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Riebold D, Mahnkopf M, Wicht K, Zubiria-Barrera C, Heise J, Frank M, Misch D, Bauer T, Stocker H, Slevogt H. Axenic Long-Term Cultivation of Pneumocystis jirovecii. J Fungi (Basel) 2023; 9:903. [PMID: 37755011 PMCID: PMC10533121 DOI: 10.3390/jof9090903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/18/2023] [Accepted: 08/29/2023] [Indexed: 09/28/2023] Open
Abstract
Pneumocystis jirovecii, a fungus causing severe Pneumocystis pneumonia (PCP) in humans, has long been described as non-culturable. Only isolated short-term experiments with P. jirovecii and a small number of experiments involving animal-derived Pneumocystis species have been published to date. However, P. jirovecii culture conditions may differ significantly from those of animal-derived Pneumocystis, as there are major genotypic and phenotypic differences between them. Establishing a well-performing P. jirovecii cultivation is crucial to understanding PCP and its pathophysiological processes. The aim of this study, therefore, was to develop an axenic culture for Pneumocystis jirovecii. To identify promising approaches for cultivation, a literature survey encompassing animal-derived Pneumocystis cultures was carried out. The variables identified, such as incubation time, pH value, vitamins, amino acids, and other components, were trialed and adjusted to find the optimum conditions for P. jirovecii culture. This allowed us to develop a medium that produced a 42.6-fold increase in P. jirovecii qPCR copy numbers after a 48-day culture. Growth was confirmed microscopically by the increasing number and size of actively growing Pneumocystis clusters in the final medium, DMEM-O3. P. jirovecii doubling time was 8.9 days (range 6.9 to 13.6 days). In conclusion, we successfully cultivated P. jirovecii under optimized cell-free conditions in a 70-day long-term culture for the first time. However, further optimization of the culture conditions for this slow grower is indispensable.
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Affiliation(s)
- Diana Riebold
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Marie Mahnkopf
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Kristina Wicht
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, B-9000 Gent, Belgium;
| | - Cristina Zubiria-Barrera
- Respiratory Infection Dynamics Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (C.Z.-B.); (H.S.)
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, German Center for Lung Research (DZL), BREATH, 30625 Hannover, Germany
| | - Jan Heise
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Marcus Frank
- Medical Biology and Electron Microscopy Centre (EMZ), University Medicine Rostock, 18057 Rostock, Germany;
| | - Daniel Misch
- Lungenklinik Heckeshorn, Helios Klinikum Emil-von-Behring, 14165 Berlin, Germany; (D.M.); (T.B.)
| | - Torsten Bauer
- Lungenklinik Heckeshorn, Helios Klinikum Emil-von-Behring, 14165 Berlin, Germany; (D.M.); (T.B.)
| | - Hartmut Stocker
- Clinic for Infectiology, St. Joseph’s Hospital Berlin, 12101 Berlin, Germany;
| | - Hortense Slevogt
- Respiratory Infection Dynamics Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (C.Z.-B.); (H.S.)
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, German Center for Lung Research (DZL), BREATH, 30625 Hannover, Germany
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2
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Xu Y, Li Z, Ouyang L, Su Y, Wang C. Successful treatment of severe Pneumocystis Jirovecii pneumonia in a diffuse large B-cell lymphoma patient after R-CHOP chemotherapy: A case report. SAGE Open Med Case Rep 2023; 11:2050313X231178050. [PMID: 37325165 PMCID: PMC10265330 DOI: 10.1177/2050313x231178050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
R-CHOP chemotherapy has been established as the first-line standard treatment for elderly patients diagnosed with diffuse large B-cell lymphoma. However, an increased risk of Pneumocystis jirovecii pneumonia in diffuse large B-cell lymphoma patients after the rituximab-based chemotherapy has been reported. We describe a case who developed intermittent cough, fever and shortness of breath after five cycles of R-CHOP treatment for diffuse large B-cell lymphoma. A rapid deterioration in patient's respiratory condition prompted us to adopt an aggressive anti- Pneumocystis jirovecii pneumonia strategy that combined the conventional trimethoprim/sulfamethoxazole and another two antimicrobials, caspofungin and clindamycin. This is the first report mentioning the successful treatment of severe Pneumocystis jirovecii pneumonia with a triple-drug regimen in a HIV-uninfected patient. The aim of our report is also to emphasize that early and correct diagnosis of Pneumocystis jirovecii pneumonia in immunocompromised HIV-uninfected patients is very important. Relevant oncologists should be alert to the risk of Pneumocystis jirovecii pneumonia in patients receiving R-CHOP chemotherapy.
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Affiliation(s)
- Yan Xu
- Department of Critical Care Medicine, Guangdong Second Provincial General Hospital, Guangzhou, People’s Republic of China
| | - Zhaolin Li
- Department of Pulmonary and Critical Care Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Lamei Ouyang
- Department of Critical Care Medicine, Guangdong Second Provincial General Hospital, Guangzhou, People’s Republic of China
| | - Yinqing Su
- Department of Critical Care Medicine, Guangdong Second Provincial General Hospital, Guangzhou, People’s Republic of China
| | - Canmin Wang
- Department of Critical Care Medicine, Guangdong Second Provincial General Hospital, Guangzhou, People’s Republic of China
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Pungan D, Fan J, Dai G, Khatun MS, Dietrich ML, Zwezdaryk KJ, Robinson JE, Landry SJ, Kolls JK. Novel Pneumocystis Antigens for Seroprevalence Studies. J Fungi (Basel) 2023; 9:602. [PMID: 37367538 PMCID: PMC10300987 DOI: 10.3390/jof9060602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 06/28/2023] Open
Abstract
Pneumocystis jirovecii is the most common cause of fungal pneumonia in children under the age of 2 years. However, the inability to culture and propagate this organism has hampered the acquisition of a fungal genome as well as the development of recombinant antigens to conduct seroprevalence studies. In this study, we performed proteomics on Pneumocystis-infected mice and used the recent P. murina and P. jirovecii genomes to prioritize antigens for recombinant protein expression. We focused on a fungal glucanase due to its conservation among fungal species. We found evidence of maternal IgG to this antigen, followed by a nadir in pediatric samples between 1 and 3 months of age, followed by an increase in prevalence over time consistent with the known epidemiology of Pneumocystis exposure. Moreover, there was a strong concordance of anti-glucanase responses and IgG against another Pneumocystis antigen, PNEG_01454. Taken together, these antigens may be useful tools for Pneumocystis seroprevalence and seroconversion studies.
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Affiliation(s)
- Dora Pungan
- John W Deming Department of Internal Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jia Fan
- Department of Biochemistry, Center for Cellular & Molecular Diagnostics, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Guixiang Dai
- John W Deming Department of Internal Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Mst Shamima Khatun
- John W Deming Department of Internal Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Monika L. Dietrich
- Department of Pediatrics, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Kevin J. Zwezdaryk
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - James E. Robinson
- Department of Pediatrics, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Samuel J. Landry
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jay K. Kolls
- John W Deming Department of Internal Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Department of Pediatrics, Tulane University School of Medicine, New Orleans, LA 70112, USA
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Wang M, Zhang Z, Dong X, Zhu B. Targeting β-glucans, vital components of the Pneumocystis cell wall. Front Immunol 2023; 14:1094464. [PMID: 36845149 PMCID: PMC9947646 DOI: 10.3389/fimmu.2023.1094464] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/16/2023] [Indexed: 02/11/2023] Open
Abstract
β-glucan is the most abundant polysaccharide in the cell wall of Pneumocystis jirovecii, which has attracted extensive attention because of its unique immunobiological characteristics. β-glucan binds to various cell surface receptors, which produces an inflammatory response and accounts for its immune effects. A deeper comprehension of the processes by Pneumocystis β-glucan recognizes its receptors, activates related signaling pathways, and regulates immunity as required. Such understanding will provide a basis for developing new therapies against Pneumocystis. Herein, we briefly review the structural composition of β-glucans as a vital component of the Pneumocystis cell wall, the host immunity mediated by β-glucans after their recognition, and discuss opportunities for the development of new strategies to combat Pneumocystis.
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Affiliation(s)
- Mengyan Wang
- Department II of Infectious Diseases, Xixi Hospital of Hangzhou, Hangzhou, China,Department of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhongdong Zhang
- Department II of Infectious Diseases, Xixi Hospital of Hangzhou, Hangzhou, China
| | - Xiaotian Dong
- Department of Clinical Laboratory, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Biao Zhu
- Department of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China,*Correspondence: Biao Zhu,
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Characterization of Paenibacillus sp. GKG Endo-β-1, 3-Glucanase, a Member of Family 81 Glycoside Hydrolases. Microorganisms 2022; 10:microorganisms10101930. [DOI: 10.3390/microorganisms10101930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 09/23/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022] Open
Abstract
Paenibacillus sp. GKG was isolated based on its ability to produce hydrolysis zones on agar plates containing yeast cell wall substrate as the single carbon source. The extracellular enzymes secreted into the culture medium were identified by LC-MS/MS proteomics. Endo-β-1,3-glucanase PsLam81A containing GH81 catalytic and the CBM56 carbohydrate-binding modules was selected for heterologous expression in Escherichia coli. The identity of the recombinant PsLam81A was confirmed by LC-MS/MS proteomics. The PsLam81A showed the highest activity at 60 °C, and the optimal pH range was between 6.5 and 8.0. The analysis of the full-length PsLam81A and truncated PsLam81AΔCBM56 enzymes showed that the CBM56 module improved the hydrolytic activity towards linear β-1,3-glucans—curdlan and pachyman but had no effect on hydrolysis of β-1,3/β1,6-branched glucans—laminarin and yeast β-glucan. The characterization of PsLam81A enzyme broadens current knowledge on the biochemical properties and substrate specificity of family 81 glycoside hydrolases and allows prediction of the necessity of CBM56 module in the process of designing new truncated or chimeric glycosidases.
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Ma J, Qin Z, Zhou P, Wang R, Yan Q, Jiang Z, Yang S. Structural insights into the substrate recognition and catalytic mechanism of a fungal glycoside hydrolase family 81 β-1,3-glucanase. Enzyme Microb Technol 2021; 153:109948. [PMID: 34801773 DOI: 10.1016/j.enzmictec.2021.109948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/08/2021] [Accepted: 11/08/2021] [Indexed: 11/03/2022]
Abstract
β-1,3-Glucan constitutes a prominent cell wall component being responsible for rigidity and strength of the cell wall structure in filamentous fungi. Glycoside hydrolase (GH) family 81 endo-β-1,3-glucanases which can cleave the long chain of β-1,3-glucans play a major role in fungal cell wall remodeling. Here, we reported the complex structures of a fungal GH family 81 endo-β-1,3-glucanase from Rhizomucor miehei (RmLam81A), revealing the triple-helical β-glucan recognition and hydrolysis patterns. In the crystals, three structured oligosaccharide ligands simultaneously interact with one enzyme molecular via seven glucose residues, and the spatial arrangement of ligands to RmLam81A was almost identical to that of β-1,3-glucan triple-helical structure. RmLam81A performed an inverting catalysis mechanism with Asp475 and Glu557 severing as the general acid and base catalyst, respectively. Furthermore, two hydrophobic patches involving Tyr93, Tyr106, Ile108, Phe619 and Tyr628 alongside the ligand-binding site possibly formed parts of the binding site. A ligand-binding motif, β31-β32, consisting of two key residues (Lys622 and Asp624), involved the recognition of a triple-helical β-glucan. Our results provided a structural basis for the unique β-1,3-glucan recognition pattern and catalytic mechanism of fungal GH family 81 endo-β-1,3-glucanases, which may be helpful in further understanding the diverse physiological functions of β-1,3-glucanases.
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Affiliation(s)
- Junwen Ma
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China; Key Laboratory of Food Bioengineering (China National Light Industry), College of Engineering, China Agricultural University, Beijing 100083, China
| | - Zhen Qin
- School of Life Science Shanghai University, Shanghai 200237, China
| | - Peng Zhou
- Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Ruiming Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China
| | - Qiaojuan Yan
- Key Laboratory of Food Bioengineering (China National Light Industry), College of Engineering, China Agricultural University, Beijing 100083, China
| | - Zhengqiang Jiang
- Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
| | - Shaoqing Yang
- Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
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Tian Q, Si J, Jiang F, Xu R, Wei B, Huang B, Li Q, Jiang Z, Zhao T. Caspofungin combined with TMP/SMZ as a first-line therapy for moderate-to-severe PCP in patients with human immunodeficiency virus infection. HIV Med 2020; 22:307-313. [PMID: 33277811 PMCID: PMC7984216 DOI: 10.1111/hiv.13013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2020] [Indexed: 01/05/2023]
Abstract
OBJECTIVES The effectiveness of trimethoprim/sulfamethoxazole (TMP/SMZ) for pneumocystis pneumonia (PCP) is limited with adverse events. Caspofungin, by inhibiting the cyst form of Pneumocystis jirovecii, may be an alternative therapy for PCP. However, the availability of clinical data about caspofungin combined with TMP/SMZ in the treatment of PCP in HIV-infected patients is limited. Thus, we aimed to examine the clinical effectiveness and safety of caspofungin combined with TMP/SMZ as a first-line therapy for moderate-to-severe PCP in HIV-infected patients. METHODS From January 2017 to December 2019, data of HIV-infected patients with moderate-to-severe PCP who received either TMP/SMZ alone or caspofungin combined with TMP/SMZ as first-line therapy were retrospectively reviewed to assess the effectiveness and safety of each regimen. The Kaplan-Meier curve and log-rank test were used for survival analysis. RESULTS A total of 278 patients met the criteria. The overall positive response rate of PCP treatment was 48.92%, and the overall all-cause in-hospital mortality rate was 33.09%. Patients who received combination therapy consisting of caspofungin and TMP/SMZ had a better positive response rate (59.44% vs. 37.78%, P < 0.001) and lower all-cause in-hospital mortality rate (24.48% vs. 42.22%, P = 0.003). Also, patients who received combination therapy had higher survival rate during a hospital stay (75.52% vs. 57.78%, P = 0.004), and those who received longer combination therapy were more likely to have higher survival rate (P = 0.042). We found that age (P = 0.019), CD4 cell count (P = 0.001) and therapeutic regimen (P = 0.002) were significant risk factors for all-cause in-hospital mortality rate in univariate analysis. In multivariate analysis, only CD4 cell count and therapeutic regimen were statistically significant factors associated with all-cause in-hospital mortality rate. Patients with a CD4 count of > 30 cells/µL and patients who received combination therapy consisting of caspofungin and TMP/SMZ were more likely to survive from PCP (P = 0.011 and P = 0.002, respectively). There were no additional severe adverse events caused by adding caspofungin. CONCLUSIONS For HIV-infected patients with moderate-to-severe PCP, combination therapy with caspofungin and TMP/SMZ is an effective and promising first-line therapy with no greater number of adverse events compared with TMP/SMZ monotherapy. Patients who received caspofungin had better positive response rates and lower all-cause in-hospital mortality rates. Also, we recommend early initiation of caspofungin.
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Affiliation(s)
- Q Tian
- The Third People's Hospital of Guilin, Guangxi, China
| | - J Si
- The First Hospital of Jiaxing, Zhejiang, China
| | - F Jiang
- The Third People's Hospital of Guilin, Guangxi, China
| | - R Xu
- The Third People's Hospital of Guilin, Guangxi, China
| | - B Wei
- The Third People's Hospital of Guilin, Guangxi, China
| | - B Huang
- The Third People's Hospital of Guilin, Guangxi, China
| | - Q Li
- The Third People's Hospital of Guilin, Guangxi, China
| | - Z Jiang
- People's Hospital of Liuzhou, Guangxi, China
| | - T Zhao
- The Third People's Hospital of Guilin, Guangxi, China
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Bishop LR, Davis AS, Bradshaw K, Gamez M, Cisse OH, Wang H, Ma L, Kovacs JA. Characterization of p57, a Stage-Specific Antigen of Pneumocystis murina. J Infect Dis 2019; 218:282-290. [PMID: 29471356 DOI: 10.1093/infdis/jiy099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/15/2018] [Indexed: 11/14/2022] Open
Abstract
Pneumocystis has a large multicopy gene family encoding proteins related to the major surface glycoprotein (Msg), whose functions are largely unknown. We expressed one such protein of Pneumocystis murina, p57, which is encoded by 3 highly conserved genes, and demonstrated by immunoblot that immunocompetent mice that were immunized with crude Pneumocystis antigens or that had cleared Pneumocystis infection developed antibodies to p57. Using hyperimmune anti-p57 serum combined with immunolabeling, we found that p57 was expressed by small trophic forms and intracystic bodies, whereas it was not expressed on larger trophic forms or externally by cysts. Expression of p57 and Msg by trophic forms was largely mutually exclusive. Treatment of infected animals with caspofungin inhibited cyst formation and markedly decreased p57 expression. While p57 expression was seen in immunocompetent mice infected with Pneumocystis, immunization with recombinant p57 did not result in altered cytokine expression by lymphocytes or in diminished infection in such mice. Thus, p57 appears to be a stage-specific antigen of Pneumocystis that is expressed on intracystic bodies and young trophic forms and may represent a mechanism to conserve resources in organisms during periods of limited exposure to host immune responses.
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Affiliation(s)
- Lisa R Bishop
- Critical Care Medicine Department, National Institutes of Health (NIH) Clinical Center, NIH, Bethesda, Maryland
| | - A Sally Davis
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan
| | - Kaitlynn Bradshaw
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan
| | - Monica Gamez
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan
| | - Ousmane H Cisse
- Critical Care Medicine Department, National Institutes of Health (NIH) Clinical Center, NIH, Bethesda, Maryland
| | - Honghui Wang
- Critical Care Medicine Department, National Institutes of Health (NIH) Clinical Center, NIH, Bethesda, Maryland
| | - Liang Ma
- Critical Care Medicine Department, National Institutes of Health (NIH) Clinical Center, NIH, Bethesda, Maryland
| | - Joseph A Kovacs
- Critical Care Medicine Department, National Institutes of Health (NIH) Clinical Center, NIH, Bethesda, Maryland
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Cissé OH, Hauser PM. Genomics and evolution of Pneumocystis species. INFECTION GENETICS AND EVOLUTION 2018; 65:308-320. [PMID: 30138710 DOI: 10.1016/j.meegid.2018.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 01/20/2023]
Abstract
The genus Pneumocystis comprises highly diversified fungal species that cause severe pneumonia in individuals with a deficient immune system. These fungi infect exclusively mammals and present a strict host species specificity. These species have co-diverged with their hosts for long periods of time (> 100 MYA). Details of their biology and evolution are fragmentary mainly because of a lack of an established long-term culture system. Recent genomic advances have unlocked new areas of research and allow new hypotheses to be tested. We review here new findings of the genomic studies in relation with the evolutionary trajectory of these fungi and discuss the impact of genomic data analysis in the context of the population genetics. The combination of slow genome decay and limited expansion of specific gene families and introns reflect intimate interactions of these species with their hosts. The evolutionary adaptation of these organisms is profoundly influenced by their population structure, which in turn is determined by intrinsic features such as their self-fertilizing mating system, high host specificity, long generation times, and transmission mode. Essential key questions concerning their adaptation and speciation remain to be answered. The next cornerstone will consist in the establishment of a long-term culture system and genetic manipulation that should allow unravelling the driving forces of Pneumocystis species evolution.
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Affiliation(s)
- Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland.
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Ma L, Cissé OH, Kovacs JA. A Molecular Window into the Biology and Epidemiology of Pneumocystis spp. Clin Microbiol Rev 2018; 31:e00009-18. [PMID: 29899010 PMCID: PMC6056843 DOI: 10.1128/cmr.00009-18] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pneumocystis, a unique atypical fungus with an elusive lifestyle, has had an important medical history. It came to prominence as an opportunistic pathogen that not only can cause life-threatening pneumonia in patients with HIV infection and other immunodeficiencies but also can colonize the lungs of healthy individuals from a very early age. The genus Pneumocystis includes a group of closely related but heterogeneous organisms that have a worldwide distribution, have been detected in multiple mammalian species, are highly host species specific, inhabit the lungs almost exclusively, and have never convincingly been cultured in vitro, making Pneumocystis a fascinating but difficult-to-study organism. Improved molecular biologic methodologies have opened a new window into the biology and epidemiology of Pneumocystis. Advances include an improved taxonomic classification, identification of an extremely reduced genome and concomitant inability to metabolize and grow independent of the host lungs, insights into its transmission mode, recognition of its widespread colonization in both immunocompetent and immunodeficient hosts, and utilization of strain variation to study drug resistance, epidemiology, and outbreaks of infection among transplant patients. This review summarizes these advances and also identifies some major questions and challenges that need to be addressed to better understand Pneumocystis biology and its relevance to clinical care.
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Affiliation(s)
- Liang Ma
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
| | - Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
| | - Joseph A Kovacs
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
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Gene Expression of Pneumocystis murina after Treatment with Anidulafungin Results in Strong Signals for Sexual Reproduction, Cell Wall Integrity, and Cell Cycle Arrest, Indicating a Requirement for Ascus Formation for Proliferation. Antimicrob Agents Chemother 2018; 62:AAC.02513-17. [PMID: 29463544 PMCID: PMC5923105 DOI: 10.1128/aac.02513-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/10/2018] [Indexed: 01/03/2023] Open
Abstract
The echinocandins are a class of antifungal agents that target β-1,3-d-glucan (BG) biosynthesis. In the ascigerous Pneumocystis species, treatment with these drugs depletes the ascus life cycle stage, which contains BG, but large numbers of forms which do not express BG remain in the infected lungs. In the present study, the gene expression profiles of Pneumocystis murina were compared between infected, untreated mice and mice treated with anidulafungin for 2 weeks to understand the metabolism of the persisting forms. Almost 80 genes were significantly up- or downregulated. Like other fungi exposed to echinocandins, genes associated with sexual replication, cell wall integrity, cell cycle arrest, and stress comprised the strongest upregulated signals in P. murina from the treated mice. The upregulation of the P. murina β-1,3-d-glucan endohydrolase and endo-1,3-glucanase was notable and may explain the disappearance of the existing asci in the lungs of treated mice since both enzymes can degrade BG. The biochemical measurement of BG in the lungs of treated mice and fluorescence microscopy with an anti-BG antibody supported the loss of BG. Downregulated signals included genes involved in cell replication, genome stability, and ribosomal biogenesis and function and the Pneumocystis-specific genes encoding the major surface glycoproteins (Msg). These studies suggest that P. murina attempted to undergo sexual replication in response to a stressed environment and was halted in any type of proliferative cycle, likely due to a lack of BG. Asci appear to be a required part of the life cycle stage of Pneumocystis, and BG may be needed to facilitate progression through the life cycle via sexual replication.
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Abstract
Morphological changes are a very common and effective strategy for pathogens to survive in the mammalian host. During interactions with their host, human pathogenic fungi undergo an array of morphological changes that are tightly associated with virulence. Candida albicans switches between yeast cells and hyphae during infection. Thermally dimorphic pathogens, such as Histoplasma capsulatum and Blastomyces species transform from hyphal growth to yeast cells in response to host stimuli. Coccidioides and Pneumocystis species produce spherules and cysts, respectively, which allow for the production of offspring in a protected environment. Finally, Cryptococcus species suppress hyphal growth and instead produce an array of yeast cells—from large polyploid titan cells to micro cells. While the morphology changes produced by human fungal pathogens are diverse, they all allow for the pathogens to evade, manipulate, and overcome host immune defenses to cause disease. In this review, we summarize the morphology changes in human fungal pathogens—focusing on morphological features, stimuli, and mechanisms of formation in the host.
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Affiliation(s)
| | - Kirsten Nielsen
- Correspondence: ; Tel.: +1-612-625-4979; Fax: +1-612-626-0623
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13
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Zhang G, Chen M, Zhang S, Zhou H, Ji X, Cai J, Lou T, Cui W, Zhang N. Efficacy of caspofungin combined with trimethoprim/sulfamethoxazole as first-line therapy to treat non-HIV patients with severe pneumocystis pneumonia. Exp Ther Med 2017; 15:1594-1601. [PMID: 29399131 DOI: 10.3892/etm.2017.5516] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 09/22/2017] [Indexed: 01/07/2023] Open
Abstract
Combined treatment with caspofungin and trimethoprim/sulfamethoxazole (TMP/SMZ) as salvage therapy in non-HIV positive patients with severe pneumocystis pneumonia (PCP) yields poor outcomes. It remains unknown whether the use of this combination strategy as a first-line therapy would improve patient outcomes. The present study aimed to assess the efficacy of caspofungin combined with TMP/SMZ as a first-line therapy in non-HIV positive patients with severe PCP. A retrospective cohort study was conducted between March 2016 and February 2017. Patient clinical characteristics and outcomes were compared between two groups receiving first-line and second-line therapy respectively. In addition, similar cases from previous studies were assessed. A total of 14 patients were included in the present study (mean age, 58.79±14.41 years); including 9 patients receiving caspofungin and TMP/SMZ as a first-line therapy and 5 that received it as a second-line therapy. The overall positive response rate was 71.43% (10/14), with 88.89 (8/9) and 40.00% (2/5) in the first-line and second-line therapy groups, respectively (P=0.095). The positive response rates of patients requiring invasive mechanical ventilation differed significantly between the first-line (5/6, 83.33%) and the second-line (0/3, 0%) therapy groups (P=0.048). All-cause hospital mortality was 42.86% (6/14), with mortality rates of 33.33 (3/9) and 60.00% (3/5) in the first-line and second-line therapy groups, respectively (P=0.580). Combined with previously reported cases (n=27), the positive response rate was significantly greater in the first-line therapy group (11/12, 91.67%) than in the second-line therapy group (8/15, 53.33%, P=0.043). No significant differences were in all-cause mortality rates between the two groups (25.00 vs. 46.67%, P=0.424) were identified, despite the fact that all-course mortality in the first-line therapy group was ~50% that of the second-line therapy group. Therefore, the results of the present study indicate that combined caspofungin and TMP/SMZ as first-line therapy may be a promising and effective strategy to treat non-HIV positive patients with severe PCP, particularly for those requiring invasive mechanical ventilation.
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Affiliation(s)
- Gensheng Zhang
- Department of Critical Care Medicine, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Miaomiao Chen
- Department of Critical Care Medicine, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.,Department of Critical Care Medicine, Lishui People's Hospital, Lishui, Zhejiang 323000, P.R. China
| | - Shufang Zhang
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Hongwei Zhou
- Microbiology Laboratory, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Xiaozhen Ji
- Department of Critical Care Medicine, Longquan People's Hospital, Lishui, Zhejiang 323700, P.R. China
| | - Jiachang Cai
- Microbiology Laboratory, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Tianzheng Lou
- Department of Critical Care Medicine, Lishui People's Hospital, Lishui, Zhejiang 323000, P.R. China
| | - Wei Cui
- Department of Critical Care Medicine, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Ning Zhang
- Department of Critical Care Medicine, Lishui People's Hospital, Lishui, Zhejiang 323000, P.R. China
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14
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Ma L, Chen Z, Huang DW, Kutty G, Ishihara M, Wang H, Abouelleil A, Bishop L, Davey E, Deng R, Deng X, Fan L, Fantoni G, Fitzgerald M, Gogineni E, Goldberg JM, Handley G, Hu X, Huber C, Jiao X, Jones K, Levin JZ, Liu Y, Macdonald P, Melnikov A, Raley C, Sassi M, Sherman BT, Song X, Sykes S, Tran B, Walsh L, Xia Y, Yang J, Young S, Zeng Q, Zheng X, Stephens R, Nusbaum C, Birren BW, Azadi P, Lempicki RA, Cuomo CA, Kovacs JA. Genome analysis of three Pneumocystis species reveals adaptation mechanisms to life exclusively in mammalian hosts. Nat Commun 2016; 7:10740. [PMID: 26899007 PMCID: PMC4764891 DOI: 10.1038/ncomms10740] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 01/13/2016] [Indexed: 02/07/2023] Open
Abstract
Pneumocystis jirovecii is a major cause of life-threatening pneumonia in immunosuppressed patients including transplant recipients and those with HIV/AIDS, yet surprisingly little is known about the biology of this fungal pathogen. Here we report near complete genome assemblies for three Pneumocystis species that infect humans, rats and mice. Pneumocystis genomes are highly compact relative to other fungi, with substantial reductions of ribosomal RNA genes, transporters, transcription factors and many metabolic pathways, but contain expansions of surface proteins, especially a unique and complex surface glycoprotein superfamily, as well as proteases and RNA processing proteins. Unexpectedly, the key fungal cell wall components chitin and outer chain N-mannans are absent, based on genome content and experimental validation. Our findings suggest that Pneumocystis has developed unique mechanisms of adaptation to life exclusively in mammalian hosts, including dependence on the lungs for gas and nutrients and highly efficient strategies to escape both host innate and acquired immune defenses.
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Affiliation(s)
- Liang Ma
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Zehua Chen
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Da Wei Huang
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Geetha Kutty
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Mayumi Ishihara
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA
| | - Honghui Wang
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Amr Abouelleil
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Lisa Bishop
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Emma Davey
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Rebecca Deng
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Xilong Deng
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Lin Fan
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Giovanna Fantoni
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Michael Fitzgerald
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Emile Gogineni
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Jonathan M. Goldberg
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Grace Handley
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Xiaojun Hu
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Charles Huber
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Xiaoli Jiao
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Kristine Jones
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Joshua Z. Levin
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Yueqin Liu
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Pendexter Macdonald
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Alexandre Melnikov
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Castle Raley
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Monica Sassi
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Brad T. Sherman
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Xiaohong Song
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Sean Sykes
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Bao Tran
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Laura Walsh
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Yun Xia
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
| | - Jun Yang
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Sarah Young
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Qiandong Zeng
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Xin Zheng
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Robert Stephens
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Chad Nusbaum
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Bruce W. Birren
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA
| | - Richard A. Lempicki
- Leidos BioMedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Christina A. Cuomo
- Genome Sequencing and Analysis Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Joseph A. Kovacs
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, 10 Center Drive, Bethesda, Maryland 20892, USA
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15
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Skalski JH, Kottom TJ, Limper AH. Pathobiology of Pneumocystis pneumonia: life cycle, cell wall and cell signal transduction. FEMS Yeast Res 2015; 15:fov046. [PMID: 26071598 DOI: 10.1093/femsyr/fov046] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2015] [Indexed: 12/28/2022] Open
Abstract
Pneumocystis is a genus of ascomycetous fungi that are highly morbid pathogens in immunosuppressed humans and other mammals. Pneumocystis cannot easily be propagated in culture, which has greatly hindered understanding of its pathobiology. The Pneumocystis life cycle is intimately associated with its mammalian host lung environment, and life cycle progression is dependent on complex interactions with host alveolar epithelial cells and the extracellular matrix. The Pneumocystis cell wall is a varied and dynamic structure containing a dominant major surface glycoprotein, β-glucans and chitins that are important for evasion of host defenses and stimulation of the host immune system. Understanding of Pneumocystis cell signaling pathways is incomplete, but much has been deduced by comparison of the Pneumocystis genome with homologous genes and proteins in related fungi. In this mini-review, the pathobiology of Pneumocystis is reviewed, with particular focus on the life cycle, cell wall components and cell signal transduction.
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Affiliation(s)
- Joseph H Skalski
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Theodore J Kottom
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Andrew H Limper
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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