The concept that T cells aye subdwided into T helper 1 (Tbl! and 77~ 2 suhcts was recently extended to suggest that T% 1 cells mntrihte to the pathoge: enesis of several organ-specific auroimnzune diseases, whereas Th2 celh iAGl) it disease development. Here, Sylvie Trembleau and colleagues examine the role of interleukin 12 (K-12/, a key qtokine gtiiding the development of ThI cells, in he ir? ductiorz of metoimmzarte diseases. and discuss potenthi immlinoilltervention strategies based OM administration of IL-12 antagonists.

Differential lymphokine production allows the subdivision of mouse* and human’CD4-and CD8’~(Ref. 3) T cells into three major subsets: T helper 1 (Th’l), characterized by secretion of interferon y (IFN-yj and interleukin 2 (IL-2); Th2, selectively producing IL-4 and IL-5; and ThO, which are not restricted in their lymphokine production. The development of Thl and Th2 cells is primarily influenced by the cytokine mitieu during the initial phase of the immune response, in which IL-12 and IL-4, respectively, play decisive roles”,‘. The cyto-