Balanced Bcl-3 expression in murine CD4+T cells is required for generation of encephalitogenic Th17 cells
The function of NF-κB family members is controlled by multiple mechanisms including the transcriptional regulator Bcl-3, an atypical member of the IκB family. By using a murine model of conditional Bcl-3 overexpression specifically in T cells, we observed impairment in the development of Th2, Th1 and Th17 cells. High expression of Bcl-3 promoted CD4+ T-cell survival, but at the same time suppressed proliferation in response to TCR stimulation, resulting in reduced CD4+ T-cell expansion. As a consequence, T cell specific overexpression of Bcl-3 led to reduced inflammation in the small intestine of mice applied with anti-CD3 in a model of gut inflammation. Moreover, impaired Th17-cell develop…
Cutting Edge: IL-6–Driven Immune Dysregulation Is Strictly Dependent on IL-6R α-Chain Expression
Abstract IL-6 binds to the IL-6R α-chain (IL-6Rα) and signals via the signal transducer gp130. Recently, IL-6 was found to also bind to the cell surface glycoprotein CD5, which would then engage gp130 in the absence of IL-6Rα. However, the biological relevance of this alternative pathway is under debate. In this study, we developed a mouse model, in which murine IL-6 is overexpressed in a CD11c-Cre–dependent manner. Transgenic mice developed a lethal immune dysregulation syndrome with increased numbers of Ly-6G+ neutrophils and Ly-6Chi monocytes/macrophages. IL-6 overexpression promoted activation of CD4+ T cells while suppressing CD5+ B-1a cell development. However, additional ablation of …
Intrinsic TNFR2 signaling in T regulatory cells provides protection in CNS autoimmunity
Significance In spite of TNF involvement in the pathogenesis of multiple sclerosis (MS), systemic TNF neutralization in MS patients was not successful. One of the possible reasons is that TNF possesses both pathogenic and protective features that may be related to TNFR1 versus TNFR2 receptor engagement. This study uncovers one of such protective functions of TNF mediated by intrinsic TNFR2 signaling in Treg cells. In mice bearing humanized TNF and TNFR2 genetic loci, TNFR2 ablation restricted to Treg cells led to reduced capacity to control Th17 cell responses, exacerbated experimental autoimmune encephalomyelitis (EAE) development, and affected the maintenance of Treg cells. These findings…