Scientists at King's College London target autoimmune disease
2007 NOV 21 -- A new study, 'Optimal induction of T helper 17 cells in humans requires T cell receptor ligation in the context of Toll-like receptor-activated monocytes,' is now available. "Recently, a new lineage of CD4+ T cells has been described in the mouse that specifically secretes IL-17 [T helper (Th) 17]. This discovery has led to a revision of the hypothesis that many autoimmune diseases are predominantly a Th1 phenomenon and may instead be critically dependent on the presence of Th17 cells," scientists writing in the journal Proceedings of the National Academy of Sciences of the United States of America report. "Murine Th17 cells differentiate from naïve T cell precursors in the presence of TGF-beta and IL-6 or IL-21. However, given their putative importance in human autoimmunity, very little is known about the pathways that control the expression of IL-17 in humans. Here we show that the factors that determine the expression of IL-17 in human CD4+ T cells are completely different from mice. IL-6 and IL-21 were unable to induce IL-17 expression in either naïve or effector T cells, and TGF-beta actually inhibited IL-17 expression. The expression of IL-17 was maximally induced from precommitted precursors present in human peripheral blood by cell-cell contact with Toll-like receptor-activated monocytes in the context of T cell receptor ligation. Furthermore, unlike IFN-gamma, IL-17 expression was not suppressed by the presence of FOXP3+ regulatory CD4+ T cells," wrote H.G. Evans and colleagues, King's College London. The researchers concluded: "Taken together, these data indicate that human and mouse Th17 cells have important biological differences that may be of critical importance in the development of therapeutic interventions in diseases characterized by aberrant T cell polarization." Evans and colleagues published their study in Proceedings of the National Academy of Sciences of the United States of America (Optimal induction of T helper 17 cells in humans requires T cell receptor ligation in the context of Toll-like receptor-activated monocytes. Proceedings of the National Academy of Sciences of the United States of America, 2007;104(43):17034-9). Additional information can be obtained by contacting H.G. Evans, King's College London, Departments of Immunobiology and Nephrology and Transplantation, London, UK. The publisher of the journal Proceedings of the National Academy of Sciences of the United States of America can be contacted at: National Acad Sciences, 2101 Constitution Avenue NW, Washington, DC 20418, USA. Keywords: United Kingdom, London, Autoimmune Disease, Autoimmune Disorder, Immunology. This article was prepared by Immunotherapy Weekly editors from staff and other reports. Copyright 2007, Immunotherapy Weekly via NewsRx.com.
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