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ABSTRACT: Although reactive oxygen species (ROS) produced by NADPH oxidase are known to regulate inflammatory responses, the impact of ROS on intracellular signaling pathways is incompletely understood. In these studies, we treated wild-type (WT) and p47(phox)-deficient mice with LPS to investigate mechanisms by which NADPH oxidase regulates signaling through the NF-κB pathway. After intratracheal instillation of LPS, ROS generation was impaired in p47(phox)(-/-) mice, whereas these mice had increased neutrophilic alveolitis and greater lung injury compared with WT controls. In mice interbred with transgenic NF-κB reporters (HIV-long terminal repeat/luciferase [HLL]), we found exaggerated LPS-induced NF-κB activation and increased expression of proinflammatory cytokines in lungs of p47(phox)(-/-)/HLL mice compared with controls. Both lung macrophages and bone marrow-derived macrophages (BMDMs) isolated from p47(phox)(-/-)/HLL mice showed enhanced LPS-stimulated NF-κB activity compared with controls. Although nuclear translocation of NF-κB proteins was similar between genotypes, EMSAs under nonreducing conditions showed increased DNA binding in p47(phox)(-/-)/HLL BMDMs, suggesting that ROS production reduces NF-κB binding to DNA without affecting nuclear translocation. Increased intracellular reduced glutathione/glutathione disulfide ratio and greater nuclear redox factor 1 (Ref-1) levels were present in p47(phox)(-/-)/HLL compared with WT BMDMs, pointing to NADPH oxidase modulating intracellular redox status in macrophages. Treatment with the Ref-1-specific inhibitor E3330 or hydrogen peroxide inhibited LPS-induced NF-κB activation in p47(phox)(-/-)/HLL BMDMs but not in WT/HLL cells. Consistent with these findings, small interfering RNA against Ref-1 selectively reduced NF-κB activity in LPS-treated p47(phox)(-/-)/HLL BMDMs. Together, these results indicate that NADPH oxidase limits LPS-induced NF-κB transcriptional activity through regulation of intracellular redox state.
The Journal of Immunology 03/2013; · 5.79 Impact Factor
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Melissa J Grimm,
R Robert Vethanayagam,
Nikolaos G Almyroudis,
Carly G Dennis,
A Nazmul H Khan,
Anthony C D'Auria,
Kelly L Singel,
Bruce A Davidson,
Paul R Knight,
Timothy S Blackwell,
Tobias M Hohl,
Michael K Mansour,
Jatin M Vyas,
Marc Röhm,
Constantin F Urban,
Tiina Kelkka,
Rikard Holmdahl, Brahm H Segal
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ABSTRACT: Chronic granulomatous disease, an inherited disorder of the NADPH oxidase in which phagocytes are defective in the generation of superoxide anion and downstream reactive oxidant species, is characterized by severe bacterial and fungal infections and excessive inflammation. Although NADPH oxidase isoforms exist in several lineages, reactive oxidant generation is greatest in neutrophils, where NADPH oxidase has been deemed vital for pathogen killing. In contrast, the function and importance of NADPH oxidase in macrophages are less clear. Therefore, we evaluated susceptibility to pulmonary aspergillosis in globally NADPH oxidase-deficient mice versus transgenic mice with monocyte/macrophage-targeted NADPH oxidase activity. We found that the lethal inoculum was >100-fold greater in transgenic versus globally NADPH oxidase-deficient mice. Consistent with these in vivo results, NADPH oxidase in mouse alveolar macrophages limited germination of phagocytosed Aspergillus fumigatus spores. Finally, globally NADPH oxidase-deficient mice developed exuberant neutrophilic lung inflammation and proinflammatory cytokine responses to zymosan, a fungal cell wall-derived product composed principally of particulate β-glucans, whereas inflammation in transgenic and wild-type mice was mild and transient. Taken together, our studies identify a central role for monocyte/macrophage NADPH oxidase in controlling fungal infection and in limiting acute lung inflammation.
The Journal of Immunology 03/2013; · 5.79 Impact Factor
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Bruce A Davidson,
R Robert Vethanayagam,
Melissa J Grimm,
Barbara A Mullan,
Krishnan Raghavendran,
Timothy S Blackwell,
Michael L Freeman,
Vanniarajan Ayyasamy,
Keshav K Singh,
Michael B Sporn,
Kiyoshi Itagaki,
Carl J Hauser,
Paul R Knight, Brahm H Segal
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ABSTRACT: Recruitment of neutrophils and release of reactive oxygen species are considered to be major pathogenic components driving acute lung injury (ALI). However, NADPH oxidase, the major source of reactive oxygen species in activated phagocytes, can paradoxically limit inflammation and injury. We hypothesized that NADPH oxidase protects against ALI by limiting neutrophilic inflammation and activating Nrf2, a transcriptional factor that induces antioxidative and cytoprotective pathways. Our objective was to delineate the roles of NADPH oxidase and Nrf2 in modulating acute lung inflammation and injury in clinically relevant models of acute gastric aspiration injury, a major cause of ALI. Acid aspiration caused increased ALI (as assessed by bronchoalveolar lavage fluid albumin concentration) in both NADPH oxidase-deficient mice and Nrf2(-/-) mice compared with wild-type mice. NADPH oxidase reduced airway neutrophil accumulation, but Nrf2 decreased ALI without affecting neutrophil recovery. Acid injury resulted in a 120-fold increase in mitochondrial DNA, a proinflammatory and injurious product of cellular necrosis, in cell-free bronchoalveolar lavage fluid. Pharmacologic activation of Nrf2 by the triterpenoid 1-[2-cyano-3-,12-dioxooleana-1,9 (11)-dien-28-oyl]imidazole limited aspiration-induced ALI in wild-type mice and reduced endothelial cell injury caused by mitochondrial extract-primed human neutrophils, leading to the conclusion that NADPH oxidase and Nrf2 have coordinated, but distinct, functions in modulating inflammation and injury. These results also point to Nrf2 as a therapeutic target to limit ALI by attenuating neutrophil-induced cellular injury.
The Journal of Immunology 01/2013; · 5.79 Impact Factor
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ABSTRACT: Neutrophils are armed with both oxidant-dependent and -independent pathways for killing pathogens. Activation of the phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase constitutes an emergency response to infectious threat and results in the generation of antimicrobial reactive oxidants. In addition, NADPH oxidase activation in neutrophils is linked to activation of granular proteases and generation of neutrophil extracellular traps (NETs). NETosis involves the release of nuclear and granular components that can target extracellular pathogens. NETosis is activated during microbial threat and in certain conditions mimicking sepsis, and can result in both augmented host defense and inflammatory injury. In contrast, apoptosis, the physiological form of neutrophil death, not only leads to non-inflammatory cell death but also contributes to alleviate inflammation. Although there are significant gaps in knowledge regarding the specific contribution of NETs to host defense, we speculate that the coordinated activation of NADPH oxidase and NETosis maximizes microbial killing. Work in engineered mice and limited patient experience point to varying susceptibility of bacterial and fungal pathogens to NADPH oxidase versus NET constituents. Since reactive oxidants and NET constituents can injure host tissue, it is important that these pathways be tightly regulated. Recent work supports a role for NETosis in both acute lung injury and in autoimmunity. Knowledge gained about mechanisms that modulate NETosis may lead to novel therapeutic approaches to limit inflammation-associated injury.
Frontiers in immunology. 01/2013; 4:45.
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ABSTRACT: Neutropenia is a common side effect of cytotoxic chemotherapy and radiation, increasing the risk of infection in these patients. Here we examined the impact of body temperature on neutrophil recovery in the blood and bone marrow after total body irradiation (TBI). Mice were exposed to either 3 or 6 Gy TBI followed by a mild heat treatment that temporarily raised core body temperature to approximately 39.5°C. Neutrophil recovery was then compared with control mice that received either TBI alone heat treatment alone. Mice that received both TBI and heat treatment exhibited a significant increase in the rate of neutrophil recovery in the blood and an increase in the number of marrow hematopoietic stem cells and neutrophil progenitors compared with that seen in mice that received either TBI or heat alone. The combination treatment also increased G-CSF concentrations in the serum, bone marrow, and intestinal tissue and IL-17, IL-1β, and IL-1α concentrations in the intestinal tissue after TBI. Neutralizing G-CSF or inhibiting IL-17 or IL-1 signaling significantly blocked the thermally mediated increase in neutrophil numbers. These findings suggest that a physiologically relevant increase in body temperature can accelerate recovery from neutropenia after TBI through a G-CSF-, IL-17-, and IL-1-dependent mechanism.
Blood 07/2012; 120(13):2600-9. · 9.90 Impact Factor
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ABSTRACT: NADPH oxidase is a critical regulator of both antimicrobial host defense and inflammation. Activated in nature by microbes and microbial-derived products, the phagocyte NADPH oxidase is rapidly assembled, and generates reactive oxidant intermediates (ROIs) in response to infectious threat. Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase characterized by recurrent and severe bacterial and fungal infections, and pathology related to excessive inflammation. Studies in CGD patients and CGD mouse models indicate that NADPH oxidase plays a key role in modulating inflammation and injury that is distinct from its antimicrobial function. The mechanisms by which NADPH oxidase mediates killing of pathogens and regulation of inflammation have broad relevance to our understanding of normal physiological immune responses and pathological states, such as acute lung injury and bacterial or fungal infections.
Free radical biology & medicine 05/2012; 53(1):72-80. · 5.42 Impact Factor
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ABSTRACT: The definitions of invasive fungal diseases are intended to guide the appropriate use of clinical, radiologic, and various
laboratory findings to increase diagnostic certainty in clinical research. The need for standardized definitions was the result
of highly variable criteria used to diagnose invasive fungal diseases in epidemiologic and therapeutic studies. We review
the original definitions published in 2002, and the need for revision. We also summarize the key changes in the revised 2008
definitions, discuss limitations and pitfalls, and comment on the potential impact of these changes.
Current Fungal Infection Reports 04/2012; 3(4):195-200.
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Angela Pizzolla,
Malin Hultqvist,
Bo Nilson,
Melissa J Grimm,
Tove Eneljung,
Ing-Marie Jonsson,
Margareta Verdrengh,
Tiina Kelkka,
Inger Gjertsson, Brahm H Segal,
Rikard Holmdahl
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ABSTRACT: Chronic granulomatous disease (CGD) is an inherited disorder characterized by recurrent life-threatening bacterial and fungal infections. CGD results from defective production of reactive oxygen species by phagocytes caused by mutations in genes encoding the NADPH oxidase 2 (NOX2) complex subunits. Mice with a spontaneous mutation in Ncf1, which encodes the NCF1 (p47(phox)) subunit of NOX2, have defective phagocyte NOX2 activity. These mice occasionally develop local spontaneous infections by Staphylococcus xylosus or by the common CGD pathogen Staphylococcus aureus. Ncf1 mutant mice were more susceptible to systemic challenge with these bacteria than were wild-type mice. Transgenic Ncf1 mutant mice harboring the wild-type Ncf1 gene under the human CD68 promoter (MN(+) mice) gained the expression of NCF1 and functional NOX2 activity specifically in monocytes/macrophages, although minimal NOX2 activity was also detected in some CD11b(+)Ly6G(+) cells defined as neutrophils. MN(+) mice did not develop spontaneous infection and were more resistant to administered staphylococcal infections compared with MN(-) mice. Most strikingly, MN(+) mice survived after being administered Burkholderia cepacia, an opportunistic pathogen in CGD patients, whereas MN(-) mice died. Thus, monocyte/macrophage expression of functional NCF1 protected against spontaneous and administered bacterial infections.
The Journal of Immunology 04/2012; 188(10):5003-11. · 5.79 Impact Factor
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ABSTRACT: NADPH oxidase is a critical enzyme that mediates antibacterial and antifungal host defense. In addition to its role in antimicrobial host defense, NADPH oxidase has critical signaling functions that modulate the inflammatory response (1). Thus, the development of a method to measure in "real-time" the kinetics of NADPH oxidase-derived ROS generation is expected to be a valuable research tool to understand mechanisms relevant to host defense, inflammation, and injury. Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase characterized by severe infections and excessive inflammation. Activation of the phagocyte NADPH oxidase requires translocation of its cytosolic subunits (p47(phox), p67(phox), and p40(phox)) and Rac to a membrane-bound flavocytochrome (composed of a gp91(phox) and p22(phox) heterodimer). Loss of function mutations in any of these NADPH oxidase components result in CGD. Similar to patients with CGD, gp91(phox) -deficient mice and p47(phox)-deficient mice have defective phagocyte NADPH oxidase activity and impaired host defense (2, 13). In addition to phagocytes, which contain the NADPH oxidase components described above, a variety of other cell types express different isoforms of NADPH oxidase. Here, we describe a method to quantify ROS production in living mice and to delineate the contribution of NADPH oxidase to ROS generation in models of inflammation and injury. This method is based on ROS reacting with L-012 (an analogue of luminol) to emit luminescence that is recorded by a charge-coupled device (CCD). In the original description of the L-012 probe, L-012-dependent chemiluminescence was completely abolished by superoxide dismutase, indicating that the main ROS detected in this reaction was superoxide anion (14). Subsequent studies have shown that L-012 can detect other free radicals, including reactive nitrogen species (15, 16). Kielland et al. (16) showed that topical application of phorbol myristate acetate, a potent activator of NADPH oxidase, led to NADPH oxidase-dependent ROS generation that could be detected in mice using the luminescent probe L-012. In this model, they showed that L-012-dependent luminescence was abolished in p47(phox)-deficient mice. We compared ROS generation in wildtype mice and NADPH oxidase-deficient p47(phox-/-) mice (2) in the following three models: 1) intratracheal administration of zymosan, a pro-inflammatory fungal cell wall-derived product that can activate NADPH oxidase; 2) cecal ligation and puncture (CLP), a model of intra-abdominal sepsis with secondary acute lung inflammation and injury; and 3) oral carbon tetrachloride (CCl4), a model of ROS-dependent hepatic injury. These models were specifically selected to evaluate NADPH oxidase-dependent ROS generation in the context of non-infectious inflammation, polymicrobial sepsis, and toxin-induced organ injury, respectively. Comparing bioluminescence in wildtype mice to p47(phox-/-) mice enables us to delineate the specific contribution of ROS generated by p47(phox)-containing NADPH oxidase to the bioluminescent signal in these models. Bioluminescence imaging results that demonstrated increased ROS levels in wildtype mice compared to p47(phox-/-) mice indicated that NADPH oxidase is the major source of ROS generation in response to inflammatory stimuli. This method provides a minimally invasive approach for "real-time" monitoring of ROS generation during inflammation in vivo.
Journal of Visualized Experiments 01/2012;
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ABSTRACT: The notion that epigenetic alterations in neoplasia are reversible has provided the rationale to identify epigenetic modifiers for their ability to induce or enhance tumor cell death. Histone deacetylase inhibitors (HDACi) represent one such class of anti-neoplastic agents. Despite great interest for clinical use, little is known regarding the molecular targets important for response to HDACi-based cancer therapy. We had previously shown that interferon regulatory factor (IRF)-8, originally discovered as a leukemia suppressor gene by regulating apoptosis, also regulates Fas-mediated killing in non-hematologic tumor models. Furthermore, we and others have shown that epigenetic mechanisms are involved in repression of IRF-8 in tumors. Therefore, in our preclinical tumor model, we tested the hypothesis that IRF-8 expression is important for response to HDACi-based antitumor activity. In the majority of experiments, we selected the pan-HDACi, Trichostatin A (TSA), because it was previously shown to restore Fas sensitivity to tumor cells. Overall, we found that: 1) TSA alone and more so in combination with IFN-γ enhanced both IRF-8 expression and Fas-mediated death of tumor cells in vitro; 2) TSA treatment enhanced IRF-8 promoter activity via a STAT1-dependent pathway; and 3) IRF-8 was required for this death response, as tumor cells rendered IRF-8 incompetent were significantly less susceptible to Fas-mediated killing in vitro and to HDACi-mediated antitumor activity in vivo. Thus, IRF-8 status may underlie a novel molecular basis for response to HDACi-based antitumor treatment.
PLoS ONE 01/2012; 7(9):e45422. · 4.09 Impact Factor
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New England Journal of Medicine 08/2011; 365(8):762-3; author reply 764-5. · 53.30 Impact Factor
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ABSTRACT: Current vancomycin dosing guidelines in our acute myeloid leukemia population too often achieve suboptimal initial drug concentrations. Our aim was to assess vancomycin pharmacokinetic parameters in acute myeloid leukemia patients and develop an improved dosing equation to attain more accurate initial therapeutic trough levels. Acute myeloid leukemia patients receiving vancomycin for a presumed or documented gram positive infection were eligible. Patients hospitalized in the intensive care unit, those with creatinine clearance <30 mL/min or with limb amputation were excluded. Three samples were collected at the following post-infusion time ranges: 1 h, 3-8 h, and 8-24 h post-infusion, contingent on the dosing interval. Pharmacokinetic data were then fit using a Bayesian-based population pharmacokinetic model. A total of 25 acute myeloid leukemia patients were studied with a mean volume in the central compartment (Vc; L/65 kg), volume of distribution at steady state (Vss; L/65 kg) and distributional clearance (CLd; L/h/65 kg) of 15, 38.9, and 9.32, respectively. CLslope was 0.59 (mg of vancomycin clearance per unit of creatinine clearance in mL/min); this value is 21.4% lower than the established literature value (0.75). The derived equation, based upon these values, was reasonably precise at achieving the desired trough concentration using a priori dosing. The mean (CV%) of the achieved trough was 94% (29%) with a range of 66-188%; 3/25 at <75% and >125%]. We have established that the derived dosing equation can place ≈ 75% of adult acute myeloid leukemia patients at vancomycin trough levels within 75-125% of the target trough level.
Journal of Oncology Pharmacy Practice 04/2011; 18(1):91-6.
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ABSTRACT: NADPH oxidase plays a critical role in antimicrobial host defense, as evident in chronic granulomatous disease (CGD), an inherited disorder of the NADPH oxidase characterized by severe bacterial and fungal diseases. Invasive aspergillosis and other moulds are the major cause of mortality in CGD. We also learn from CGD patients that NADPH oxidase plays an important role in regulating inflammation; CGD patients are prone to developing inflammatory diseases such as inflammatory bowel disease, obstructive granulomata of the genitourinary tract, and hypersensitivity pneumonitis. Indeed, the NADPH oxidase plays an essential role in calibrating innate and T-cell responses to control the growth of inhaled fungi while protecting against excessive and injurious inflammation. Knowledge gained on the mechanisms by which NADPH oxidase kills fungi and regulates inflammation may lead to new therapeutics for CGD and will have broad relevance to understanding host-pathogen interactions between mammals and ubiquitous moulds to which we are continually exposed.
Medical mycology: official publication of the International Society for Human and Animal Mycology 04/2011; 49 Suppl 1:S144-9. · 2.13 Impact Factor
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Immunological Investigations 01/2011; 40(7-8):670-5. · 1.47 Impact Factor
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ABSTRACT: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency with X-linked or autosomal recessive inheritance involving defects in genes encoding phox proteins, which are the subunits of the phagocyte NADPH oxidase. This results in failure to produce superoxide anion and downstream antimicrobial oxidant metabolites and to activate antimicrobial proteases. Affected patients are susceptible to severe, life-threatening bacterial and fungal infections and excessive inflammation characterized by granulomatous enteritis resembling Crohn's disease and genitourinary obstruction. Early diagnosis of CGD and rapid treatment of infections are critical. Prophylaxis with antibacterial and mold-active antifungal agents and the administration of interferon-γ has significantly improved the natural history of CGD. Currently, the only cure is allogeneic hematopoietic cell transplant (HCT), although there remains controversy as to which patients with CGD should get a transplant. Allele-based HLA typing of alternative donors, improved supportive care measures, and use of reduced toxicity conditioning have resulted in event-free survival (EFS) of at least 80% even with an unrelated donor and even better when the patient has no active infections/inflammation. Gene correction of CGD would eliminate the risks of graft-versus-host disease (GVHD) and the immunoablative chemotherapy required for allogeneic HCT. Based on gene therapy trials in patients with SCID-X1, ADA-SCID, and the early experience with CGD, it is clear that at least some degree of myeloablation will be necessary for CGD as there is no inherent selective growth advantage for gene-corrected cells. Current efforts for gene therapy focus on use of lentivector constructs, which are thought to be safer from the standpoint of insertional mutagenesis and more efficient in transducing hematopoietic stem cells (HSCs).
Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 01/2011; 17(1 Suppl):S123-31. · 3.15 Impact Factor
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ABSTRACT: Nrf2 is a leucine zipper transcription factor that protects against oxidant-induced injury. Nontypeable Haemophilus influenzae is responsible for frequent disease exacerbations in patients with chronic obstructive pulmonary disease and is responsible for causing otitis media in young children. We hypothesized that Nrf2 would limit inflammatory responses to nontypeable H. influenzae. The objective of this study was to assess the role of Nrf2 in chronic lung inflammation and regulation of immune responses to nontypeable H. influenzae in mice. Wild-type (C57BL/6) mice and Nrf2(-/-) mice were instilled by oropharyngeal aspiration of 1 × 10(6) colony-forming units of live, nontypeable H. influenzae (NTHI) twice a week for 4 to 16 consecutive weeks to generate a chronic inflammatory milieu within the lungs that models chronic bronchitis. Nrf2(-/-) mice had increased lymphocytic airway inflammation compared with WT mice after NTHI challenge. Although the extent of NTHI-induced peribronchovascular inflammation did not significantly differ between the genotypes, plasma cell infiltration was significantly more abundant in Nrf2(-/-) mice. Most strikingly, Nrf2(-/-) mice generated significantly enhanced and persistent levels of serum antibodies against P6, a key outer membrane protein of NTHI. Lung dendritic cells from Nrf2(-/-) mice challenged with NTHI had increased activation markers compared with dendritic cells from similarly treated WT mice. Nrf2 regulates NTHI-induced airway inflammation characterized by lymphocytic and plasma cell infiltration and the activation of lung dendritic cells and B-cell responses in mice. Nrf2 may be a potential therapeutic target in limiting the bacterial infection-induced airway inflammation that drives exacerbations of chronic obstructive pulmonary disease.
American Journal of Respiratory Cell and Molecular Biology 01/2011; 45(3):557-65. · 5.13 Impact Factor
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R Robert Vethanayagam,
Nikolaos G Almyroudis,
Melissa J Grimm,
David C Lewandowski,
Christine T N Pham,
Timothy S Blackwell,
Ruta Petraitiene,
Vidmantas Petraitis,
Thomas J Walsh,
Constantin F Urban, Brahm H Segal
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ABSTRACT: NADPH oxidase is a crucial enzyme in mediating antimicrobial host defense and in regulating inflammation. Patients with chronic granulomatous disease, an inherited disorder of NADPH oxidase in which phagocytes are defective in generation of reactive oxidant intermediates (ROIs), suffer from life-threatening bacterial and fungal infections. The mechanisms by which NADPH oxidase mediate host defense are unclear. In addition to ROI generation, neutrophil NADPH oxidase activation is linked to the release of sequestered proteases that are posited to be critical effectors of host defense. To definitively determine the contribution of NADPH oxidase versus neutrophil serine proteases, we evaluated susceptibility to fungal and bacterial infection in mice with engineered disruptions of these pathways. NADPH oxidase-deficient mice (p47(phox-/-)) were highly susceptible to pulmonary infection with Aspergillus fumigatus. In contrast, double knockout neutrophil elastase (NE)(-/-)×cathepsin G (CG)(-/-) mice and lysosomal cysteine protease cathepsin C/dipeptidyl peptidase I (DPPI)-deficient mice that are defective in neutrophil serine protease activation demonstrated no impairment in antifungal host defense. In separate studies of systemic Burkholderia cepacia infection, uniform fatality occurred in p47(phox-/-) mice, whereas NE(-/-)×CG(-/-) mice cleared infection. Together, these results show a critical role for NADPH oxidase in antimicrobial host defense against A. fumigatus and B. cepacia, whereas the proteases we evaluated were dispensable. Our results indicate that NADPH oxidase dependent pathways separate from neutrophil serine protease activation are required for host defense against specific pathogens.
PLoS ONE 01/2011; 6(12):e28149. · 4.09 Impact Factor
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ABSTRACT: Patients with acute leukemia and hematopoietic stem cell transplant recipients are at risk of a spectrum of invasive fungal diseases corresponding to the type and intensity of immunosuppression. The development of newer antifungal agents has broadened therapeutic options. In the 1990s, lipid formulations of amphotericin B became widely used as safer alternatives to amphotericin B deoxycholate. In addition, fluconazole was shown to be beneficial as a yeast-active prophylaxis in hematopoietic stem cell transplant recipients. In the past decade, the antifungal armamentarium was further enhanced with the availability of extended-spectrum azoles and echinocandins. The development of effective broad-spectrum antifungal agents has led to their use as prophylaxis rather than delaying treatment until clinical signs of infection manifest. Antigen-based and PCR-based diagnostic adjuncts facilitate earlier detection of invasive fungal diseases compared with conventional culture, and have been incorporated into strategies in which initiation or modification of an antifungal regimen is targeted to patients with the highest likelihood of having fungal disease. Here, we review the pharmacological data and major clinical trials that guide the use of antifungals, as well as areas of uncertainty and future perspectives.
Expert Review of Anticancer Therapy 12/2010; 8(12):1451-66. · 3.28 Impact Factor
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Medical mycology: official publication of the International Society for Human and Animal Mycology 11/2010; 49 Suppl 1:S5-176. · 2.13 Impact Factor
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ABSTRACT: When functioning properly, the immune system recognizes inhaled fungi and controls their growth, while avoiding injurious inflammation and allergy. 'Aspergillosis' represents a spectrum of clinical diseases resulting from impaired or excessive immune responses. Invasive aspergillosis is principally disease of severely immunocompromised patients, whereas allergic forms of aspergillosis result from an excessive inflammatory response to hyphae colonizing the sinopulmonary tract. We will review insights gained in host defense against Aspergillus species and the immunopathogenesis of Aspergillus-related diseases as well as important advances made in fungal diagnostics and antifungal therapy.
Important advances have been made in diagnosis of invasive aspergillosis and in antifungal agents. Voriconazole was superior to amphotericin B deoxycholate as primary therapy for invasive aspergillosis. There is significant interest in combination antifungal therapy for invasive aspergillosis. Fungal genomics offers a powerful opportunity to gain knowledge about fungal virulence factors that can be targets for drug development. In addition, new insights have been gained regarding host defense against Aspergillus species that may be exploited therapeutically.
We have gained substantial knowledge regarding how the immune system recognizes inhaled fungi and calibrates the inflammatory response. There has also been substantial progress in tools to diagnose aspergillosis and in antifungal therapeutics. Future progress will likely involve the development of more refined diagnostic tools, new classes of antifungal agents, and greater knowledge of pathogen and host factors that predispose to aspergillosis.
Current opinion in pulmonary medicine 05/2010; 16(3):242-50. · 3.08 Impact Factor
