Brucella Lipopolysaccharides Induce Cyclooxygenase-2 Expression in Monocytic Cells

López-Urrutia, Luis; Bayón, Yolanda; Nieto, Marı́a Luisa; Orduña, Antonio; Crespo, Mariano Sánchez

doi:10.1006/bbrc.2001.5995

Cited by 18 publications

(8 citation statements)

References 20 publications

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“…On the other hand, B. melitensis LPS has strong anti-complement and adjuvant activities. The low level of biological activities of B. melitensis M16 LPS is consistent with the previous studies on B. melitensis LPS (7,(23)(24)(25). The lower biological activities of B. melitensis LPS may be based on the lipid A structure.…”

Section: Discussionsupporting

confidence: 91%

“…However, the chemical structure of B. melitensis LPS is not as fully clarified as that of B. abortus LPS. Further, there is no systemic study on the biological activities of B. melitensis LPS, although some biological activities are reported (7,(23)(24)(25). In the present study, we compared the biological activities of B. melitensis LPS with those of enterobacterial LPS in order to characterize the biological activities of B. melitensis LPS.…”

mentioning

confidence: 97%

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Characterization of Biological Activities of Brucella melitensis Lipopolysaccharide

Tumurkhuu

Koide

Takahashi

et al. 2006

Microbiology and Immunology

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Brucella are Gram-negative intracellular pathogens which survive within a variety of cells including macrophages and maintain a long-lasting interaction with the host cells (11,15). The infection leads to acute and chronic inflammation related to the brisk interaction of Brucella-derived products, such as lipopolysaccharide (LPS) with the host cells. In fact, Brucella LPS is reported to act as a virulence factor of the infection (19,22). Most wild-type Brucella have smooth type LPS (S-LPS) consisting of three domains: lipid A, core oligosaccharide, and O-specific polysaccharide (21). Among Brucella LPSs, LPS from B. abortus has been extensively characterized (reviewed in 22). The lipid A moiety of B. abortus LPS has a fatty acid composition quite distinct from that of enterobacterial LPS. Specifically, the lipid A moiety of B. abortus LPS possesses a diaminoglucose backbone, and the acyl groups are longer (C18-19, C28) and are only linked to the core by amide bounds (22,30). Further, the O antigen of Brucella LPS is a homopolymer of perosamine (4,6-dideoxy-4-formamido-d-mannopyranosyl) (3, 27, 37). The biological activities such as cytokine production and lethality of S-LPS and rough types of LPS (R-LPS) from various Brucella strains are reported to be lower than those of enterobacterial LPS (4,14,25,29). The lower endotoxicity seems to be responsible for the unique lipid A structure of Brucella LPS. Thus, LPS from B. abortus has been studied as a representative of Brucella. On the other hand, B. melitensis is another main pathogenic species for humans worldwide (6). However, the chemical structure of B. melitensis LPS is not as fully clarified as that of B. abortus LPS. Further, there is no systemic study on the biological activities of B. melitensis LPS, although some biological activities are reported (7,(23)(24)(25). In the present study, we compared the biological activities of B. melitensis LPS with those of enterobacterial LPS in order to characterize the biological activities of B. melitensis LPS. Materials and Methods LPS.Crude LPS preparation was extracted from B. melitensis 16M (biotype 1). Briefly, washed cells of B. melitensis were autoclaved at 120 C for 30 min. After removal of the cell debris by centrifugation, the crude LPS fraction was precipitated with methanol, dialyzed and freeze-dried. For further purification, the LPS preparation was digested with DNase I, RNase and pro- Characterization of Biological Activities of

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Section: Discussionsupporting

confidence: 91%

mentioning

confidence: 97%

Characterization of Biological Activities of Brucella melitensis Lipopolysaccharide

Tumurkhuu

Koide

Takahashi

et al. 2006

Microbiology and Immunology

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“…COX-1 is constitutively expressed, whereas COX-2 is expressed at low level by most normal resting cells. COX-2 expression is induced by various TLR ligands (11,12) and release of PGs is significantly increased in various animal models of endotoxemia or sepsis (13,14). In particular, PGE 2 has been shown to function as a mediator of sepsis-induced immunosuppression, an inhibitor of proinflammatory cytokine production by macrophages, and an inducer of IL-10 production (15).…”

Section: T Riggering Receptor Expressed On Myeloid Cells-1 (Trem-1)mentioning

confidence: 99%

Lipopolysaccharide-Induced Up-Regulation of Triggering Receptor Expressed on Myeloid Cells-1 Expression on Macrophages Is Regulated by Endogenous Prostaglandin E2

Murakami

Kohsaka

Kitasato

et al. 2007

The Journal of Immunology

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Triggering receptor expressed on myeloid cells-1 (TREM-1) is a recently identified cell surface molecule that is expressed by neutrophils and monocytes. TREM-1 expression is modulated by various ligands for TLRs in vitro and in vivo. However, the influence of PGE2, a potential mediator of inflammation, on TREM-1 expression has not been elucidated. In this study, we examined the effects of PGE2 on LPS-induced TREM-1 expression by resident murine peritoneal macrophages (RPM) and human PBMC. PGE2 significantly induced murine TREM-1 (mTREM-1) expression by RPM. Up-regulation of TREM-1 expression was specific to PGE2 among arachidonic acid metabolites, while ligands for chemoattractant receptor-homologous molecule expressed on Th2 cells and the thomboxane-like prostanoid receptor failed to induce mTREM-1 expression. PGE2 also increased expression of the soluble form of TREM-1 by PBMC. LPS-induced TREM-1 expression was regulated by endogenous PGE2 especially in late phase (>2 h after stimulation), because cyclooxygenase-1 and -2 inhibitors abolished this effect at that points. A synthetic EP4 agonist and 8-Br-cAMP also enhanced mTREM-1 expression by RPM. Furthermore, protein kinase A, PI3K, and p38 MAPK inhibitors prevented PGE2-induced mTREM-1 expression by RPM. Activation of TREM-1 expressed on PGE2-pretreated PBMC by an agonistic TREM-1 mAb significantly enhanced the production of IL-8 and TNF-α. These findings indicate that LPS-induced TREM-1 expression on macrophages is mediated, at least partly, by endogenous PGE2 followed by EP4 and cAMP, protein kinase A, p38 MAPK, and PI3K-mediated signaling. Regulation of TREM-1 and the soluble form of TREM-1 expression by PGE2 may modulate the inflammatory response to microbial pathogens.

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“…ЦОГ 1 конститутивно представлена на покоящихся клет ках. При эндотоксемии и сепсисе лиганды TLR индуцируют экспрессию ЦОГ 2, значительно повышая синтез простаглан динов [30,31], что, в свою очередь, стимулирует экспрессию TREM 1.…”

Section: рис 1 схема основных сигнальных путей Tlrs и Tremunclassified

Role of Triggering Receptor Expressed on Myeloid Cells in the Activation of Innate Immunity

Матвеева¹,

Головкин²,

Григорьев³

et al. 2011

rmt

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Brucella Lipopolysaccharides Induce Cyclooxygenase-2 Expression in Monocytic Cells

Cited by 18 publications

References 20 publications

Characterization of Biological Activities of Brucella melitensis Lipopolysaccharide

Characterization of Biological Activities of Brucella melitensis Lipopolysaccharide

Lipopolysaccharide-Induced Up-Regulation of Triggering Receptor Expressed on Myeloid Cells-1 Expression on Macrophages Is Regulated by Endogenous Prostaglandin E2

Role of Triggering Receptor Expressed on Myeloid Cells in the Activation of Innate Immunity

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