The recessive mutation 'Heedless' (hdl) was detected in third-generation N-ethyl-N-nitrosourea-mutated mice that showed defective responses to microbial inducers. Macrophages from Heedless homozygotes signaled by the MyD88-dependent pathway in response to rough lipopolysaccharide (LPS) and lipid A, but not in response to smooth LPS. In addition, the Heedless mutation prevented TRAM-TRIF-dependent signaling in response to all LPS chemotypes. Heedless also abolished macrophage responses to vesicular stomatitis virus and substantially inhibited responses to specific ligands for the Toll-like receptor 2 (TLR2)-TLR6 heterodimer. The Heedless phenotype was positionally ascribed to a premature stop codon in Cd14. Our data suggest that the TLR4-MD-2 complex distinguishes LPS chemotypes, but CD14 nullifies this distinction. Thus, the TLR4-MD-2 complex receptor can function in two separate modes: one in which full signaling occurs and one limited to MyD88-dependent signaling.

Download full-text PDF

Source
http://dx.doi.org/10.1038/ni1207DOI Listing

Publication Analysis

Top Keywords

lps chemotypes
8
tlr4-md-2 complex
8
lps
5
cd14 required
4
required myd88-independent
4
myd88-independent lps
4
signaling
4
lps signaling
4
signaling recessive
4
recessive mutation
4

Similar Publications

Lipopolysaccharide (LPS) is the primary pathogenic factor in Gram-negative sepsis. While the presence of LPS in the bloodstream during infection is associated with disseminated intravascular coagulation, the mechanistic link between LPS and blood coagulation activation remains ill-defined. The contact pathway of coagulation-a series of biochemical reactions that initiates blood clotting when plasma factors XII (FXII) and XI (FXI), prekallikrein (PK) and high molecular weight kininogen (HK) interact with anionic surfaces-has been shown to be activated in Gram-negative septic patients.

View Article and Find Full Text PDF

Structure-based discovery of a 4,5-Dihydropyrazole-cored PET ligand for imaging of receptor-interacting serine/threonine-protein kinase 1 (RIPK1) in the brain.

Eur J Med Chem

December 2024

Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, PR China; Center for Advanced Materials Research & Faculty of Arts and Sciences, Beijing Normal University, Zhuhai, 519087, PR China.

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) regulates programmed cell death and inflammation, contributing to a wide range of human pathologies, including inflammatory disorders, neurodegenerative conditions, and cancer. Despite this, no RIPK1 positron emission tomography (PET) ligand with significant in vivo specificity has been reported to date. In this work, we designed and synthesized a new family of dihydropyrazole-cored ligands suitable for F-labeling at the late stage.

View Article and Find Full Text PDF

Introduction: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by neuroinflammation, demyelination and axonal loss. Cannabis, an immunomodulating agent, is known for its ability to treat MS effectively. However, due to variations in the profile of secondary metabolites, especially cannabinoids, among cannabis cultivars, the effectiveness of cannabis treatment can vary, with significant variability in the effects on different biological parameters.

View Article and Find Full Text PDF

Novel chemotype NLRP3 inhibitors that target the CRID3-binding pocket with high potency.

Life Sci Alliance

June 2024

Laboratory of Medical Immunology, Department of Internal Medicine and Paediatrics, Ghent University, Ghent, Belgium

The NLRP3 inflammasome plays a central role in various human diseases. Despite significant interest, most clinical-grade NLRP3 inhibitors are derived from sulfonylurea inhibitor CRID3 (also called MCC950). Here, we describe a novel chemical class of NLRP3-inhibiting compounds (NIC) that exhibit potent and selective NLRP3 inflammasome inhibition in human monocytes and mouse macrophages.

View Article and Find Full Text PDF
Article Synopsis
  • The outer membrane of Gram-negative bacteria protects against environmental stressors and is composed of glycerophospholipids and lipopolysaccharides (LPS) or lipooligosaccharides (LOS), which play a crucial role in bacterial growth and defense.
  • This study delves into the synthesis of LOS core oligosaccharides in strains with mutations, using tandem mass spectrometry to identify essential genes for their assembly.
  • The research also suggests a novel connection between LOS and the peptidoglycan cell wall, highlighting a unique mechanism for core oligosaccharide assembly that could enhance our understanding of bacterial outer membrane integrity and tackle multidrug-resistant pathogens.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!