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Economides MP, Ballester LY, Kumar VA, Jiang Y, Tarrand J, Prieto V, Torres HA, Kontoyiannis DP. Invasive mold infections of the central nervous system in patients with hematologic cancer or stem cell transplantation (2000–2016): Uncommon, with improved survival but still deadly often. J Infect 2017; 75:572-580. [DOI: 10.1016/j.jinf.2017.09.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/04/2017] [Accepted: 09/11/2017] [Indexed: 11/25/2022]
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Pasupneti S, Manouvakhova O, Nicolls MR, Hsu JL. Aspergillus-related pulmonary diseases in lung transplantation. Med Mycol 2016; 55:96-102. [PMID: 27816902 DOI: 10.1093/mmy/myw121] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 09/14/2016] [Accepted: 10/05/2016] [Indexed: 12/31/2022] Open
Abstract
While lung transplantation is an attractive treatment option for many end stage lung diseases, the relatively high 5-year mortality continues to be a significant limiting factor. Among the foremost reasons for this is the eventual development of obstructive chronic lung allograft dysfunction. Infections, which the lung allograft is especially prone to, are a major risk factor. Specifically, the Aspergillus species cause a higher burden of disease among lung transplant recipients, due to unique risk factors, such as relative hypoxemia. However, these risk factors also provide unique opportunities for treatment and preventative strategies, as outlined in this review.
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Affiliation(s)
- S Pasupneti
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, California, USA.,Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, USA
| | - O Manouvakhova
- Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, USA
| | - M R Nicolls
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, California, USA.,Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, USA
| | - J L Hsu
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, California, USA .,Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, USA
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Jiang X, Hsu JL, Tian W, Yuan K, Olcholski M, Perez VDJ, Semenza GL, Nicolls MR. Tie2-dependent VHL knockdown promotes airway microvascular regeneration and attenuates invasive growth of Aspergillus fumigatus. J Mol Med (Berl) 2014; 91:1081-93. [PMID: 23797537 PMCID: PMC3761091 DOI: 10.1007/s00109-013-1063-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/24/2013] [Accepted: 05/30/2013] [Indexed: 01/09/2023]
Abstract
Abstract Microvascular ischemia and infections are associated with the development of chronic rejection following lung transplantation. The von Hippel–Lindau protein (VHL) controls protein levels of hypoxia-inducible factors (HIFs), regulates vascular repair, and improves tissue perfusion. Here, we studied the role of VHL in microvascular repair by orthotopically transplanting tracheas into mice with VHL haplodeficiency in Tie2 lineage cells. We showed that VHL haplodeficiency prolonged airway microvascular perfusion and promoted tissue blood flow through the production of the angiogenic factors, SDF-1 and angiopoietin 1. VHL-haplodeficient pulmonary endothelial cells exhibited increased angiogenic activity, resistance to serum deprivation-induced cell death, and enhanced microvascular repair. By contrast, in recipient mice with HIF-1α deficiency in Tie2 lineage cells, microvascular repair was significantly diminished and suggested that recipient-derived HIF-1α normally participates in the repair of alloimmune-mediated microvascular damage. To evaluate the translational impact of our findings, we compared VHL-haplodeficient mice with wild-type controls using a model of Aspergillus airway infection. In 83 % of the VHL-haplodeficient recipients, Aspergillus fumigatus was noninvasive in contrast to 75 % of wild-type mice in which the mold was deeply invasive. Our study demonstrated that stabilization of HIF-1α in angiogenic cells, through Tie2 cell VHL haplodeficiency, promoted airway microvascular regeneration and vascular normalization and thereby minimized tissue ischemia and hypoxia. By also mitigating the virulence of A. fumigatus, a common pathogen and itself a risk factor for the development of lung transplant rejection, the selective enhancement of HIF-1α expression has the prospect of offering several novel therapeutic effects to transplant recipients. Key message Microvascular loss and prolonged ischemia occurs with acute rejection. Von Hippel-Lindau (VHL) protein controls hypoxia inducible factors (HIFs). In tracheal allografts, VHL haplodeficient Tie2 cells promote neovascularization. Reduced transplant ischemia limits Aspergillus invasion.
Electronic supplementary material The online version of this article (doi:10.1007/s00109-013-1063-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xinguo Jiang
- Medical Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
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Kontoyiannis DP. Are respiratory complications more likely in patients with pulmonary aspergillosis treated with echinocandins in the setting of neutrophil influx? Virulence 2014; 5:375-7. [PMID: 24569451 DOI: 10.4161/viru.28291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Dimitrios P Kontoyiannis
- Department of Infectious Diseases, Infection Control and Employee Health; The University of Texas M.D. Anderson Cancer Center; Houston, TX USA
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Hsu JL, Khan MA, Sobel RA, Jiang X, Clemons KV, Nguyen TT, Stevens DA, Martinez M, Nicolls MR. Aspergillus fumigatus invasion increases with progressive airway ischemia. PLoS One 2013; 8:e77136. [PMID: 24155924 PMCID: PMC3796538 DOI: 10.1371/journal.pone.0077136] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 08/20/2013] [Indexed: 01/30/2023] Open
Abstract
Despite the prevalence of Aspergillus-related disease in immune suppressed lung transplant patients, little is known of the host-pathogen interaction. Because of the mould’s angiotropic nature and because of its capacity to thrive in hypoxic conditions, we hypothesized that the degree of Aspergillus invasion would increase with progressive rejection-mediated ischemia of the allograft. To study this relationship, we utilized a novel orthotopic tracheal transplant model of Aspergillus infection, in which it was possible to assess the effects of tissue hypoxia and ischemia on airway infectivity. Laser Doppler flowmetry and FITC-lectin were used to determine blood perfusion, and a fiber optic microsensor was used to measure airway tissue oxygen tension. Fungal burden and depth of invasion were graded using histopathology. We demonstrated a high efficacy (80%) for producing a localized fungal tracheal infection with the majority of infection occurring at the donor-recipient anastomosis; Aspergillus was more invasive in allogeneic compared to syngeneic groups. During the study period, the overall kinetics of both non-infected and infected allografts was similar, demonstrating a progressive loss of perfusion and oxygenation, which reached a nadir by days 10-12 post-transplantation. The extent of Aspergillus invasion directly correlated with the degree of graft hypoxia and ischemia. Compared to the midtrachea, the donor-recipient anastomotic site exhibited lower perfusion and more invasive disease; a finding consistent with clinical experience. For the first time, we identify ischemia as a putative risk factor for Aspergillus invasion. Therapeutic approaches focused on preserving vascular health may play an important role in limiting Aspergillus infections.
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Affiliation(s)
- Joe L. Hsu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, United States of America
- * E-mail:
| | - Mohammad A. Khan
- Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, United States of America
| | - Raymond A. Sobel
- Veterans Affairs Palo Alto Health Care System, Pathology and Laboratory Service, Palo Alto, California, United States of America
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Xinguo Jiang
- Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, United States of America
| | - Karl V. Clemons
- Infectious Diseases Research Laboratory, California Institute for Medical Research, San Jose, California, United States of America
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Tom T. Nguyen
- Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, United States of America
| | - David A. Stevens
- Infectious Diseases Research Laboratory, California Institute for Medical Research, San Jose, California, United States of America
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Marife Martinez
- Infectious Diseases Research Laboratory, California Institute for Medical Research, San Jose, California, United States of America
| | - Mark R. Nicolls
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Medical Service, Palo Alto, California, United States of America
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Varanat M, Maggi RG, Linder KE, Breitschwerdt EB. Infection of human brain vascular pericytes (HBVPs) by Bartonella henselae. Med Microbiol Immunol 2012. [PMID: 23184416 DOI: 10.1007/s00430-012-0279-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Angiogenesis is an important physiological and pathological process. Bartonella is the only genus of bacteria known to induce pathological angiogenesis in the mammalian host. Bartonella-induced angiogenesis leads to the formation of vascular tumors including verruga peruana and bacillary angiomatosis. The mechanism of Bartonella-induced angiogenesis is not completely understood. Pericytes, along with endothelial cells, play an important role in physiological angiogenesis, and their role in tumor angiogenesis has been extensively studied. Abnormal signaling between endothelial cells and pericytes contributes to tumor angiogenesis and metastasis; however, the role of pericytes in Bartonella-induced angiogenesis is not known. In this study, after infecting human brain vascular pericytes (HBVPs) with Bartonella henselae, we found that these bacteria were able to invade HBVPs and that bacterial infection resulted in decreased pericyte proliferation and increased pericyte production of vascular endothelial growth factor (VEGF) when compared to the uninfected control cells. In the context of pathological angiogenesis, reduced pericyte coverage, accompanied by increased VEGF production, may promote endothelial cell proliferation and the formation of new vessels.
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Affiliation(s)
- Mrudula Varanat
- Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
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Hamilos G, Samonis G, Kontoyiannis DP. Recent Advances in the Use of Drosophila melanogaster as a Model to Study Immunopathogenesis of Medically Important Filamentous Fungi. Int J Microbiol 2012; 2012:583792. [PMID: 22518146 PMCID: PMC3299265 DOI: 10.1155/2012/583792] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/07/2011] [Indexed: 01/30/2023] Open
Abstract
Airborne opportunistic fungi, including Aspergillus and other less common saprophytic molds, have recently emerged as important causes of mortality in immunocompromised individuals. Understanding the molecular mechanisms of host-fungal interplay in robust experimental pathosystems is becoming a research priority for development of novel therapeutics to combat these devastating infections. Over the past decade, invertebrate hosts with evolutionarily conserved innate immune signaling pathways and powerful genetics, such as Drosophila melanogaster, have been employed as a means to overcome logistic restrains associated with the use mammalian models of fungal infections. Recent studies in Drosophila models of filamentous fungi demonstrated that several genes implicated in fungal virulence in mammals also play a similarly important pathogenic role in fruit flies, and important host-related aspects in fungal pathogenesis are evolutionarily conserved. In view of recent advances in Drosophila genetics, fruit flies will become an invaluable surrogate model to study immunopathogenesis of fungal diseases.
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Affiliation(s)
- Georgios Hamilos
- Department of Internal Medicine, School of Medicine, University of Crete, Stavrakia, Voutes, 71110 Heraklion, Crete, Greece
| | - George Samonis
- Department of Internal Medicine, School of Medicine, University of Crete, Stavrakia, Voutes, 71110 Heraklion, Crete, Greece
| | - Dimitrios P. Kontoyiannis
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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