Genomics

Dataset Information

0

Local restriction of sterile inflammation by auto-inhibitory regulation of S100A8/S100A9-alarmin activity


ABSTRACT: Autoimmune diseases, like psoriasis or arthritis, show a patchy distribution of inflammation despite systemic dysregulation of adaptive immunity. Thus, additional tissue-derived signals like Danger-Associated Molecular Pattern molecules (DAMPs) are indispensable for manifestation of local inflammation. S100A8/100A9-complexes are the most abundant DAMPs in many autoimmune diseases. However, regulatory mechanisms locally restricting DAMP-activities are barely understood. We now unravel for the first time a novel mechanism of auto-inhibition in mice and man restricting S100-DAMP activity to local sites of inflammation. Combining protease degradation, pull-down assays, mass spectrometry and targeted mutations we identified specific peptide sequences within the second calcium-binding EF-hands triggering TLR4/MD2-dependent inflammation. These binding sites are free when S100A8/S100A9-heterodimers are released at sites of inflammation. Subsequently, S100A8/S100A9-activities are locally restricted by calcium-induced (S100A8/S100A9)2-tetramer formation now hiding the TLR4/MD2-binding site within the tetramer interphase thus preventing undesirable systemic effects. Loss of this auto-inhibitory mechanism in vivo results in TNFa-driven fatal inflammation as shown by lack of tetramer formation crossing S100A9-/- mice with two independent TNFa-transgene mouse strains. Since S100A8/S100A9 is the most abundant DAMP in many inflammatory diseases, specifically blocking of the TLR4-binding site of active S100-dimers represents an innovative approach for local suppression of inflammatory diseases avoiding systemic side effects.

ORGANISM(S): Homo sapiens

PROVIDER: GSE109426 | GEO | 2019/04/08

REPOSITORIES: GEO

Similar Datasets

2015-11-29 | GSE53735 | GEO
2021-12-01 | GSE174796 | GEO
2021-05-21 | GSE150465 | GEO
2016-12-01 | GSE90042 | GEO
2020-07-02 | GSE129691 | GEO
2011-11-20 | E-GEOD-33768 | biostudies-arrayexpress
2018-10-26 | PXD005539 | Pride
2011-11-20 | GSE33768 | GEO
2021-01-01 | GSE155421 | GEO
2022-08-05 | GSE201850 | GEO