Role of PAR2 in murine pulmonary pseudomonal infection

Proteinases can influence lung inflammation by various mechanisms, including via cleavage and activation of protease-activated receptors (PAR) such as PAR2. In addition, proteinases such as neutrophil and/or Pseudomonas-derived elastase can disarm PAR2 resulting in loss of PAR2 signaling. Currently, the role of PAR2 in host defense against bacterial infection is not known. Using a murine model of acute Pseudomonas aeruginosa pneumonia, we examined differences in the pulmonary inflammatory response between wild-type and PAR2−/−mice. Compared with wild-type mice, PAR2−/−mice displayed more severe lung inflammation and injury in response to P. aeruginosa infection as indicated by higher bronchoalveolar lavage fluid neutrophil numbers, protein concentration, and TNF-α levels. By contrast, IFN-γ levels were markedly reduced in PAR2−/−compared with wild-type mice. Importantly, clearance of P. aeruginosa was diminished in PAR2−/−mice. In vitro testing revealed that PAR2−/−neutrophils killed significantly less bacteria than wild-type murine neutrophils. Further, both neutrophils and macrophages from PAR2−/−mice displayed significantly reduced phagocytic efficiency compared with wild-type phagocytes. Stimulation of PAR2 on macrophages using a PAR2-activating peptide resulted in enhanced phagocytosis directly implicating PAR2 signaling in the phagocytic process. We conclude that genetic deletion of PAR2 is associated with decreased clearance of P. aeruginosa. Our data suggest that a deficiency in IFN-γ production and impaired bacterial phagocytosis are two potential mechanisms responsible for this defect.

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Effect of PAR-2 Deficiency in Mice on KC Expression after Intratracheal LPS Administration

Journal of Signal Transduction ◽

10.1155/2011/415195 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 7

Author(s):

Julie C. Williams ◽

Rebecca D. Lee ◽

Claire M. Doerschuk ◽

Nigel Mackman

Keyword(s):

Lung Inflammation ◽

Lavage Fluid ◽

Peritoneal Macrophages ◽

Wild Type ◽

Protease Activated Receptors ◽

Tlr4 Signaling ◽

Bronchial Lavage ◽

Lps Activation ◽

Deficient Mice

Protease activated receptors (PAR) have been shown to play a role in inflammation. PAR-2 is expressed by numerous cells in the lung and has either proinflammatory, anti-inflammatory, or no effect depending on the model. Here, we examined the role of PAR-2 in a model of LPS-induced lung inflammation. We found that PAR-2-deficient mice had significantly less KC expression in bronchial lavage fluid compared with wild-type mice but there was no difference in MIP-2 or TNF-α expression. We also found that isolated alveolar and resident peritoneal macrophages lacking PAR-2 showed a similar deficit in KC after LPS stimulation without differences in MIP-2 or TNF-α. Infiltration of neutrophils and macrophages into the lung following LPS administration was not affected by an absence of PAR-2. Our results support the notion that PAR-2 plays a role in LPS activation of TLR4 signaling in macrophages.

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Cellular recruitment and cytokine generation in a rat model of allergic lung inflammation are differentially modulated by progesterone and estradiol

AJP Cell Physiology ◽

10.1152/ajpcell.00286.2006 ◽

2007 ◽

Vol 293 (3) ◽

pp. C1120-C1128 ◽

Cited By ~ 45

Author(s):

Ana Paula Ligeiro de Oliveira ◽

Helori Vanni Domingos ◽

Gabriela Cavriani ◽

Amilcar Sabino Damazo ◽

Adriana Lino dos Santos Franco ◽

...

Keyword(s):

Lung Inflammation ◽

Estradiol Treatment ◽

Cell Recruitment ◽

Ovx Rats ◽

Allergic Lung Inflammation ◽

Tnf Α ◽

Cellular Recruitment ◽

Additional Reduction

We evaluated the role of estradiol and progesterone in allergic lung inflammation. Rats were ovariectomized (Ovx) and, 7 days later, were sensitized with ovalbumin (OA) and challenged after 2 wk with inhaled OA; experiments were performed 1 day thereafter. Ovx-allergic rats showed reduced cell recruitment into the bronchoalveolar lavage (BAL) fluid relative to sham-Ovx allergic rats, as was observed in intact allergic rats treated with ICI-182,780. Estradiol increased the number of cells in the BAL of Ovx-allergic rats, whereas progesterone induced an additional reduction. Cells of BAL and bone marrow (BM) of Ovx-allergic rats released elevated amounts of IL-10 and reduced IL-1β and TNF-α. BM cells of Ovx-allergic rats released increased amounts of IL-10 and lower amounts of IL-4. Estradiol treatment of Ovx-allergic rats decreased the release of IL-10 but increased that of IL-4 by BM cells. Estradiol also caused an increased release of IL-1β and TNF-α by BAL cells. Progesterone significantly increased the release of IL-10, IL-1β, and TNF-α by BAL cells and augmented that of IL-4 by BM cells. Degranulation of bronchial mast cells from Ovx rats was reduced after in vitro challenge, an effect reverted by estradiol but not by progesterone. We suggest that the serum estradiol-to-progesterone ratio might drive cellular recruitment, modulating the pulmonary allergy and profile of release of anti-inflammatory or inflammatory cytokines. The existence of such dual hormonal effects suggests that the hormone therapy of asthmatic postmenopausal women and of those suffering of premenstrual asthma should take into account the possibility of worsening the pulmonary conditions.

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Adiponectin deficiency does not affect development and progression of spontaneous colitis in IL-10 knockout mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.90593.2008 ◽

2009 ◽

Vol 296 (2) ◽

pp. G382-G387 ◽

Cited By ~ 15

Author(s):

Maria Pini ◽

Melissa E. Gove ◽

Raja Fayad ◽

Robert J. Cabay ◽

Giamila Fantuzzi

Keyword(s):

Colonic Tissue ◽

Mesenteric Lymph Nodes ◽

Amyloid A ◽

Mesenteric Lymph ◽

Tnf Α ◽

Ifn Γ ◽

Circulating Levels ◽

Similar Decrease

The goal of this study was to investigate the role of the adipokine adiponectin (APN) in development of spontaneous colitis in IL-10 knockout (KO) mice. To this aim, we generated double IL-10 APN KO mice and compared their disease development to that of single IL-10 KO mice. Both IL-10 KO and double IL-10 APN KO mice spontaneously developed colitis of comparable severity. No significant differences in inflammatory infiltrate or crypt elongation were observed in colonic tissue obtained from IL-10 KO and double IL-10 APN KO mice at either 12 or 20 wk of age. A comparable increase in circulating levels of serum amyloid A and IFN-γ was observed in IL-10 KO and double IL-10 APN KO mice as disease progressed. In vitro stimulation of lymphocytes from mesenteric lymph nodes with anti-CD3 and anti-CD28 induced a significantly higher production of IL-17 and TNF-α in IL-10 KO and double IL-10 APN KO mice compared with their healthy littermates. No significant differences in cytokine production from lymphocytes or colonic mRNA expression of cytokines were observed between IL-10 KO and double IL-10 APN KO mice. Both IL-10 KO and double IL-10 APN KO mice had a similar decrease in body weight and bone mass compared with their respective healthy littermates. Finally, APN deficiency did not lead to development of insulin resistance, either in APN KO or double IL-10 APN KO mice. In conclusion, lack of APN does not play a significant role in the pathogenesis of spontaneous colonic inflammation in the IL-10 KO model.

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IL-1R and MyD88 signalling in CD4+ T cells promote Th17 immunity and atherosclerosis

Cardiovascular Research ◽

10.1093/cvr/cvx196 ◽

2017 ◽

Vol 114 (1) ◽

pp. 180-187 ◽

Cited By ~ 10

Author(s):

Daniel Engelbertsen ◽

Sara Rattik ◽

Maria Wigren ◽

Jenifer Vallejo ◽

Goran Marinkovic ◽

...

Keyword(s):

T Cells ◽

High Fat Diet ◽

Cd4 T Cells ◽

Wild Type ◽

T Helper ◽

High Fat ◽

Lesion Development ◽

Ifn Γ

Abstract Aims The role of CD4+ T cells in atherosclerosis has been shown to be dependent on cytokine cues that regulate lineage commitment into mature T helper sub-sets. In this study, we tested the roles of IL-1R1 and MyD88 signalling in CD4+ T cells in atherosclerosis. Methods and results We transferred apoe-/-myd88+/+ or apoe-/-myd88-/- CD4+ T cells to T- and B-cell-deficient rag1-/-apoe-/- mice fed high fat diet. Mice given apoe-/-myd88-/- CD4+ T cells exhibited reduced atherosclerosis compared with mice given apoe-/-myd88+/+ CD4+ T cells. CD4+ T cells from apoe-/-myd88-/- produced less IL-17 but similar levels of IFN-γ. Treatment of human CD4+ T cells with a MyD88 inhibitor inhibited IL-17 secretion in vitro. Transfer of il1r1-/- CD4+ T cells recapitulated the phenotype seen by transfer of myd88-/- CD4+ T cells with reduced lesion development and a reduction in Th17 and IL-17 production compared with wild type CD4+ T cell recipients. Relative collagen content of lesions was reduced in mice receiving il1r1-/- CD4+ T cells. Conclusion We demonstrate that both IL1R and MyD88 signalling in CD4+ T cells promote Th17 immunity, plaque growth and may regulate plaque collagen levels.

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Less Airway Inflammation and Goblet Cell Metaplasia in an IL-33-Induced Asthma Model of Leptin-Deficient Obese Mice

10.21203/rs.3.rs-82709/v1 ◽

2020 ◽

Author(s):

Atsushi Kurokawa ◽

Mitsuko Kondo ◽

Ken Arimura ◽

Shigeru Ashino ◽

Etsuko Tagaya

Keyword(s):

Goblet Cell ◽

In Vitro Study ◽

Lavage Fluid ◽

Forced Oscillation Technique ◽

Wild Type ◽

Asthma Model ◽

Goblet Cell Metaplasia

Abstract BackgroundAsthma with obesity is a phenotype of severe asthma. Leptin exerts an immunomodulatory effect and its level is increased in obesity. IL-33 is associated with innate immunity and induces type 2 inflammation, and is present in adipose tissue. However, the role of IL-33 and leptin in obesity-associated asthma is not fully understood. We examined the effect of IL-33 on eosinophilic inflammation, goblet cell metaplasia, and airway responsiveness in leptin-deficient obese (ob/ob) and wild-type mice, and examined the effect of exogenous leptin pretreatment. MethodsIn ob/ob and wild-type mice, IL-33 was instilled intranasally on three consecutive days. In part of the animals, leptin was injected intraperitoneally prior to IL-33 treatment. The mice were challenged with methacholine and resistance of the respiratory system (Rrs) was measured using the forced oscillation technique. Cell differentiation, IL-5, IL-13, eotaxin, KC in bronchoalveolar lavage fluid (BALF), and histology of the lung were analyzed. For the in vitro study, NCI-H292 cells were stimulated with IL-33 in the presence or absence of leptin, and MUC5AC levels were measured by ELISA. ResultsOb/ob mice showed greater baseline Rrs than wild-type mice. IL-33 and IL-33 with leptin did not enhance Rrs challenged with methacholine compared to non-treatment in ob/ob mice, whereas IL-33 with leptin enhanced Rrs in wild-type mice. Ob/ob mice showed less IL-33-induced eosinophil numbers, IL-5, IL-13, eotaxin, and KC levels in BALF and eosinophilic infiltration around bronchi and goblet cell metaplasia than wild-type mice, but leptin pretreatment attenuated these changes in ob/ob mice. MUC5AC levels were increased by co-stimulation with IL-33 and leptin in vitro . ConclusionsLeptin plays an important role in IL-33-induced inflammation and goblet cell metaplasia in the airway, but obesity per se increases airway hyperresponsiveness independent of inflammation. These results explain some aspects of the pathogenesis of obesity-related asthma.

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IFN-γ deficiency attenuates hepatic inflammation and fibrosis in a steatohepatitis model induced by a methionine- and choline-deficient high-fat diet

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00193.2013 ◽

2013 ◽

Vol 305 (12) ◽

pp. G891-G899 ◽

Cited By ~ 33

Author(s):

Xiao-Yu Luo ◽

Terumi Takahara ◽

Kengo Kawai ◽

Masayuki Fujino ◽

Toshiro Sugiyama ◽

...

Keyword(s):

Tumor Necrosis ◽

Tumor Necrosis Factor Α ◽

Wild Type ◽

High Fat ◽

Tnf Α ◽

Ifn Γ ◽

Factor Α ◽

Deficient Mice ◽

Necrosis Factor

Cytokines play important roles in all stages of steatohepatitis, including hepatocyte injury, the inflammatory response, and the altered function of sinusoidal cells. This study examined the involvement of a major inflammatory cytokine, interferon-γ (IFN-γ), in the progression of steatohepatitis. In a steatohepatitis model by feeding a methionine- and choline-deficient high-fat (MCDHF) diet to both wild-type and IFN-γ-deficient mice, the liver histology, expression of genes encoding inflammatory cytokines, and fibrosis-related markers were examined. To analyze the effects of IFN-γ on Kupffer cells in vitro, we examined the tumor necrosis factor-α (TNF-α) production by a mouse macrophage cell line. Forty two days of MCDHF diet resulted in weight loss, elevated aminotransferases, liver steatosis, and inflammation in wild-type mice. However, the IFN-γ-deficient mice exhibited less extensive changes. RT-PCR revealed that the expression of tumor necrosis factor-α (TNF-α), transforming growth factor-β, inducible nitric oxide synthase, interleukin-4 and osteopontin were increased in wild-type mice, although they were suppressed in IFN-γ-deficient mice. Seventy days of MCDHF diet induced much more liver fibrosis in wild-type mice than in IFN-γ-deficient mice. The expression levels of fibrosis-related genes, α-smooth muscle actin, type I collagen, tissue inhibitor of matrix metalloproteinase-1, and matrix metalloproteinase-2, were dramatically increased in wild-type mice, whereas they were significantly suppressed in IFN-γ-deficient mice. Moreover, in vitro experiments showed that, when RAW 264.7 macrophages were treated with IFN-γ, they produced TNF-α in a dose-dependent manner. The present study showed that IFN-γ deficiency might inhibit the inflammatory response of macrophages cells and subsequently suppress stellate cell activation and liver fibrosis. These findings highlight the critical role of IFN-γ in the progression of steatohepatitis.

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Regulation of macrophage procoagulant responses by the tissue factor cytoplasmic domain in endotoxemia

Blood ◽

10.1182/blood-2006-10-051334 ◽

2007 ◽

Vol 109 (12) ◽

pp. 5251-5259 ◽

Cited By ~ 37

Author(s):

Jasimuddin Ahamed ◽

Frank Niessen ◽

Toru Kurokawa ◽

Young Kyung Lee ◽

Gourab Bhattacharjee ◽

...

Keyword(s):

Tissue Factor ◽

Cytoplasmic Domain ◽

Interferon Γ ◽

Wild Type ◽

Coagulation Activation ◽

Proinflammatory Response ◽

Protease Activated Receptors ◽

Lps Challenge

Abstract Tissue factor (TF) is the primary initiator of coagulation, and the TF pathway mediates signaling through protease-activated receptors (PARs). In sepsis, TF is up-regulated as part of the proinflammatory response in lipopolysaccharide (LPS)–stimulated monocytes leading to systemic coagulation activation. Here we demonstrate that TF cytoplasmic domain–deleted (TFΔCT) mice show enhanced and prolonged systemic coagulation activation relative to wild-type upon LPS challenge. However, TFΔCT mice resolve inflammation earlier and are protected from lethality independent of changes in coagulation. Macrophages from LPS-challenged TFΔCT mice or LPS-stimulated, in vitro–differentiated bone marrow–derived macrophages show increased TF mRNA and functional activity relative to wild-type, identifying up-regulation of macrophage TF expression as a possible cause for the increase in coagulation of TFΔCT mice. Increased TF expression of TFΔCT macrophages does not require PAR2 and is specific for toll-like receptor, but not interferon γ receptor, signaling. The presence of the TF cytoplasmic domain suppresses ERK1/2 phosphorylation that is reversed by p38 inhibition leading to enhanced TF expression specifically in wild-type but not TFΔCT mice. The present study demonstrates a new role of the TF cytoplasmic domain in an autoregulatory pathway that controls LPS-induced TF expression in macrophages and procoagulant responses in endotoxemia.

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Hydrogen sulfide dysregulates the immune response by suppressing central carbon metabolism to promote tuberculosis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1919211117 ◽

2020 ◽

Vol 117 (12) ◽

pp. 6663-6674 ◽

Cited By ~ 9

Author(s):

Md. Aejazur Rahman ◽

Bridgette M. Cumming ◽

Kelvin W. Addicott ◽

Hayden T. Pacl ◽

Shannon L. Russell ◽

...

Keyword(s):

Immune Response ◽

Hydrogen Sulfide ◽

Adaptive Immune Response ◽

Central Carbon Metabolism ◽

Pentose Phosphate ◽

Colony Forming Units ◽

Tnf Α ◽

Ifn Γ

The ubiquitous gasotransmitter hydrogen sulfide (H2S) has been recognized to play a crucial role in human health. Using cystathionine γ-lyase (CSE)-deficient mice, we demonstrate an unexpected role of H2S inMycobacterium tuberculosis(Mtb) pathogenesis. We showed thatMtb-infected CSE−/−mice survive longer than WT mice, and support reduced pathology and lower bacterial burdens in the lung, spleen, and liver. Similarly, in vitroMtbinfection of macrophages resulted in reduced colony forming units in CSE−/−cells. Chemical complementation of infected WT and CSE−/−macrophages using the slow H2S releaser GYY3147 and the CSE inhibitor DL-propargylglycine demonstrated that H2S is the effector molecule regulatingMtbsurvival in macrophages. Furthermore, we demonstrate that CSE promotes an excessive innate immune response, suppresses the adaptive immune response, and reduces circulating IL-1β, IL-6, TNF-α, and IFN-γ levels in response toMtbinfection. Notably,Mtbinfected CSE−/−macrophages show increased flux through glycolysis and the pentose phosphate pathway, thereby establishing a critical link between H2S and central metabolism. Our data suggest that excessive H2S produced by the infected WT mice reduce HIF-1α levels, thereby suppressing glycolysis and production of IL-1β, IL-6, and IL-12, and increasing bacterial burden. Clinical relevance was demonstrated by the spatial distribution of H2S-producing enzymes in human necrotic, nonnecrotic, and cavitary pulmonary tuberculosis (TB) lesions. In summary, CSE exacerbates TB pathogenesis by altering immunometabolism in mice and inhibiting CSE or modulating glycolysis are potential targets for host-directed TB control.

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Multiple T Cell Subsets Control Francisella tularensis LVS Intracellular Growth Without Stimulation Through Macrophage Interferon γ Receptors

Journal of Experimental Medicine ◽

10.1084/jem.20030687 ◽

2003 ◽

Vol 198 (3) ◽

pp. 379-389 ◽

Cited By ~ 81

Author(s):

Siobhán C. Cowley ◽

Karen L. Elkins

Keyword(s):

T Cells ◽

T Cell ◽

Francisella Tularensis ◽

T Cell Subsets ◽

Wild Type ◽

Intracellular Growth ◽

Tnf Α ◽

Ifn Γ

A variety of data suggest that in vivo production of interferon (IFN)-γ is necessary, but not sufficient, for expression of secondary protective immunity against intracellular pathogens. To discover specific IFN-γ–independent T cell mediated mechanisms, we took advantage of an in vitro culture system that models in vivo immune responses to the intracellular bacterium Francisella tularensis live vaccine strain (LVS). LVS-immune lymphocytes specifically controlled 99% of the growth of LVS in wild-type murine bone marrow–derived macrophages. Surprisingly, LVS-immune lymphocytes also inhibited LVS intracellular growth by as much as 95% in macrophages derived from IFN-γ receptor knockout (IFNγR KO) mice. CD8+ T cells, and to a lesser degree CD4+ T cells, controlled LVS intracellular growth in both wild-type and IFNγR KO macrophages. Further, a unique population of Thy1+αβ+CD4−CD8− cells that was previously suggested to operate during secondary immunity to LVS in vivo strongly controlled LVS intracellular growth in vitro. A large proportion of the inhibition of LVS intracellular growth in IFNγR KO macrophages by all three T cell subsets could be attributed to tumor necrosis factor (TNF) α. Thus, T cell mechanisms exist that control LVS intracellular growth without acting through the IFN-γ receptor; such control is due in large part to TNF-α, and is partially mediated by a unique double negative T cell subpopulation.

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Streptococcus pneumoniae evades host cell phagocytosis and limits host mortality through its cell wall anchoring protein PfbA

10.1101/599001 ◽

2019 ◽

Author(s):

Masaya Yamaguchi ◽

Yujiro Hirose ◽

Moe Takemura ◽

Masayuki Ono ◽

Tomoko Sumitomo ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Bronchoalveolar Lavage Fluid ◽

Lavage Fluid ◽

Bacterial Burden ◽

Wild Type ◽

Tnf Α ◽

Anchoring Protein ◽

Host Mortality ◽

Peptide Treatment

AbstractStreptococcus pneumoniae is a Gram-positive bacterium belonging to the oral streptococcus species, mitis group. This pathogen is a leading cause of community-acquired pneumonia, which often evades host immunity and causes systemic diseases, such as sepsis and meningitis. Previously, we reported that PfbA is a β-helical cell surface protein contributing to pneumococcal adhesion to and invasion of human epithelial cells in addition to its survival in blood. In the present study, we investigated the role of PfbA in pneumococcal pathogenesis. Phylogenetic analysis indicated that the pfbA gene is specific to S. pneumoniae within the mitis group. Our in vitro assays showed that PfbA inhibits neutrophil phagocytosis, leading to pneumococcal survival. We found that PfbA activates NF-κB through TLR2, but not TLR4. In addition, TLR2/4 inhibitor peptide treatment of neutrophils enhanced the survival of the S. pneumoniae ΔpfbA strain as compared to a control peptide treatment, whereas the treatment did not affect survival of a wild-type strain. In a mouse pneumonia model, the host mortality and level of TNF-α in bronchoalveolar lavage fluid were comparable between wild-type and ΔpfbA-infected mice, while deletion of pfbA increased the bacterial burden in bronchoalveolar lavage fluid. In a mouse sepsis model, the ΔpfbA strain demonstrated significantly increased host mortality and TNF-α levels in plasma, but showed reduced bacterial burden in lung and liver. These results indicate that PfbA may contribute to the success of S. pneumoniae species by inhibiting host cell phagocytosis, excess inflammation, and mortality.ImportanceStreptococcus pneumoniae is often isolated from the nasopharynx of healthy children, but the bacterium is also a leading cause of pneumonia, meningitis, and sepsis. In this study, we focused on the role of a cell wall anchoring protein, PfbA, in the pathogenesis of S. pneumoniae-related disease. We found that PfbA is a pneumococcus-specific anti-phagocytic factor that functions as a TLR2 ligand, indicating that PfbA may represent a pneumococcal-specific therapeutic target. However, a mouse pneumonia model revealed that PfbA deficiency reduced the bacterial burden, but did not decrease host mortality. Furthermore, in a mouse sepsis model, PfbA deficiency increased host mortality. These results suggest that S. pneumoniae optimizes reproduction by regulating host mortality through PfbA; therefore, PfbA inhibition would not be an effective strategy for combatting pneumococcal infection. Our findings underscore the challenges involved in drug development for a bacterium harboring both commensal and pathogenic states.

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