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Fernández-Torres J, Zamudio-Cuevas Y, Martínez-Flores K, Franco-Cendejas R. Relationship between biofilm-forming microorganisms (BFM: Staphylococcus aureus and Pseudomonas aeruginosa) and DEFB1 gene variants on β-defensin levels in periprosthetic joint infection (PJI). Mol Biol Rep 2024; 51:237. [PMID: 38285273 DOI: 10.1007/s11033-023-09126-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 12/06/2023] [Indexed: 01/30/2024]
Abstract
BACKGROUND The purpose of this study was to investigate the relationship between biofilm-forming microorganisms (BFM) and DEFB1 gene variants on β-defensin levels in patients with periprosthetic joint infection (PJI) of Mexican origin. METHODS AND RESULTS One hundred and five clinical aspirates were obtained from patients with suspected PJI. After microbiologic culture, samples were classified as non-septic and septic; of the latter, only those positive for Staphylococcus aureus and Pseudomonas aeruginosa were selected. β-Defensin levels were quantified by ELISA, DNA was extracted from total leukocytes of the samples, and - 20G > A (rs11362) and - 44 C > G (rs1800972) variants were genotyped using TaqMan probes. Forty-one clinical aspirates were non-septic, 18 were positive for S. aureus and 18 were positive for P. aeruginosa. It was observed that β-defensin levels were higher in the P. aeruginosa group compared to S. aureus group (2339.0 pg/mL IQR = 1809.2 vs. 1821.3 pg/mL IQR = 1536.4) and non-septic group (2339.0 pg/mL IQR = 1809.2 vs. 1099.7 pg/mL IQR = 1744.5, P < 0.001). The CG genotype of the rs1800972 variant was associated with higher β-defensin levels compared to the CC genotype for both P. aeruginosa and S. aureus (1905.8 vs. 421.7 pg/mL, P = 0.004; and 1878.2 vs. 256.4 pg/mL, P = 0.006, respectively). CONCLUSIONS Our results show that β-defensin levels are significantly elevated in patients with BFM-associated PJI compared to those without infection. Furthermore, carriers of the CG genotype of the rs1800972 variant have an increased risk of PJI. Further research is needed to replicate these findings in a larger population.
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Affiliation(s)
- Javier Fernández-Torres
- Laboratorio de Líquido Sinovial, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, 14389, Ciudad de México, México.
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de Mexico (UNAM), 04510, Ciudad de México, México.
| | - Yessica Zamudio-Cuevas
- Laboratorio de Líquido Sinovial, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, 14389, Ciudad de México, México
| | - Karina Martínez-Flores
- Laboratorio de Líquido Sinovial, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, 14389, Ciudad de México, México
| | - Rafael Franco-Cendejas
- División de Infectología, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, 14389, Ciudad de México, México
- Subdirección de Investigación Biomédica, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, 14389, Ciudad de México, México
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van Dijk A, Guabiraba R, Bailleul G, Schouler C, Haagsman HP, Lalmanach AC. Evolutionary diversification of defensins and cathelicidins in birds and primates. Mol Immunol 2023; 157:53-69. [PMID: 36996595 DOI: 10.1016/j.molimm.2023.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023]
Abstract
Divergent evolution for more than 310 million years has resulted in an avian immune system that is complex and more compact than that of primates, sharing much of its structure and functions. Not surprisingly, well conserved ancient host defense molecules, such as defensins and cathelicidins, have diversified over time. In this review, we describe how evolution influenced the host defense peptides repertoire, its distribution, and the relationship between structure and biological functions. Marked features of primate and avian HDPs are linked to species-specific characteristics, biological requirements, and environmental challenge.
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Gibaly DE, Labib DA, Fayed HL, Eldash A. Serum human β-defensin-1 (hBD-1) and -20G/A DEFB1 gene polymorphism in Behçet’s disease patients: Relation to clinical characteristics. THE EGYPTIAN RHEUMATOLOGIST 2023. [DOI: 10.1016/j.ejr.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Pandoraea pnomenusa Superinfection in a Patient with SARS-CoV-2 Pneumonia: First Case in the Literature. Infect Dis Rep 2022; 14:205-212. [PMID: 35314655 PMCID: PMC8938804 DOI: 10.3390/idr14020025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/13/2022] [Accepted: 03/14/2022] [Indexed: 12/12/2022] Open
Abstract
Pandoraea pnomenusa is a Gram-negative bacterium of the Pandoraea genus and is mainly associated with the colonization of structurally abnormal airways. During the COVID-19 pandemic, many microorganisms have been associated with coinfection and superinfection in SARS-CoV-2 pneumonia, but so far, no coinfection or superinfection by P. pnomenusa has been reported. We present the first case describing this association in a previously healthy patient. Clinical manifestations, treatment, and outcomes are shown.
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Constitutive immune mechanisms: mediators of host defence and immune regulation. Nat Rev Immunol 2020; 21:137-150. [PMID: 32782357 PMCID: PMC7418297 DOI: 10.1038/s41577-020-0391-5] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2020] [Indexed: 02/07/2023]
Abstract
The immune system enables organisms to combat infections and to eliminate endogenous challenges. Immune responses can be evoked through diverse inducible pathways. However, various constitutive mechanisms are also required for immunocompetence. The inducible responses of pattern recognition receptors of the innate immune system and antigen-specific receptors of the adaptive immune system are highly effective, but they also have the potential to cause extensive immunopathology and tissue damage, as seen in many infectious and autoinflammatory diseases. By contrast, constitutive innate immune mechanisms, including restriction factors, basal autophagy and proteasomal degradation, tend to limit immune responses, with loss-of-function mutations in these pathways leading to inflammation. Although they function through a broad and heterogeneous set of mechanisms, the constitutive immune responses all function as early barriers to infection and aim to minimize any disruption of homeostasis. Supported by recent human and mouse data, in this Review we compare and contrast the inducible and constitutive mechanisms of immunosurveillance.
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Pero R, Brancaccio M, Mennitti C, Gentile L, Franco A, Laneri S, De Biasi MG, Pagliuca C, Colicchio R, Salvatore P, D’Alicandro G, Terracciano D, Cennamo M, La Civita E, Liotti A, Mazzaccara C, Frisso G, Lombardo B, Scudiero O. HNP-1 and HBD-1 as Biomarkers for the Immune Systems of Elite Basketball Athletes. Antibiotics (Basel) 2020; 9:antibiotics9060306. [PMID: 32517339 PMCID: PMC7345027 DOI: 10.3390/antibiotics9060306] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 12/13/2022] Open
Abstract
Acute or strenuous exercise is sometimes related to upper respiratory tract infections in athletes. Practicing intense and regular exercise can lead to incorrect activation of the immune system, causing athletes to be excluded from training programs and competitions. Defensins are small antimicrobial peptides that are part of the innate immune system and dynamically involved in several biological activities. In this study, we highlight the role of human defensins in competitive basketball athletes. In particular, we consider the behavior of alpha- and beta-defensins together with white blood cells in a cohort of players. Moreover, we focus our attention on cortisol, a physiological indicator of stress, and testosterone, both of which are human hormones involved in muscle metabolism. The free-testosterone/cortisol ratio is considered to be an indicator of overtraining among athletes. This paper provides an up-to-date information of the role of human defensins as self-defense molecules during a continuous stressor such as long-term exercise, and it recognizes them as potential markers of infection.
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Affiliation(s)
- Raffaela Pero
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
- Task Force on Microbiome Studies, University of Naples Federico II, 80100 Naples, Italy
- Correspondence: (R.P.); (O.S.); Tel.: +39-339-459-6163 (R.P.); +39-339-613-9908 (O.S.)
| | - Mariarita Brancaccio
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
| | - Cristina Mennitti
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
| | - Luca Gentile
- Ceinge Biotecnologie Avanzate S. C. a R. L., 80131 Naples, Italy;
| | - Adelaide Franco
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy; (A.F.); (S.L.); (M.G.D.B.)
| | - Sonia Laneri
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy; (A.F.); (S.L.); (M.G.D.B.)
| | - Margherita G. De Biasi
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy; (A.F.); (S.L.); (M.G.D.B.)
| | - Chiara Pagliuca
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
| | - Roberta Colicchio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
| | - Paola Salvatore
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
- Task Force on Microbiome Studies, University of Naples Federico II, 80100 Naples, Italy
- Ceinge Biotecnologie Avanzate S. C. a R. L., 80131 Naples, Italy;
| | - Giovanni D’Alicandro
- Department of Neuroscience and Rehabilitation, Center of Sports Medicine and Disability, AORN, Santobono-Pausillipon, 80122 Naples, Italy;
| | - Daniela Terracciano
- Department of Translational Medical Sciences, University of Naples “Federico II”, 80131 Naples, Italy; (D.T.); (M.C.); (E.L.C.); (A.L.)
| | - Michele Cennamo
- Department of Translational Medical Sciences, University of Naples “Federico II”, 80131 Naples, Italy; (D.T.); (M.C.); (E.L.C.); (A.L.)
| | - Evelina La Civita
- Department of Translational Medical Sciences, University of Naples “Federico II”, 80131 Naples, Italy; (D.T.); (M.C.); (E.L.C.); (A.L.)
| | - Antonietta Liotti
- Department of Translational Medical Sciences, University of Naples “Federico II”, 80131 Naples, Italy; (D.T.); (M.C.); (E.L.C.); (A.L.)
| | - Cristina Mazzaccara
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
- Ceinge Biotecnologie Avanzate S. C. a R. L., 80131 Naples, Italy;
| | - Giulia Frisso
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
- Ceinge Biotecnologie Avanzate S. C. a R. L., 80131 Naples, Italy;
| | - Barbara Lombardo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
- Ceinge Biotecnologie Avanzate S. C. a R. L., 80131 Naples, Italy;
| | - Olga Scudiero
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (C.M.); (C.P.); (R.C.); (P.S.); (C.M.); (G.F.); (B.L.)
- Task Force on Microbiome Studies, University of Naples Federico II, 80100 Naples, Italy
- Ceinge Biotecnologie Avanzate S. C. a R. L., 80131 Naples, Italy;
- Correspondence: (R.P.); (O.S.); Tel.: +39-339-459-6163 (R.P.); +39-339-613-9908 (O.S.)
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Rossi GA, Morelli P, Galietta LJ, Colin AA. Airway microenvironment alterations and pathogen growth in cystic fibrosis. Pediatr Pulmonol 2019; 54:497-506. [PMID: 30620146 DOI: 10.1002/ppul.24246] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 11/30/2018] [Indexed: 12/18/2022]
Abstract
Cystic Fibrosis Transmembrane Regulator (CFTR) dysfunction is associated with epithelial cell vulnerability and with dysregulation of the local inflammatory responses resulting in excessive airway neutrophilic inflammation and pathogen growth. In combination with impaired mucociliary clearance, and dysregulation of defense function, bacterial infection follows with eventual airway damage and remodeling. Because of these inherent vulnerabilities, viral infections are also more severe and prolonged and appear to render the airway even more prone to bacterial infection. Airway acidity, deficient nitric oxide production and increased iron concentrations, further enhance the airway milieu's susceptibility to infection. Novel diagnostic techniques of the airway microbiome elucidate the coexistence of an array of non-virulent taxa beyond the recognized virulent organisms, predominantly Pseudomonas aeruginosa. The complex interplay between these two bacterial populations, including upregulation of virulence genes and utilization of mucin as a nutrient source, modulates the action of pathogens, modifies the CF airway milieu and contributes to the processes leading to airway derangement. The review provides an update on recent advances of the complex mechanisms that render the CF airway vulnerable to inflammation, infection and ultimately structural damage, the key pathogenetic elements of CF. The recent contributions on CF pathogenesis will hopefully help in identifying new prophylactic measures and therapeutic targets for this highly destructive disorder.
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Affiliation(s)
- Giovanni A Rossi
- Department of Pediatrics, Pulmonary and Allergy Disease Unit and Cystic Fibrosis Center, Genoa, Italy
| | - Patrizia Morelli
- Microbiology Laboratory, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Luis J Galietta
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Andrew A Colin
- Division of Pediatric Pulmonology, Miller School of Medicine, University of Miami, Miami, FL
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De Rose V, Molloy K, Gohy S, Pilette C, Greene CM. Airway Epithelium Dysfunction in Cystic Fibrosis and COPD. Mediators Inflamm 2018; 2018:1309746. [PMID: 29849481 PMCID: PMC5911336 DOI: 10.1155/2018/1309746] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/15/2018] [Accepted: 02/01/2018] [Indexed: 12/22/2022] Open
Abstract
Cystic fibrosis is a genetic disease caused by mutations in the CFTR gene, whereas chronic obstructive pulmonary disease (COPD) is mainly caused by environmental factors (mostly cigarette smoking) on a genetically susceptible background. Although the etiology and pathogenesis of these diseases are different, both are associated with progressive airflow obstruction, airway neutrophilic inflammation, and recurrent exacerbations, suggesting common mechanisms. The airway epithelium plays a crucial role in maintaining normal airway functions. Major molecular and morphologic changes occur in the airway epithelium in both CF and COPD, and growing evidence suggests that airway epithelial dysfunction is involved in disease initiation and progression in both diseases. Structural and functional abnormalities in both airway and alveolar epithelium have a relevant impact on alteration of host defences, immune/inflammatory response, and the repair process leading to progressive lung damage and impaired lung function. In this review, we address the evidence for a critical role of dysfunctional airway epithelial cells in chronic airway inflammation and remodelling in CF and COPD, highlighting the common mechanisms involved in the epithelial dysfunction as well as the similarities and differences of the two diseases.
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Affiliation(s)
- Virginia De Rose
- Department of Clinical and Biological Sciences, University of Torino, A.O.U. S. Luigi Gonzaga, Regione Gonzole 10, 10043 Orbassano, Torino, Italy
| | - Kevin Molloy
- Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Dublin, Ireland
| | - Sophie Gohy
- Institute of Experimental and Clinical Research, Pole of Pneumology, ENT and Dermatology, Université Catholique de Louvain (UCL), Brussels, Belgium
- Department of Pneumology, Cliniques Universitaires St-Luc, Brussels, Belgium
| | - Charles Pilette
- Institute of Experimental and Clinical Research, Pole of Pneumology, ENT and Dermatology, Université Catholique de Louvain (UCL), Brussels, Belgium
- Department of Pneumology, Cliniques Universitaires St-Luc, Brussels, Belgium
| | - Catherine M. Greene
- Lung Biology Group, Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Dublin, Ireland
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Cadwell K, Niranji SS, Armstrong VL, Mowbray CA, Bailey R, Watson KA, Hall J. AvBD1 nucleotide polymorphisms, peptide antimicrobial activities and microbial colonisation of the broiler chicken gut. BMC Genomics 2017; 18:637. [PMID: 28821240 PMCID: PMC5563022 DOI: 10.1186/s12864-017-4034-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 08/08/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The importance of poultry as a global source of protein underpins the chicken genome and associated SNP data as key tools in selecting and breeding healthy robust birds with improved disease resistance. SNPs affecting host peptides involved in the innate defences tend to be rare, but three non-synonymous SNPs in the avian β-defensin (AvBD1) gene encoding the variant peptides NYH, SSY and NYY were identified that segregated specifically to three lines of commercial broiler chickens Line X (LX), Line Y(LY) and Line Z. The impacts of such amino acid changes on peptide antimicrobial properties were analysed in vitro and described in relation to the caecal microbiota and gut health of LX and LY birds. RESULTS Time-kill and radial immune diffusion assays indicated all three peptides to have antimicrobial properties against gram negative and positive bacteria with a hierarchy of NYH > SSY > NYY. Calcein leakage assays supported AvBD1 NYH as the most potent membrane permeabilising agent although no significant differences in secondary structure were identified to explain this. However, distinct claw regions, identified by 3D modelling and proposed to play a key role in microbial membrane attachment, and permeation, were more distinct in the NYH model. In vivo AvBD1 synthesis was detected in the bird gut epithelia. Analyses of the caecal gut microbiota of young day 4 birds suggested trends in Lactobacilli sp. colonisation at days 4 (9% LX vs × 30% LY) and 28 (20% LX vs 12% LY) respectively, but these were not statistically significant (P > 0.05). CONCLUSION Amino acid changes altering the killing capacity of the AvBD1 peptide were associated with two different bird lines, but such changes did not impact significantly on caecal gut microbiota.
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Affiliation(s)
- Kevin Cadwell
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Sherko S Niranji
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,Present address: College of Veterinary Medicine, University of Sulaimani, Sulaymaniyah, Iraq
| | - Vanessa L Armstrong
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,Present address: School of Biomedical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Catherine A Mowbray
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | | | | | - Judith Hall
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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10
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Vargas Buonfiglio LG, Mudunkotuwa IA, Abou Alaiwa MH, Vanegas Calderón OG, Borcherding JA, Gerke AK, Zabner J, Grassian VH, Comellas AP. Effects of Coal Fly Ash Particulate Matter on the Antimicrobial Activity of Airway Surface Liquid. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:077003. [PMID: 28696208 PMCID: PMC5744695 DOI: 10.1289/ehp876] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 12/30/2016] [Accepted: 01/19/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Sustained exposure to ambient particulate matter (PM) is a global cause of mortality. Coal fly ash (CFA) is a byproduct of coal combustion and is a source of anthropogenic PM with worldwide health relevance. The airway epithelia are lined with fluid called airway surface liquid (ASL), which contains antimicrobial proteins and peptides (AMPs). Cationic AMPs bind negatively charged bacteria to exert their antimicrobial activity. PM arriving in the airways could potentially interact with AMPs in the ASL to affect their antimicrobial activity. OBJECTIVES We hypothesized that PM can interact with ASL AMPs to impair their antimicrobial activity. METHODS We exposed pig and human airway explants, pig and human ASL, and the human cationic AMPs β-defensin-3, LL-37, and lysozyme to CFA or control. Thereafter, we assessed the antimicrobial activity of exposed airway samples using both bioluminescence and standard colony-forming unit assays. We investigated PM-AMP electrostatic interaction by attenuated total reflection Fourier-transform infrared spectroscopy and measuring the zeta potential. We also studied the adsorption of AMPs on PM. RESULTS We found increased bacterial survival in CFA-exposed airway explants, ASL, and AMPs. In addition, we report that PM with a negative surface charge can adsorb cationic AMPs and form negative particle-protein complexes. CONCLUSION We propose that when CFA arrives at the airway, it rapidly adsorbs AMPs and creates negative complexes, thereby decreasing the functional amount of AMPs capable of killing pathogens. These results provide a novel translational insight into an early mechanism for how ambient PM increases the susceptibility of the airways to bacterial infection. https://doi.org/10.1289/EHP876.
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Affiliation(s)
| | | | | | - Oriana G Vanegas Calderón
- Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | | | - Alicia K Gerke
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine
| | - Joseph Zabner
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry
- Department of Nanoengineering, and
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Alejandro P Comellas
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine
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11
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Beta-defensin gene (DEFB1) polymorphisms are associated with the susceptibility to chronic respiratory diseases. Genes Genomics 2016. [DOI: 10.1007/s13258-016-0388-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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pH modulates the activity and synergism of the airway surface liquid antimicrobials β-defensin-3 and LL-37. Proc Natl Acad Sci U S A 2014; 111:18703-8. [PMID: 25512526 DOI: 10.1073/pnas.1422091112] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The pulmonary airways are continuously exposed to bacteria. As a first line of defense against infection, the airway surface liquid (ASL) contains a complex mixture of antimicrobial factors that kill inhaled and aspirated bacteria. The composition of ASL is critical for antimicrobial effectiveness. For example, in cystic fibrosis an abnormally acidic ASL inhibits antimicrobial activity. Here, we tested the effect of pH on the activity of an ASL defensin, human β-defensin-3 (hBD-3), and the cathelicidin-related peptide, LL-37. We found that reducing pH from 8.0 to 6.8 reduced the ability of both peptides to kill Staphylococcus aureus. An acidic pH also attenuated LL-37 killing of Pseudomonas aeruginosa. In addition, we discovered synergism between hBD-3 and LL-37 in killing S. aureus. LL-37 and lysozyme were also synergistic. Importantly, an acidic pH reduced the synergistic effects of combinations of ASL antibacterials. These results indicate that an acidic pH reduces the activity of individual ASL antimicrobials, impairs synergism between them, and thus may disrupt an important airway host defense mechanism.
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Nielsen KL, Dynesen P, Larsen P, Jakobsen L, Andersen PS, Frimodt-Møller N. Role of urinary cathelicidin LL-37 and human β-defensin 1 in uncomplicated Escherichia coli urinary tract infections. Infect Immun 2014; 82:1572-8. [PMID: 24452682 PMCID: PMC3993379 DOI: 10.1128/iai.01393-13] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/14/2014] [Indexed: 01/19/2023] Open
Abstract
Cathelicidin (LL-37) and human β-defensin 1 (hBD-1) are important components of the innate defense in the urinary tract. The aim of this study was to characterize whether these peptides are important for developing uncomplicated Escherichia coli urinary tract infections (UTIs). This was investigated by comparing urinary peptide levels of UTI patients during and after infection to those of controls, as well as characterizing the fecal flora of participants with respect to susceptibility to LL-37 and in vivo virulence. Forty-seven UTI patients and 50 controls who had never had a UTI were included. Participants were otherwise healthy, premenopausal, adult women. LL-37 MIC levels were compared for fecal E. coli clones from patients and controls and were also compared based on phylotypes (A, B1, B2, and D). In vivo virulence was investigated in the murine UTI model by use of selected fecal isolates from patients and controls. On average, UTI patients had significantly more LL-37 in urine during infection than postinfection, and patient LL-37 levels postinfection were significantly lower than those of controls. hBD-1 showed similar urine levels for UTI patients and controls. Fecal E. coli isolates from controls had higher LL-37 susceptibility than fecal and UTI E. coli isolates from UTI patients. In vivo studies showed a high level of virulence of fecal E. coli isolates from both patients and controls and showed no difference in virulence correlated with the LL-37 MIC level. The results indicate that the concentration of LL-37 in the urinary tract and low susceptibility to LL-37 may increase the likelihood of UTI in a complex interplay between host and pathogen attributes.
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Affiliation(s)
- Karen L. Nielsen
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen S, Denmark
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | | | | | - Lotte Jakobsen
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen S, Denmark
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | - Paal S. Andersen
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen S, Denmark
| | - Niels Frimodt-Møller
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen S, Denmark
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
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14
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Guillot L, Beucher J, Tabary O, Le Rouzic P, Clement A, Corvol H. Lung disease modifier genes in cystic fibrosis. Int J Biochem Cell Biol 2014; 52:83-93. [PMID: 24569122 DOI: 10.1016/j.biocel.2014.02.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 11/30/2022]
Abstract
Cystic fibrosis (CF) is recognized as a single gene disorder. However, a considerable diversity in its clinical phenotype has been documented since the description of the disease. Identification of additional gene alleles, so called "modifier genes" that directly influence the phenotype of CF disease became a challenge in the late '90ies, not only for the insight it provides into the CF pathophysiology, but also for the development of new potential therapeutic targets. One of the most studied phenotype has been the lung disease severity as lung dysfunction is the major cause of morbidity and mortality in CF. This review details the results of two main genetic approaches that have mainly been explored so far: (1) an "a priori" approach, i.e. the candidate gene approach; (2) a "without a priori" approach, analyzing the whole genome by linkage and genome-wide association studies (GWAS), or the whole exome by exome sequencing.
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Affiliation(s)
- Loic Guillot
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France.
| | - Julie Beucher
- Centre Hospiyalo-Universitaire (CHU), Rennes, France
| | - Olivier Tabary
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France
| | - Philippe Le Rouzic
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France
| | - Annick Clement
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France; Hôpital Trousseau, Pediatric Respiratory Department, AP-HP, Paris, France
| | - Harriet Corvol
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France; Hôpital Trousseau, Pediatric Respiratory Department, AP-HP, Paris, France
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15
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Ikuta T, Inagaki Y, Tanaka K, Saito T, Nakajima Y, Bando M, Kido JI, Nagata T. Gene polymorphism of β-defensin-1 is associated with susceptibility to periodontitis in Japanese. Odontology 2013; 103:66-74. [PMID: 24276427 DOI: 10.1007/s10266-013-0139-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Accepted: 10/23/2013] [Indexed: 12/13/2022]
Abstract
Periodontitis is a multifactorial disease associated with genetic and environmental factors. Single-nucleotide polymorphisms (SNPs) are associated with susceptibility to common diseases such as diabetes and periodontitis. Although the oral cavity is exposed to various organisms, the conditions are well controlled by innate and acquired immune systems. Antimicrobial peptides (AMPs) play an important role in the innate immune system; however, the association of AMP-SNPs with periodontitis has not been fully elucidated. This study investigated the relationship between AMP-SNPs and periodontitis in Japanese. One hundred and five Japanese subjects were recruited, which included patients with aggressive, severe, moderate and mild periodontitis, and age-matched healthy controls. Genomic DNA was isolated from peripheral blood and genotypes of SNPs of β-defensin-1 and lactoferrin genes (DEFB1: rs1799946, rs1800972 and rs11362; and LTF: rs1126478) were investigated using the PCR-Invader assay. Protein level of AMPs in gingival crevicular fluid (GCF) was quantified by ELISA. Case-control studies revealed that the -44 CC genotype of DEFB1 (rs1800972) was associated with periodontitis (OR 2.51), particularly with severe chronic periodontitis (OR 4.15) and with combined severe and moderate chronic periodontitis (OR 4.04). No statistical differences were found in other genotypes. The β-defensin-1 concentrations in GCF were significantly lower in subjects with the -44 CC genotype of DEFB1 than in those without this genotype. No significant differences between GCF concentrations of AMPs and other genotypes were detected. The -44 CC genotype of the β-defensin-1 gene (DEFB1 rs1800972) may be associated with susceptibility to chronic periodontitis in Japanese.
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Affiliation(s)
- Takahisa Ikuta
- Department of Periodontology and Endodontology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8504, Japan
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16
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Haerynck F, Mahachie John JM, Van Steen K, Schelstraete P, Van daele S, Loeys B, Van Thielen M, De Canck I, Nuytinck L, De Baets F. Genetic variations in toll-like receptor pathway and lung function decline in Cystic fibrosis patients. Hum Immunol 2013; 74:1649-55. [PMID: 23994582 DOI: 10.1016/j.humimm.2013.08.282] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 08/03/2013] [Accepted: 08/20/2013] [Indexed: 01/03/2023]
Abstract
The toll-like receptor (TLR) family maintains pulmonary homeostasis by pathogen recognition, clearance and regulation of inflammation. Genes affecting inflammation response play a key role in modifying Cystic fibrosis (CF) lung disease severity. We assessed the impact of single nucleotide polymorphisms (SNPs) of TLR genes (TLR1 to TLR10, CD14, lipopolyssacharide-binding protein (LBP)) on lung function in CF patients. Each SNP was tested for time-dependent effect on FEV1, using six genetic models. In addition, we investigated associations between SNP genotypes and extreme subject specific slopes of FEV1 decline. Variant alleles of polymorphisms of TLR2 rs1898830, rs5743708, and rs3804100 demonstrated a consistent association with lung disease severity (p = 0.008, p = 0.006 and p = 0.029 respectively). Patients homozygous for variant C allele of TLR5 polymorphism rs5744174 are more frequently associated with extreme fast FEV1 decline (OR: 20 (95% Confidence Interval:1.85-216.18)). Patients homozygous AA for TLR1 polymorphism rs5743551 are more frequently associated with faster decline of FEV1 compared to heterozygous genotype (OR:7.33 (95% CI:1.63-33.11). Our findings indicate that variations in TLR1, TLR2 and TLR5 genes may influence CF lung function decline. Further functional analysis is required to provide new insights into the pathogenesis of TLRs in CF lung disease severity.
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Affiliation(s)
- F Haerynck
- Department of Pediatric Pulmonology and Immunology, Ghent University Hospital Ghent, Gent, Belgium.
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17
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Weiler CA, Drumm ML. Genetic influences on cystic fibrosis lung disease severity. Front Pharmacol 2013; 4:40. [PMID: 23630497 PMCID: PMC3632778 DOI: 10.3389/fphar.2013.00040] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 03/21/2013] [Indexed: 12/19/2022] Open
Abstract
Understanding the causes of variation in clinical manifestations of disease should allow for design of new or improved therapeutic strategies to treat the disease. If variation is caused by genetic differences between individuals, identifying the genes involved should present therapeutic targets, either in the proteins encoded by those genes or the pathways in which they function. The technology to identify and genotype the millions of variants present in the human genome has evolved rapidly over the past two decades. Originally only a small number of polymorphisms in a small number of subjects could be studied realistically, but speed and scope have increased nearly as dramatically as cost has decreased, making it feasible to determine genotypes of hundreds of thousands of polymorphisms in thousands of subjects. The use of such genetic technology has been applied to cystic fibrosis (CF) to identify genetic variation that alters the outcome of this single gene disorder. Candidate gene strategies to identify these variants, referred to as “modifier genes,” has yielded several genes that act in pathways known to be important in CF and for these the clinical implications are relatively clear. More recently, whole-genome surveys that probe hundreds of thousands of variants have been carried out and have identified genes and chromosomal regions for which a role in CF is not at all clear. Identification of these genes is exciting, as it provides the possibility for new areas of therapeutic development.
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Affiliation(s)
- Colleen A Weiler
- Department of Pediatrics, Case Western Reserve University Cleveland, OH, USA
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18
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Nurjadi D, Herrmann E, Hinderberger I, Zanger P. Impaired β-defensin expression in human skin links DEFB1 promoter polymorphisms with persistent Staphylococcus aureus nasal carriage. J Infect Dis 2012. [PMID: 23204181 DOI: 10.1093/infdis/jis735] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Genetically determined variation in the expression of innate defense molecules may explain differences in the propensity to be colonized with Staphylococcus aureus. METHODS We determined S. aureus nasal carriage in 603 volunteers; analyzed polymorphisms in the DEFB1 promoter at positions -52 G>A (rs1799946), -44 C>G (rs1800972), and -20 G>A (rs11362); and measured the content of human β-defensin 1 (hBD-1) and hBD-3 messenger RNA (mRNA) in 192 samples of healthy and experimentally wounded human skin. RESULTS Compared with GGG at the positions -52/-44/-20, the ACG haplotype was more common among persistent S. aureus nasal carriers (odds ratio, 1.93; 95% confidence interval [CI], 1.2-3.1; P = .006) and was associated with reduced expression of hBD-1 (GGG>ACG>GCA; P < .001) and hBD-3 (GGG>GCA>ACG; P = .04) in skin when measured 72 hours after wounding. Furthermore, a 50% decrease in hBD-1 and hBD-3 mRNA expression in wounded skin increased the odds of persistent carriage by 1.45 (95% CI, .93-2.26; P = .1) and 1.48 (95% CI, 1.01-2.17; P = .04), respectively. Adjustment for known risk factors of persistent S. aureus carriage did not substantially change the associations of both DEFB1 haplotypes and β-defensin expression with S. aureus colonization. CONCLUSIONS DEFB1 polymorphisms may promote persistent S. aureus colonization by altering β-defensin expression in keratinocytes of human skin.
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Affiliation(s)
- Dennis Nurjadi
- Institut für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany
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19
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de Oca EPM. Antimicrobial peptide elicitors: New hope for the post-antibiotic era. Innate Immun 2012; 19:227-41. [DOI: 10.1177/1753425912460708] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Antimicrobial peptides or host defense peptides are fundamental components of human innate immunity. Recent and growing evidence suggests they have a role in a broad range of diseases, including cancer, allergies and susceptibility to infection, including HIV/AIDS. Antimicrobial peptide elicitors (APEs) are physical, biological or chemical agents that boost human antimicrobial peptide expression. The current knowledge of APEs and their potential use in the treatment of human infectious diseases are reviewed, and a classification system for APEs is proposed. The efficient use of APEs in clinical practice could mark the beginning of the urgently needed post-antibiotic era, but further trials assessing their efficacy and safety are required.
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Affiliation(s)
- Ernesto Prado Montes de Oca
- Molecular Biology Laboratory, Biosecurity Area, CIATEJ – National Council of Science and Technology, Guadalajara, Jalisco, Mexico
- In silico Laboratory, Pharmaceutical and Medical Biotechnology Unit, CIATEJ – National Council of Science and Technology, Guadalajara, Jalisco, Mexico
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20
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Carnt NA, Willcox MD, Hau S, Keay L, Dart JK, Chakrabarti S, Stapleton F. Immune Defense Single Nucleotide Polymorphisms and Recruitment Strategies Associated with Contact Lens Keratitis. Ophthalmology 2012; 119:1997-2002. [DOI: 10.1016/j.ophtha.2012.05.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 04/03/2012] [Accepted: 05/11/2012] [Indexed: 11/29/2022] Open
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21
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Tiszlavicz Z, Somogyvári F, Szolnoki Z, Sztriha LK, Németh B, Vécsei L, Mándi Y. Genetic polymorphisms of human β-defensins in patients with ischemic stroke. Acta Neurol Scand 2012; 126:109-15. [PMID: 22050386 DOI: 10.1111/j.1600-0404.2011.01613.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVES AND METHODS Genetic predisposition of the inflammatory host response may affect the development of stroke. On the basis of the theory of infectious burden and risk of stroke, we considered it of interest to investigate the relevance of the single-nucleotide polymorphisms (SNPs) in the DEFB1 gene and the copy number variant (CNV) of the DEFB4 genes in ischemic stroke. RESULTS There were no significant differences in the genotype frequencies of the three SNPs of the DEFB1 gene between the patients with stroke (n = 312) and the healthy blood donors (n = 221). However, a higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with ischemic stroke as compared with the healthy controls (40% vs 24%, respectively). Additionally, low plasma concentrations of hBD-2 (187 ± 20 pg/ml) were characteristic of the patients with fewer than four copy numbers relative to those with more than four copy numbers (385 ± 35 pg/ml). CONCLUSIONS The low copy number of the DEFB4 gene, involving a weakened antimicrobial defense of the host, might be important in the pathogenesis of stroke.
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Affiliation(s)
- Z Tiszlavicz
- Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary
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22
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Wanniarachchi YA, Kaczmarek P, Wan A, Nolan EM. Human defensin 5 disulfide array mutants: disulfide bond deletion attenuates antibacterial activity against Staphylococcus aureus. Biochemistry 2011; 50:8005-17. [PMID: 21861459 DOI: 10.1021/bi201043j] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human α-defensin 5 (HD5, HD5(ox) to specify the oxidized and disulfide linked form) is a 32-residue cysteine-rich host-defense peptide, expressed and released by small intestinal Paneth cells, that exhibits antibacterial activity against a number of Gram-negative and -positive bacterial strains. To ascertain the contributions of its disulfide array to structure, antimicrobial activity, and proteolytic stability, a series of HD5 double mutant peptides where pairs of cysteine residues corresponding to native disulfide linkages (Cys(3)-Cys(31), Cys(5)-Cys(20), Cys(10)-Cys(30)) were mutated to Ser or Ala residues, overexpressed in E. coli, purified, and characterized. A hexa mutant peptide, HD5[Ser(hexa)], where all six native Cys residues are replaced by Ser residues, was also evaluated. Removal of a single native S-S linkage influences oxidative folding and regioisomerization, antibacterial activity, Gram-negative bacterial membrane permeabilization, and proteolytic stability. Whereas the majority of the HD5 mutant peptides show low micromolar activity against Gram-negative E. coli ATCC 25922 in colony counting assays, the wild-type disulfide array is essential for low micromolar activity against Gram-positive S. aureus ATCC 25923. Removal of a single disulfide bond attenuates the activity observed for HD5(ox) against this Gram-positive bacterial strain. This observation supports the notion that the HD5(ox) mechanism of antibacterial action differs for Gram-negative and Gram-positive species [Wei et al. (2009) J. Biol. Chem. 284, 29180-29192] and that the native disulfide array is a requirement for its activity against S. aureus.
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Affiliation(s)
- Yoshitha A Wanniarachchi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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23
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Crovella S, Segat L, Amato A, Athanasakis E, Bezzerri V, Braggion C, Casciaro R, Castaldo G, Colombo C, Covone AE, De Rose V, Gagliardini R, Lanzara C, Minicucci L, Morgutti M, Nicolis E, Pardo F, Quattrucci S, Raia V, Ravazzolo R, Seia M, Stanzial V, Termini L, Zazzeron L, Cabrini G, Gasparini P. A polymorphism in the 5’ UTR of the DEFB1 gene is associated with the lung phenotype in F508del homozygous Italian cystic fibrosis patients. Clin Chem Lab Med 2011; 49:49-54. [DOI: 10.1515/cclm.2011.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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PTX3 genetic variations affect the risk of Pseudomonas aeruginosa airway colonization in cystic fibrosis patients. Genes Immun 2010; 11:665-70. [PMID: 20927127 PMCID: PMC3001954 DOI: 10.1038/gene.2010.41] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cystic fibrosis (CF) is a common life-threatening autosomal recessive disorder in the Caucasian population, and the gene responsible is the CF transmembrane conductance regulator (CFTR). Patients with CF have repeated bacterial infection of the airways caused by Pseudomonas aeruginosa (PA), which is one of the predominant pathogen, and endobronchial chronic infection represents a major cause of morbidity and mortality. Pentraxin 3 (PTX3) is a gene that encodes the antimicrobial protein, PTX3, which is believed to have an important role in innate immunity of lung. To address the role of PTX3 in the risk of PA lung colonization, we investigated five single nucleotide polymorphisms of PTX3 gene in 172 Caucasian CF patients who were homozygous for the F508del mutation. We observed that PTX3 haplotype frequencies were significantly different between patients with PA colonization, as compared with noncolonized patients. Moreover, a protective effect was found in association with a specific haplotype (odds ratio 0.524). Our data suggest that variations within PTX3 affect lung colonization of Pseudomonas in patients with CF.
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25
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Tiszlavicz Z, Szabolcs A, Takács T, Farkas G, Kovács-Nagy R, Szántai E, Sasvári-Székely M, Mándi Y. Polymorphisms of beta defensins are associated with the risk of severe acute pancreatitis. Pancreatology 2010; 10:483-90. [PMID: 20720450 DOI: 10.1159/000276987] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 01/06/2010] [Indexed: 12/11/2022]
Abstract
AIMS Bacterial translocation from the intestinal tract plays an important role in severe acute pancreatitis (AP). Human β-defensins are a family of antimicrobial peptides present at the mucosal surface. The aim of this study was to investigate the relevance of single nucleotide polymorphisms (SNPs) in the DEFB1 gene and copy number polymorphisms of the DEFB4 genes in AP. METHODS 124 AP patients (30 with mild and 94 with severe disease) and 100 healthy controls were enrolled in the study. Three SNPs of the DEFB1 gene [G-20A (c.-20G→A), C-44G (c.-44C→G) and G-52A (c.-52G→A)] were genotyped by Custom TaqMan assay. The DEFB4 gene copy number was determined by means of a TaqMan real-time PCR assay. RESULTS Significantly higher frequencies of the AA genotype of G-20A (c.-20G→A) and the AA genotype of G-52A (c.-52G→A) were observed among the patients with severe AP (SAP) compared with the healthy controls (38 vs. 20 and 41 vs. 18%, respectively). The GG protective genotype of C-44G (c.-44C→G) SNP was much less frequent (1%) among the patients than among the controls (9%). A higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with SAP compared with the healthy controls (62 vs. 24%, respectively). CONCLUSIONS The variations in the genes encoding human β-defensin-1 and -2 may be associated with the risk of SAP. and IAP.
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Affiliation(s)
- Z Tiszlavicz
- Department of Medical Microbiology and Immunology, University of Szeged, Szeged, Hungary
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26
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Abstract
Lung infections caused by the opportunistic pathogen Pseudomonas aeruginosa can present as a spectrum of clinical entities from a rapidly fatal pneumonia in a neutropenic patient to a multi-decade bronchitis in patients with cystic fibrosis. P. aeruginosa is ubiquitous in our environment, and one of the most versatile pathogens studied, capable of infecting a number of diverse life forms and surviving harsh environmental factors. It is also able to quickly adapt to new environments, including the lung, where it orchestrates virulence factors to acquire necessary nutrients, and if necessary, turn them off to prevent immune recognition. Despite these capabilities, P. aeruginosa rarely infects healthy human lungs. This is secondary to a highly evolved host defence mechanism that efficiently removes inhaled or aspirated pseudomonads. Many arms of the respiratory host defence have been elucidated using P. aeruginosa as a model pathogen. Human infections with P. aeruginosa have demonstrated the importance of the mechanical barrier functions including mucus clearance, and the innate immune system, including the critical role of the neutrophilic response. As more models of persistent or biofilm P. aeruginosa infections are developed, the role of the adaptive immune response will likely become more evident. Understanding the pathogenesis of P. aeruginosa, and the respiratory host defence response to it has, and will continue to, lead to novel therapeutic strategies to help patients.
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Affiliation(s)
- Bryan J Williams
- Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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27
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Underwood MA, Bevins CL. Defensin-barbed innate immunity: clinical associations in the pediatric population. Pediatrics 2010; 125:1237-47. [PMID: 20478936 DOI: 10.1542/peds.2009-3289] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Defensins and related antimicrobial peptides serve a central role in innate immunity in all species of plants and animals. In humans, defensins are widely expressed, including in neutrophils, skin, and mucosal epithelia. Most defensins are potent antibiotics, and some have chemotactic and toxin-neutralizing activities. Results of recent studies on the homeostatic and disease-fighting activities of human defensins point to a key relevance in several pediatric disorders. Inherited variation in defensin gene expression may contribute to susceptibility to several diseases, including psoriasis and Crohn disease. We review here the recent discoveries in innate immunity that shed light on the potential roles of defensins, and other antimicrobial molecules, in the pathophysiology of common pediatric diseases such as atopic dermatitis, necrotizing enterocolitis, cystic fibrosis, and otitis media.
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Affiliation(s)
- Mark A Underwood
- UC Davis School of Medicine, 2516 Stockton Blvd, Sacramento, CA 95817, USA.
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28
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Ozturk A, Famili P, Vieira AR. The antimicrobial peptide DEFB1 is associated with caries. J Dent Res 2010; 89:631-6. [PMID: 20371866 DOI: 10.1177/0022034510364491] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Genetics is an important component in the determination of individual susceptibility to caries and periodontal diseases. Since beta defensin 1 (DEFB1) localizes in the oral cavity, we tested if variation in DEFB1 is associated with caries and periodontitis. We analyzed 3 single-nucleotide polymorphisms in DEFB1 in DNA samples from unrelated individuals. Carrying a copy of the variant allele of the DEFB1 marker rs11362 (G-20A) increased the DMFT and DMFS scores more than five-fold. Also, carrying a copy of the variant allele of the DEFB1 marker rs179946 (G-52A) correlated with low DMFT scores. We found a high-caries-experience haplotype (GCA), which increased DMFT scores two-fold, and a low- caries-experience haplotype (ACG), which decreased DMFT scores two-fold, in the DEFB1 promoter. No association between DEFB1 genetic markers and periodontal disease was found. Our results suggest that functional polymorphisms of DEFB1 are potential markers for caries.
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Affiliation(s)
- A Ozturk
- Department of Periodontics and Preventive Dentistry, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
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29
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Segat L, Morgutti M, Athanasakis E, Trevisiol C, Amaddeo A, Poli F, Crovella S. Analysis of DEFB1 regulatory SNPs in cystic fibrosis patients from North-Eastern Italy. Int J Immunogenet 2010; 37:169-75. [DOI: 10.1111/j.1744-313x.2010.00907.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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30
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The sound of silence: human beta-defensin-1 gene untranslated SNPs change the predicted mRNA secondary structure in a length-dependent manner. Immunol Lett 2010; 129:53-5. [PMID: 20060856 DOI: 10.1016/j.imlet.2009.12.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 12/17/2009] [Accepted: 12/23/2009] [Indexed: 10/20/2022]
Abstract
This study investigated how 5'-UTR of DEFB1 gene (encoding for the human beta-defensin-1) affects mRNA secondary structure and its correlation with translation efficiency in the susceptibility of diseases. It was possible to determine DEFB1 mRNA folding under the influence of 5'-UTR SNPs haplotypes and putative alternative transcript lengths. Different DEFB1 mRNAs that fold in a pattern that is haplotype and length-dependent are potentially able to drive changes in peptide expression dynamics.
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Abstract
Cystic fibrosis (CF) is characterised by respiratory and pancreatic deficiencies that stem from the loss of fully functional CFTR (CF transmembrane conductance regulator) at the membrane of epithelial cells. Current treatment modalities aim to delay the deterioration in lung function, Which is mostly responsible for the relatively short life expectancy of CF sufferers; however none have so far successfully dealt with the underlying molecular defect. Novel pharmacological approaches to ameliorate the lack of active CFTR in respiratory epithelial cells are beginning to address more of the pathophysiological defects caused by CFTR mutations. However, CFTR gene replacement by gene therapy remains the most likely option for addressing the basic defects, including ion transport and inflammatory functions of CFTR. In this chapter, We will review the latest preclinical and clinical advances in pharmacotherapy and gene therapy for CF lung disease.
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32
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Schaefer AS, Richter GM, Nothnagel M, Laine ML, Rühling A, Schäfer C, Cordes N, Noack B, Folwaczny M, Glas J, Dörfer C, Dommisch H, Groessner-Schreiber B, Jepsen S, Loos BG, Schreiber S. A 3' UTR transition within DEFB1 is associated with chronic and aggressive periodontitis. Genes Immun 2009; 11:45-54. [PMID: 19829306 DOI: 10.1038/gene.2009.75] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Periodontal diseases are complex inflammatory diseases and affect up to 20% of the worldwide population. An unbalanced reaction of the immune system toward microbial pathogens is considered as the key factor in the development of periodontitis. Defensins have a strong antimicrobial function and are important contributors of the immune system toward maintaining health. Here, we present the first systematic association study of DEFB1. Using a haplotype-tagging single nucleotide polymorphism (SNP) approach, including described promoter SNPs of DEFB1, we investigated the associations of the selected variants in a large population (N=1337 cases and 2887 ethnically matched controls). The 3' untranslated region SNP, rs1047031, showed the most significant association signal for homozygous carriers of the rare A allele (P=0.002) with an increased genetic risk of 1.3 (95% confidence interval: 1.11-1.57). The association was consistent with the specific periodontitis forms: chronic periodontitis (odds ratio=2.2 (95% confidence interval: 1.16-4.35), P=0.02), and aggressive periodontitis (odds ratio=1.3 (95% confidence interval 1.04-1.68), P=0.02). Sequencing of regulatory and exonic regions of DEFB1 identified no other associated variant, pointing toward rs1047031 as likely being the causative variant. Prediction of microRNA targets identified a potential microRNA-binding site at the position of rs1047031.
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Affiliation(s)
- A S Schaefer
- Institute for Clinical Molecular Biology, University Medical Center Schleswig-Holstein, Kiel, Germany.
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Predicting alternative candidates as binding sites to DEFB1 668 (-44) SNP: a long way from statistical association with multifactorial diseases. INFECTION GENETICS AND EVOLUTION 2009; 9:1129-31. [PMID: 19712755 DOI: 10.1016/j.meegid.2009.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 08/02/2009] [Accepted: 08/18/2009] [Indexed: 11/22/2022]
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Role of beta-defensin-1 polymorphisms in mother-to-child transmission of HIV-1. J Acquir Immune Defic Syndr 2009; 51:13-9. [PMID: 19390326 DOI: 10.1097/qai.0b013e31819df249] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND OBJECTIVES Mother-to-child transmission (MTCT) of HIV-1, the main source of pediatric AIDS, is multifactorial. Defensins provide microbial barriers and function as effectors of innate immunity. This study investigated the relationship between genetic variants of beta-defensin-1 gene and MTCT of HIV-1. PATIENTS AND METHODS Three hundred children, 118 HIV-1 infected and 182 HIV-1 uninfected, born to HIV-1-infected mothers who had not undergone antiretroviral therapy during pregnancy, and 84 HIV-1-infected mothers were analyzed. The single nucleotide polymorphisms -44C/G (rs1800972) and -52G/A (rs1799946) were genotyped by TaqMan allelic discrimination assay and sequencing. Statistical analyses were performed using SNPStats and Bonferroni correction for multiple tests. RESULTS In children, the -52GG genotype and the -44G/-52G haplotype had a protective role against HIV-1 infection [odds ratio (OR) = 0.52, 95% confidence interval (CI) 0.31 to 0.86, P = 0.03 and OR = 0.50, 95% CI 0.31 to 0.83, P = 0.014, respectively]. In mothers, the -52GG genotype and the -44G/-52G haplotype were associated with low levels of HIV-1 plasma viremia (<1000 copies/mL) and a lower risk of maternal HIV-1 transmission (OR = 0.14, 95% CI 0.03 to 0.67, P = 0.009 and OR = 0.23, 95% CI 0.08 to 0.66, P = 0.012, respectively). CONCLUSIONS These results demonstrate a significant relationship between genetic variants of beta-defensin-1 gene, viral load, and MTCT of HIV-1, thus supporting a critical role of innate immunity in pediatric HIV-1 infection.
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Kocsis AK, Kiss ZF, Tiszlavicz L, Tiszlavicz Z, Mándi Y. Potential role of human beta-defensin 1 in Helicobacter pylori-induced gastritis. Scand J Gastroenterol 2009; 44:289-95. [PMID: 18991164 DOI: 10.1080/00365520802530879] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Helicobacter pylori-induced gastric inflammation is dependent on the persistence of the microorganism in the gastric epithelium. Modulation of the host epithelial antimicrobial responses may be a critical determinant in H. pylori-induced gastritis. Human beta-defensins (hBDs) are important components of the host defence at mucosal surfaces. The aim of the present study was to investigate the relevance of three single nucleotide polymorphisms (SNPs) of the human beta defensin-1 (hBD-1) gene in H. pylori-induced gastritis and to assess the mRNA expression of hBD-1 in H. pylori-infected AGS cells. MATERIAL AND METHODS Three SNPs of the beta defensin DEFB1 gene, DEFB1 G-20A (rs11362), DEFB1 C-44G (rs1800972) and DEFB1 G-52A (rs1799946), were genotyped either by Custom TaqMan SNP genotyping assays or by restriction fragment length polymorphism (RFLP) in 150 patients with chronic active gastritis; 100 serologically H. pylori-positive subjects without gastric or duodenal symptoms served as controls. hBD-1 mRNA expression in AGS cells was measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS Significant differences in frequencies of the GA and AA genotypes of G-52A SNPs were observed between patients with chronic active gastritis and healthy controls. The maximum level of hBD-1 mRNA expression in AGS cells was observed at 24 h after infection with H. pylori, this not being dependent on the presence of the cag pathogenicity island (PAI). CONCLUSIONS The results of these genetic and in vitro experiments suggest that not only the inducible, but also the constitutive form of hBD may be important in the pathogenesis of H. pylori-induced gastritis.
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Affiliation(s)
- Agnes Katalin Kocsis
- Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary
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Corvol H, Boelle PY, Brouard J, Knauer N, Chadelat K, Henrion-Caude A, Flamant C, Muselet-Charlier C, Boule M, Fauroux B, Vallet C, Feingold J, Ratjen F, Grasemann H, Clement A. Genetic variations in inflammatory mediators influence lung disease progression in cystic fibrosis. Pediatr Pulmonol 2008; 43:1224-32. [PMID: 19009622 DOI: 10.1002/ppul.20935] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The clinical course of cystic fibrosis (CF) varies considerably among patients carrying the same CF-causing gene mutation. Additional genetic modifiers may contribute to this variability. As airway inflammation is a key component of CF pathophysiology, we investigated whether major cytokine variants represent such modifiers in young CF patients. We tested 13 polymorphisms in 8 genes that play a key role in the inflammatory response: tumor necrosis factor, lymphotoxin alpha, interleukin (IL) 1B, IL1 receptor antagonist, IL6, IL8, IL10 and transforming growth factor beta 1 (TGFB1), for an association with lung disease progression and nutritional status in 329 CF patients. Variants in the TGFB1 gene at position +869T/C demonstrated a significant association with lung function decline. A less pronounced rate of decline in forced expiratory volume in 1 sec (FEV(1)) and forced vital capacity (FVC) were observed in patients heterozygous for TGFB1 +869 (+869CT), when compared to patients carrying either TGFB1 +869TT or +869CC genotypes. These findings support the concept that TGFB1 gene variants appear to be important genetic modifiers of lung disease progression in CF.
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Affiliation(s)
- Harriet Corvol
- AP-HP, Hôpital Trousseau, Pediatric Pulmonary Department, Paris, France.
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Cagliani R, Fumagalli M, Riva S, Pozzoli U, Comi GP, Menozzi G, Bresolin N, Sironi M. The signature of long-standing balancing selection at the human defensin beta-1 promoter. Genome Biol 2008; 9:R143. [PMID: 18817538 PMCID: PMC2592704 DOI: 10.1186/gb-2008-9-9-r143] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 05/21/2008] [Accepted: 09/25/2008] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Defensins, small endogenous peptides with antimicrobial activity, are pivotal components of the innate immune response. A large cluster of defensin genes is located on human chromosome 8p; among them the beta defensin 1 (DEFB1) promoterhas been extensively studied since discovery that specific polymorphisms and haplotypes associate with asthma and atopy, susceptibility to severe sepsis, as well as HIV and Candida infection predisposition. RESULTS Here, we characterize the sequence variation and haplotype structure of the DEFB1 promoter region in six human populations. In all of them, we observed high levels of nucleotide variation, an excess of intermediate-frequency alleles, reduced population differentiation and a genealogy with common haplotypes separated by deep branches. Indeed, a significant departure from the expectation of evolutionary neutrality was observed in all populations and the possibility that this is due to demographic history alone was ruled out. Also, we verified that the selection signature is restricted to the promoter region and not due to a linked balanced polymorphism. A phylogeny-based estimation indicated that the two major haplotype clades separated around 4.5 million years ago, approximately the time when the human and chimpanzee lineages split. CONCLUSION Altogether, these features represent strong molecular signatures of long-term balancing selection, a process that is thought to be extremely rare outside major histocompatibility complex genes. Our data indicate that the DEFB1 promoter region carries functional variants and support previous hypotheses whereby alleles predisposing to atopic disorders are widespread in modern societies because they conferred resistance to pathogens in ancient settings.
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Affiliation(s)
- Rachele Cagliani
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
| | - Matteo Fumagalli
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
- Bioengineering Department, Politecnico di Milano, Pzza L. da Vinci, 32, 20133 Milan, Italy
| | - Stefania Riva
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
| | - Uberto Pozzoli
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
| | - Giacomo P Comi
- Dino Ferrari Centre, Department of Neurological Sciences, University of Milan, IRCCS Ospedale Maggiore Policlinico, Mangiagalli and Regina Elena Foundation, Via F. Sforza 35, 20100 Milan, Italy
| | - Giorgia Menozzi
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
| | - Nereo Bresolin
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
- Dino Ferrari Centre, Department of Neurological Sciences, University of Milan, IRCCS Ospedale Maggiore Policlinico, Mangiagalli and Regina Elena Foundation, Via F. Sforza 35, 20100 Milan, Italy
| | - Manuela Sironi
- Scientific Institute IRCCS E. Medea, Bioinformatic Lab, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy
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Suh L, Coffin S, Leckerman KH, Gelfand JM, Honig PJ, Yan AC. Methicillin-resistant Staphylococcus aureus colonization in children with atopic dermatitis. Pediatr Dermatol 2008; 25:528-34. [PMID: 18950393 DOI: 10.1111/j.1525-1470.2008.00768.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Children with atopic dermatitis are more frequently colonized with Staphylococcus aureus than children without atopic dermatitis. However, little epidemiological data exist regarding the prevalence of methicillin-resistant S. aureus among children with atopic dermatitis. Recent studies have revealed an increasing prevalence of community-associated methicillin-resistant S. aureus among patients presenting to hospitals with serious bacterial infections, particularly those with cutaneous and soft tissue infections. As many atopic dermatitis patients are treated empirically with antibiotics for secondary skin infections, an understanding of the epidemiology of bacterial colonization and superinfection is essential for directing proper treatment in the atopic patient population. This study investigates the prevalence of risk factors for community-associated, methicillin-resistant S. aureus colonization among pediatric atopic dermatitis patients encountered at an academic pediatric dermatology clinic. An observational cross-sectional study was conducted at the Children's Hospital of Philadelphia in which 54 patients previously diagnosed with atopic dermatitis were enrolled. A detailed patient questionnaire, a complete cutaneous examination, and an evaluation of eczema severity according to the Eczema Area and Severity Index were completed at the time of enrollment. Bacterial cultures from the skin and nares were obtained to determine the frequency of colonization with either methicillin-sensitive S. aureus or methicillin-resistant S. aureus. Although most atopic dermatitis patients studied were colonized with S. aureus (43/54 [80%]), methicillin-resistant S. aureus was isolated from only seven atopic dermatitis patients (7/43 [16%]). Patients colonized with S. aureus were more likely to be male, to have been previously hospitalized, to have used a topical calcineurin inhibitor in combination with a topical steroid, and less likely to have used topical antibiotics. Bivariable analysis, however, revealed that only previous hospitalization was independently associated with an increased risk of methicillin-resistant S. aureus colonization. We observed that 80% of atopic dermatitis patients were colonized with S. aureus, and that of these patients, 16% of colonized patients were colonized with a methicillin-resistant strain. Methicillin-resistant S. aureus colonization was found to be significantly associated with previous hospitalization. Evidence also indicates that topical calcineurin inhibitors used in conjunction with topical steroids is associated with increased S. aureus colonization, while topical antibiotic use appears to decrease S. aureus colonization.
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Affiliation(s)
- Liza Suh
- Department of Pediatrics, University of California-San Francisco, San Francisco, California, USA
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