Biology subjects

Sparwasser, T.

Publications and source records attributed to Sparwasser, T..

2 recordsLinked to original sources

bioRxiv2020

Notch and TLR signaling coordinate monocyte cell fate and inflammation

Conventional Ly6Chi monocytes have developmental plasticity for a spectrum of differentiated phagocytes. Here we show, using conditional deletion strategies in a mouse model of Toll-like receptor (TLR) 7-induced inflammation, that the spectrum of developmental cell fates of Ly6Chi monocytes, and the resultant inflammation, is coordinately regulated by TLR and Notch signaling. Cell-intrinsic Notch2 and TLR7-Myd88 pathways independently and synergistically promote Ly6Clo patrolling monocyte development from Ly6Chi monocytes under inflammatory conditions, while impairment in either signaling axis impairs Ly6Clo monocyte development. At the same time, TLR7 stimulation in the absence of functional Notch2 signaling promotes resident tissue macrophage gene expression signatures in monocytes and ectopic differentiation of Ly6Chi monocytes into macrophages and dendritic cells, which appear in the blood stream and infiltrate the spleen and major blood vessels, resulting in unrestrained systemic inflammation. Thus, Notch2 is a master regulator of Ly6Chi monocyte cell fate and inflammation in response to TLR signaling.

immunology↗

bioRxiv2019

Ribosome-targeting antibiotics impair T cell effector function and ameliorate autoimmunity by blocking mitochondrial protein synthesis

While antibiotics are intended to specifically target bacteria, most are known to affect host cell physiology. In addition, some antibiotic classes are reported as immunosuppressive, for reasons that remain unclear. Here we show that linezolid, a ribosomal-targeting antibiotic (RAbo), effectively blocked the course of a T cell-mediated autoimmune disease. Linezolid and other RAbos were strong inhibitors of Th17 effector function in vitro, showing that this effect was independent of their antibiotic activity. Perturbing mitochondrial translation in differentiating T cells, either with RAbos or through the inhibition of mitochondrial elongation factor G1 (mEF-G1) progressively compromises the integrity of the electron transport chain (ETC). Ultimately, this leads to loss of mitochondrial metabolism and cytokine production in differentiating Th cells. In accordance, mice lacking Gfm1 in T cells are protected from EAE, demonstrating that this pathway plays a key role in maintaining T cell function and pathogenicity.

immunology↗