• BMB Reports
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• v.50 no.2
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• pp.55-57
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• 2017

Toll-like receptor 4 (TLR4) together with MD2, one of the key pattern recognition receptors for a pathogen-associated molecular pattern, activates innate immunity by recognizing lipopolysaccharide (LPS) of Gram-negative bacteria. Although LBP and CD14 catalyze LPS transfer to the TLR4/MD2 complex, the detail mechanisms underlying this dynamic LPS transfer remain elusive. Using negative-stain electron microscopy, we visualized the dynamic intermediate complexes during LPS transfer-LBP/LPS micelles and ternary CD14/LBP/LPS micelle complexes. We also reconstituted the entire cascade of LPS transfer to TLR4/MD2 in a total internal reflection fluorescence (TIRF) microscope for a single molecule fluorescence analysis. These analyses reveal longitudinal LBP binding to the surface of LPS micelles and multi-round binding/unbinding of CD14 to single LBP/LPS micelles via key charged residues on LBP and CD14. Finally, we reveal that a single LPS molecule bound to CD14 is transferred to TLR4/MD2 in a TLR4-dependent manner. These discoveries, which clarify the molecular mechanism of dynamic LPS transfer to TLR4/MD2 via LBP and CD14, provide novel insights into the initiation of innate immune responses.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.273-279
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• 2015

Leptospiral lipopolysaccharide (L-LPS) has shown potency in activating toll-like receptor 2 (TLR2) in pig fibroblasts (PEFs_NCC1), and causes the expression of proinflammatory cytokines. However, the stimulation by L-LPS was weak eliciting the function of TLR2 sufficiently in pig innate immunity responses during Leptospira infection. In this study, the immune response of pig embryonic fibroblast cell line (PEFs_SV40) was investigated and was found to be the high immune response, thus TLR2 is the predominate receptor of L-LPS in pig cells. Further, we found a strategy using the antibody against L-LPS, to prevent L-LPS interaction with TLR2 in pig cells which could impact on immune activation.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.299-304
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• 2000

The activated immune systems with lipopolysaccharide(LPS) were evaluates by ${\gamma}$- globulin levels in domestic cats. Especially, cats were in a stress condition, which was unfamiliar environmental change. Effect of continuous unfamiliar environmental stressor was a diminution of production of serum total globulin auld ${\gamma}$- globulin on feline infectious peritonitis(FIP) vaccination. The ${\gamma}$-globulin production on FIP vaccination more increased in LPS treated 77ups than non-LPS treated group. Also. the ${\gamma}$-globulin production on FIP vaccination was maintained in LPS treated group under stress condition. These results imply that that the ${\gamma}$-globulin can be produced under a stress condition by mitogen like as LPS.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.696-706
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• 2011

The objective of this study was to characterize serum immunoglobulins and lymphocytes subpopulations in the peripheral blood mononuclear cells (PBMCs) of Holstein calves in response to lipopolysaccharide (LPS) challenge from Escherichia coli. Fourteen calves received subcutaneous injections of E. coli LPS at 10 weeks of age, and six calves were injected with saline as a control. The concentrations of total serum IgG and the relative amount of LPS-specific IgG in calves challenged with LPS were significantly higher (p<0.05) compared to control animals and LPS challenge significantly increased (p<0.05) the percentage of $CD5^+$ and $CD21^+$ T cells in PBMCs. Meanwhile, LPS challenge significantly increased (p<0.05, p<0.01) the percentage of $CD8^+$ and $CD25^+$ T cells in peripheral blood mononuclear cells (PBMC) at 7 and 14 Day-post LPS challenge (DPLC), respectively. The composition of $CD4^+CD25^+$ T cells and $CD8^+CD25^+$ T cells from calves challenged with LPS was also higher (p<0.05 and p = 0.562, respectively) than those of control calves at 14 DPLC. In conclusion, LPS challenge not only induces production of IgG with expression of B-cell immune response related cell surface molecules, but also stimulates activation of T-lymphocytes in PBMC. Our results suggest that LPS challenge in calves is a good model to elucidate cellular immune response against Gram-negative bacterial infections.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.2
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• pp.135-143
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• 2018

Tumor necrosis $factor-{\alpha}$ ($TNF{\alpha}$) and the angiotensin system are involved in inflammatory diseases and may contribute to acute kidney injury. We investigated the mechanisms by which $TNF{\alpha}$-converting enzyme (TACE) contributes to lipopolysaccharide (LPS)-induced renal inflammation and the effect of TACE inhibitor treatment on LPS-induced cellular injury in human renal proximal tubule epithelial (HK-2) cells. Mice were treated with LPS (10 mg/kg, i.p.) and HK-2 cells were cultured with or without LPS ($10{\mu}g/ml$) in the presence or absence of a type 1 TACE inhibitor ($1{\mu}M$) or type 2 TACE inhibitor ($10{\mu}M$). LPS treatment induced increased serum creatinine, $TNF{\alpha}$, and urinary neutrophil gelatinase-associated lipocalin. Angiotensin II type 1 receptor, mitogen activated protein kinase (MAPK), and TACE increased, while angiotensin-converting enzyme-2 (ACE2) expression decreased in LPS-induced acute kidney injury and LPS-treated HK-2 cells. LPS induced reactive oxygen species and the down-regulation of ACE2, and these responses were prevented by TACE inhibitors in HK-2 cells. TACE inhibitors increased cell viability in LPS-treated HK-2 cells and attenuated oxidative stress and inflammatory cytokines. Our findings indicate that LPS activates renin angiotensin system components via the activation of TACE. Furthermore, inhibitors of TACE are potential therapeutic agents for kidney injury.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.132-141
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• 2021

Objective: Lipopolysaccharide (LPS) from Gram-negative bacteria causes poor uterine receptivity by inducing excessive inflammation at the maternal-fetal interface. This study aimed to investigate the detrimental effects of LPS on the attachment and outgrowth of various types of trophoblastic spheroids on endometrial epithelial cells (ECC-1 cells) in an in vitro model of implantation. Methods: Three types of spheroids with JAr, JEG-3, and JAr mixed JEG-3 (JmJ) cells were used to evaluate the effect of LPS on early implantation events. ECC-1 cells were treated with LPS to mimic endometrial infection, and the expression of inflammatory cytokines and adhesion molecules was analyzed by quantitative real-time polymerase chain reaction and western blotting. The attachment rates and outgrowth areas were evaluated in the various trophoblastic spheroids and ECC-1 cells treated with LPS. Results: LPS treatment significantly increased the mRNA expression of inflammatory cytokines (CXCL1, IL-8, and IL-33) and decreased the protein expression of adhesion molecules (ITGβ3 and ITGβ5) in ECC-1 cells. The attachment rates of JAr and JmJ spheroids on ECC-1 cells significantly decreased after treating the ECC-1 cells with 1 and 10 ㎍/mL LPS. In the outgrowth assay, JAr spheroids did not show any outgrowth areas. However, the outgrowth areas of JEG-3 spheroids were similar regardless of LPS treatment. LPS treatment of JmJ spheroids significantly decreased the outgrowth area after 72 hours of coincubation. Conclusion: An in vitro implantation model using novel JmJ spheroids was established, and the inhibitory effects of LPS on ECC-1 endometrial epithelial cells were confirmed in the early implantation process.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.605-613
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• 2020

This study was conducted to evaluate the effects of dietary supplementation of plant flavonoid (quercetin) on immune parameters, growth performance, and nutrient digestibility in growing pigs challenged with Escherichia coli lipopolysaccharide (LPS). A total of 40 crossbred ([Landrace × Yorkshire] × Duroc) growing pigs; initial body weight (BW) of 26.95 ± 1.26 kg were used in a six-week experimental trial. Pigs were randomly allocated into one of four treatment groups in a 2 × 2 factorial arrangement with the following factors; without LPS challenge and with LPS challenge (day 21) supplemented with or without 0.1% flavonoid according to BW (2 replicate pens per treatment with 2 gilts and 3 barrows per pen). The single-dose LPS (100 ug / kg BW) injection showed trends tended to be increased in interleukin-6 (IL-6) after 2 h and 6 h of challenge compared with unchallenged pigs. However, other measured immune indices (white blood cell, immunoglobulin G, lymphocyte, and tumor necrosis factor), growth performance, and nutrient digestibility were not significantly different between challenged and non-challenged animals. The supplementation of flavonoid significantly increased (p < 0.05) average daily gain (ADG) during day 0-21, tended to increase dry matter and nitrogen digestibility, significantly reduced IL-6, increased Ig-G and WBC concentrations and increased lymphocytes percentage regardless of LPS challenge.

• The Journal of Internal Korean Medicine
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• v.24 no.1
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• pp.113-122
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• 2003

Objective : The aim of this study was to evaluate the efficacy of Gagamchunggan-tang on anti-inflammation reaction with lipopolysaccharide (LPS)-induced HepG2 cell. Method : We examined the effects of the Gagamchunggan-tang, a traditional drug for liver inflammation, on the process of lipopolysaccharide(LPS)-induced nuclear factor-${\kappa}Bp65(NF-{\kappa}Bp65)$ activation in HepG2 cell. SDS-PAGE, Western blotting, Immunofluorescence staining were studied. Results : Immunoblot analysis showed that the level of nucleic $NF-{\kappa}Bp65$ was rapidly up-regulated and cytosolic inhibitory $I-{\kappa}B{\alpha}$ was down-regulated by LPS challenge. While Gagamchunggan-tang inhibited an increase of $NF-{\kappa}Bp65$ and degradation of $I-{\kappa}B{\alpha}$ in HepG2 cell. Besides LPS-induced expression of a group of genes, such as tumor necrosis factor-${\alpha}(TNF-{\alpha})$, inducible nitric oxide synthase(iNOS) and cyclooxygenase-2 (COX-2), are repressed by Gagamchunggan-tang. It may be concluded that Gagamchunggan-tang attenuates the progress of LPS-induced inflammation by reduction of $NF-{\kappa}Bp65$ activation. Conclusion : The Gagamchunggan-tang would be useful as a therapeutic agent for endotoxin-induced liver disease.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.63-71
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• 2000

An immunogenic, high molecular weight lipopolysaccharide (LPS)-protein complex isolated from a potassium thioncyanate extract of a Pasteurella multocida (P multocida ; strain P-2383, capsular type A and somatic type 3) was characterized. Chemical analysis of the complex by gas chromatography on a capillary column demonstrated that this complex contained most of the chemical constituents characteristic of LPS extracted by the phenol-water methed from the whole bacterium. However, there was proportionately more carbohydrate than fatty acid in the complex in contrast to LPS in which fatty acid seemed to be in excess. When toxicity of the complex was evaluated in 10-day-old chicken embryos, the complex was less toxic ($LD_{50}=12.72{\mu}g$) than the purified LPS ($LD_{50}=0.44{\mu}g$). The $LD_{50}$, of the LPS moiety extracted from the complex was $5.24{\mu}g$. Composition of the complex was analyzed by SDS-PAGE with silver staining and Western immunoblotting. The complex did not migrate through the polyacrylamide gel unless dissociated with SDS. The complex dissociated with SDS contained at least 32 different protein and polysaccharide components: 18 components reacted with an antiserum against the complex. There was no significant compositional variation between the complexes from different strains, but quantitative differences in individual components were noted. When cross-protectivity of the complex was evaluated in mice, this complex provided substantial protection not only against the homologous bacteriun but also against different P multocida strains of the same serotype. LPS-protein complexes isolated by the same method from other strains also induced protection against an challenge with P-2383.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.491-497
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• 2018

Lipopolysaccharide (LPS), a component of the cell wall of gram-negative bacteria, elicits the secretion of cytokines, such as interferons, that stimulate the host defense system. Previously, we demonstrated that interferons induce interferon regulatory factors (IRFs) 1, 3, and 7, which regulate the transcription of Noxa and alter the expression profiles of Bcl-2 family proteins in tumors. However, the immediate consequences of LPS stimulation on Noxa and BH3 expression in tumor cells remain uncharacterized. In this study, we determined that LPS induced Noxa expression in CT26 cells. Furthermore, studies in HCT116 parental and HCT116 p53-deficient cells revealed that LPS-mediated Noxa was independent of p53. Meanwhile, IRF1, 3, and 7 in CT26, HCT116 parental, and HT116 p53-deficient cells were upregulated by LPS stimulation, suggesting that LPS induces the expression of these IRFs in a p53-independent manner. The responsiveness of IRF1, 3, 4, and 7 binding to the Noxa promoter region to LPS indicated that IRF1, 3, and 7 activated Noxa expression, whereas IRF4 repressed Noxa expression. Together, these results suggest that LPS directly affects Noxa expression in tumor cells through IRFs, implicating that it may contribute to LPS-induced tumor regression.