scholarly journals Contribution of Bordetella Filamentous Hemagglutinin and Adenylate Cyclase Toxin to Suppression and Evasion of Interleukin-17-Mediated Inflammation

2012 ◽  
Vol 80 (6) ◽  
pp. 2061-2075 ◽  
Author(s):  
Michael W. Henderson ◽  
Carol S. Inatsuka ◽  
Amanda J. Sheets ◽  
Corinne L. Williams ◽  
David J. Benaron ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Adenylate Cyclase ◽  
Respiratory Infections ◽  
Interleukin 17 ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Filamentous Hemagglutinin ◽  
Factor Alpha ◽  
Adenylate Cyclase Toxin

ABSTRACTBordetella pertussisandBordetella bronchisepticaestablish respiratory infections with notorious efficiency. Our previous studies showed that thefhaBgenes ofB. pertussisandB. bronchiseptica, which encode filamentous hemagglutinin (FHA), are functionally interchangeable and provided evidence that FHA-deficientB. bronchisepticainduces more inflammation in the lungs of mice than wild-typeB. bronchiseptica. We show here that the robust inflammatory response to FHA-deficientB. bronchisepticais characterized by the early and sustained influx of interleukin-17 (IL-17)-positive neutrophils and macrophages and, at 72 h postinoculation, IL-17-positive CD4+T cells, suggesting that FHA allows the bacteria to suppress the development of an IL-17-mediated inflammatory response. We also show that thecyaAgenes ofB. pertussisandB. bronchiseptica, which encode adenylate cyclase toxin (ACT), are functionally interchangeable and that ACT, specifically its catalytic activity, is required forB. bronchisepticato resist phagocytic clearance but is neither required for nor inhibitory of the induction of inflammation if bacteria are present in numbers sufficient to persist during the first 3 days postinoculation. Incubation of bone marrow-derived macrophages with a ΔcyaAstrain caused decreased production of IL-1β and increased production of tumor necrosis factor alpha (TNF-α) and IL-12, while incubation with a ΔcyaAΔfhaBstrain caused increased production of IL-23. These data suggest that FHA and ACT both contribute to suppress the recruitment of neutrophils and the development of an IL-17-mediated immune response. To our knowledge, this is the first demonstration of a microbial pathogen suppressing IL-17-mediated inflammationin vivoas a strategy to evade innate immunity.

scholarly journals Enterococcus faecalisDemonstrates Pathogenicity through Increased Attachment in anEx VivoPolymicrobial Pulpal Infection

2018 ◽  
Vol 86 (5) ◽  
Author(s):  
Wayne Nishio Ayre ◽  
Genevieve Melling ◽  
Camille Cuveillier ◽  
Madhan Natarajan ◽  
Jessica L. Roberts ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Host Response ◽  
Ex Vivo ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Streptococcus Anginosus ◽  
Cell Counts ◽  
Tnf Α ◽  
Factor Alpha ◽  
Infection Types

ABSTRACTThis study investigated the host response to a polymicrobial pulpal infection consisting ofStreptococcus anginosusandEnterococcus faecalis, bacteria commonly implicated in dental abscesses and endodontic failure, using a validatedex vivorat tooth model. Tooth slices were inoculated with planktonic cultures ofS. anginosusorE. faecalisalone or in coculture atS. anginosus/E. faecalisratios of 50:50 and 90:10. Attachment was semiquantified by measuring the area covered by fluorescently labeled bacteria. Host response was established by viable histological cell counts, and inflammatory response was measured using reverse transcription-quantitative PCR (RT-qPCR) and immunohistochemistry. A significant reduction in cell viability was observed for single and polymicrobial infections, with no significant differences between infection types (∼2,000 cells/mm2for infected pulps compared to ∼4,000 cells/mm2for uninfected pulps).E. faecalisdemonstrated significantly higher levels of attachment (6.5%) thanS. anginosusalone (2.3%) and mixed-species infections (3.4% for 50:50 and 2.3% for 90:10), with a remarkable affinity for the pulpal vasculature. Infections withE. faecalisdemonstrated the greatest increase in tumor necrosis factor alpha (TNF-α) (47.1-fold forE. faecalis, 14.6-fold forS. anginosus, 60.1-fold for 50:50, and 25.0-fold for 90:10) and interleukin 1β (IL-1β) expression (54.8-fold forE. faecalis, 8.8-fold forS. anginosus, 54.5-fold for 50:50, and 39.9-fold for 90:10) compared to uninfected samples. Immunohistochemistry confirmed this, with the majority of inflammation localized to the pulpal vasculature and odontoblast regions. Interestingly,E. faecalissupernatant and heat-killedE. faecalistreatments were unable to induce the same inflammatory response, suggestingE. faecalispathogenicity in pulpitis is linked to its greater ability to attach to the pulpal vasculature.

scholarly journals In Vivo Biomarker Analysis of the Effects of Intranasally Dosed PC945, a Novel Antifungal Triazole, on Aspergillus fumigatus Infection in Immunocompromised Mice

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Genki Kimura ◽  
Takahiro Nakaoki ◽  
Thomas Colley ◽  
Garth Rapeport ◽  
Pete Strong ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Interleukin 17 ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Once Daily ◽  
Content Type ◽  
Treatment Regimens ◽  
Biomarker Analysis ◽  
Immunocompromised Mice

ABSTRACT PC945 is a novel triazole optimized for lung delivery, and the objective of this study is to determine the effects of intranasally dosed PC945 on Aspergillus fumigatus infection and associated biomarkers in immunocompromised mice. PC945, posaconazole, or voriconazole was administered intranasally once daily on days 0 to 3 (early intervention) or days 1 to 3 (late intervention) postinfection in temporarily neutropenic A/J mice infected intranasally with A. fumigatus, and bronchoalveolar lavage fluid (BALF) and serum were collected on day 3. The effects of extended prophylaxis treatment (daily from days −7 to +3 or days −7 to 0) were also compared with those of the shorter treatment regimens (days −1 to +3 or days −1 and 0). Early and late interventions with PC945 (2.8 to 350 μg/mouse; approximately 0.11 to ∼14 mg/kg of body weight) were found to inhibit lung fungal loads and to decrease the concentrations of galactomannan (GM) in both BALF and serum as well as several biomarkers in BALF (interferon gamma [IFN-γ], interleukin-17 [IL-17], and malondialdehyde) and serum (tumor necrosis factor alpha [TNF-α] and IL-6) in a dose-dependent manner and were >3- and >47-fold more potent than intranasally dosed posaconazole and voriconazole, respectively. Furthermore, extended prophylaxis with low-dose PC945 (0.56 μg/mouse; 0.022 mg/kg) was found to inhibit fungal loads and to decrease the concentrations biomarkers more potently than did the shorter treatment regimens. Thus, PC945 dosed intranasally once daily showed potent antifungal effects, and the effects of PC945 accumulated upon repeat dosing and were persistent. Therefore, PC945 has the potential to be a novel inhaled therapy for the treatment of A. fumigatus infection in humans.

scholarly journals Quantification of the Adenylate Cyclase Toxin of Bordetella pertussisIn Vitroand during Respiratory Infection

2013 ◽  
Vol 81 (5) ◽  
pp. 1390-1398 ◽  
Author(s):  
Joshua C. Eby ◽  
Mary C. Gray ◽  
Jason M. Warfel ◽  
Christopher D. Paddock ◽  
Tara F. Jones ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Respiratory Tract ◽  
Whooping Cough ◽  
Extensive Study ◽  
Target Cells ◽  
Human Infants ◽  
Content Type ◽  
Adenylate Cyclase Toxin

ABSTRACTWhooping cough results from infection of the respiratory tract withBordetella pertussis, and the secreted adenylate cyclase toxin (ACT) is essential for the bacterium to establish infection. Despite extensive study of the mechanism of ACT cytotoxicity and its effects over a range of concentrationsin vitro, ACT has not been observed or quantifiedin vivo, and thus the concentration of ACT at the site of infection is unknown. The recently developed baboon model of infection mimics the prolonged cough and transmissibility of pertussis, and we hypothesized that measurement of ACT in nasopharyngeal washes (NPW) from baboons, combined with human andin vitrodata, would provide an estimate of the ACT concentration in the airway during infection. NPW contained up to ∼108CFU/mlB. pertussisand 1 to 5 ng/ml ACT at the peak of infection. Nasal aspirate specimens from two human infants with pertussis contained bacterial concentrations similar to those in the baboons, with 12 to 20 ng/ml ACT. When ∼108CFU/ml of a laboratory strain ofB. pertussiswas culturedin vitro, ACT production was detected in 60 min and reached a plateau of ∼60 ng/ml in 6 h. Furthermore, when bacteria were brought into close proximity to target cells by centrifugation, intoxication was increased 4-fold. Collectively, these data suggest that at the bacterium-target cell interface during infection of the respiratory tract, the concentration of ACT can exceed 100 ng/ml, providing a reference point for future studies of ACT and pertussis pathogenesis.

scholarly journals Interleukin 17 Receptor E (IL-17RE) and IL-17C Mediate the Recruitment of Neutrophils during Acute Streptococcus pneumoniae Pneumonia

2019 ◽  
Vol 87 (11) ◽  
Author(s):  
Patrick Steck ◽  
Felix Ritzmann ◽  
Anja Honecker ◽  
Giovanna Vella ◽  
Christian Herr ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Alveolar Macrophages ◽  
Pulmonary Inflammation ◽  
Interleukin 17 ◽  
Immune Functions ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α ◽  
Factor Alpha ◽  
Functional Receptor

ABSTRACT Neutrophils contribute to lung injury in acute pneumococcal pneumonia. The interleukin 17 receptor E (IL-17RE) is the functional receptor for the epithelial-derived cytokine IL-17C, which is known to mediate innate immune functions. The aim of this study was to investigate the contribution of IL-17RE/IL-17C to pulmonary inflammation in a mouse model of acute Streptococcus pneumoniae pneumonia. Numbers of neutrophils and the expression levels of the cytokine granulocyte colony-stimulating factor (G-CSF) and tumor necrosis factor alpha (TNF-α) were decreased in lungs of IL-17RE-deficient (Il-17re−/−) mice infected with S. pneumoniae. Numbers of alveolar macrophages rapidly declined in both wild-type (WT) and Il-17re−/− mice and recovered 72 h after infection. There were no clear differences in the elimination of bacteria and numbers of blood granulocytes between infected WT and Il-17re−/− mice. The fractions of granulocyte-monocyte progenitors (GMPs) were significantly reduced in infected Il-17re−/− mice. Numbers of neutrophils were significantly reduced in lungs of mice deficient for IL-17C 24 h after infection with S. pneumoniae. These data indicate that the IL-17C/IL-17RE axis promotes the recruitment of neutrophils without affecting the recovery of alveolar macrophages in the acute phase of S. pneumoniae lung infection.

scholarly journals A Purified Capsular Polysaccharide Markedly Inhibits Inflammatory Response during Endotoxic Shock

2012 ◽  
Vol 81 (1) ◽  
pp. 90-98 ◽  
Author(s):  
M. Piccioni ◽  
C. Monari ◽  
S. Kenno ◽  
E. Pericolini ◽  
E. Gabrielli ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Capsular Polysaccharide ◽  
Endotoxic Shock ◽  
Experimental System ◽  
Inhibitory Effect ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α ◽  
Factor Alpha

Capsular material of the opportunistic fungusCryptococcus neoformansis composed mainly of a polysaccharide named glucuronoxylomannan (GXM). In this study, the effects of GXM were analyzed in anin vivoexperimental system of lipopolysaccharide (LPS)-induced shock. Endotoxic shock was induced in mice by a single intraperitoneal injection of LPS fromEscherichia coli. GXM treatment reduced the mortality of mice at early stages. Mice treated with LPS alone showed markedly increased plasma levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6, whereas mice that were also treated with GXM showed significantly lower plasma levels of these cytokines. This effect was related to a marked suppression of Akt and IκBα activation. Importantly, the inhibitory effect of GXM on proinflammatory cytokine secretion was reproduced by treatment with wortmannin, an inhibitor of the Akt transcription pathway. Our results indicate that GXM has a beneficial effect on endotoxic shock, resulting in a significant increase in the rate of survival by dampening the hyperinflammatory response.

scholarly journals Ecto-5′-Nucleotidase (CD73) Deficiency in Mycobacterium tuberculosis-Infected Mice Enhances Neutrophil Recruitment

2015 ◽  
Vol 83 (9) ◽  
pp. 3666-3674 ◽  
Author(s):  
Laetitia Petit-Jentreau ◽  
Grégory Jouvion ◽  
Patricia Charles ◽  
Laleh Majlessi ◽  
Brigitte Gicquel ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Immune System ◽  
Proinflammatory Response ◽  
Necrosis Factor Alpha ◽  
Effective Response ◽  
Content Type ◽  
Factor Alpha ◽  
Endothelial Growth Factor

The immune system needs safeguards that prevent collateral tissue damage mediated by the immune system while enabling an effective response against a pathogen. The purinergic pathway is one such mechanism and finely modulates inflammation by sensing nucleotides in the environment. Extracellular ATP is considered to be a danger signal leading to a proinflammatory response, whereas adenosine is immunosuppressive. CD73, also called ecto-5′-nucleotidase, occupies a strategic position in this pathway, as it is the main enzyme responsible for the generation of adenosine from ATP. Here, we explore the role of CD73 during tuberculosis, a disease characterized by an immune response that is harmful to the host and unable to eradicateMycobacterium tuberculosis. Using CD73 knockout (KO) mice, we found that CD73 regulates the response toM. tuberculosisinfectionin vitroandin vivo. Mycobacterium-infected murine macrophages derived from CD73 KO mice secrete more keratinocyte chemoattractant (KC), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) and release less vascular endothelial growth factor (VEGF) upon ATP stimulation than do those derived from wild-type (WT) mice.In vivo, CD73 limits the early influx of neutrophils to the lungs without affecting bacterial growth and dissemination. Collectively, our results support the view that CD73 fine-tunes antimycobacterial immune responses.

scholarly journals Amidate Prodrugs of 9-[2-(Phosphonomethoxy)Ethyl]Adenine as Inhibitors of Adenylate Cyclase Toxin from Bordetella pertussis

2013 ◽  
Vol 58 (2) ◽  
pp. 664-671 ◽  
Author(s):  
Markéta Šmídková ◽  
Alexandra Dvořáková ◽  
Eva Tloušt'ová ◽  
Michal Česnek ◽  
Zlatko Janeba ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Inhibitory Activity ◽  
Antimicrobial Agents ◽  
Antiviral Drug ◽  
Content Type ◽  
Intracellular Ca ◽  
Adenylate Cyclase Toxin ◽  
Apoptotic Effects

ABSTRACTAdenylate cyclase toxin (ACT) is the key virulence factor ofBordetella pertussisthat facilitates its invasion into the mammalian body. 9-[2-(Phosphonomethoxy)ethyl]adenine diphosphate (PMEApp), the active metabolite of the antiviral drug bis(POM)PMEA (adefovir dipivoxil), has been shown to inhibit ACT. The objective of this study was to evaluate six novel amidate prodrugs of PMEA, both phenyloxy phosphonamidates and phosphonodiamidates, for their ability to inhibit ACT activity in the J774A.1 macrophage cell line. The two phenyloxy phosphonamidate prodrugs exhibited greater inhibitory activity (50% inhibitory concentration [IC50] = 22 and 46 nM) than the phosphonodiamidates (IC50= 84 to 3,960 nM). The inhibitory activity of the prodrugs correlated with their lipophilicity and the degree of their hydrolysis into free PMEA in J774A.1 cells. Although the prodrugs did not inhibit ACT as effectively as bis(POM)PMEA (IC50= 6 nM), they were significantly less cytotoxic. Moreover, they all reduced apoptotic effects of ACT and prevented an ACT-induced elevation of intracellular [Ca2+]i. The amidate prodrugs were less susceptible to degradation in Caco-2 cells compared to bis(POM)PMEA, while they exerted good transepithelial permeability in this assay. As a consequence, a large amount of intact amidate prodrug is expected to be available to target macrophagesin vivo. This feature makes nontoxic amidate prodrugs attractive candidates for further investigation as novel antimicrobial agents.

scholarly journals Effect of Inflammatory Response onIn VivoCompetition between Two Chlamydial Variants in the Guinea Pig Model of Inclusion Conjunctivitis

2011 ◽  
Vol 80 (2) ◽  
pp. 612-619 ◽  
Author(s):  
Roger G. Rank ◽  
Anne K. Bowlin ◽  
Kati I. Tormanen ◽  
Yin Wang ◽  
Anthony T. Maurelli
Keyword(s):  
Inflammatory Response ◽  
Guinea Pig ◽  
Mixed Infection ◽  
Resistant Mutant ◽  
Pig Model ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Guinea Pig Model ◽  
The Impact

ABSTRACTIn order to study the interaction of variants inin vivoinfection, we employed an azithromycin-resistant mutant (AZ2) and its wild-type parent (SP6) in the guinea pig model ofChlamydia caviaeconjunctival infection. When each strain was inoculated individually into conjunctiva, both attained the same level of growth, but AZ2elicited less pathology. However, when equal numbers of the two strains were inoculated together into the guinea pig conjunctiva, SP6produced a significantly greater number of inclusion-forming units than AZ2, and the pathology reflected that of a SP6monoinfection. The goal of this study was to further characterize the dynamics of concomitant infection of these two distinct variants, with particular emphasis on the impact of the host response on thein vivogrowth of each organism and the development of pathology. Animals infected with AZ2had reduced conjunctival infiltration with CD45+cells and neutrophils as well as a reduced interleukin-8 (IL-8) response. Gene expression of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), CCL2, and CCL5 was also significantly lower in AZ2-infected animals. The lower inflammatory response induced by AZ2was associated with its decreased ability to activate NF-κB via Toll-like receptor 2 (TLR2). In general, the inflammatory response in animals infected with both variants was greater than in infection with AZ2alone, resulting in lower numbers of AZ2than those of SP6in the mixed infection. Our results suggest that the ability to elicit an inflammatory response is an important factor in the dynamics of mixed infection with strains that display different pathological phenotypes.

scholarly journals ‘Educated’ Osteoblasts Reduce Osteoclastogenesis in a Bone-Tumor Mimetic Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 263
Author(s):  
Alexus D. Kolb ◽  
Jinlu Dai ◽  
Evan T. Keller ◽  
Karen M. Bussard
Keyword(s):  
Bone Resorption ◽  
Bone Tumor ◽  
Bone Matrix ◽  
Necrosis Factor Alpha ◽  
Tumor Bearing ◽  
Receptor Activator ◽  
Factor Alpha ◽  
Osteoclast Resorption ◽  
Necrosis Factor

Breast cancer (BC) metastases to bone disrupt the balance between osteoblasts and osteoclasts, leading to excessive bone resorption. We identified a novel subpopulation of osteoblasts with tumor-inhibitory properties, called educated osteoblasts (EOs). Here we sought to examine the effect of EOs on osteoclastogenesis during tumor progression. We hypothesized that EOs affect osteoclast development in the bone-tumor niche, leading to suppressed pre-osteoclast fusion and bone resorption. Conditioned media (CM) was analyzed for protein expression of osteoclast factors receptor activator of nuclear factor kappa-β ligand (RANKL), osteoprotegerin (OPG), and tumor necrosis factor alpha (TNFα) via ELISA. EOs were co-cultured with pre-osteoclasts on a bone mimetic matrix to assess osteoclast resorption. Pre-osteoclasts were tri-cultured with EOs plus metastatic BC cells and assessed for tartrate-resistance acid phosphatase (TRAP)-positive, multinucleated (≥3 nuclei), mature osteoclasts. Tumor-bearing murine tibias were stained for TRAP to determine osteoclast number in-vivo. EO CM expressed reduced amounts of soluble TNFα and OPG compared to naïve osteoblast CM. Osteoclasts formed in the presence of EOs were smaller and less in number. Upon co-culture on a mimetic bone matrix, a 50% reduction in the number of TRAP-positive osteoclasts formed in the presence of EOs was observed. The tibia of mice inoculated with BC cells had less osteoclasts per bone surface in bones with increased numbers of EO cells. These data suggest EOs reduce osteoclastogenesis and bone resorption. The data imply EOs provide a protective effect against bone resorption in bone metastatic BC.

Sign in / Sign up

Export Citation Format

Share Document