Lipopolysaccharide Inflammation Model: Core Mechanisms, Applications and High-Quality Reagent Solutions

1. Introduction to Lipopolysaccharide (LPS)

Lipopolysaccharides (LPS), a unique component of the cell wall of Gram-negative bacteria, are also known as endotoxins. Upon infecting the host, LPS can induce sepsis, septic shock, and multiple organ dysfunction syndrome (MODS), posing a significant threat to the host's physiological homeostasis. LPS triggers host responses through specific signal transduction pathways, stimulating immune cells to produce a large number of pyrogenic inflammatory cytokines, which in turn leads to excessive activation of the immune system. Due to its strong pro-inflammatory properties and clear mechanism of action, LPS has become a classic tool in immunology and pathology research, widely used in the construction of inflammatory models and the exploration of inflammatory response mechanisms.

2. LPS Signaling Pathway

LPS exerts its pro-inflammatory effects by binding to specific receptors on the surface of host cells, activating the expression of inflammatory cytokine genes, and initiating the pathogenic process of bacterial infection. Figure 1 shows a schematic diagram of the LPS signaling pathway [1]. After entering the bloodstream, LPS is first recognized and enriched by LPS-binding protein (LBP) in the serum, forming an LPS-LBP complex. This complex then binds to the CD14 receptor molecule anchored on the cell membrane surface of monocytes/macrophages and neutrophils. Subsequently, the LPS-LBP-CD14 trimeric complex interacts with Toll-like receptor 4 (TLR4) and its associated factor myeloid differential protein 2 (MD2), transmitting signals across the membrane and triggering subsequent intracellular signal transduction processes.

Notably, LPS can activate the nuclear factor-κB (NF-κB) signaling pathway, thereby promoting the transcription and expression of downstream inflammatory factors. For this reason, LPS is also commonly used as an activator of the NF-κB signaling pathway in research. In addition, LPS can upregulate the level of inducible nitric oxide synthase (iNOS) in hepatocytes. In recent years, breakthroughs have been made in studying the role of the LPS receptor TLR4 and its signal transduction in innate and adaptive immunity, as well as the complex regulatory mechanisms of the LPS signaling pathway. Among them, the research on the involvement of post-translational protein modification in the regulation of the LPS signaling pathway has become one of the new hotspots in this field.

3. Important Applications of LPS

3.1 As a Mitogen

LPS can induce the activation and proliferation of mouse B cells or the activation of other immune cells to express cytokines. It is particularly suitable for the activation of mouse B cells but not human B cells, as human B cells do not express the binding receptors such as CD14 and TLR4 required for LPS recognition and binding. This species-specific characteristic makes LPS a targeted tool for studying mouse B cell-related immune responses.

3.2 Establishment of Disease-Related Animal Models

Due to its ability to effectively induce systemic inflammatory responses, LPS is widely used in the construction of various disease animal models, providing important experimental platforms for the research and development of new drugs and the exploration of disease mechanisms. The key models constructed using LPS are as follows:

1)    Acute Lung Injury (ALI): The injection dose of LPS varies depending on the animal species and administration method. Studies have shown that intraperitoneal injection of LPS and intratracheal administration of LPS are more suitable for establishing acute lung injury models and subsequent animal experiments of drug application. These administration routes can directly or indirectly induce inflammatory damage to lung tissue, simulating the pathological process of ALI in clinical practice.

2) Acute Pancreatitis (AP): As an endotoxin, LPS can activate monocytes to release cytokines, thereby initiating a systemic inflammatory response. The synergistic effect of Caerulein and LPS in establishing a severe acute pancreatitis (SAP) model is mainly manifested as follows: Caerulein stimulates pancreatic enzymes to damage the pancreas and continuously activates inflammatory cells to release inflammatory factors; subsequently, LPS disrupts the normal response of inflammatory mediators, further developing local pancreatitis into a systemic severe inflammatory response. This combined modeling method can better simulate the severe inflammatory state of SAP, providing a reliable model for related research.

3) Acute Hepatic Failure: LPS is often used in combination with D-(+)-Galactosamine to induce acute hepatic failure models for new drug research. D-(+)-Galactosamine can sensitize the liver to the toxic effects of LPS, and the combined use of the two can effectively induce severe liver damage and inflammatory response, which is of great significance for studying the pathogenesis of acute hepatic failure and evaluating the therapeutic effect of new drugs.

4. ANT BIO PTE. LTD. LPS Selection Guide and Product Applications

LPS derived from Escherichia coli is a commonly used B cell mitogen in laboratory immunology and is suitable for cell culture. The LPS products of ANT BIO PTE. LTD. (Table 1) are favored by researchers, and a series of high-impact papers have been published continuously. Among them, Lipopolysaccharide (O55:B5) is the LPS with the highest number of literature citations of the company. Since 2020, 8 high-impact papers have been published in different English journals. For example, on April 25, 2022, Gu et al. [2] published a research paper entitled "Porcine Reproductive and Respiratory Syndrome Virus Adapts Antiviral Innate Immunity via Manipulating MALT1" in mBio (IF=7.867). This paper shows that porcine reproductive and respiratory syndrome virus (PRRSV) adapts to antiviral innate immunity by manipulating MALT1, revealing the mechanism by which the virus establishes homeostasis in the infected immune system for colonization (Figure 2).

Table 1 Application Guide of E. coli-derived LPS Products

Figure 2 (A) PAMs were infected with HNxx16 or ZJnb16-2 strains, and MALT1 protein was detected at the specified time points.
(B) MALT1 mRNA and protein levels were detected after stimulating Marc-145 cells with 1µg/mL LPS.

In addition to high-quality LPS products, ANT BIO PTE. LTD. also provides a full range of supporting reagents for LPS-related research, including model-inducing reagents, signaling pathway regulators, etc. These products have the characteristics of high purity, stable performance, and reliable quality, which can fully meet the diverse experimental needs of researchers in the process of LPS inflammation model construction and mechanism research. The detailed product information is shown in Table 2.

Table 2 Recommended Related Products

5. Brand Mission

ANT BIO PTE. LTD. is committed to advancing life science research through high-quality, reliable reagents and comprehensive solutions. We deeply recognize the important role of LPS inflammation models in immunology, pathology, and new drug research, and have been dedicated to providing researchers with high-performance LPS and supporting products. Our professional R&D team strictly controls the product quality, ensuring that each batch of products has stable performance and reliable results. The strict quality inspection system covers every link from raw material selection to production and delivery, providing a solid guarantee for the accuracy and reproducibility of experimental results.

With our specialized sub-brands (Absin, Starter, UA), we cover a full spectrum of research needs from general reagents and kits to antibodies and recombinant proteins. In addition to LPS-related products, we also provide a complete set of solutions for cell culture, molecular cloning, and other research fields. Our professional technical support team can provide personalized technical guidance for researchers in model construction, experimental design, and data analysis. We strive to be a trusted partner for researchers worldwide, providing powerful tool support for unlocking scientific mysteries, promoting the development of life sciences and medical care, and realizing the clinical transformation of scientific research achievements.

6. Disclaimer

This article is AI-compiled and interpreted based on the original work in the uploaded document (Molecular Interaction Research.docx). All intellectual property (e.g., product data, technical information, literature citations) of the original content shall belong to ANT BIO PTE. LTD. and the corresponding research teams. For any infringement, please contact us promptly and we will take immediate action.

7. Brand Promotion Copy

ANT BIO PTE. LTD. – Empowering Scientific Breakthroughs

At ANTBIO, we are committed to advancing life science research through high-quality, reliable reagents and comprehensive solutions. Our specialized sub-brands (Absin, Starter, UA) cover a full spectrum of research needs, from general reagents and kits to antibodies and recombinant proteins. With a focus on innovation, quality, and customer-centricity, we strive to be your trusted partner in unlocking scientific mysteries and driving medical progress. Explore our LPS and related product portfolio today and elevate your research to new heights.