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Pulmonary lipopolysaccharide (LPS)-binding protein inhibits the LPS-induced lung inflammation in vivo 总被引:1,自引:0,他引:1
Knapp S Florquin S Golenbock DT van der Poll T 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(5):3189-3195
LPS-binding protein (LBP) facilitates the interaction of the Gram-negative cell wall component LPS with CD14, thereby enhancing the immune response to LPS. Although lung epithelial cells have been reported to produce LBP in vitro, knowledge of the in vivo role of pulmonary LBP is limited. Therefore, in the present study we sought to determine the function of pulmonary LBP in lung inflammation induced by intranasal administration of LPS in vivo. Using LBP-deficient (LBP-/-) and normal wild-type mice, we show that the contribution of LBP to pulmonary LPS responsiveness depended entirely on the LPS dose. Although the inflammatory response to low dose (1 ng) LPS was attenuated in LBP-/- mice, neutrophil influx and cytokine/chemokine concentrations in the bronchoalveolar compartment were enhanced in LBP-/- mice treated with higher (>10 ng) LPS doses. This finding was specific for LBP, because the exogenous administration of LBP to LBP-/- mice reversed this phenotype and reduced the local inflammatory response to higher LPS doses. Our results indicate that pulmonary LBP acts as an important modulator of the LPS response in the respiratory tract in vivo. This newly identified function of pulmonary LBP might prove beneficial by enabling a protective immune response to low LPS doses while preventing an overwhelming, potentially harmful immune response to higher doses of LPS. 相似文献
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Leoratti FM Trevelin SC Cunha FQ Rocha BC Costa PA Gravina HD Tada MS Pereira DB Golenbock DT Antonelli LR Gazzinelli RT 《PLoS neglected tropical diseases》2012,6(6):e1710
Background
The activation of innate immune responses by Plasmodium vivax results in activation of effector cells and an excessive production of pro-inflammatory cytokines that may culminate in deleterious effects. Here, we examined the activation and function of neutrophils during acute episodes of malaria.Materials and Methods
Blood samples were collected from P. vivax-infected patients at admission (day 0) and 30–45 days after treatment with chloroquine and primaquine. Expression of activation markers and cytokine levels produced by highly purified monocytes and neutrophils were measured by the Cytometric Bead Assay. Phagocytic activity, superoxide production, chemotaxis and the presence of G protein-coupled receptor (GRK2) were also evaluated in neutrophils from malaria patients.Principal Findings
Both monocytes and neutrophils from P. vivax-infected patients were highly activated. While monocytes were found to be the main source of cytokines in response to TLR ligands, neutrophils showed enhanced phagocytic activity and superoxide production. Interestingly, neutrophils from the malaria patients expressed high levels of GRK2, low levels of CXCR2, and displayed impaired chemotaxis towards IL-8 (CXCL8).Conclusion
Activated neutrophils from malaria patients are a poor source of pro-inflammatory cytokines and display reduced chemotactic activity, suggesting a possible mechanism for an enhanced susceptibility to secondary bacterial infection during malaria. 相似文献14.
Recruitment and endo-lysosomal activation of TLR9 in dendritic cells infected with Trypanosoma cruzi
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Lisa K. Ryan Douglas T. Golenbock Jiayi Wu Mary W. Vermeulen 《In vitro cellular & developmental biology. Animal》1997,33(8):647-653
Summary Alveolar macrophages, which play a central role in lung defense, produce cytokines that help orchestrate local inflammatory
responses. In sepsis and other pathological conditions, bacterial lipopolysaccharide endotoxin can induce alveolar macrophages
(AM) to release proinflammatory cytokines, including tumor necrosis factor-alpha, interleukin-1, and interleukin-6. Studying
the mechanisms that control alveolar macrophage cytokine production may lead to better therapies for conditions involving
inflammatory lung injury. We and others have noted significant differences between alveolar macrophages and peritoneal macrophages,
but large numbers of human or murine alveolar macrophages are rarely available for detailed mechanistic studies. We have obtained
three murine alveolar macrophage cell lines (AMJ2C8, AMJ2C11, and AMJ2C20) and have begun to characterize their cytokine responses
to proinflammatory stimuli. We measured the effects of endotoxin, interferon gamma, and the combination of the two on production
of tumor necrosis factor, interleukin-1 beta, and interleukin-6 in each line. We also studied the expression of the endotoxin
receptor CD14 by these cells, and investigated the effect of serum on their endotoxin responsiveness. We show here that all
three of the cell lines responded in a manner comparable to that of primary murine alveolar macrophages. Observed variations
between these lines may reflect the documented heterogeneity seen in populations of primary alveolar macrophages. These cell
lines should expand the repertoire of tools available to investigators studying regulation of murine alveolar macrophage responses. 相似文献
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Distribution of amiloride-sensitive sodium channels in the oral cavity of the hamster 总被引:3,自引:3,他引:0
The distribution of amiloride-sensitive sodium channels (ASSCs) in taste
buds isolated from the oral cavity of hamsters was assessed by patch clamp
recording. In contrast to the case for rats, taste cells from the
fungiform, foliate and vallate papillae and from the soft palate all
contain functional ASSCs. The differential distribution of ASSCs between
the hamster and the rat may be important for understanding the physiology
underlying the differing behavioral responses of these species to sodium
salts.
相似文献
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Tobias Strunk Melanie R. Power Coombs Andrew J. Currie Peter Richmond Douglas T. Golenbock Liat Stoler-Barak Leighanne C. Gallington Michael Otto David Burgner Ofer Levy 《PloS one》2010,5(4)
Background
Staphylococcus epidermidis (SE) is a nosocomial pathogen that causes catheter-associated bacteremia in the immunocompromised, including those at the extremes of age, motivating study of host clearance mechanisms. SE-derived soluble components engage TLR2; but additional signaling pathways have also been implicated, and TLR2 can play complex, at times detrimental, roles in host defense against other Staphylococcal spp. The role of TLR2 in responses of primary blood leukocytes to live SE and in clearance of SE bacteremia, the most common clinical manifestation of SE infection, is unknown.Methodology/Principal Findings
We studied TLR2-mediated recognition of live clinical SE strain 1457 employing TLR2-transfected cells, neutralizing anti-TLR antibodies and TLR2-deficient mice. TLR2 mediated SE-induced cytokine production in human embryonic kidney cells, human whole blood and murine primary macrophages, in part via recognition of a soluble TLR2 agonist. After i.v. challenge with SE, early (1 h) cytokine/chemokine production and subsequent clearance of bacteremia (24–48 h) were markedly impaired in TLR2-deficient mice.Conclusions/Significance
TLR2 mediates recognition of live SE and clearance of SE bacteremia in vivo. 相似文献19.
Caetano BC Carmo BB Melo MB Cerny A dos Santos SL Bartholomeu DC Golenbock DT Gazzinelli RT 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(4):1903-1911
UNC93B1 associates with TLR3, 7, and 9, mediating their translocation from the endoplasmic reticulum to the endolysosome, thus allowing proper activation by microbial nucleic acids. We found that the triple-deficient 3d mice, which lack functional UNC93B1 as well as functional endosomal TLRs, are highly susceptible to infection with Trypanosoma cruzi. The enhanced parasitemia and mortality in 3d animals were associated with impaired proinflammatory response, including reduced levels of IL-12p40 and IFN-γ. Importantly, the phenotype of 3d mice was intermediary between MyD88(-/-) (highly susceptible) and TLR9(-/-) (moderately susceptible), indicating the involvement of an additional UN93B1-dependent TLR(s) on host resistance to T. cruzi. Hence, our experiments also revealed that TLR7 is a critical innate immune receptor involved in recognition of parasite RNA, induction of IL-12p40 by dendritic cells, and consequent IFN-γ by T lymphocytes. Furthermore, we show that upon T. cruzi infection, triple TLR3/7/9(-/-) mice had similar phenotype than 3d mice. These data imply that the nucleic acid-sensing TLRs are critical determinants of host resistance to primary infection with T. cruzi. 相似文献
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