — which entered clinical trials in March — that stimulates these cells, called regulatory T cells. And in January, Celgene of Summit, New Jersey, announced plans to buy a company working on a similar therapy for $300 million. Other companies, from tiny biotechs to pharmaceutical heavyweights, are also investing in an approach that could yield treatments for a variety of disorders caused by an immune attack on the body’s own cells. Such conditions include type 1 diabetes, lupus and rheumatoid arthritis.
…T cells are often thought of as key foot soldiers in the immune system’s battle against foreign invaders. But there are many kinds of T cell, each armed with a different set of skills. Regulatory T cells serve to dampen immune responses — rather than attack invaders — and are important for preventing autoimmunity. People with disorders caused by an autoimmune attack often also have reduced levels of regulatory T-cell activity, leading scientists to suspect that bolstering such cells could reduce the immune system’s attack on the body. To boost these cells, many researchers — now including those at Lilly and Celgene — are turning to a molecule called interleukin-2 (IL-2). High doses of IL-2 stimulate the ‘effector’ T cells that attack invaders, and in 1992, US regulators approved the treatment for some people with cancer, to prompt immune responses against the tumours. But low doses of IL-2 — roughly ten times lower than those used to treat cancer — instead stimulate regulatory T cells, and have relatively little effect on effector T cells.
More here.