1
|
Schnell A, Tamm S, Hedtfeld S, Rodriguez Gonzalez C, Hoerning A, Lachmann N, Stanke F, Dittrich AM, Munder A. Analysis of CFTR mRNA and Protein in Peripheral Blood Mononuclear Cells via Quantitative Real-Time PCR and Western Blot. Int J Mol Sci 2024; 25:6367. [PMID: 38928073 PMCID: PMC11203434 DOI: 10.3390/ijms25126367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 05/31/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
The Cystic Fibrosis Conductance Transmembrane Regulator gene encodes for the CFTR ion channel, which is responsible for the transport of chloride and bicarbonate across the plasma membrane. Mutations in the gene result in impaired ion transport, subsequently leading to perturbed secretion in all exocrine glands and, therefore, the multi-organ disease cystic fibrosis (CF). In recent years, several studies have reported on CFTR expression in immune cells as demonstrated by immunofluorescence, flow cytometry, and immunoblotting. However, these data are mainly restricted to single-cell populations and show significant variation depending on the methodology used. Here, we investigated CFTR transcription and protein expression using standardized protocols in a comprehensive panel of immune cells. Methods: We applied a high-resolution Western blot protocol using a combination of highly specific monoclonal CFTR antibodies that have been optimized for the detection of CFTR in epithelial cells and healthy primary immune cell subpopulations sorted by flow cytometry and used immortalized cell lines as controls. The specificity of CFTR protein detection was controlled by peptide competition and enzymatic Peptide-N-Glycosidase-F (PNGase) digest. CFTR transcripts were analyzed using quantitative real-time PCR and normalized to the level of epithelial T84 cells as a reference. Results: CFTR mRNA expression could be shown for primary CD4+ T cells, NK cells, as well as differentiated THP-1 and Jurkat T cells. In contrast, we failed to detect CFTR transcripts for CD14+ monocytes and undifferentiated THP-1 cells, as well as for B cells and CD8+ T cells. Prominent immunoreactive bands were detectable by immunoblotting with the combination of four CFTR antibodies targeting different epitopes of the CFTR protein. However, in biosamples of non-epithelial origin, these CFTR-like protein bands could be unmasked as false positives through peptide competition or PNGase digest, meaning that the observed mRNA transcripts were not necessarily translated into CFTR proteins, which could be detected via immunoblotting. Our results confirm that mRNA expression in immune cells is many times lower than in that cells of epithelial origin. The immunoreactive signals in immune cells turned out to be false positives, and may be provoked by the presence of a high-affinity protein with a similar epitope. Non-specific binding (e.g., Fab-interaction with glycosyl branches) might also contribute to false positive signals. Our findings highlight the necessity of accurate controls, such as CFTR-negative cells, as well as peptide competition and glycolytic digest in order to identify genuine CFTR protein by immunoblotting. Our data suggest, furthermore, that CFTR protein expression data from techniques such as histology, for which the absence of a molecular weight or other independent control prevents the unmasking of false positive immunoreactive signals, must be interpreted carefully as well.
Collapse
Affiliation(s)
- Alexander Schnell
- Department of Pediatric and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany;
| | - Stephanie Tamm
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, 30625 Hannover, Germany
| | - Silke Hedtfeld
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, 30625 Hannover, Germany
| | - Claudio Rodriguez Gonzalez
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
| | - Andre Hoerning
- Department of Pediatric and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany;
| | - Nico Lachmann
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, 30625 Hannover, Germany
- Fraunhofer Institute for Toxicology and Experimental Medicine, 30625 Hannover, Germany
| | - Frauke Stanke
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, 30625 Hannover, Germany
| | - Anna-Maria Dittrich
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, 30625 Hannover, Germany
| | - Antje Munder
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, 30625 Hannover, Germany
| |
Collapse
|
2
|
De M, Serpa G, Zuiker E, Hisert KB, Liles WC, Manicone AM, Hemann EA, Long ME. MEK1/2 inhibition decreases pro-inflammatory responses in macrophages from people with cystic fibrosis and mitigates severity of illness in experimental murine methicillin-resistant Staphylococcus aureus infection. Front Cell Infect Microbiol 2024; 14:1275940. [PMID: 38352056 PMCID: PMC10861668 DOI: 10.3389/fcimb.2024.1275940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 01/09/2024] [Indexed: 02/16/2024] Open
Abstract
Chronic pulmonary bacterial infections and associated inflammation remain a cause of morbidity and mortality in people with cystic fibrosis (PwCF) despite new modulator therapies. Therapies targeting host factors that dampen detrimental inflammation without suppressing immune responses critical for controlling infections remain limited, while the development of lung infections caused by antimicrobial resistant bacteria is an increasing global problem, and a significant challenge in CF. Pharmacological compounds targeting the mammalian MAPK proteins MEK1 and MEK2, referred to as MEK1/2 inhibitor compounds, have potential combined anti-microbial and anti-inflammatory effects. Here we examined the immunomodulatory properties of MEK1/2 inhibitor compounds PD0325901, trametinib, and CI-1040 on CF innate immune cells. Human CF macrophage and neutrophil phagocytic functions were assessed by quantifying phagocytosis of serum opsonized pHrodo red E. coli, Staphylococcus aureus, and zymosan bioparticles. MEK1/2 inhibitor compounds reduced CF macrophage pro-inflammatory cytokine production without impairing CF macrophage or neutrophil phagocytic abilities. Wild-type C57BL6/J and Cftr tm1kth (F508del homozygous) mice were used to evaluate the in vivo therapeutic potential of PD0325901 compared to vehicle treatment in an intranasal methicillin-resistant Staphylococcus aureus (MRSA) infection with the community-acquired MRSA strain USA300. In both wild-type and CF mice, PD0325901 reduced inflammation associated body mass loss. Wild-type mice treated with PD0325901 had significant reduction in neutrophil-mediated inflammation compared to vehicle treatment groups, with preserved clearance of bacteria in lung, liver, or spleen 1 day after infection in either wild-type or CF mouse models. In summary, this study provides the first data evaluating the therapeutic potential of MEK1/2 inhibitor to modulate CF immune cells and demonstrates that MEK1/2 inhibitors diminish pro-inflammatory responses without impairing host defense mechanisms required for acute pathogen clearance.
Collapse
Affiliation(s)
- Mithu De
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University, Columbus, OH, United States
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Gregory Serpa
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University, Columbus, OH, United States
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Eryn Zuiker
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University, Columbus, OH, United States
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | | | - W. Conrad Liles
- Department of Medicine, Division of Infectious Diseases, University of Washington, Seattle, WA, United States
- Center for Lung Biology, University of Washington, Seattle, WA, United States
| | - Anne M. Manicone
- Center for Lung Biology, University of Washington, Seattle, WA, United States
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of Washington, Seattle, WA, United States
| | - Emily A. Hemann
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Matthew E. Long
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University, Columbus, OH, United States
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| |
Collapse
|
3
|
Lotti V, Lagni A, Diani E, Sorio C, Gibellini D. Crosslink between SARS-CoV-2 replication and cystic fibrosis hallmarks. Front Microbiol 2023; 14:1162470. [PMID: 37250046 PMCID: PMC10213757 DOI: 10.3389/fmicb.2023.1162470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Abstract
SARS-CoV-2, the etiological cause of the COVID-19 pandemic, can cause severe illness in certain at-risk populations, including people with cystic fibrosis (pwCF). Nevertheless, several studies indicated that pwCF do not have higher risks of SARS-CoV-2 infection nor do they demonstrate worse clinical outcomes than those of the general population. Recent in vitro studies indicate cellular and molecular processes to be significant drivers in pwCF lower infection rates and milder symptoms than expected in cases of SARS-CoV-2 infection. These range from cytokine releases to biochemical alterations leading to morphological rearrangements inside the cells associated with CFTR impairment. Based on available data, the reported low incidence of SARS-CoV-2 infection among pwCF is likely a result of several variables linked to CFTR dysfunction, such as thick mucus, IL-6 reduction, altered ACE2 and TMPRSS2 processing and/or functioning, defective anions exchange, and autophagosome formation. An extensive analysis of the relation between SARS-CoV-2 infection and pwCF is essential to elucidate the mechanisms involved in this lower-than-expected infection impact and to possibly suggest potential new antiviral strategies.
Collapse
Affiliation(s)
- Virginia Lotti
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Anna Lagni
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Erica Diani
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Claudio Sorio
- General Pathology Section, Department of Medicine, University of Verona, Verona, Italy
| | - Davide Gibellini
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| |
Collapse
|
4
|
Margraf A, Perretti M. Immune Cell Plasticity in Inflammation: Insights into Description and Regulation of Immune Cell Phenotypes. Cells 2022; 11:cells11111824. [PMID: 35681519 PMCID: PMC9180515 DOI: 10.3390/cells11111824] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 02/01/2023] Open
Abstract
Inflammation is a life-saving immune reaction occurring in response to invading pathogens. Nonetheless, inflammation can also occur in an uncontrolled, unrestricted manner, leading to chronic disease and organ damage. Mechanisms triggering an inflammatory response, hindering such a response, or leading to its resolution are well-studied but so far insufficiently elucidated with regard to precise therapeutic interventions. Notably, as an immune reaction evolves, requirements and environments for immune cells change, and thus cellular phenotypes adapt and shift, leading to the appearance of distinct cellular subpopulations with new functional features. In this article, we aim to highlight properties of, and overarching regulatory factors involved in, the occurrence of immune cell phenotypes with a special focus on neutrophils, macrophages and platelets. Additionally, we point out implications for both diagnostics and therapeutics in inflammation research.
Collapse
|
5
|
Bhattacharya R, Blankenheim Z, Scott PM, Cormier RT. CFTR and Gastrointestinal Cancers: An Update. J Pers Med 2022; 12:868. [PMID: 35743652 PMCID: PMC9224611 DOI: 10.3390/jpm12060868] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 11/17/2022] Open
Abstract
Cystic Fibrosis (CF) is a disease caused by mutations in the CFTR gene that severely affects the lungs as well as extra-pulmonary tissues, including the gastrointestinal (GI) tract. CFTR dysfunction resulting from either mutations or the downregulation of its expression has been shown to promote carcinogenesis. An example is the enhanced risk for several types of cancer in patients with CF, especially cancers of the GI tract. CFTR also acts as a tumor suppressor in diverse sporadic epithelial cancers in many tissues, primarily due to the silencing of CFTR expression via multiple mechanisms, but especially due to epigenetic regulation. This review provides an update on the latest research linking CFTR-deficiency to GI cancers, in both CF patients and in sporadic GI cancers, with a particular focus on cancer of the intestinal tract. It will discuss changes in the tissue landscape linked to CFTR-deficiency that may promote cancer development such as breakdowns in physical barriers, microbial dysbiosis and inflammation. It will also discuss molecular pathways and mechanisms that act upstream to modulate CFTR expression, such as by epigenetic silencing, as well as molecular pathways that act downstream of CFTR-deficiency, such as the dysregulation of the Wnt/β-catenin and NF-κB signaling pathways. Finally, it will discuss the emerging CFTR modulator drugs that have shown promising results in improving CFTR function in CF patients. The potential impact of these modulator drugs on the treatment and prevention of GI cancers can provide a new example of personalized cancer medicine.
Collapse
Affiliation(s)
| | | | - Patricia M. Scott
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA or (R.B.); (Z.B.)
| | - Robert T. Cormier
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA or (R.B.); (Z.B.)
| |
Collapse
|
6
|
Wang G, Nauseef WM. Neutrophil dysfunction in the pathogenesis of cystic fibrosis. Blood 2022; 139:2622-2631. [PMID: 35213685 PMCID: PMC9053701 DOI: 10.1182/blood.2021014699] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/31/2022] [Indexed: 11/20/2022] Open
Abstract
Polymorphonuclear neutrophils (PMNs) figure prominently in host defense against infection and in noninfectious inflammation. Mobilized early in an inflammatory response, PMNs mediate immediate cellular defense against microbes and orchestrate events that culminate in cessation of inflammation and restoration of homeostasis. Failure to terminate the inflammatory response and its causes can fuel exuberant inflammation characteristic of many human diseases, including cystic fibrosis (CF), an autosomal recessive genetic disease caused by mutations in the CF transmembrane conductance regulator. CF affects multiple end organs, with persistent bacterial infection and chronic neutrophilic inflammation in airways predominating the clinical picture. To match the diverse microbial challenges that they may encounter, PMNs possess a variety of antimicrobial systems to slow or kill invading microorganisms confined in their phagosomes. Prominent among PMN defense systems is their ability to generate hypochlorous acid, a potent microbicide, by reacting oxidants generated by the NADPH oxidase with myeloperoxidase (MPO) released from azurophilic granules in the presence of chloride (Cl-). Products of the MPO-H2O2-Cl system oxidize susceptible biomolecules and support robust antimicrobial action against many, but not all, potential human pathogens. Underscoring that the MPO-H2O2-Cl system is integral to optimal host defense and proper regulation of inflammation, individuals with defects in any component of this system, as seen in chronic granulomatous disease or MPO deficiency, incur increased rates or severity of infection and signs of dysregulated inflammatory responses. We focus attention in this review on the molecular basis for and the clinical consequences of defects in the MPO-H2O2-Cl system because of the compromised Cl transport seen in CF. We will discuss first how the MPO-H2O2-Cl system in healthy PMNs participates in host defense and resolution of inflammation and then review how a defective MPO-H2O2-Cl system contributes to the increased susceptibility to infection and dysregulated inflammation associated with the clinical manifestations of CF.
Collapse
Affiliation(s)
- Guoshun Wang
- Department of Microbiology, Immunology, and Parasitology, and
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA
| | - William M Nauseef
- Inflammation Program, Department of Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA; and
- Veterans Administration Medical Center, Iowa City, IA
| |
Collapse
|
7
|
Ley K. Neutrophil ion currents matter. Cardiovasc Res 2022; 118:1165-1166. [PMID: 35238344 DOI: 10.1093/cvr/cvac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Klaus Ley
- Center for Autoimmunity and Inflammation, Inflammation Biology Laboratory, La Jolla Institute for Immunology, 9420 Athena Circle Drive, La Jolla, CA 92037, USA
| |
Collapse
|