CH 13 - Role of Th17 cells and interleukin 17 in graft-versus-host disease and graft-versus-leukemia reactivity

Abstract

The discovery of Th17 cells has altered the landscape of immunology and led to numerous studies directed at defining the role that these cells play in inflammatory disorders. Graft-versus-host disease (GVHD) is one such prototypical inflammatory syndrome that has been thought to be primarily a Th1-mediated process. This review summarizes preclinical data derived from experimental murine models that have examined the role of IL-17 and Th17 cells in the biology of acute and chronic GVHD. The role of cytokines (IL-23, IL-6, IL-21) that are either secreted by Th17 cells or are important for the differentiation and/or maintenance of Th17 cells in the biology of experimental GVHD are also examined. Finally, a review of clinical studies that have utilized single nucleotide polymorphism differences between donor and recipient or the acquisition of patient blood and tissue samples to determine how IL-17 and IL-17-related cytokines impact GVHD severity is presented.