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 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 Azole Resistance of Aspergillus fumigatus Biofilms Is Partly Associated with Efflux Pump Activity

2011 ◽  
Vol 55 (5) ◽  
pp. 2092-2097 ◽  
Author(s):  
Ranjith Rajendran ◽  
Eilidh Mowat ◽  
Elaine McCulloch ◽  
David F. Lappin ◽  
Brian Jones ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Azole Resistance ◽  
Dependent Manner ◽  
Content Type ◽  
Quantitative Expression ◽  
Pump Activity ◽  
Competitive Substrate

ABSTRACTThis study investigated the phase-dependent expression and activity of efflux pumps inAspergillus fumigatustreated with voriconazole. Fourteen strains were shown to become increasingly resistant in the 12-h (16- to 128-fold) and 24-h (>512-fold) phases compared to 8-h germlings. An Ala-Nap uptake assay demonstrated a significant increase in efflux pump activity in the 12-h and 24-h phases (P< 0.0001). The efflux pump activity of the 8-h germling cells was also significantly induced by voriconazole (P< 0.001) after 24 h of treatment. Inhibition of efflux pump activity with the competitive substrate MC-207,110 reduced the voriconazole MIC values for theA. fumigatusgermling cells by 2- to 8-fold. Quantitative expression analysis ofAfuMDR4mRNA transcripts showed a phase-dependent increase as the mycelial complexity increased, which was coincidental with a strain-dependent increase in azole resistance. Voriconazole also significantly induced this in a time-dependent manner (P< 0.001). Finally, anin vivomouse biofilm model was used to evaluate efflux pump expression, and it was shown thatAfuMDR4was constitutively expressed and significantly induced by treatment with voriconazole after 24 h (P< 0.01). Our results demonstrate that efflux pumps are expressed in complexA. fumigatusbiofilm populations and that this contributes to azole resistance. Moreover, voriconazole treatment induces efflux pump expression. Collectively, these data may provide evidence for azole treatment failures in clinical cases of aspergillosis.

scholarly journals Pharmacodynamics of Anidulafungin against Clinical Aspergillus fumigatus Isolates in a Nonneutropenic Murine Model of Disseminated Aspergillosis

2012 ◽  
Vol 57 (1) ◽  
pp. 303-308 ◽  
Author(s):  
Seyedmojtaba Seyedmousavi ◽  
Roger J. M. Brüggemann ◽  
Willem J. G. Melchers ◽  
Paul E. Verweij ◽  
Johan W. Mouton
Keyword(s):  
Aspergillus Fumigatus ◽  
Murine Model ◽  
Resistance Mechanism ◽  
Maximal Response ◽  
Dependent Manner ◽  
Time Curve ◽  
Content Type ◽  
Disseminated Aspergillosis ◽  
The Hill

ABSTRACTAzole resistance is an emerging increasing problem inAspergillus fumigatusthat results in treatment failure. Alternative treatments may improve the therapeutic outcome in patients with azole-resistant invasive aspergillosis (IA). Little is known about thein vivoefficacy of the echinocandin anidulafungin (AFG) in IA. Thein vivoefficacy of 2.5, 5, 10, and 20 mg/kg of body weight AFG was assessed against two clinicalAspergillus fumigatusisolates with identical AFG minimum effective concentrations (MECs; 0.03 mg/liter) in a murine model of IA: a wild-type voriconazole (VCZ)-susceptible (VCZs)A. fumigatusisolate (AZN 8196) and a VCZ-resistant (VCZr)A. fumigatusisolate (V52-35) harboring the TR34/L98H resistance mechanism (substitution at codon L98 in combination with a 34-bp tandem repeat in the promoter region of theCYP51Agene). The pharmacokinetics of AFG were also assessed for each dose. Increasing doses increased survival for both isolates in a manner dependent on the AFG dose level (R2= 0.99 and 0.95, respectively) up to a maximum of 72.7% and 45.45% for the VCZsand VCZrisolates, respectively. The area under the concentration-time curve (AUC) correlated significantly with the dose in a linear fashion over the entire dosing range (R2= 0.86). The Hill equation with a variable slope fitted the relationship between the 24-h AUC/MEC ratio and 14-day survival well (R2= 0.87;P< 0.05). The 50% effective AUC/MEC for total AFG was 126.5 (95% confidence interval, 79.09 to 202.03). AFG treatment improved the survival of mice in a dose-dependent manner; however, a maximal response was not achieved with either isolate even in those treated with the highest AFG dose.

scholarly journals In Vivo Biomarker Analysis of Intranasally Dosed PC945, a Novel Antifungal Agent, in Aspergillus Fumigatus Infection in Immunocompromised Mice

2016 ◽  
Vol 3 (suppl_1) ◽  
Author(s):  
Kazuhiro Ito ◽  
Yasuo Kizawa ◽  
Genki Kimura ◽  
Takahiro Nakaoki ◽  
Lindsey Cass ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Antifungal Agent ◽  
Biomarker Analysis ◽  
Immunocompromised Mice

scholarly journals In Vitro and In Vivo Antifungal Profile of a Novel and Long-Acting Inhaled Azole, PC945, on Aspergillus fumigatus Infection

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Thomas Colley ◽  
Alexandre Alanio ◽  
Steven L. Kelly ◽  
Gurpreet Sehra ◽  
Yasuo Kizawa ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Rhizopus Oryzae ◽  
Pathogenic Fungi ◽  
Spectrophotometric Analysis ◽  
Characteristic Type ◽  
Content Type ◽  
Long Acting ◽  
Immunocompromised Mice

ABSTRACT The profile of PC945, a novel triazole antifungal designed for administration via inhalation, was assessed in a range of in vitro and in vivo studies. PC945 was characterized as a potent, tightly binding inhibitor of Aspergillus fumigatus sterol 14α-demethylase (CYP51A and CYP51B) activity (50% inhibitory concentrations [IC50s], 0.23 μM and 0.22 μM, respectively) with characteristic type II azole binding spectra. Against 96 clinically isolated A. fumigatus strains, the MIC values of PC945 ranged from 0.032 to >8 μg/ml, while those of voriconazole ranged from 0.064 to 4 μg/ml. Spectrophotometric analysis of the effects of PC945 against itraconazole-susceptible and -resistant A. fumigatus growth yielded IC50 (determined based on optical density [OD]) values of 0.0012 to 0.034 μg/ml, whereas voriconazole (0.019 to >1 μg/ml) was less effective than PC945. PC945 was effective against a broad spectrum of pathogenic fungi (with MICs ranging from 0.0078 to 2 μg/ml), including Aspergillus terreus, Trichophyton rubrum, Candida albicans, Candida glabrata, Candida krusei, Cryptococcus gattii, Cryptococcus neoformans, and Rhizopus oryzae (1 or 2 isolates each). In addition, when A. fumigatus hyphae or human bronchial cells were treated with PC945 and then washed, PC945 was found to be absorbed quickly into both target and nontarget cells and to produce persistent antifungal effects. Among temporarily neutropenic immunocompromised mice infected with A. fumigatus intranasally, 50% of the animals survived until day 7 when treated intranasally with PC945 at 0.56 μg/mouse, while posaconazole showed similar effects (44%) at 14 μg/mouse. This profile affirms that topical treatment with PC945 should provide potent antifungal activity in the lung.

scholarly journals Neurons Are Host Cells for Mycobacterium tuberculosis

2014 ◽  
Vol 82 (5) ◽  
pp. 1880-1890 ◽  
Author(s):  
Philippa J. Randall ◽  
Nai-Jen Hsu ◽  
Dirk Lang ◽  
Susan Cooper ◽  
Boipelo Sebesho ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mycobacterium Tuberculosis ◽  
Host Cells ◽  
Productive Infection ◽  
Target Cells ◽  
Dependent Manner ◽  
Content Type ◽  
The Central Nervous System

ABSTRACTMycobacterium tuberculosisinfection of the central nervous system is thought to be initiated once the bacilli have breached the blood brain barrier and are phagocytosed, primarily by microglial cells. In this study, the interactions ofM. tuberculosiswith neuronsin vitroandin vivowere investigated. The data obtained demonstrate that neurons can act as host cells forM. tuberculosis.M. tuberculosisbacilli were internalized by murine neuronal cultured cells in a time-dependent manner after exposure, with superior uptake by HT22 cells compared to Neuro-2a cells (17.7% versus 9.8%). Internalization ofM. tuberculosisbacilli by human SK-N-SH cultured neurons suggested the clinical relevance of the findings. Moreover, primary murine hippocampus-derived neuronal cultures could similarly internalizeM. tuberculosis. InternalizedM. tuberculosisbacilli represented a productive infection with retention of bacterial viability and replicative potential, increasing 2- to 4-fold within 48 h.M. tuberculosisbacillus infection of neurons was confirmedin vivoin the brains of C57BL/6 mice after intracerebral challenge. This study, therefore, demonstrates neurons as potential new target cells forM. tuberculosiswithin the central nervous system.

scholarly journals Cotranslational Coat Protein-Mediated Inhibition of Potyviral RNA Translation

2015 ◽  
Vol 89 (8) ◽  
pp. 4237-4248 ◽  
Author(s):  
Jane Besong-Ndika ◽  
Konstantin I. Ivanov ◽  
Anders Hafrèn ◽  
Thierry Michon ◽  
Kristiina Mäkinen
Keyword(s):  
Coat Protein ◽  
Stop Codon ◽  
Rna Virus ◽  
Viral Rna ◽  
Dependent Manner ◽  
Content Type ◽  
Virion Assembly ◽  
Rna Translation ◽  
Intrinsic Capacity

ABSTRACTPotato virus A(PVA) is a single-stranded positive-sense RNA virus and a member of the familyPotyviridae. The PVA coat protein (CP) has an intrinsic capacity to self-assemble into filamentous virus-like particles, but the mechanism responsible for the initiation of viral RNA encapsidationin vivoremains unclear. Apart from virion assembly, PVA CP is also involved in the inhibition of viral RNA translation. In this study, we show that CP inhibits PVA RNA translation in a dose-dependent manner, through a mechanism involving the CP-encoding region. Analysis of this region, however, failed to identify any RNA secondary structure(s) preferentially recognized by CP, suggesting that the inhibition depends on CP-CP rather than CP-RNA interactions. In agreement with this possibility, insertion of an in-frame stop codon upstream of the CP sequence led to a marked decrease in the inhibition of viral RNA translation. Based on these results, we propose a model in which the cotranslational interactions between excess CP accumulating intransand CP translated from viral RNA incisare required to initiate the translational repression. This model suggests a mechanism for how viral RNA can be sequestered from translation and specifically selected for encapsidation at the late stages of viral infection.IMPORTANCEThe main functions of the CP during potyvirus infection are to protect viral RNA from degradation and to transport it locally, systemically, and from host to host. Although virion assembly is a key step in the potyviral infectious cycle, little is known about how it is initiated and how viral RNA is selected for encapsidation. The results presented here suggest that CP-CP rather than CP-RNA interactions are predominantly involved in the sequestration of viral RNA away from translation. We propose that the cotranslational nature of these interactions may represent a mechanism for the selection of viral RNA for encapsidation. A better understanding of the mechanism of virion assembly may lead to development of crops resistant to potyviruses at the level of viral RNA encapsidation, thereby reducing the detrimental effects of potyvirus infections on food production.

scholarly journals The Fungal Cyp51-Specific Inhibitor VT-1598 DemonstratesIn VitroandIn VivoActivity againstCandida auris

2018 ◽  
Vol 63 (3) ◽  
Author(s):  
Nathan P. Wiederhold ◽  
Shawn R. Lockhart ◽  
Laura K. Najvar ◽  
Elizabeth L. Berkow ◽  
Rosie Jaramillo ◽  
...  
Keyword(s):  
Specific Inhibitor ◽  
Candida Auris ◽  
Once Daily ◽  
Content Type ◽  
Fungal Burden ◽  
Invasive Infections ◽  
Trough Concentrations ◽  
Dose Dependent

ABSTRACTCandida aurisis an emerging pathogen associated with significant mortality and often multidrug resistance. VT-1598, a tetrazole-based fungal CYP51-specific inhibitor, was evaluatedin vitroandin vivoagainstC. auris. Susceptibility testing was performed against 100 clinical isolates ofC. aurisby broth microdilution. Neutropenic mice were infected intravenously withC. auris, and treatment began 24 h postinoculation with a vehicle control, oral VT-1598 (5, 15, and 50 mg/kg of body weight once daily), oral fluconazole (20 mg/kg once daily), or intraperitoneal caspofungin (10 mg/kg once daily), which continued for 7 days. Fungal burden was assessed in the kidneys and brains on day 8 in the fungal burden arm and on the days the mice succumbed to infection or on day 21 in the survival arm. VT-1598 plasma trough concentrations were also assessed on day 8. VT-1598 demonstratedin vitroactivity againstC. auris, with a mode MIC of 0.25 μg/ml and MICs ranging from 0.03 to 8 μg/ml. Treatment with VT-1598 resulted in significant and dose-dependent improvements in survival (median survival, 15 and >21 days for VT-1598 at 15 and 50 mg/kg, respectively) and reductions in kidney and brain fungal burden (reductions of 1.88 to 3.61 log10CFU/g) compared to the control (5 days). The reductions in fungal burden correlated with plasma trough concentrations. Treatment with caspofungin, but not fluconazole, also resulted in significant improvements in survival and reductions in fungal burden compared to those with the control. These results suggest that VT-1598 may be a future option for the treatment of invasive infections caused byC. auris.

scholarly journals The Host Antimicrobial Protein Calgranulin C Participates in the Control ofCampylobacter jejuniGrowth via Zinc Sequestration

2018 ◽  
Vol 86 (6) ◽  
Author(s):  
Janette M. Shank ◽  
Brittni R. Kelley ◽  
Joseph W. Jackson ◽  
Jessica L. Tweedie ◽  
Dana Franklin ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Serum Levels ◽  
Interleukin 10 ◽  
Poultry Meat ◽  
Antimicrobial Protein ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Full Resolution ◽  
Factor Alpha

ABSTRACTCampylobacter jejuniis a leading cause of bacterially derived gastroenteritis worldwide.Campylobacteris most commonly acquired through the consumption of undercooked poultry meat or through drinking contaminated water. Following ingestion,Campylobacteradheres to the intestinal epithelium and mucus layer, causing toxin-mediated inflammation and inhibition of fluid reabsorption. Currently, the human response to infection is relatively unknown, and animal hosts that model these responses are rare. As such, we examined patient fecal samples for the accumulation of the neutrophil protein calgranulin C during infection withCampylobacter jejuni. In response to infection, calgranulin C was significantly increased in the feces of humans. To determine whether calgranulin C accumulation occurs in an animal model, we examined disease in ferrets. Ferrets were effectively infected byC. jejuni, with peak fecal loads observed at day 3 postinfection and full resolution by day 12. Serum levels of interleukin-10 (IL-10) and tumor necrosis factor alpha (TNF-α) significantly increased in response to infection, which resulted in leukocyte trafficking to the colon. As a result, calgranulin C increased in the feces of ferrets at the time whenC. jejuniloads decreased. Further, the addition of purified calgranulin C toC. jejunicultures was found to inhibit growth in a zinc-dependent manner. These results suggest that upon infection withC. jejuni, leukocytes trafficked to the intestine release calgranulin C as a mechanism for inhibitingC. jejunigrowth.

scholarly journals The Novel Arylamidine T-2307 Demonstrates In Vitro and In Vivo Activity against Candida auris

2019 ◽  
Vol 64 (3) ◽  
Author(s):  
Nathan P. Wiederhold ◽  
Laura K. Najvar ◽  
Rosie Jaramillo ◽  
Marcos Olivo ◽  
Hoja Patterson ◽  
...  
Keyword(s):  
The Novel ◽  
Candida Auris ◽  
Once Daily ◽  
Content Type ◽  
Fungal Burden

ABSTRACT The in vitro and in vivo activity of the arylamidine T-2307 against Candida auris was evaluated. T-2307 demonstrated in vitro activity (MIC ranges ≤ 0.008 to 0.015 μg/ml at 50% inhibition; 0.125 to >4 μg/ml at 100% inhibition). Treatment with T-2307 (3 mg/kg subcutaneous [SC] once daily) also significantly improved survival (70% at 21 days postinfection) and reduced kidney fungal burden (5.06 log10 CFU/g) compared to control (0% survival and 7.09 log10 CFU/g) (P < 0.01).

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