Value added: neural progenitor cells suppress inflammation and autoimmunity

Highlights of the advances in basic immunology in 2011

In this review, we summarize the major fundamental advances in immunological research reported in 2011. The highlights focus on the improved understanding of key questions in basic immunology, including the initiation and activation of innate responses as well as mechanisms for the development and function of various T-cell subsets. The research includes the identification of novel cytosolic RNA and DNA sensors as well as the identification of the novel regulators of the Toll-like receptor (TLR) and retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway. Moreover, remarkable advances have been made in the developmental and functional properties of innate lymphoid cells (ILCs). Helper T cells and regulatory T (Treg) cells play indispensable roles in orchestrating adaptive immunity. There have been exciting discoveries regarding the regulatory mechanisms of the development of distinct T-cell subsets, particularly Th17 cells and Treg cells. The emerging roles of microRNAs (miRNAs) in T cell immunity are discussed, as is the recent identification of a novel T-cell subset referred to as follicular regulatory T (TFR) cells.

Th17 response and inflammatory autoimmune diseases

The proinflammatory activity of T helper 17 (Th17) cells can be beneficial to the host during infection. However, uncontrolled or inappropriate Th17 activation has been linked to several autoimmune and autoinflammatory pathologies. Indeed, preclinical and clinical data show that Th17 cells are associated with several autoimmune diseases such as arthritis, multiple sclerosis, psoriasis, and lupus. Furthermore, targeting the interleukin-17 (IL-17) pathway has attenuated disease severity in preclinical models of autoimmune diseases. Interestingly, a recent report brings to light a potential role for Th17 cells in the autoinflammatory disorder adult-onset Still's disease (AOSD). Whether Th17 cells are the cause or are directly involved in AOSD remains to be shown. In this paper, we discuss the biology of Th17 cells, their role in autoimmune disease development, and in AOSD in particular, as well as the growing interest of the pharmaceutical industry in their use as therapeutic targets.