Displaying publications 1 - 20 of 30 in total

Abstract:
Sort:
  1. Osman AY, Saharee AA, Jesse FF, Kadir AA
    Microb Pathog, 2017 Sep;110:365-374.
    PMID: 28710016 DOI: 10.1016/j.micpath.2017.07.014
    In this study, we developed a mouse model and characterized the effects of intranasal inoculation of virulent Brucella melitensis strain 16M and its lipopolysaccharide (LPS). The effects of the exposure were compared with respective control groups. Both Brucella melitensis-infected and LPS-infected groups showed no significant clinical presentation with minor relevance in the mortality associated with the infection. In Brucella melitensis-infected group, significant histopathological changes in comparison to the LPS infected group with increase bacterial burden in the lungs, reproductive and reticuloendothelial organs were observed. However, both infected groups showed elevated levels of pro-inflammatory cytokine expression (IL-1β and IL6) and antibody production (IgM an IgG) as early as 3 days post-infection with predominance in LPS infected group. In contrast, low levels of sex related hormonal changes was recorded in both infected groups throughout the experimental period. This is the first detailed investigation comparing the infection progression and host responses in relation to the immunopathophysiological aspects in mouse model after intranasal inoculation with B. melitensis and its lipopolysaccharide. The study revealed a significant difference between infected and control groups with overlap in clinical, pathological, and immunological responses as well as sex related hormonal changes resulting from the infections.
    Matched MeSH terms: Lipopolysaccharides/immunology
  2. Sosroseno W, Bird PS, Seymour GJ
    J Periodontal Res, 2009 Aug;44(4):529-36.
    PMID: 18973550 DOI: 10.1111/j.1600-0765.2008.01157.x
    Elevated nitric oxide (NO) has been associated with destructive periodontal disease. The aim of the present study was to test the hypothesis that exogenous NO may inhibit a protective immune response to Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) in a murine model.
    Matched MeSH terms: Lipopolysaccharides/immunology*
  3. Kassim M, Mansor M, Kamalden TA, Shariffuddin II, Hasan MS, Ong G, et al.
    Shock, 2014 Aug;42(2):154-60.
    PMID: 24667629 DOI: 10.1097/SHK.0000000000000179
    Excessive free radical production by immune cells has been linked to cell death and tissue injury during sepsis. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death that has been identified in several pathological conditions. Caffeic acid phenethyl ester (CAPE) is an active component of honeybee products and exhibits antioxidant, anti-inflammatory, and immunomodulatory activities. The present study examined the ability of CAPE to scavenge peroxynitrite in RAW 264.7 murine macrophages stimulated with lipopolysaccharide/interferon-γ that was used as an in vitro model. Conversion of 123-dihydrorhodamine to its oxidation product 123-rhodamine was used to measure peroxynitrite production. Two mouse models of sepsis (endotoxemia and cecal ligation and puncture) were used as in vivo models. The level of serum 3-nitrotyrosine was used as an in vivo marker of peroxynitrite. The results demonstrated that CAPE significantly improved the viability of lipopolysaccharide/interferon-γ-treated RAW 264.7 cells and significantly inhibited nitric oxide production, with effects similar to those observed with an inhibitor of inducible nitric oxide synthase (1400W). In addition, CAPE exclusively inhibited the synthesis of peroxynitrite from the artificial substrate SIN-1 and directly prevented the peroxynitrite-mediated conversion of dihydrorhodamine-123 to its fluorescent oxidation product rhodamine-123. In both sepsis models, CAPE inhibited cellular peroxynitrite synthesis, as evidenced by the absence of serum 3-nitrotyrosine, an in vivo marker of peroxynitrite. Thus, CAPE attenuates the inflammatory responses that lead to cell damage and, potentially, cell death through suppression of the production of cytotoxic molecules such as nitric oxide and peroxynitrite. These observations provide evidence of the therapeutic potential of CAPE treatment for a wide range of inflammatory disorders.
    Matched MeSH terms: Lipopolysaccharides/immunology
  4. Sumatoh HR, Oliver BG, Kumar M, Elliott JH, Vonthanak S, Vun MC, et al.
    Biomark Med, 2011 Dec;5(6):847-53.
    PMID: 22103621 DOI: 10.2217/bmm.11.79
    Immune restoration disease (IRD) associated with Mycobacterium tuberculosis parallels the reconstitution of a pathogen-specific Th1 response. However, it is not clear whether humoral responses to M. tuberculosis antigens also rise, or whether antibody levels predict IRD. Here, humoral immunity to M. tuberculosis antigens was investigated in four Asian cohorts.
    Matched MeSH terms: Lipopolysaccharides/immunology
  5. Sosroseno W, Bird PS, Seymour GJ
    Anaerobe, 2011 Oct;17(5):246-51.
    PMID: 21736946 DOI: 10.1016/j.anaerobe.2011.06.006
    Nitric oxide (NO) may play a crucial role in the pathogenesis of periodontal disease and, hence, the aim of the present study was to test the hypothesis that Aggregatibacter actinomycetemcomitans surface-associated material (SAM) stimulates inducible nitric oxide synthase (iNOS) activity and NO production by the murine macrophage cell line RAW264.7. Cells were stimulated with untreated or heat-treated A. actinomycetemcomitans SAM and with or without pre-treatment with L-N(6)-(1-Iminoethyl)-lysine (L-NIL) (an iNOS inhibitor), polymyxin B, interferon-gamma (IFN-γ) and Interleukin-4 (IL-4), IL-10, genistein [a protein tyrosine kinase (PTK) inhibitor], bisindolylmaleimide [a protein kinase C (PKC) inhibitor], bromophenacyl bromide (BPB) [a phospholipase A(2) (PLA2) inhibitor] or wortmannin [phosphatidylinositol 3-kinase (PI-3K) inhibitor]. The iNOS activity and nitrite production in the cell cultures were determined. Untreated but not heat-treated A. actinomycetemcomitans SAM-stimulated both iNOS activity and nitrite production in RAW264.7 cells. L-NIL, IL-4, IL-10, genistein, bisindolylmaleimide, or BPB, suppressed but IFN-γ enhanced both iNOS activity and nitrite production by A. actinomycetemcomitans SAM-stimulated cells. Wortmannin and polymyxin B failed to alter both iNOS activity or nitrite production by A. actinomycetemcomitans SAM treated cells. Therefore, the present study suggests that a heat-sensitive protein constituent(s) of A. actinomycetemcomitans SAM stimulates both iNOS activity and nitrite production by RAW264.7 cells in a cytokine, PTK, PKC, and PLA(2) but not PI-3K-dependent fashion.
    Matched MeSH terms: Lipopolysaccharides/immunology*
  6. Sosroseno W, Bird PS, Seymour GJ
    Oral Microbiol. Immunol., 2009 Feb;24(1):50-5.
    PMID: 19121070 DOI: 10.1111/j.1399-302X.2008.00475.x
    Human osteoblasts induced by inflammatory stimuli express an inducible nitric oxide synthase (iNOS). The aim of the present study was to test the hypothesis that Aggregatibacter actinomycetemcomitans lipopolysaccharide stimulates the production of nitric oxide (NO) by a human osteoblast-like cell line (HOS cells).
    Matched MeSH terms: Lipopolysaccharides/immunology
  7. Sosroseno W, Musa M, Ravichandran M, Fikri Ibrahim M, Bird PS, Seymour GJ
    Oral Microbiol. Immunol., 2006 Jun;21(3):145-50.
    PMID: 16626370
    The aim of the present study was to determine whether or not lipopolysaccharide from Actinobacillus actinomycetemcomitans could stimulate arginase activity in a murine macrophage cell line (RAW264.7 cells).
    Matched MeSH terms: Lipopolysaccharides/immunology
  8. Ravichandran M, Ali SA, Rashid NH, Kurunathan S, Yean CY, Ting LC, et al.
    Vaccine, 2006 May 1;24(18):3750-61.
    PMID: 16102875
    In this paper, we describe the development of VCUSM2, a live metabolic auxotroph of Vibrio cholerae O139. Auxotrophy was achieved by mutating a house keeping gene, hemA, that encodes for glutamyl-tRNA reductase, an important enzyme in the C5 pathway for delta-aminolevulenic acid (ALA) biosynthesis, which renders this strain dependent on exogenous ALA for survival. Experiments using the infant mouse and adult rabbit models show that VCUSM2 is a good colonizer of the small intestine and elicits greater than a four-fold rise in vibriocidal antibodies in vaccinated rabbits. Rabbits vaccinated with VCUSM2 were fully protected against subsequent challenge with 1 x 10(11) CFU of the virulent wild type (WT) strain. Experiments using ligated ileal loops of rabbits show that VCUSM2 is 2.5-fold less toxic at the dose of 1 x 10(6) CFU compared to the WT strain. Shedding of VCUSM2 in rabbits were found to occur for no longer than 4 days and its maximum survival rate in environmental waters is 8 days compared to the greater than 20 days for the WT strain. VCUSM2 is thus a potential vaccine candidate against infection by V. cholerae O139.
    Matched MeSH terms: Lipopolysaccharides/immunology
  9. George L, Ramasamy T, Sirajudeen K, Manickam V
    Immunol Invest, 2019 Jul;48(5):451-465.
    PMID: 30689461 DOI: 10.1080/08820139.2019.1566355
    Lipopolysaccharide (LPS) induces apoptosis in murine macrophages through the autocrine secretion of tumor necrosis factor (TNF)-α and nitric oxide (NO). LPS-induced inflammation in murine macrophages is associated with hydrogen sulfide (H2S) production. In this present study, we reported the novel role of H2S in LPS-induced apoptosis and its underlying molecular mechanism specifically at late phases in murine macrophage cells. Stimulation of RAW 264.7 macrophages with LPS resulted in a time- and dose-dependent induction of apoptosis. We observed that the LPS-induced early apoptosis (associated with TNF-α secretion) in macrophages was not inhibited in the presence of H2S inhibitor (DL-propargylglycine), whereas early apoptosis was absent in the presence of TNF receptor antibody. Interestingly, LPS-induced late apoptosis paralleled with H2S production was reduced in the presence of H2S inhibitor but not with TNF receptor antibody. The late apoptotic events mediated by H2S and not the TNF-α induced early apoptosis correlated significantly with the induction of p53 and Bax expression in LPS-induced macrophages. Thus, it is possible that RAW 264.7 murine macrophages treated with LPS mediated early apoptosis through TNF-α and the late apoptotic events through the production of H2S.
    Matched MeSH terms: Lipopolysaccharides/immunology
  10. Liew CY, Tham CL, Lam KW, Mohamad AS, Kim MK, Cheah YK, et al.
    Immunopharmacol Immunotoxicol, 2010 Sep;32(3):495-506.
    PMID: 20109039 DOI: 10.3109/08923970903575708
    HMP [3-(2-hydroxyphenyl)-1-(5-methyl-furan-2-y-l) propenone] was evaluated for its ability to inhibit the synthesis of major proinflammatory mediators and cytokines in interferon-gamma (IFN-gamma)- and lipopolysaccharide (LPS)-induced RAW 264.7 cells and phorbol myristate acetate (PMA)-differentiated/LPS-induced U937 cells. HMP suppressed the production of nitric oxide (NO) with significant inhibitory effects at doses as low as 0.78 microM (P < 0.05). Prostaglandin E2 (PGE2) secretion was also inhibited at doses of 12.5 microM and above (P < 0.01). The secretion of both TNF-alpha and IL-6 were only inhibited at the highest dose used (25 microM; P < 0.001). IL-1beta secretion was also inhibited from 12.5 microM onwards (P < 0.01). This inhibition was demonstrated to be caused by down-regulation of inducible enzymes, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), without direct effect upon iNOS or COX-2 enzyme activity. HMP only inhibited iNOS (P < 0.001) and IL-1beta (P < 0.05) gene expression at the highest tested concentration. HMP did not affect the secretion of chemokines IL-8 and monocyte chemotactic protein-1 (MCP-1) and the anti-inflammatory cytokine IL-10. The most striking effect of HMP was its NO inhibitory activity and therefore we conclude that HMP is a selective inhibitor of iNOS.
    Matched MeSH terms: Lipopolysaccharides/immunology
  11. Mohamad D, Suppian R, Mohd Nor N
    Hum Vaccin Immunother, 2014;10(7):1880-6.
    PMID: 25424796 DOI: 10.4161/hv.28695
    Macrophage phagocytosis is the first line of defense of the innate immune system against malaria parasite infection. This study evaluated the immunomodulatory effects of BCG and recombinant BCG (rBCG) strains expressing the C-terminus of the merozoite surface protein-1 (MSP-1C) of Plasmodium falciparum on mouse macrophage cell line J774A.1 in the presence or absence of lipopolysaccharide (LPS) or LPS + IFN-γ. The rBCG strain significantly enhanced phagocytic activity, production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, nitric oxide (NO), and inducible nitric oxide synthase (iNOS) as compared with parental BCG strain, and these activities increased in the presence of LPS and LPS+IFN-γ. Furthermore, the rBCG strain also significantly reduced the macrophage viability as well as the rBCG growth suggesting the involvement of macrophage apoptosis. Taken together, these data indicate that the rBCG strain has an immunomodulatory effect on macrophages, thus strengthen the rational use of rBCG to control malaria infection.
    Matched MeSH terms: Lipopolysaccharides/immunology*
  12. Ismail IH, Boyle RJ, Mah LJ, Licciardi PV, Tang ML
    Pediatr Allergy Immunol, 2014 Nov;25(7):674-84.
    PMID: 25376403 DOI: 10.1111/pai.12303
    Regulatory T cells (Treg) play an essential role in early immune programming and shaping the immune response towards a pro-allergic or tolerant state. We evaluated cord blood Treg and cytokine responses to microbial and non-microbial stimuli in infants at high risk of allergic disease and their associations with development of allergic disease in the first year.
    Matched MeSH terms: Lipopolysaccharides/immunology
  13. Sosroseno W, Bird PS, Seymour GJ
    Anaerobe, 2009 Jun;15(3):95-8.
    PMID: 19402196 DOI: 10.1016/j.anaerobe.2009.01.002
    The aim of this study was to determine the effect of exogenous nitric oxide (NO) on the induction of murine splenic immune response to Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) in vitro. BALB/c mice were immunized with A. actinomycetemcomitans LPS and a control group was sham-immunized. Spleen cells were obtained, cultured and stimulated with A. actinomycetemcomitans LPS with or without the presence of S-nitroso acetyl-penicillamine (SNAP), a NO donor, and carboxy-PTIO, an NO scavenger. Culture supernatants were assessed for inducible nitric oxide synthase (iNOS) activity, specific IgG subclass levels, and both IFN-gamma and IL-4 levels. The results showed that in A. actinomycetemcomitans LPS-stimulated cells, SNAP enhances iNOS activity but inhibits the levels of specific IgG2a and IFN-gamma suggesting a Th1 response. The effect of SNAP on these immune parameters was ablated by carboxy-PTIO. These results suggest that exogenous NO may suppress the Th1-like immune response of A. actinomycetemcomitans LPS-stimulated murine spleen cells.
    Matched MeSH terms: Lipopolysaccharides/immunology*
  14. Muniandy N, Love DN, Mukkur TK
    Comp Immunol Microbiol Infect Dis, 1998 Oct;21(4):257-79.
    PMID: 9775357
    Purified lipopolysaccharide (LPS) of Pasteurella multocida type 6:B, while toxic at higher doses, was protective at lower dose levels against experimentally-induced pasteurellosis in mice. However, the observed protection was abrogated if such LPS was digested with proteinase K prior to use in immunisation. The O-antigen polysaccharide side-chain (OS) of LPS did not appear to contribute to the observed protection as judged by the fact that immunisation of mice with purified OS or OS-protein conjugates, all of which were nontoxic, failed to confer protection against challenge with homologous virulent organisms. This was despite generation of significant levels of OS-specific antibodies, predominantly either of the IgM or IgG isotypes, in immunised mice.
    Matched MeSH terms: Lipopolysaccharides/immunology*
  15. Ibrahim ZA, Armour CL, Phipps S, Sukkar MB
    Mol Immunol, 2013 Dec;56(4):739-44.
    PMID: 23954397 DOI: 10.1016/j.molimm.2013.07.008
    The innate immune system forms the first line of protection against infectious and non-infectious tissue injury. Cells of the innate immune system detect pathogen-associated molecular patterns or endogenous molecules released as a result of tissue injury or inflammation through various innate immune receptors, collectively termed pattern-recognition receptors. Members of the Toll-like receptor (TLR) family of pattern-recognition receptors have well established roles in the host immune response to infection, while the receptor for advanced glycation end products (RAGE) is a pattern-recognition receptor predominantly involved in the recognition of endogenous molecules released in the context of infection, physiological stress or chronic inflammation. RAGE and TLRs share common ligands and signaling pathways, and accumulating evidence points towards their co-operative interaction in the host immune response. At present however, little is known about the mechanisms that result in TLR versus RAGE signalling or RAGE-TLR cross-talk in response to their shared ligands. Here we review what is known in relation to the physicochemical basis of ligand interactions between TLRs and RAGE, focusing on three shared ligands of these receptors: HMGB1, S100A8/A9 and LPS. Our aim is to discuss what is known about differential ligand interactions with RAGE and TLRs and to highlight important areas for further investigation so that we may better understand the role of these receptors and their relationship in host defense.
    Matched MeSH terms: Lipopolysaccharides/immunology
  16. Haque MA, Jantan I, Harikrishnan H
    Int Immunopharmacol, 2018 Feb;55:312-322.
    PMID: 29310107 DOI: 10.1016/j.intimp.2018.01.001
    Zerumbone (ZER), isolated mainly from the Zingiber zerumbet (Z. zerumbet) rhizomes was found to be effective against numerous inflammatory and immune disorders, however, the molecular and biochemical mechanisms underlying its anti-inflammatory and immunosuppressive properties have not been well studied. This study was carried out to examine the profound effects of ZER on inflammatory mediated MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways in LPS-stimulated U937 human macrophages. ZER significantly suppressed the up-regulation pro-inflammatory mediators, TNF-α, IL-1β, PGE2, and COX-2 protein in LPS-induced human macrophages. Moreover, ZER significantly downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/β as well as restored the degradation of IκBα. ZER correspondingly showed remarkable attenuation of the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a concentration-dependent manner. ZER also diminished the expression of upstream signaling molecules TLR4 and MyD88, which are prerequisite for the NF-κB, MAPK and PI3K-Akt activation. Additionally, quantification of relative gene expression of TNF-α, IL-1β, and COX-2 indicated that, at a higher dose (50μM), ZER significantly downregulated the elevated mRNA transcription levels of the stated pro-inflammatory markers in LPS-stimulated U937 macrophages. The strong suppressive effects of ZER on the activation of inflammatory markers in the macrophages via MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways suggest that ZER can be a preventive and potent therapeutic candidate for the management of various inflammatory-mediated immune disorders.
    Matched MeSH terms: Lipopolysaccharides/immunology
  17. Ng WL, Marinov GK, Liau ES, Lam YL, Lim YY, Ea CK
    RNA Biol, 2016 09;13(9):861-71.
    PMID: 27362560 DOI: 10.1080/15476286.2016.1207036
    Circular RNAs (circRNAs) constitute a large class of RNA species formed by the back-splicing of co-linear exons, often within protein-coding transcripts. Despite much progress in the field, it remains elusive whether the majority of circRNAs are merely aberrant splicing by-products with unknown functions, or their production is spatially and temporally regulated to carry out specific biological functions. To date, the majority of circRNAs have been cataloged in resting cells. Here, we identify an LPS-inducible circRNA: mcircRasGEF1B, which is predominantly localized in cytoplasm, shows cell-type specific expression, and has a human homolog with similar properties, hcircRasGEF1B. We show that knockdown of the expression of mcircRasGEF1B reduces LPS-induced ICAM-1 expression. Additionally, we demonstrate that mcircRasGEF1B regulates the stability of mature ICAM-1 mRNAs. These findings expand the inventory of functionally characterized circRNAs with a novel RNA species that may play a critical role in fine-tuning immune responses and protecting cells against microbial infection.
    Matched MeSH terms: Lipopolysaccharides/immunology
  18. Jesse FF, Ibrahim HH, Abba Y, Chung EL, Marza AD, Mazlan M, et al.
    BMC Vet Res, 2017 Apr 05;13(1):88.
    PMID: 28381248 DOI: 10.1186/s12917-017-1010-y
    BACKGROUND: Hemorrhagic septicemia is a fatal disease of cattle and buffaloes caused by P. multocida. Although the pathogenesis of the bacteria has been well established in literature, there is a paucity of information on the possible role of the bacteria and its immunogens; lipopolysaccharide (LPS) and outer membrane proteins (OMPs) on the reproductive capacity of buffalo heifers.

    METHODS: In this study, twenty one healthy prepubertal female buffaloes aged 8 months were divided into seven groups of 3 buffaloes each (G1-G7). Group 1 (G1) served as the negative control group and were inoculated orally with 10 mL sterile Phosphate Buffer Saline (PBS), groups 2 (G2) and 3 (G3) were inoculated orally and subcutaneously with 10 mL of 10(12) colony forming unit (cfu) of P.multocida type B: 2, while groups 4 (G4) and 5 (G5) received 10 mL of bacterial LPS orally and intravenously, respectively. Lastly, groups 6 (G6) and 7 (G7) were orally and subcutaneously inoculated with 10 mL of bacterial OMPs. Whole blood was collected in EDTA vials at stipulated time points (0, 2, 4, 6, 8, 10, 12, 24, 36, 48, 72, 120, 168, 216, 264, 312, 360, 408, 456 and 504 h), while tissue sections of the pituitary glands were collected and transported to the histopathology laboratory in 10% buffered formalin for processing and Hematoxylin and eosin staining. Plasma levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (PG), estradiol (EST) and gonadotrophin releasing hormone (GnRH) were determined.

    RESULTS: The histopathological lesions observed in the pituitary gland included hemorrhage, congestion, inflammatory cell infiltration, hydropic degeneration, necrosis and edema. These changes were higher (p 

    Matched MeSH terms: Lipopolysaccharides/immunology*
  19. Johnson RB, Dawkins HJ, Spencer TL, Saharee AA, Bahaman AR, Ramdani, et al.
    Res Vet Sci, 1989 Sep;47(2):277-9.
    PMID: 2508206
    ELISA and immunoblotting techniques were used to examine the humoral immune response to Pasteurella multocida, in bovine sera from Indonesia and Malaysia. Elevated levels of antibody to a crude lipopolysaccharide preparation were found in vaccinated animals. In addition to the response to lipopolysaccharide, antibodies from the vaccinated cattle strongly labelled five to six of the 40 protein bands in this organism.
    Matched MeSH terms: Lipopolysaccharides/immunology*
  20. Yu CY, Ang GY, Chua AL, Tan EH, Lee SY, Falero-Diaz G, et al.
    J Microbiol Methods, 2011 Sep;86(3):277-82.
    PMID: 21571011 DOI: 10.1016/j.mimet.2011.04.020
    Cholera is a communicable disease caused by consumption of contaminated food and water. This potentially fatal intestinal infection is characterised by profuse secretion of rice watery stool that can rapidly lead to severe dehydration and shock, thus requiring treatment to be given immediately. Epidemic and pandemic cholera are exclusively associated with Vibrio cholerae serogroups O1 and O139. In light of the need for rapid diagnosis of cholera and to prevent spread of outbreaks, we have developed and evaluated a direct one-step lateral flow biosensor for the simultaneous detection of both V. cholerae O1 and O139 serogroups using alkaline peptone water culture. Serogroup specific monoclonal antibodies raised against lipopolysaccharides (LPS) were used to functionalize the colloidal gold nanoparticles for dual detection in the biosensor. The assay is based on immunochromatographic principle where antigen-antibody reaction would result in the accumulation of gold nanoparticles and thus, the appearance of a red line on the strip. The dry-reagent dipstick format of the biosensor ensure user-friendly application, rapid result that can be read with the naked eyes and cold-chain free storage that is well-suited to be performed at resource-limited settings.
    Matched MeSH terms: Lipopolysaccharides/immunology
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links