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Lipid-Protein and Protein-Protein Interactions in the Pulmonary Surfactant System and Their Role in Lung Homeostasis. Int J Mol Sci 2020; 21:ijms21103708. [PMID: 32466119 PMCID: PMC7279303 DOI: 10.3390/ijms21103708] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Pulmonary surfactant is a lipid/protein complex synthesized by the alveolar epithelium and secreted into the airspaces, where it coats and protects the large respiratory air–liquid interface. Surfactant, assembled as a complex network of membranous structures, integrates elements in charge of reducing surface tension to a minimum along the breathing cycle, thus maintaining a large surface open to gas exchange and also protecting the lung and the body from the entrance of a myriad of potentially pathogenic entities. Different molecules in the surfactant establish a multivalent crosstalk with the epithelium, the immune system and the lung microbiota, constituting a crucial platform to sustain homeostasis, under health and disease. This review summarizes some of the most important molecules and interactions within lung surfactant and how multiple lipid–protein and protein–protein interactions contribute to the proper maintenance of an operative respiratory surface.
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Hudalla H, Karenberg K, Kuon RJ, Pöschl J, Tschada R, Frommhold D. LPS-induced maternal inflammation promotes fetal leukocyte recruitment and prenatal organ infiltration in mice. Pediatr Res 2018; 84:757-764. [PMID: 30135596 DOI: 10.1038/s41390-018-0030-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 03/03/2018] [Accepted: 04/04/2018] [Indexed: 11/09/2022]
Abstract
BACKGROUND A pro-inflammatory intrauterine milieu accounts for increased perinatal morbidity and mortality. We asked how maternal inflammation as seen in endotoxemia affects fetal leukocyte recruitment in vivo during late gestation. METHODS Inflammation was induced in pregnant LysEGFP-mice by intraperitoneal LPS injection between gestational day 14 and 18 (E14-E18). After 20 h, intravital fluorescence microscopy was performed on fetal yolk sac venules to examine leukocyte rolling (number of rolling cells/min) and adhesion (>30 s). Infiltration of neutrophils into chorion/amnion, lung, and kidney were quantified by immunofluorescence microscopy. RESULTS At high doses (2 × 1 mg/kg), LPS triggered preterm birth (PTB) and intrauterine fetal death (IUFD), with early gestations at high risk of IUFD and late gestations prone to PTB. Lower LPS dosing (2 × 0.25 mg/kg) did not induce labor, but promoted maternal and fetal cytokine production, as well as neutrophilic infiltration of fetal membranes, as seen in chorioamnionitis (CAM). Baseline fetal leukocyte recruitment increased throughout gestation, and maternal inflammation further augmented adhesion at E16-E18. Enhanced leukocyte recruitment ultimately translated into prominent infiltration of fetal lung and kidney. CONCLUSION LPS-induced maternal endotoxemia promotes IUFD, PTB, and fetal leukocyte recruitment depending on gestational age. Our proposed model may serve as a platform to test novel perinatal immune modulators.
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Affiliation(s)
- Hannes Hudalla
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany.,Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Katinka Karenberg
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - Ruben-Jeremias Kuon
- Department of Gynecological Endocrinology and Fertility Disorders, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - Johannes Pöschl
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - Raphaela Tschada
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany
| | - David Frommhold
- Department of Neonatology, Heidelberg University Children's Hospital, 69120, Heidelberg, Germany.
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Wang F, Fu X, Wu X, Zhang J, Zhu J, Zou Y, Li J. Bone marrow derived M 2 macrophages protected against lipopolysaccharide-induced acute lung injury through inhibiting oxidative stress and inflammation by modulating neutrophils and T lymphocytes responses. Int Immunopharmacol 2018; 61:162-168. [PMID: 29883961 DOI: 10.1016/j.intimp.2018.05.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 05/06/2018] [Accepted: 05/20/2018] [Indexed: 01/31/2023]
Abstract
Acute lung injury (ALI) is characterized by aggravated inflammatory responses and the subsequent alveolar-capillary injury for which there are no specific therapies available currently. The present study was designed to investigate the protective roles of bone marrow derived M2 macrophages (M2 BMDMs) in lipopolysaccharide (LPS) induced ALI. M2 BMDMs were obtained from bone marrow cells stimulated with M-CSF and IL-4. Mice received M2 BMDMs intratracheally 3 h after LPS administration. Histology and wet/dry (W/D) weight ratio, activated immune cells and total protein were detected. Cytokines production were measured in vivo and vitro study. The effects of PD-L1 blockade on M2 BMDMs were calculated. The results showed that M2 BMDMs administration reduced the infiltration of neutrophils, inhibited the oxidative stress, while increased the counts of CD3+T lymphocytes as well as CD4+CD25+ regulatory T lymphocytes. Further, M2 BMDMs suppressed the TNF-α, IL-1β and IL-6 production, while increased the IL-10 production. Blockade of PD-L1/PD-1 pathway reversed cytokines production of M2 BMDMs in the BALF. These findings indicated that M2 BMDMs might be a promising therapeutic strategy for LPS-induced ALI through inhibiting oxidative stress and inflammation by modulating neutrophils and T lymphocytes responses.
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Affiliation(s)
- Fang Wang
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 20080, China; Department of Anesthesiology and Intensive Care, Changhai Hospital, the Second Military Medical University, Shanghai 200433, China
| | - Xiazhen Fu
- Department of Anesthesiology, Weifang Medical University, Weifang 261053, China
| | - Xinwan Wu
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 20080, China
| | - Jianhai Zhang
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 20080, China
| | - Jiali Zhu
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 20080, China
| | - Yun Zou
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 20080, China; Department of Anesthesiology and Intensive Care, Changhai Hospital, the Second Military Medical University, Shanghai 200433, China.
| | - Jinbao Li
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 20080, China.
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Glaser K, Fehrholz M, Curstedt T, Kunzmann S, Speer CP. Effects of the New Generation Synthetic Reconstituted Surfactant CHF5633 on Pro- and Anti-Inflammatory Cytokine Expression in Native and LPS-Stimulated Adult CD14+ Monocytes. PLoS One 2016; 11:e0146898. [PMID: 26790130 PMCID: PMC4720484 DOI: 10.1371/journal.pone.0146898] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/24/2015] [Indexed: 02/01/2023] Open
Abstract
Background Surfactant replacement therapy is the standard of care for the prevention and treatment of neonatal respiratory distress syndrome. New generation synthetic surfactants represent a promising alternative to animal-derived surfactants. CHF5633, a new generation reconstituted synthetic surfactant containing SP-B and SP-C analogs and two synthetic phospholipids has demonstrated biophysical effectiveness in vitro and in vivo. While several surfactant preparations have previously been ascribed immunomodulatory capacities, in vitro data on immunomodulation by CHF5633 are limited, so far. Our study aimed to investigate pro- and anti-inflammatory effects of CHF5633 on native and LPS-stimulated human adult monocytes. Methods Highly purified adult CD14+ cells, either native or simultaneously stimulated with LPS, were exposed to CHF5633, its components, or poractant alfa (Curosurf®). Subsequent expression of TNF-α, IL-1β, IL-8 and IL-10 mRNA was quantified by real-time quantitative PCR, corresponding intracellular cytokine synthesis was analyzed by flow cytometry. Potential effects on TLR2 and TLR4 mRNA and protein expression were monitored by qPCR and flow cytometry. Results Neither CHF5633 nor any of its components induced inflammation or apoptosis in native adult CD14+ monocytes. Moreover, LPS-induced pro-inflammatory responses were not aggravated by simultaneous exposure of monocytes to CHF5633 or its components. In LPS-stimulated monocytes, exposure to CHF5633 led to a significant decrease in TNF-α mRNA (0.57 ± 0.23-fold, p = 0.043 at 4h; 0.56 ± 0.27-fold, p = 0.042 at 14h). Reduction of LPS-induced IL-1β mRNA expression was not significant (0.73 ± 0.16, p = 0.17 at 4h). LPS-induced IL-8 and IL-10 mRNA and protein expression were unaffected by CHF5633. For all cytokines, the observed CHF5633 effects paralleled a Curosurf®-induced modulation of cytokine response. TLR2 and TLR4 mRNA and protein expression were not affected by CHF5633 and Curosurf®, neither in native nor in LPS-stimulated adult monocytes. Conclusion The new generation reconstituted synthetic surfactant CHF5633 was tested for potential immunomodulation on native and LPS-activated adult human monocytes. Our data confirm that CHF5633 does not exert unintended pro-inflammatory effects in both settings. On the contrary, CHF5633 significantly suppressed TNF-α mRNA expression in LPS-stimulated adult monocytes, indicating potential anti-inflammatory effects.
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Affiliation(s)
- Kirsten Glaser
- University Children´s Hospital, University of Würzburg, Würzburg, Germany
- * E-mail:
| | - Markus Fehrholz
- University Children´s Hospital, University of Würzburg, Würzburg, Germany
| | - Tore Curstedt
- Department of Molecular Medicine and Surgery, Karolinska Institutet at Karolinska University Hospital, Stockholm, Sweden
| | - Steffen Kunzmann
- University Children´s Hospital, University of Würzburg, Würzburg, Germany
| | - Christian P. Speer
- University Children´s Hospital, University of Würzburg, Würzburg, Germany
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Zhang L, Cao HY, Zhao S, Yuan LJ, Han D, Jiang H, Wu S, Wu HM. Effect of exogenous pulmonary surfactants on mortality rate in neonatal respiratory distress syndrome: A network meta-analysis of randomized controlled trials. Pulm Pharmacol Ther 2015; 34:46-54. [DOI: 10.1016/j.pupt.2015.08.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 07/15/2015] [Accepted: 08/17/2015] [Indexed: 01/01/2023]
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Glaser K, Fehrholz M, Seidenspinner S, Ottensmeier B, Wollny B, Kunzmann S. Pitfalls in flow cytometric analyses of surfactant-exposed human leukocytes. Immunol Lett 2015; 166:19-27. [PMID: 25977119 DOI: 10.1016/j.imlet.2015.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 04/29/2015] [Accepted: 05/04/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Surfactant replacement treatment is the standard of care for the prevention and treatment of neonatal respiratory distress syndrome in preterm infants and may also improve oxygenation in acute respiratory distress syndrome in children, adolescents and adults. Beside surface tension- and mechanical shear-reducing functions, natural surfactants have been ascribed immunomodulatory capacities. Current in vitro studies on immunomodulatory effects of pulmonary surfactant preparations on human leukocytes rely on ELISA, Western blot and polymerase chain reaction. Data obtained by flow cytometry are missing, so far, most likely due to confounding phospholipid residues. Intracellular cytokine flow cytometry in surfactant-exposed immune cells would provide information on pro- and anti-inflammatory immunomodulation at the single-cell level and would allow for integrating detailed immunophenotyping, functional assays and assessment of viability. AIM We implemented a flow cytometry protocol for reliable quantitative assessment of in vitro intracellular cytokine production in surfactant-exposed human lymphocytes (CD4(+)) and monocytes (CD14(+)). METHODS Two different permeabilization techniques were tested for their ability to provide intracellular cytokine staining in surfactant-exposed CD14(+) monocytes and CD4(+) lymphocytes. Both a commercially available solution containing saponin and ice-cold methanol were used as permeabilization reagents. RESULTS For both cell types, flow cytometry following saponin-based permeabilization revealed pronounced unspecific fluorescence signals in surfactant-exposed samples overlapping with the fluorescence spectra of the majority of conjugates. Autofluorescence of surfactant phospholipid particles interfered significantly with reliable quantification of fluorochrome-specific signals and conclusive analysis. Implementation of a methanol-based permeabilization protocol resulted in the elimination of confounding non-cell particle signals allowing for an accurate quantification of intracellular cytokine production. CONCLUSION Reliable detection of intracellular cytokines by flow cytometry may be challenging in surfactant-exposed cell samples due to significant autofluorescence of aggregated phospholipid particles. This issue has been addressed for the first time and may be of high relevance for all types of surfactant research. We demonstrate that a methanol-based permeabilization approach completely removes interfering fluorescent surfactant micelles and allows for correct evaluation of data. The successful removal of confounding surfactant phospholipids opens up a wide variety of multiparameter flow cytometry; a method that has not been applied in the field of surfactant research, yet.
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Affiliation(s)
- Kirsten Glaser
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany
| | - Markus Fehrholz
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany.
| | | | | | - Brigitte Wollny
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany
| | - Steffen Kunzmann
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany
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Ni Q, Sun K, Chen G, Shang D. In vitro effects of emodin on peritoneal macrophages that express membrane-bound CD14 protein in a rat model of severe acute pancreatitis/systemic inflammatory response syndrome. Mol Med Rep 2013; 9:355-9. [PMID: 24189982 DOI: 10.3892/mmr.2013.1771] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 10/28/2013] [Indexed: 02/06/2023] Open
Abstract
Emodin is the main active constituent of rhubarb and is often used in Chinese herbal medicine for the treatment of systemic inflammatory response syndrome (SIRS). The present study aimed to determine the in vitro effects of emodin on the expression of membrane-bound cluster of differentiation 14 (mCD14) protein in peritoneal macrophages (pMΦs). The severe acute pancreatitis (SAP)̸SIRS model was established in Sprague‑Dawley (SD) rats via retrograde injection of 1.5% sodium deoxycholate into the common biliopancreatic duct. The 40 SD rats were randomly divided into the sham‑operated (n=10) group (SO) and the model group (n=30). After 24 h, pMΦs were harvested and the model group was randomly divided into three subgroups (n=10 per group), the 5 µg/ml emodin group (EMO), the 0.1 µmol/ml dexamethasone group (DEX) and the SIRS/SAP group (SI). Treatment agents were administered following macrophage adhesion for 24 h. Compared with that of the SO group, the SI group showed significantly increased pathological changes (P<0.01). Compared with that of the SO group, mCD14 expression in pMΦs was significantly decreased in the SI group (P<0.01). Additionally, compared with that of the SI group, mCD14 expression in pMΦs was significantly increased in the EMO group (P<0.01) and in the DEX group (P<0.01). Compared with that of the DEX group, mCD14 expression in pMΦs was significantly increased in the EMO group (25.60±2.79 vs. 20.87±1.99; P<0.01). The pathological changes observed in the pancreas of rats in the model groups were more severe than that of the SO group. Moreover, mCD14 expression levels in pMΦs were significantly decreased in the SI group. The pathological changes of each intervention group improved to various degrees, particularly in the EMO group.
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Affiliation(s)
- Qingqiang Ni
- Department of General Surgery, First Affiliated Hospital, Dalian Medical University, Dalian, Liaoning 116011, P.R. China
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Bersani I, Kunzmann S, Speer CP. Immunomodulatory properties of surfactant preparations. Expert Rev Anti Infect Ther 2013; 11:99-110. [PMID: 23428105 DOI: 10.1586/eri.12.156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Surfactant replacement significantly decreased acute pulmonary morbidity and mortality among preterm neonates with respiratory distress syndrome. Besides improving lung function and oxygenation, surfactant is also a key modulator of pulmonary innate and acquired immunity regulating lung inflammatory processes. In this review, we describe the immunomodulatory features of surfactant preparations. Various surfactant preparations decrease the proinflammatory cytokine and chemokine release, the oxidative burst activity, and the nitric oxide production in lung inflammatory cells such as alveolar neutrophils, monocytes and macrophages; they also affect lymphocyte proliferative response and immunoglobulin production, as well as natural killer and lymphokine-activated killer cell activity. In addition, surfactant preparations are involved in airway remodeling, as they decrease lung fibroblast proliferation capacity and the release of mediators involved in remodeling. Moreover, they increase cell transepithelial resistance and VEGF synthesis in lung epithelial cells. A number of different signaling pathways and molecules are involved in these processes. Because the inhibition of local immune response may decrease lung injury, surfactant therapeutic efficacy may be related not only to its biophysical characteristics but, at least in part, to its anti-inflammatory features and its effects on remodeling processes. However, further studies are required to identify which surfactant preparation ensures the highest anti-inflammatory activity, thereby potentially decreasing the inflammatory process underlying respiratory distress syndrome. In perspective, detailed characterization of these anti-inflammatory effects could help to improve the next generation of surfactant preparations.
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Affiliation(s)
- Iliana Bersani
- University Children's Hospital, University of Würzburg, Germany
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Ni Q, Zhang W, Sun K, Yin C, An J, Shang D. In vitro effects of emodin on peritoneal macrophage intercellular adhesion molecule-3 in a rat model of severe acute pancreatitis/systemic inflammatory response syndrome. Biomed Rep 2013; 2:63-68. [PMID: 24649070 DOI: 10.3892/br.2013.178] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 09/18/2013] [Indexed: 02/07/2023] Open
Abstract
Rhubarb is often used in Chinese herbal medicine for the treatment of systemic inflammatory response syndrome (SIRS). Emodin is the main active constituent of rhubarb. This study was performed to investigate the in vitro effects of emodin and dexamethasone on peritoneal macrophage (pMΦ) phagocytosis and the expression of intercellular adhesion molecule-3 (ICAM-3). A total of 40 Sprague-Dawley (SD) rats were randomly divided into sham surgery (n=10) and model groups (n=30). After 24 h, pMΦs were harvested and the model group was randomly divided into three subgroups (n=10 rats/subgroup): the 5 μg/ml emodin, 0.1 μmol/ml dexamethasone and control groups. The drugs were administered following macrophage (MΦ) adhesion for 24 h. pMΦ phagocytosis was significantly increased in the emodin group compared to that in the control group. Moreover, pMΦ phagocytosis was significantly increased in the emodin group compared to that in the dexamethasone group. The expression of ICAM-3 was significantly increased in the emodin group compared to that in the control group. The expression of ICAM-3 was significantly increased in the emodin group compared to that in the dexamethasone group. The expression of ICAM-3 was significantly increased in the emodin and dexamethasone groups compared to that in the control group. pMΦ phagocytosis and ICAM-3 expression were significantly increased following emodin treatment compared to those in the control and dexamethasone groups, indicating that emodin may enhance pMΦ phagocytosis and apoptotic cell clearance by altering ICAM-3 expression.
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Affiliation(s)
- Qingqiang Ni
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Wei Zhang
- Department of Pharmacy, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Kang Sun
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Chao Yin
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Jizhong An
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Dong Shang
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
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Abstract
In healthy individuals, billions of cells die by apoptosis each day. Clearance of these apoptotic cells, termed "efferocytosis," must be efficient to prevent secondary necrosis and the release of proinflammatory cell contents that disrupt tissue homeostasis and potentially foster autoimmunity. During inflammation, most apoptotic cells are cleared by macrophages; the efferocytic process actively induces a macrophage phenotype that favors tissue repair and suppression of inflammation. Several chronic lung diseases, particularly airways diseases such as chronic obstructive lung disease, asthma, and cystic fibrosis, are characterized by an increased lung burden of uningested apoptotic cells. Alveolar macrophages from individuals with these chronic airways diseases have decreased efferocytosis relative to alveolar macrophages from healthy subjects. These two findings have led to the hypothesis that impaired apoptotic cell clearance may contribute causally to sustained lung inflammation and that therapies to enhance efferocytosis might be beneficial. This review of the English-language scientific literature (2006 to mid-2012) explains how such existing therapies as corticosteroids, statins, and macrolides may act in part by augmenting apoptotic cell clearance. However, efferocytosis can also impede host defenses against lung infection. Thus, determining whether novel therapies to augment efferocytosis should be developed and in whom they should be used lies at the heart of efforts to differentiate specific phenotypes within complex chronic lung diseases to provide appropriately personalized therapies.
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Affiliation(s)
| | - Jeffrey L Curtis
- Graduate Program in Immunology, VA Ann Arbor Healthcare System, Ann Arbor, MI; Division of Pulmonary and Critical Care Medicine, VA Ann Arbor Healthcare System, Ann Arbor, MI; Department of Internal Medicine, University of Michigan Health System; and the Pulmonary and Critical Care Medicine Section, VA Ann Arbor Healthcare System, Ann Arbor, MI.
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