What is Lipopolysaccharide?

Lipopolysaccharide (LPS), a component of the outer membrane of Gram-negative bacteria, is a potent stimulator of the vertebrate innate immune system.  This innate immune system, mediated by macrophages and dendritic cells, generates a rapid response to infectious agents.  Structural patterns common to diverse LPS molecules are recognized by Toll-like receptors (TLR) and accessory proteins in serum.  LPS released from bacterial membranes is bound to LPS binding protein (LBP) in serum, transferred to CD 14, an LPS receptor glycoprotein, and presented to the TLR-4-MD-2 complex, stimulating production of cytokines.

LPS has a wide range of uses in research and drug development.  It may be used to stimulate immune cells and investigate the innate immune response.  In drug development, structurally modified LPS forms, such as Lipid A, have been used as vaccine adjuvants.  LPS-derived oligosaccharides have been conjugated to carrier proteins in the development of LPS containing human vaccines.  On the other side of the spectrum of uses, LPS stimulation of the inflammation cascade is the cause of sepsis; thus, LPS and the triggered signaling pathways which lead to production of cytokines are targets for drug development.

The newest LPS from List Labs:

List Labs provides LPS types referenced in the studies below, E. coli O111:B4, Product # 421 and E. coli O55:B5, Product # 423.  We have also added a highly purified LPS from E. coli O113, Product #433, a valuable tool in immunology research.  Additionally, to support work with whooping cough vaccines, we now provide LPS from Bordetella pertussis, Product #400.  New product descriptions follow:

#433, HPT™ LPS, highly purified from Escherichia coli O113

HPT^TM Lipopolysaccharide (LPS) serotype O113, Highly Purified Toxin, is produced by methods ensuring the greater purity of the product.  This process uses a hot phenol extraction and proprietary chromatographic methods that effectively remove traces of protein and nucleic acid while maintaining consistently high activity reported in units of endotoxin.  Removal of these intrinsic proteins is important in that they may activate TLR 2 if present.  If there is any concern that signaling pathways are triggered by protein contaminants, this is a good LPS to use.  This LPS type was used for the National Reference Endotoxin and for the Second International Standard for Endotoxin.

#400, HPT™ LPS, highly purified from Bordetella pertussis strain 165

List Labs has developed new products in the Bordetella pertussis family due to the whooping cough outbreaks and the renewed interest in evaluation of vaccines.  B. pertussis LPS, product # 400, is isolated from native cultures of B. pertussis strain 165, and as such has an abbreviated structure, comprised of lipid A and a core oligosaccharide without an O-specific polysaccharide side chain.  In isolated B. pertussis LPS, some congeners have a trisaccharide in place of the O-chain and some do not.  HPT^TM, Highly Purified Toxin, is prepared by hot phenol extraction and proprietary chromatographic methods that effectively remove traces of protein and nucleic acid while maintaining a consistently high concentration of endotoxin units.

For more information on LPS from List Labs click here.

Use our useful Citation Finder to see List Labs lipopolysaccharides used in research.

Other citations include:

Kubler-Kielb J (2011) Conjugation of LPS-Derived Oligosaccharides to Proteins Using Oxime Chemistry. Bioconjugation Protocols, Methods in Molecular Biology 751:317-327. PMID: 21674340.

To determine if a potential drug could attenuate the consequences of exposure to LPS, a mouse model of LPS induced sepsis was created through injection of 10 mg/kg E. coli O111:B4 LPS.

Chang Y-C,Tsai M-H, Sheu W, Hsieh S-C and Chiang A-N (2013) The Therapeutic Potential and Mechanisms of Action of Quercetin in Relation to Lipopolysaccharide-Induced Sepsis In Vitro and In Vivo. PLoS One 8(11):e80744. PMC3834323.

In a study of the activation of coagulation, Pawlinski et al created a mouse model of endotoxemia with a single intraperitoneal injection of 5 mg/kg of E. coli O111:B4 LPS.

Pawlinski R, Wang JG, Owens AP 3rd, Williams J, Antoniak S, Tencati M, Luther T, Rowley JW, Low EN, Weyrich AS and Mackman N (2010) Hematopoietic and Nonhematopoietic Cell Tissue Factor Activates the Coagulation Cascade in Endotoxemic Mice. Blood 116(5):806–814. PMC2918334.

LPS induces a model of inflammatory pain in the mouse paw.  With the use of mutant mice, Calil et al were able to identify the signaling pathway involved in this pain model.

Calil IL, Zarpelon AC, Guerrero AT, Alves-Filho JC, Ferreira SH, et al. (2014) Lipopolysaccharide Induces Inflammatory Hyperalgesia Triggering a TLR4/MyD88-Dependent Cytokine Cascade in the Mice Paw. PLoS ONE 9(3):e90013. PMC3940714.

Mühlbauer et al carried out experiments in cell culture using 0.5 to 1 µg/ml of E. coli O111:B4 to demonstrate the induction of the intracellular pattern recognition receptor Nod2.

Mühlbauer M, Cheely AW,Yenugu S and Jobim C (2008) Regulation and Functional Impact of Lipopolysaccharide Induced Nod2 Gene Expression in the Murine Epididymal Epithelial Cell Line PC1. Immunology 124:256-264. PMC2566630.

Systemic administration of LPS exacerbates the formation of brain lesions in brains of mice.  These lesions play a key role both in acute brain disorders such as stroke, traumatic brain injury, and in chronic neurodegenerative disorders such as Alzheimer disease, Parkinson disease, or amyotrophic lateral sclerosis.

Degos V, Peineau S, Nijboer C, Kaindl AM, Sigaut S, Favrais G, Plaisant F, Teissier N, Gouadon E,Lombet A, Saliba E,Collingridge GL, Maze M, Nicoletti F,  Heijnen C,  Mantz J, Kavelaars A, and Gressens P (2013) GRK2 and Group I mGluR Mediate Inflammation-Induced Sensitization to Excitotoxic Neurodegeneration. Ann Neurol. 73(5):667-678. PMC3837433.