Development of immune cells associated with allergy and asthma

Arthritis and allergy are 'two sides of the same coin' as immune responses. Both are caused by overproduction of otherwise important immune molecules. Two papers in the November issue of Nature Immunology describe how one type of immune cell associated with allergic inflammation and autoimmunity ultimately causes disease. This new work clarifies how such cells develop, which may help bring treatment for inflammatory diseases such as asthma and allergy.

CD4 lymphocytes (or 'T helper' cells) are immune 'helper' cells that were formerly thought to function in one of two ways during immune responses. Now, work from the laboratories of Casey Weaver and Chen Dong describe how a novel third type of T helper cell develops. Molecules such as antiviral interferon-gamma (IFN-g) and allergy-associated interleukin 4 (IL-4) are well known to be produced by distinct 'lineages' of T helper cells, whereas distinct molecules have been linked to some T helper cells found in people with autoimmunity. Both Weaver and Dong demonstrate that CD4 T cells can be become producers of interleukin 17 (IL-17), a powerful chemical that stimulates inflammation and has been linked to autoimmunity and allergy. IL-17 is triggered by a unique set of signals that defines this new 'lineage' of CD4 T cells.

This new information may allow treatments for people before they develop symptoms of allergy and autoimmunity instead of only after symptoms occur, which is the basis of the present, less effective treatment.

Nature Journal
DOI: 10.1038/ni1254 &
DOI: 10.1038/ni1261
http://www.nature.com