Lipopolysaccharide (Escherichia coli 0111:B4)

Overview

Lipopolysaccharide is a glycolipid composed of carbohydrates linked to fatty acids. It is a characteristic component of the cell wall of Gram-negative bacteria. A typical LPS molecule consists of lipid A (a glucosamine-based phospholipid), a relatively short core oligosaccharide, and a distal polysaccharide (O-antigen). LPS contributes to the integrity of the outer membrane and can protect cells from the action of bile salts and lipophilic antibiotics. They stimulate host cells through TLR2 and TLR4 (toll-like receptors). This stimulation can lead to the generation of various pro-inflammatory cytokines, such as TNFα (tumor necrosis factor), IL-1 (interleukin-1), and IL-6. The product is extracted from the Escherichia coli serotype O111:B4 by phenol extraction. This LPS serotype has been used to stimulate B cells and induce NOS in human hepatocytes.