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Depicolzuane L, Phelps DS, Floros J. Surfactant Protein-A Function: Knowledge Gained From SP-A Knockout Mice. Front Pediatr 2021; 9:799693. [PMID: 35071140 PMCID: PMC8777267 DOI: 10.3389/fped.2021.799693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/03/2021] [Indexed: 02/04/2023] Open
Abstract
Pulmonary surfactant proteins have many roles in surfactant- related functions and innate immunity. One of these proteins is the surfactant protein A (SP-A) that plays a role in both surfactant-related processes and host defense and is the focus in this review. SP-A interacts with the sentinel host defense cell in the alveolus, the alveolar macrophage (AM), to modulate its function and expression profile under various conditions, as well as other alveolar epithelial cells such as the Type II cell. Via these interactions, SP-A has an impact on the alveolar microenvironment. SP-A is also important for surfactant structure and function. Much of what is understood of the function of SP-A and its various roles in lung health has been learned from SP-A knockout (KO) mouse experiments, as reviewed here. A vast majority of this work has been done with infection models that are bacterial, viral, and fungal in nature. Other models have also been used, including those of bleomycin-induced lung injury and ozone-induced oxidative stress either alone or in combination with an infectious agent, bone marrow transplantation, and other. In addition, models investigating the effects of SP-A on surfactant components or surfactant structure have contributed important information. SP-A also appears to play a role in pathways involved in sex differences in response to infection and/or oxidative stress, as well as at baseline conditions. To date, this is the first review to provide a comprehensive report of the functions of SP-A as learned through KO mice.
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Affiliation(s)
| | | | - Joanna Floros
- Departments of Pediatrics, Hershey, PA, United States.,Obstetrics and Gynecology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
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2
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Raevens S, Fallon MB. Potential Clinical Targets in Hepatopulmonary Syndrome: Lessons From Experimental Models. Hepatology 2018; 68:2016-2028. [PMID: 29729196 PMCID: PMC6204081 DOI: 10.1002/hep.30079] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/20/2018] [Accepted: 04/27/2018] [Indexed: 12/12/2022]
Abstract
Hepatopulmonary syndrome (HPS) is a relatively common and potentially severe pulmonary complication of cirrhosis with increased risk of mortality. In experimental models, a complex interaction between pulmonary endothelial cells, monocytes, and the respiratory epithelium, which produces chemokines, cytokines, and angiogenic growth factors, causes alterations in the alveolar microvasculature, resulting in impaired oxygenation. Model systems are critical for evaluating mechanisms and for preclinical testing in HPS, due to the challenges of evaluating the lung in the setting of advanced liver disease in humans. This review provides an overview of current knowledge and recent findings in the rodent common bile duct ligation model of HPS, which recapitulates many features of human disease. We focus on the concepts of endothelial derangement, monocyte infiltration, angiogenesis, and alveolar type II cell dysfunction as main contributors and potential targets for therapy.
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Affiliation(s)
- Sarah Raevens
- Department of Gastroenterology and Hepatology – Hepatology Research Unit, Ghent University – Ghent University Hospital, Ghent, Belgium
- Department of Internal Medicine, University of Arizona College of Medicine, Phoenix, Arizona, USA
| | - Michael B. Fallon
- Department of Internal Medicine, University of Arizona College of Medicine, Phoenix, Arizona, USA
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3
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Elbahlawan L, Srinivasan A, Morrison RR. A Critical Care and Transplantation-Based Approach to Acute Respiratory Failure after Hematopoietic Stem Cell Transplantation in Children. Biol Blood Marrow Transplant 2015; 22:617-626. [PMID: 26409244 PMCID: PMC5033513 DOI: 10.1016/j.bbmt.2015.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022]
Abstract
Acute respiratory failure contributes significantly to nonrelapse mortality after allogeneic hematopoietic stem cell transplantation. Although there is a trend of improved survival over time, mortality remains unacceptably high. An understanding of the pathophysiology of early respiratory failure, opportunities for targeted therapy, assessment of the patient at risk, optimal use of noninvasive positive pressure ventilation, strategies to improve alveolar recruitment, appropriate fluid management, care of the patient with chronic lung disease, and importantly, a team approach between critical care and transplantation services may improve outcomes. Outcomes from acute respiratory failure after hematopoietic stem cell transplantation remain unacceptably high. The review focuses on strategies to improve these outcomes.
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Affiliation(s)
- Lama Elbahlawan
- Department of Pediatric Medicine, Division of Critical Care, St. Jude Children's Research Hospital, Memphis, Tennessee.,Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ashok Srinivasan
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee.,Department of Bone Marrow Transplantation and Cellular Therapy, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - R Ray Morrison
- Department of Pediatric Medicine, Division of Critical Care, St. Jude Children's Research Hospital, Memphis, Tennessee.,Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
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SP-R210 (Myo18A) Isoforms as Intrinsic Modulators of Macrophage Priming and Activation. PLoS One 2015; 10:e0126576. [PMID: 25965346 PMCID: PMC4428707 DOI: 10.1371/journal.pone.0126576] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 04/06/2015] [Indexed: 11/19/2022] Open
Abstract
The surfactant protein (SP-A) receptor SP-R210 has been shown to increase phagocytosis of SP-A-bound pathogens and to modulate cytokine secretion by immune cells. SP-A plays an important role in pulmonary immunity by enhancing opsonization and clearance of pathogens and by modulating macrophage inflammatory responses. Alternative splicing of the Myo18A gene results in two isoforms: SP-R210S and SP-R210L, with the latter predominantly expressed in alveolar macrophages. In this study we show that SP-A is required for optimal expression of SP-R210L on alveolar macrophages. Interestingly, pre-treatment with SP-A prepared by different methods either enhances or suppresses responsiveness to LPS, possibly due to differential co-isolation of SP-B or other proteins. We also report that dominant negative disruption of SP-R210L augments expression of receptors including SR-A, CD14, and CD36, and enhances macrophages' inflammatory response to TLR stimulation. Finally, because SP-A is known to modulate CD14, we used a variety of techniques to investigate how SP-R210 mediates the effect of SP-A on CD14. These studies revealed a novel physical association between SP-R210S, CD14, and SR-A leading to an enhanced response to LPS, and found that SP-R210L and SP-R210S regulate internalization of CD14 via distinct macropinocytosis-like mechanisms. Together, our findings support a model in which SP-R210 isoforms differentially regulate trafficking, expression, and activation of innate immune receptors on macrophages.
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Yang W, Hu B, Wu W, Batra S, Blackburn MR, Alcorn JL, Fallon MB, Zhang J. Alveolar type II epithelial cell dysfunction in rat experimental hepatopulmonary syndrome (HPS). PLoS One 2014; 9:e113451. [PMID: 25419825 PMCID: PMC4242631 DOI: 10.1371/journal.pone.0113451] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 10/24/2014] [Indexed: 12/18/2022] Open
Abstract
The hepatopulmonary syndrome (HPS) develops when pulmonary vasodilatation leads to abnormal gas exchange. However, in human HPS, restrictive ventilatory defects are also observed supporting that the alveolar epithelial compartment may also be affected. Alveolar type II epithelial cells (AT2) play a critical role in maintaining the alveolar compartment by producing four surfactant proteins (SPs, SP-A, SP-B, SP-C and SP-D) which also facilitate alveolar repair following injury. However, no studies have evaluated the alveolar epithelial compartment in experimental HPS. In this study, we evaluated the alveolar epithelial compartment and particularly AT2 cells in experimental HPS induced by common bile duct ligation (CBDL). We found a significant reduction in pulmonary SP production associated with increased apoptosis in AT2 cells after CBDL relative to controls. Lung morphology showed decreased mean alveolar chord length and lung volumes in CBDL animals that were not seen in control models supporting a selective reduction of alveolar airspace. Furthermore, we found that administration of TNF-α, the bile acid, chenodeoxycholic acid, and FXR nuclear receptor activation (GW4064) induced apoptosis and impaired SP-B and SP-C production in alveolar epithelial cells in vitro. These results imply that AT2 cell dysfunction occurs in experimental HPS and is associated with alterations in the alveolar epithelial compartment. Our findings support a novel contributing mechanism in experimental HPS that may be relevant to humans and a potential therapeutic target.
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Affiliation(s)
- Wenli Yang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Bingqian Hu
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Wei Wu
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Sachin Batra
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Michael R. Blackburn
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Joseph L. Alcorn
- Division of Neonatology, Department of Pediatrics, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Michael B. Fallon
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Junlan Zhang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
- * E-mail:
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6
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Xu X, Xiong M, Xu Y, Su Y, Zou P, Zhou H. Triptolide attenuates idiopathic pneumonia syndrome in a mouse bone marrow transplantation model by down-regulation of IL-17. Int Immunopharmacol 2012; 14:704-9. [DOI: 10.1016/j.intimp.2012.09.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 08/19/2012] [Accepted: 09/21/2012] [Indexed: 10/27/2022]
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Gowdy KM, Cardona DM, Nugent JL, Giamberardino C, Thomas JM, Mukherjee S, Mukherjee S, Martinu T, Foster WM, Plevy SE, Pastva AM, Wright JR, Palmer SM. Novel role for surfactant protein A in gastrointestinal graft-versus-host disease. THE JOURNAL OF IMMUNOLOGY 2012; 188:4897-905. [PMID: 22508928 DOI: 10.4049/jimmunol.1103558] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Graft-versus-host disease (GVHD) is a severe and frequent complication of allogeneic bone marrow transplantation (BMT) that involves the gastrointestinal (GI) tract and lungs. The pathobiology of GVHD is complex and involves immune cell recognition of host Ags as foreign. We hypothesize a central role for the collectin surfactant protein A (SP-A) in regulating the development of GVHD after allogeneic BMT. C57BL/6 (H2b; WT) and SP-A-deficient mice on a C57BL/6 background (H2b; SP-A(-/-)) mice underwent allogeneic or syngeneic BMT with cells from either C3HeB/FeJ (H2k; SP-A-deficient recipient mice that have undergone an allogeneic BMT [SP-A(-/-)alloBMT] or SP-A-sufficient recipient mice that have undergone an allogeneic BMT) or C57BL/6 (H2b; SP-A-deficient recipient mice that have undergone a syngeneic BMT or SP-A-sufficient recipient mice that have undergone a syngeneic BMT) mice. Five weeks post-BMT, mice were necropsied, and lung and GI tissue were analyzed. SP-A(-/-) alloBMT or SP-A-sufficient recipient mice that have undergone an allogeneic BMT had no significant differences in lung pathology; however, SP-A(-/-)alloBMT mice developed marked features of GI GVHD, including decreased body weight, increased tissue inflammation, and lymphocytic infiltration. SP-A(-/-)alloBMT mice also had increased colon expression of IL-1β, IL-6, TNF-α, and IFN-γ and as well as increased Th17 cells and diminished regulatory T cells. Our results demonstrate the first evidence, to our knowledge, of a critical role for SP-A in modulating GI GVHD. In these studies, we demonstrate that mice deficient in SP-A that have undergone an allogeneic BMT have a greater incidence of GI GVHD that is associated with increased Th17 cells and decreased regulatory T cells. The results of these studies demonstrate that SP-A protects against the development of GI GVHD and establishes a role for SP-A in regulating the immune response in the GI tract.
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Affiliation(s)
- Kymberly M Gowdy
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
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Mukherjee S, Giamberardino C, Thomas J, Evans K, Goto H, Ledford JG, Hsia B, Pastva AM, Wright JR. Surfactant protein A integrates activation signal strength to differentially modulate T cell proliferation. THE JOURNAL OF IMMUNOLOGY 2012; 188:957-67. [PMID: 22219327 DOI: 10.4049/jimmunol.1100461] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pulmonary surfactant lipoproteins lower the surface tension at the alveolar-airway interface of the lung and participate in host defense. Previous studies reported that surfactant protein A (SP-A) inhibits lymphocyte proliferation. We hypothesized that SP-A-mediated modulation of T cell activation depends upon the strength, duration, and type of lymphocyte activating signals. Modulation of T cell signal strength imparted by different activating agents ex vivo and in vivo in different mouse models and in vitro with human T cells shows a strong correlation between strength of signal (SoS) and functional effects of SP-A interactions. T cell proliferation is enhanced in the presence of SP-A at low SoS imparted by exogenous mitogens, specific Abs, APCs, or in homeostatic proliferation. Proliferation is inhibited at higher SoS imparted by different doses of the same T cell mitogens or indirect stimuli such as LPS. Importantly, reconstitution with exogenous SP-A into the lungs of SP-A(-/-) mice stimulated with a strong signal also resulted in suppression of T cell proliferation while elevating baseline proliferation in unstimulated T cells. These signal strength and SP-A-dependent effects are mediated by changes in intracellular Ca(2+) levels over time, involving extrinsic Ca(2+)-activated channels late during activation. These effects are intrinsic to the global T cell population and are manifested in vivo in naive as well as memory phenotype T cells. Thus, SP-A appears to integrate signal thresholds to control T cell proliferation.
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Affiliation(s)
- Sambuddho Mukherjee
- Department of Cell Biology, Duke University Medical Center, Durham NC 27710, USA
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9
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Pulmonary Collectins in Diagnosis and Prevention of Lung Diseases. ANIMAL LECTINS: FORM, FUNCTION AND CLINICAL APPLICATIONS 2012. [PMCID: PMC7121960 DOI: 10.1007/978-3-7091-1065-2_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Pulmonary surfactant is a complex mixture of lipids and proteins, and is synthesized and secreted by alveolar type II epithelial cells and bronchiolar Clara cells. It acts to keep alveoli from collapsing during the expiratory phase of the respiratory cycle. After its secretion, lung surfactant forms a lattice structure on the alveolar surface, known as tubular myelin. Surfactant proteins (SP)-A, B, C and D make up to 10% of the total surfactant. SP-B and SPC are relatively small hydrophobic proteins, and are involved in the reduction of surface-tension at the air-liquid interface. SP-A and SP-D, on the other hand, are large oligomeric, hydrophilic proteins that belong to the collagenous Ca2+-dependent C-type lectin family (known as “Collectins”), and play an important role in host defense and in the recycling and transport of lung surfactant (Awasthi 2010) (Fig. 43.1). In particular, there is increasing evidence that surfactant-associated proteins A and -D (SP-A and SP-D, respectively) contribute to the host defense against inhaled microorganisms (see 10.1007/978-3-7091-1065_24 and 10.1007/978-3-7091-1065_25). Based on their ability to recognize pathogens and to regulate the host defense, SP-A and SP-D have been recently categorized as “Secretory Pathogen Recognition Receptors”. While SP-A and SP-D were first identified in the lung; the expression of these proteins has also been observed at other mucosal surfaces, such as lacrimal glands, gastrointestinal mucosa, genitourinary epithelium and periodontal surfaces. SP-A is the most prominent among four proteins in the pulmonary surfactant-system. The expression of SP-A is complexly regulated on the transcriptional and the chromosomal level. SP-A is a major player in the pulmonary cytokine-network and moreover has been described to act in the pulmonary host defense. This chapter gives an overview on the understanding of role of SP-A and SP-D in for human pulmonary disorders and points out the importance for pathology-orientated research to further elucidate the role of these molecules in adult lung diseases. As an outlook, it will become an issue of pulmonary pathology which might provide promising perspectives for applications in research, diagnosis and therapy (Awasthi 2010).
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Phelps DS, Umstead TM, Quintero OA, Yengo CM, Floros J. In vivo rescue of alveolar macrophages from SP-A knockout mice with exogenous SP-A nearly restores a wild type intracellular proteome; actin involvement. Proteome Sci 2011; 9:67. [PMID: 22035134 PMCID: PMC3219558 DOI: 10.1186/1477-5956-9-67] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 10/28/2011] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Mice lacking surfactant protein-A (SP-A-/-; knockout; KO) exhibit increased vulnerability to infection and injury. Although many bronchoalveolar lavage (BAL) protein differences between KO and wild-type (WT) are rapidly reversed in KO after infection, their clinical course is still compromised. We studied the impact of SP-A on the alveolar macrophage (AM) proteome under basal conditions. Male SP-A KO mice were SP-A-treated (5 micrograms/mouse) and sacrificed in 6 or 18 hr. The AM proteomes of KO, SP-A-treated KO, and WT mice were studied by 2D-DIGE coupled with MALDI-ToF/ToF and AM actin distribution was examined by phalloidon staining. RESULTS We observed: a) significant differences from KO in WT or exogenous SP-A-treated in 45 of 76 identified proteins (both increases and decreases). These included actin-related/cytoskeletal proteins (involved in motility, phagocytosis, endocytosis), proteins of intracellular signaling, cell differentiation/regulation, regulation of inflammation, protease/chaperone function, and proteins related to Nrf2-mediated oxidative stress response pathway; b) SP-A-induced changes causing the AM proteome of the KO to resemble that of WT; and c) that SP-A treatment altered cell size and F-actin distribution. CONCLUSIONS These differences are likely to enhance AM function. The observations show for the first time that acute in vivo SP-A treatment of KO mice, under basal or unstimulated conditions, affects the expression of multiple AM proteins, alters F-actin distribution, and can restore much of the WT phenotype. We postulate that the SP-A-mediated expression profile of the AM places it in a state of "readiness" to successfully conduct its innate immune functions and ensure lung health.
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Affiliation(s)
- David S Phelps
- Center for Host defense, Inflammation, and Lung Disease (CHILD) Research and Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
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Panoskaltsis-Mortari A, Griese M, Madtes DK, Belperio JA, Haddad IY, Folz RJ, Cooke KR. An official American Thoracic Society research statement: noninfectious lung injury after hematopoietic stem cell transplantation: idiopathic pneumonia syndrome. Am J Respir Crit Care Med 2011; 183:1262-79. [PMID: 21531955 DOI: 10.1164/rccm.2007-413st] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
RATIONALE Acute lung dysfunction of noninfectious etiology, known as idiopathic pneumonia syndrome (IPS), is a severe complication following hematopoietic stem cell transplantation (HSCT). Several mouse models have been recently developed to determine the underlying causes of IPS. A cohesive interpretation of experimental data and their relationship to the findings of clinical research studies in humans is needed to better understand the basis for current and future clinical trials for the prevention/treatment of IPS. OBJECTIVES Our goal was to perform a comprehensive review of the preclinical (i.e., murine models) and clinical research on IPS. METHODS An ATS committee performed PubMed and OVID searches for published, peer-reviewed articles using the keywords "idiopathic pneumonia syndrome" or "lung injury" or "pulmonary complications" AND "bone marrow transplant" or "hematopoietic stem cell transplant." No specific inclusion or exclusion criteria were determined a priori for this review. MEASUREMENTS AND MAIN RESULTS Experimental models that reproduce the various patterns of lung injury observed after HSCT have identified that both soluble and cellular inflammatory mediators contribute to the inflammation engendered during the development of IPS. To date, 10 preclinical murine models of the IPS spectrum have been established using various donor and host strain combinations used to study graft-versus-host disease (GVHD). This, as well as the demonstrated T cell dependency of IPS development in these models, supports the concept that the lung is a target of immune-mediated attack after HSCT. The most developed therapeutic strategy for IPS involves blocking TNF signaling with etanercept, which is currently being evaluated in clinical trials. CONCLUSIONS IPS remains a frequently fatal complication that limits the broader use of allogeneic HSCT as a successful treatment modality. Faced with the clinical syndrome of IPS, one can categorize the disease entity with the appropriate tools, although cases of unclassifiable IPS will remain. Significant research efforts have resulted in a paradigm shift away from identifying noninfectious lung injury after HSCT solely as an idiopathic clinical syndrome and toward understanding IPS as a process involving aspects of both the adaptive and the innate immune response. Importantly, new laboratory insights are currently being translated to the clinic and will likely prove important to the development of future strategies to prevent or treat this serious disorder.
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Chroneos ZC, Sever-Chroneos Z, Shepherd VL. Pulmonary surfactant: an immunological perspective. Cell Physiol Biochem 2009; 25:13-26. [PMID: 20054141 DOI: 10.1159/000272047] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2009] [Indexed: 11/19/2022] Open
Abstract
Pulmonary surfactant has two crucial roles in respiratory function; first, as a biophysical entity it reduces surface tension at the air water interface, facilitating gas exchange and alveolar stability during breathing, and, second, as an innate component of the lung's immune system it helps maintain sterility and balance immune reactions in the distal airways. Pulmonary surfactant consists of 90% lipids and 10% protein. There are four surfactant proteins named SP-A, SP-B, SP-C, and SP-D; their distinct interactions with surfactant phospholipids are necessary for the ultra-structural organization, stability, metabolism, and lowering of surface tension. In addition, SP-A and SP-D bind pathogens, inflict damage to microbial membranes, and regulate microbial phagocytosis and activation or deactivation of inflammatory responses by alveolar macrophages. SP-A and SP-D, also known as pulmonary collectins, mediate microbial phagocytosis via SP-A and SP-D receptors and the coordinated induction of other innate receptors. Several receptors (SP-R210, CD91/calreticulin, SIRPalpha, and toll-like receptors) mediate the immunological functions of SP-A and SP-D. However, accumulating evidence indicate that SP-B and SP-C and one or more lipid constituents of surfactant share similar immuno-regulatory properties as SP-A and SP-D. The present review discusses current knowledge on the interaction of surfactant with lung innate host defense.
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Affiliation(s)
- Zissis C Chroneos
- The Center of Biomedical Research, University of Texas Health Science Center at Tyler, Tyler, TX 75708-3154, USA.
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Abstract
Surfactant protein A (SP-A) is a lung collectin with diverse immunoregulatory activities. SP-A regulates the innate host defense by enhancing phagocytosis of pathogens and modulating the production of nitric oxide and cytokines by immune cells. Additionally, SP-A also modulates the phenotypic and functional properties of the cells of adaptive immune response such as dendritic cells (DCs) and lymphocytes. Bone marrow-derived DCs generated in the presence of SP-A fail to increase lipopolysaccharide-induced upregulation of major histocompatibility complex (MHC) class II and CD86 costimulatory molecule on DCs surface and behaves like "tolerogenic DCs". SP-A may also induce tolerance by suppressing the proliferation of activated T lymphocytes. Thus, based on immunoregulatory properties of SP-A, it may be employed as a therapeutic agent for the treatment of autoimmune disease and organ transplantation.
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Affiliation(s)
- Shabbir Hussain
- Autoimmunity/Diabetes Group, Robarts Research Institute, 107 SDRI. 1400 Western Road, London, ON, Canada.
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Pulmonary function changes in experimental graft-versus-host disease of the lung. Biol Blood Marrow Transplant 2008; 14:1004-1016. [PMID: 18721763 DOI: 10.1016/j.bbmt.2008.06.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 06/17/2008] [Indexed: 11/22/2022]
Abstract
Pulmonary graft-versus-host disease (p-GVHD) is a serious complication after allogeneic stem cell transplantation (allo-SCT) of high morbidity and high mortality. We characterized breathing patterns and pulmonary function changes in correlation to lung histopathology and survival by using a well-established murine model of p-GVHD. Lethally irradiated B6D2F1 mice received SCT from either syngeneic B6D2F1 or allogeneic C57BL/6 animals. Within 6 weeks, severe p-GVHD developed in allogeneic recipients characterized by progressive interstitial, alveolar, peribronchial, and periluminal inflammatory cell infiltration, whereas in syngeneic recipients lung histology remained normal. Allogeneic recipients demonstrated decreased minute ventilation (MV), reduced peak inspiratory and expiratory flow rates as early as 1 week after SCT. In addition, allo-SCT resulted in restrictive pulmonary function changes as early as 7 days after transplantation and in progressive airflow obstruction within 6 weeks. Decreased breathing abilities and pulmonary function changes of allogeneic recipients were associated with increased mortality and the severity of acute graft-versus-host disease (aGVHD). These findings show that p-GVHD can be characterized by changes in pulmonary function and functional respiratory insufficiency. Furthermore, our data strengthen the understanding, that the lung is a critical target organ of aGVHD.
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Gram K, Yang S, Steiner M, Somani A, Hawgood S, Blazar BR, Panoskaltsis-Mortari A, Haddad IY. Simultaneous absence of surfactant proteins A and D increases lung inflammation and injury after allogeneic HSCT in mice. Am J Physiol Lung Cell Mol Physiol 2008; 296:L167-75. [PMID: 18996902 DOI: 10.1152/ajplung.90253.2008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The relative contributions of the hydrophilic surfactant proteins (SP)-A and -D to early inflammatory responses associated with lung dysfunction after experimental allogeneic hematopoietic stem cell transplantation (HSCT) were investigated. We hypothesized that the absence of SP-A and SP-D would exaggerate allogeneic T cell-dependent inflammation and exacerbate lung injury. Wild-type, SP-D-deficient (SP-D(-/-)), and SP-A and -D double knockout (SP-A/D(-/-)) C57BL/6 mice were lethally conditioned with cyclophosphamide and total body irradiation and given allogeneic bone marrow plus donor spleen T cells, simulating clinical HSCT regimens. On day 7, after HSCT, permeability edema progressively increased in SP-D(-/-) and SP-A/D(-/-) mice. Allogeneic T cell-dependent inflammatory responses were also increased in SP-D(-/-) and SP-A/D(-/-) mice, but the altered mediators of inflammation were not identical. Compared with wild-type, bronchoalveolar lavage fluid (BALF) levels of nitrite plus nitrate, GM-CSF, and MCP-1, but not TNF-alpha and IFN-gamma, were higher in SP-D-deficient mice before and after HSCT. In SP-A/D(-/-) mice, day 7 post-HSCT BALF levels of TNF-alpha and IFN-gamma, in addition to nitrite plus nitrate and MCP-1, were higher compared with mice lacking SP-D alone. After HSCT, both SP-A and SP-D exhibited anti-inflammatory lung-protective functions that were not completely redundant in vivo.
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Affiliation(s)
- Kendra Gram
- Banner Children's Hospital, Mesa, AZ 85202, USA
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Post hoc analysis of calfactant use in immunocompromised children with acute lung injury: Impact and feasibility of further clinical trials. Pediatr Crit Care Med 2008; 9:459-64. [PMID: 18679142 DOI: 10.1097/pcc.0b013e3181849bec] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To assess the impact of calfactant (a modified natural bovine lung surfactant) in immunocompromised children with acute lung injury and to determine the number of patients required for a definitive clinical trial of calfactant in this population. DESIGN Post hoc analysis of data from a previous randomized, control trial. SETTING Tertiary care pediatric intensive care units. PATIENTS All children, defined as immunocompromised, enrolled in a multicenter, masked, randomized, control trial of calfactant for acute lung injury conducted between July 2000 and July 2003. INTERVENTIONS Patients received either an intratracheal instillation of calfactant or an equal volume of air placebo in a protocolized manner. MEASUREMENTS AND MAIN RESULTS Eleven of 22 (50%) calfactant-treated patients died when compared with 18 of 30 (60%) placebo patients (absolute risk reduction 10.0%, 95% confidence interval [CI] -17.3, 37.3). Among the 23 patients with an initial oxygen index (OI) >/=13 and </=37, 44% (4 of 9) of calfactant-treated patients died in comparison with 71% (10 of 14) of placebo (absolute risk reduction 27.0%, 95% CI -13.2, 67.2). Only 33% (3 of 9) of calfactant patients died before intensive care discharge in comparison with 71% (10 of 14) of placebo (absolute risk reduction 38.1%, 95% CI -0.7, 76.9). Calfactant therapy was associated with improved oxygenation in these 23 patients. Using an OI entry criterion of (13 </= OI </= 37), stratifying on the presence of hematopoietic stem cell transplantation, and accepting the 27% difference in mortality observed in this analysis, 63 patients would be required in each arm of a randomized, control trial to demonstrate a significant effect of calfactant on mortality in this patient population assuming a two-sided alpha of 0.05 and a power of 0.85. CONCLUSIONS These preliminary data suggest a potential benefit of calfactant in this high-risk population. A clinical trial powered to appropriately assess these findings seems warranted and feasible.
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Nakane T, Nakamae H, Kamoi H, Koh H, Takeoka Y, Sakamoto E, Kanashima H, Nakamae M, Ohta K, Terada Y, Koh KR, Yamane T, Hino M. Prognostic value of serum surfactant protein D level prior to transplant for the development of bronchiolitis obliterans syndrome and idiopathic pneumonia syndrome following allogeneic hematopoietic stem cell transplantation. Bone Marrow Transplant 2008; 42:43-9. [DOI: 10.1038/bmt.2008.73] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Yang CH, Szeliga J, Jordan J, Faske S, Sever-Chroneos Z, Dorsett B, Christian RE, Settlage RE, Shabanowitz J, Hunt DF, Whitsett JA, Chroneos ZC. Identification of the surfactant protein A receptor 210 as the unconventional myosin 18A. J Biol Chem 2005; 280:34447-57. [PMID: 16087679 PMCID: PMC1762002 DOI: 10.1074/jbc.m505229200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mass spectrometric characterization of the surfactant protein A (SP-A) receptor 210 (SP-R210) led to the identification of myosin (Myo) XVIIIA and nonmuscle myosin IIA. Antibodies generated against the unique C-terminal tail of MyoXVIIIA revealed that MyoXVIIIA, MyoIIA, and SP-R210 have overlapping tissue distribution, all being highly expressed in myeloid cells, bone marrow, spleen, lymph nodes, and lung. Western blot analysis of COS-1 cells stably transfected with either MyoXVIIIA or MyoIIA indicated that SP-R210 antibodies recognize MyoXVIIIA. Furthermore, MyoXVIIIA but not MyoIIA localized to the surface of COS-1 cells, and most importantly, expression of MyoXVIIIA in COS-1 cells conferred SP-A binding. Western analysis of recombinant MyoXVIIIA domains expressed in bacteria mapped the epitopes of previously derived SP-R210 antibodies to the neck region of MyoXVIIIA. Antibodies raised against the neck domain of MyoXVIIIA blocked the binding of SP-A to macrophages. Together, these findings indicate that MyoXVIIIA constitutes a novel receptor for SP-A.
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MESH Headings
- Amino Acid Sequence
- Animals
- Bacteria/metabolism
- Base Sequence
- Blotting, Northern
- Blotting, Western
- COS Cells
- Cell Membrane/metabolism
- Cells, Cultured
- Chlorocebus aethiops
- DNA, Complementary/metabolism
- Dose-Response Relationship, Drug
- Epitopes/chemistry
- Flow Cytometry
- Humans
- Immunoglobulin G/chemistry
- Immunoprecipitation
- Macrophages/metabolism
- Mass Spectrometry
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Myosins/chemistry
- Myosins/physiology
- Nonmuscle Myosin Type IIA/chemistry
- Peptides/chemistry
- Protein Binding
- Protein Isoforms
- Protein Structure, Tertiary
- Pulmonary Surfactant-Associated Protein A/chemistry
- Rats
- Receptors, Cell Surface/chemistry
- Recombinant Proteins/chemistry
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Tissue Distribution
- Transfection
- U937 Cells
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Affiliation(s)
- Ching-Hui Yang
- Center of Biomedical Research, University of Texas Health Center, Tyler, Texas 75708-3154, USA
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19
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Tesfaigzi Y, McDonald JD, Reed MD, Singh SP, De Sanctis GT, Eynott PR, Hahn FF, Campen MJ, Mauderly JL. Low-level subchronic exposure to wood smoke exacerbates inflammatory responses in allergic rats. Toxicol Sci 2005; 88:505-13. [PMID: 16162849 DOI: 10.1093/toxsci/kfi317] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Epidemiological studies have implicated wood smoke as a risk factor for exacerbating asthma. However, comparisons of findings in animal models with those in humans are currently not possible, because detailed clinically relevant measurements of pulmonary function are not available in animal studies. Brown Norway rats were immunized with ovalbumin and exposed to either filtered air or wood smoke at 1 mg particulate matter/m(3) for 70 days and challenged with allergen during the last 4 days of exposure. Baseline values for dynamic lung compliance were lower while functional residual capacity was increased in rats exposed to wood smoke compared to rats exposed to filtered air. IFN-gamma levels were reduced and IL-4 levels increased in the bronchoalveolar lavage fluid and blood plasma, inflammatory lesions in the lungs were 21% greater, and airway mucous cells/mm basal lamina were non-significantly increased in rats exposed to wood smoke compared to controls. Collectively, these studies suggest that the pulmonary function was affected in rats by exposure to wood smoke and this decline was associated with only minor increases in inflammation of the lung. Therefore, this animal model may be useful to elucidate the mechanisms of the decline in pulmonary function caused by environmental pollutants when asthmatics are exposed to allergen.
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Deshpande DA, White TA, Guedes AGP, Milla C, Walseth TF, Lund FE, Kannan MS. Altered airway responsiveness in CD38-deficient mice. Am J Respir Cell Mol Biol 2004; 32:149-56. [PMID: 15557017 DOI: 10.1165/rcmb.2004-0243oc] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cyclic ADP-ribose (cADPR) mobilizes calcium from intracellular stores and contributes to agonist-induced intracellular calcium elevation in airway smooth muscle (ASM). In this study we determined the functional role of CD38/cADPR signaling in the regulation of airway tone using CD38 deficient (cd38(-/-)) mice. The responsiveness to different doses of methacholine, as determined by changes in lung resistance and dynamic compliance, was significantly (P < or = 0.05) lower in cd38(-/-) mice compared with wild-type controls. To determine the mechanism responsible for the reduced responsiveness, we measured the intracellular calcium responses to contractile agonists in ASM cells. In ASM cells isolated from cd38(-/-) mice, the intracellular calcium responses to acetylcholine and endothelin-1 were significantly lower than in controls. Pretreatment of ASM cells with a cADPR antagonist resulted in attenuated intracellular calcium responses to endothelin-1 in cells isolated from wild-type mice, but not in those isolated from the cd38(-/-) mice. Very low cADPR levels and no detectable ADP-ribosyl cyclase activity were observed in lung tissue from cd38(-/-) mice, suggesting that CD38 is a critical source for cADPR synthesis. The results of the present study demonstrate that CD38/cADPR contributes to airway smooth muscle tone and responsiveness through its effects on agonist-induced elevation of intracellular calcium in ASM cells.
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Affiliation(s)
- Deepak A Deshpande
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, Saint Paul, MN 55108, USA
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Milla C, Yang S, Cornfield DN, Brennan ML, Hazen SL, Panoskaltsis-Mortari A, Blazar BR, Haddad IY. Myeloperoxidase deficiency enhances inflammation after allogeneic marrow transplantation. Am J Physiol Lung Cell Mol Physiol 2004; 287:L706-14. [PMID: 15020295 DOI: 10.1152/ajplung.00015.2004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Myeloperoxidase (MPO)-derived oxidants participate in the respiratory antimicrobial defense system but are also implicated in oxidant-mediated acute lung injury. We hypothesized that MPO contributes to lung injury commonly observed after bone marrow transplantation (BMT). MPO-sufficient (MPO+/+) and -deficient (MPO−/−) mice were given cyclophosphamide and lethally irradiated followed by infusion of inflammation-inducing donor spleen T cells at time of BMT. Despite suppressed generation of nitrative stress, MPO−/− recipient mice unexpectedly exhibited accelerated weight loss and increased markers of lung dysfunction compared with MPO+/+ mice. The increased lung injury during MPO deficiency was a result of donor T cell-dependent inflammatory responses because bronchoalveolar lavage fluids (BALF) from MPO−/− mice contained increased numbers of inflammatory cells and higher levels of the proinflammatory cytokine TNF-α and the monocyte chemoattractant protein-1 compared with wild-type mice. Enhanced inflammation in MPO−/− mice was associated with suppressed apoptosis of BALF inflammatory cells. The inflammatory process in MPO−/− recipients was also associated with enhanced necrosis of freshly isolated alveolar type II cells, critical for preventing capillary leak. We conclude that suppressed MPO-derived oxidative/nitrative stress is associated with enhanced lung inflammation and persistent alveolar epithelial injury.
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Affiliation(s)
- Carlos Milla
- Division of Pulmonary and Critical Care, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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22
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Haddad IY, Milla C, Yang S, Panoskaltsis-Mortari A, Hawgood S, Lacey DL, Blazar BR. Surfactant protein A is a required mediator of keratinocyte growth factor after experimental marrow transplantation. Am J Physiol Lung Cell Mol Physiol 2003; 285:L602-10. [PMID: 12740217 DOI: 10.1152/ajplung.00088.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We reported an association between the ability of recombinant human keratinocyte growth factor (rHuKGF) to upregulate the expression of surfactant protein A (SP-A) and to downregulate pulmonary inflammation that occurs after allogeneic bone marrow transplantation (BMT). To establish a causal relationship, rHuKGF (5 mg/kg) was administered subcutaneously for three consecutive days before irradiation to SP-A-sufficient and -deficient [SP-A(+/+) and SP-A(-/-), respectively] mice given inflammation-inducing allogeneic spleen T cells at the time of BMT. In contrast with SP-A(+/+) mice, rHuKGF failed to suppress the high levels of TNF-alpha, IFN-gamma, and nitric oxide contained in bronchoalveolar lavage fluids collected on day 7 after BMT from SP-A(-/-) mice. Early post-BMT weight loss was attenuated by rHuKGF in both SP-A(+/+) and SP-A(-/-) recipients. In the absence of supportive respiratory care, however, SP-A deficiency eventually abolished the ability of rHuKGF to prevent weight loss and to improve survival monitored for 1 mo after allogeneic BMT. In further experiments, the addition of cyclophosphamide (which is known to cause severe injury to the alveolar epithelium in donor T cell-recipient mice) to the conditioning regimen prevented rHuKGF-induced upregulation of SP-A and suppression of lung inflammation in both SP-A(+/+) and SP-A(-/-) mice. We conclude that endogenous baseline SP-A levels and optimal upregulation of SP-A are required for the anti-inflammatory protective effects of KGF after allogeneic transplantation.
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Affiliation(s)
- Imad Y Haddad
- Univ. of Minnesota, Dept. of Pediatrics, 420 Delaware St. S.E., Minneapolis, MN 55455, USA.
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