Project Summary Discovery of novel modulatory targets and their modulators would lead innovative strategies for enhancing the effectiveness of current regimens of for neuroinflammatory disorders such as multiple sclerosis (MS) and is in urgent need. Recent studies strongly suggest that nucleus accumbens-associated protein-1 (NAC1) may have an important role in metabolic reprogramming. NAC1 is a transcription co-regulator of the BTB/POZ (broad complex, tramtrack, bric-a-brac/poxvirus and zinc finger) gene family, and is highly expressed in various immune cells including T cells. Published studies, including this research team have shown that NAC1 not only bestows disease potential, but also undermines therapeutic consequence through its transcription-dependent or - independent functions. Lately, this research team revealed that NAC1 could promote glycolysis through interacting with HIF-1a and regulate the transcription factor FoxP3, and NAC1 deficiency in mice results in the resistance to the induction of chronic inflammation and autoimmune disorders. Based on these intriguing findings, this research team hypothesizes that NAC1 plays a key role in the regulation of regulatory T cells (Tregs) that modulate the immune system, maintain tolerance to self-antigens, and prevent chronic inflammation and autoimmune diseases, and that targeting NAC1 could be exploited as a novel strategy for reinforcing Treg-based immunotherapy for neuroinflammatory disorders. To test this hypothesis, the current application proposes the following two specific aims: (1) To determine the mechanism of NAC1 in regulating Tregs; and (2) To evaluate the impact of targeting NAC1 in Treg-based immunotherapy of neuroinflammatory disorders. The research team has already obtained NAC1 deficient (NAC1-/-) and conditional knockout (NAC1cKO) mice, developed adoptive cell transfer (ACT) of Tregs and murine models of neuroinflammatory disorders for the proposed studies, and are well poised to accomplish the above aims. Under the 1st aim, in vitro and in vivo approaches, which have been established as feasible in the applicant’s laboratory, will be used. The critical roles of NAC1 in regulating Tregs will be defined. Under the 2nd aim, using ACT of Tregs in which NAC1 is deleted in a murine model of MS, i.e., experimental allergic encephalomyelitis (EAE), the most common animal model for brain inflammation, the impact of targeting NAC1 in Treg-based immunotherapy for neuroinflammatory disorders will be determined. Furthermore, whether inflammation can alter Treg stability through the upregulation of NAC1 to inhibit FoxP3 expression will also be identified. The approach is innovative, because the concept of targeting NAC1 in neuroinflammatory disorders has not been previously explored. The proposed research is significant, because defining the roles and mechanisms of NAC1 in controlling Tregs should yield a better understanding of the development of neuroinflammatory disorders, and shed ne...