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Morakinyo OM, Mokgobu MI, Mukhola MS, Godobedzha T. Biological Composition of Respirable Particulate Matter in an Industrial Vicinity in South Africa. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16040629. [PMID: 30795513 PMCID: PMC6406656 DOI: 10.3390/ijerph16040629] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/16/2019] [Accepted: 02/18/2019] [Indexed: 01/15/2023]
Abstract
There is a growing concern that exposure to particulate matter of aerodynamic diameter of less than 2.5 µm (PM2.5) with biological composition (bioaerosols) may play a key role in the prevalence of adverse health outcomes in humans. This study determined the bacterial and fungal concentrations in PM2.5 and their inhalation health risks in an industrial vicinity in South Africa. Samples of PM2.5 collected on a 47-mm glass fiber filter during winter and summer months were analysed for bacterial and fungal content using standard methods. The health risks from inhalation of bioaerosols were done by estimating the age-specific dose rate. The concentration of bacteria (168⁻378 CFU/m³) was higher than fungi (58⁻155 CFU/m³). Bacterial and fungal concentrations in PM2.5 were lower in winter than in the summer season. Bacteria identified in summer were similar to those identified in winter: Staphylococcus sp., Bacillus sp., Micrococcus sp., Flavobacterium sp., Klebsiella sp. and Pseudomonas sp. Moreover, the fungal floras identified include Cladosporium spp., Aspergillus spp., Penicillium spp., Fusarium spp. and Alternaria spp. Children inhaled a higher dose of bacterial and fungal aerosols than adults. Bacteria and fungi are part of the bioaerosol components of PM2.5. Bioaerosol exposure may present additional health risks for children.
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Affiliation(s)
- Oyewale Mayowa Morakinyo
- Department of Environmental Health, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
- Department of Environmental Health Sciences, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan 200284, Nigeria.
| | - Matlou Ingrid Mokgobu
- Department of Environmental Health, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
| | - Murembiwa Stanley Mukhola
- Department of Environmental Health, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
| | - Tshifhiwa Godobedzha
- Air Quality Management, Environment and Agriculture Management Department, City of Tshwane Municipality Private Bag 440, Pretoria 0001, South Africa.
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Yang IV, Lozupone CA, Schwartz DA. The environment, epigenome, and asthma. J Allergy Clin Immunol 2017; 140:14-23. [PMID: 28673400 DOI: 10.1016/j.jaci.2017.05.011] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/10/2017] [Accepted: 05/12/2017] [Indexed: 12/21/2022]
Abstract
Asthma prevalence has been on the increase, especially in North America compared with other continents. However, the prevalence of asthma differs worldwide, and in many countries the prevalence is stable or decreasing. This highlights the influence of environmental exposures, such as allergens, air pollution, and the environmental microbiome, on disease etiology and pathogenesis. The epigenome might provide the unifying mechanism that translates the influence of environmental exposures to changes in gene expression, respiratory epithelial function, and immune cell skewing that are hallmarks of asthma. In this review we will introduce the concept of the environmental epigenome in asthmatic patients, summarize previous publications of relevance to this field, and discuss future directions.
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Affiliation(s)
- Ivana V Yang
- Department of Medicine, University of Colorado, School of Medicine, Aurora, Colo; National Jewish Health, Denver, Colo; Department of Epidemiology, Colorado School of Public Health, University of Colorado, Aurora, Colo.
| | - Catherine A Lozupone
- Department of Medicine, University of Colorado, School of Medicine, Aurora, Colo
| | - David A Schwartz
- Department of Medicine, University of Colorado, School of Medicine, Aurora, Colo; National Jewish Health, Denver, Colo; Department of Immunology, University of Colorado, Denver, Colo
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Jessop F, Holian A. Extracellular HMGB1 regulates multi-walled carbon nanotube-induced inflammation in vivo. Nanotoxicology 2014; 9:365-72. [PMID: 24983895 DOI: 10.3109/17435390.2014.933904] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endotoxin is often used to activate NF-κB in vitro when assessing NLRP3 inflammasome activation by various exogenous particles including nanoparticles. However, the endogenous source of this signal 1 is unknown. High-mobility group box 1 (HMGB1) is known to play a critical role in acute lung injury, however the potential contribution of the alarmin HMGB1 to NLRP3 Inflammasome activation has not been determined in response to nanoparticles in vivo. In this study, the ability of multi-walled carbon nanotubes (MWCNT) to cause release of HMGB1 in vitro and in vivo, as well as the potential of HMGB1 to function as signal 1 in vitro and in vivo, was determined. HMGB1 activity in vivo was assessed by administration of HMGB1 neutralization antibodies following MWCNT exposure. Caspase-1(-/-) mice were utilized to elucidate the dependence of HMGB1 secretion on NLRP3 inflammasome activity. MWCNT exposure increased extracellular HMGB1 levels in primary alveolar macrophages from C57Bl/6 mice and C10 mouse epithelial cell culture supernatants, and in C57Bl/6 mouse lung lavage fluid. MWCNT-induced HMGB1 secretion was dependent upon caspase-1. HMGB1 increased MWCNT-induced IL-1β release from macrophages in vitro, and neutralization of extracellular HMGB1 reduced MWCNT-induced IL-1β secretion in vivo. HMGB1 neutralization was accompanied with overall decreased inflammation. In summary, this study suggests extracellular HMGB1 participates in NLRP3 inflammasome activity and regulates IL-1β associated sterile inflammation induced by MWCNT.
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Affiliation(s)
- Forrest Jessop
- Center for Environmental Health Sciences, University of Montana , Missoula, MT , USA
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Wujcicka W, Wilczyński J, Nowakowska D. Do the placental barrier, parasite genotype and Toll-like receptor polymorphisms contribute to the course of primary infection with various Toxoplasma gondii genotypes in pregnant women? Eur J Clin Microbiol Infect Dis 2013; 33:703-9. [PMID: 24292064 PMCID: PMC3996274 DOI: 10.1007/s10096-013-2017-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 11/06/2013] [Indexed: 11/24/2022]
Abstract
Toxoplasma gondii has a highly clonal genetic structure classified into three major genetic types, I, II, and III, plus additional recombinant and atypical strains. In humans, type I and atypical strains usually associate with severe toxoplasmosis. Type II strains, predominantly identified in European countries and the United States, correlate with a differential course of toxoplasmosis. During pregnancy, the important protective role of the placenta against maternal–fetal T. gondii transmission has been reported. T. gondii preferentially colonizes extravillous trophoblasts as compared to syncytiotrophoblasts. The latter compartment was suggested to act as the real barrier to the fetal dissemination of T. gondii. Alterations in immune response to particular T. gondii strains were observed. Higher transcription levels of IP-10, IL-1β, IL-6, IL-10, IL-12 cytokines, and NF-κB translocation to the nucleus were more often documented for type II strains than type I strains. Since the induction of IL-12 during type II infection was Myd88-dependent, the involvement of Toll-like receptors (TLRs) in the immunity against these strains was suggested. Differential expression of TLRs depends on placental cell types and gestational age. The expression of TLR2 and TLR4 in the first trimester of pregnancy was reported only for villous cytotrophoblasts and extravillous trophoblasts, but not for syncytiotrophoblasts. The involvement of single-nucleotide polymorphisms (SNPs) in the TLR genes in infectious pathogenicity, including toxoplasmic retinochoroiditis, points at a possible involvement of TLR alterations in immunity against T. gondii. We conclude that studies on TLR contributions in the maternal–fetal transmission of particular parasite strains and congenital toxoplasmosis are warranted.
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Affiliation(s)
- W Wujcicka
- Department of Fetal-Maternal Medicine and Gynecology, Polish Mother's Memorial Hospital Research Institute in Lodz, 281/289 Rzgowska Street, Lodz, 93-338, Poland
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Bønløkke JH, Cormier Y, Veillette M, Radu A, Mériaux A, Duchaine C. Immunologic mechanisms in the adaptation of swine farm workers to their work environment. Innate Immun 2012; 19:403-10. [PMID: 23222887 DOI: 10.1177/1753425912466576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Swine building exposure causes inflammatory reactions that appear to be attenuated with prolonged periods of contact. The mechanisms behind this adaptation to a dusty and endotoxin-rich environment are poorly understood. Our aim was to compare levels of selected inflammatory mediators in swine farm workers at times with differences in exposure. Participants had blood sampling done before and after each of three work shifts-two in winter and one in summer. Before one of the winter visits they had avoided pulmonary exposure to the swine buildings by wearing respiratory protection for 4 d. The other visits were done after non-protected periods of work. Protein and mRNA concentrations were measured in blood. Mixed models were used for the statistics. During summer higher concentrations of mRNA to IL-8, lymphocyte function-associated antigen 1 and bactericidal/permeability-increasing protein (BPI) were observed. BPI mRNA increased only over the work shift after the unprotected winter period (P = 0.039). BPI decreased from elevated levels across the shift after use of respiratory protection (P = 0.003), but was unchanged during the other two visits. The findings suggest possible roles for these proteins in adaptation to the swine building environment after repeated exposures.
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Affiliation(s)
- Jakob H Bønløkke
- Department of Environmental and Occupational Health, Institute of Public Health, Aarhus University, Denmark
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Koch A, Hamann L, Schott M, Boehm O, Grotemeyer D, Kurt M, Schwenke C, Schumann RR, Bornstein SR, Zacharowski K. Genetic variation of TLR4 influences immunoendocrine stress response: an observational study in cardiac surgical patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2011; 15:R109. [PMID: 21466684 PMCID: PMC3219387 DOI: 10.1186/cc10130] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 03/16/2011] [Accepted: 04/05/2011] [Indexed: 12/12/2022]
Abstract
Introduction Systemic inflammation (for example, following surgery) involves Toll-like receptor (TLR) signaling and leads to an endocrine stress response. This study aims to investigate a possible influence of TLR2 and TLR4 single nucleotide polymorphisms (SNPs) on perioperative adrenocorticotropic hormone (ACTH) and cortisol regulation in serum of cardiac surgical patients. To investigate the link to systemic inflammation in this context, we additionally measured 10 different cytokines in the serum. Methods A total of 338 patients admitted for elective cardiac surgery were included in this prospective observational clinical cohort study. Genomic DNA of patients was screened for TLR2 and TLR4 SNPs. Serum concentrations of ACTH, cortisol, interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α and granulocyte macrophage-colony stimulating factor (GM-CSF) were determined before surgery, immediately post surgery and on the first postoperative day. Results Thirteen patients were identified as TLR2 SNP carriers, 51 as TLR4 SNP carriers and 274 patients as non-carriers. Basal levels of ACTH, cortisol and cytokines did not differ among groups. In all three groups a significant, transient perioperative rise of cortisol could be observed. However, only in the non-carrier group this was accompanied by a significant ACTH rise. TLR4 SNP carriers had significant lower ACTH levels compared to non-carriers (mean (95% confidence intervals)) non-carriers: 201.9 (187.7 to 216.1) pg/ml; TLR4 SNP carriers: 149.9 (118.4 to 181.5) pg/ml; TLR2 SNP carriers: 176.4 ((110.5 to 242.3) pg/ml). Compared to non-carriers, TLR4 SNP carriers showed significant lower serum IL-8, IL-10 and GM-CSF peaks (mean (95% confidence intervals)): IL-8: non-carriers: 42.6 (36.7 to 48.5) pg/ml, TLR4 SNP carriers: 23.7 (10.7 to 36.8) pg/ml; IL-10: non-carriers: 83.8 (70.3 to 97.4) pg/ml, TLR4 SNP carriers: 54.2 (24.1 to 84.2) pg/ml; GM-CSF: non-carriers: 33.0 (27.8 to 38.3) pg/ml, TLR4 SNP carriers: 20.2 (8.6 to 31.8) pg/ml). No significant changes over time or between the groups were found for the other cytokines. Conclusions Regulation of the immunoendocrine stress response during systemic inflammation is influenced by the presence of a TLR4 SNP. Cardiac surgical patients carrying this genotype showed decreased serum concentrations of ACTH, IL-8, IL-10 and GM-CSF. This finding might have impact on interpreting previous and designing future trials on diagnosing and modulating immunoendocrine dysregulation (for example, adrenal insufficiency) during systemic inflammation and sepsis.
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Affiliation(s)
- Alexander Koch
- Clinic of Anaesthesiology, Intensive Care Medicine and Pain Therapy, JW-Goethe-University Hospital, Theodor-Stern-Kai 7, Frankfurt am Main 60590, Germany.
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Létourneau V, Mériaux A, Goyer N, Chakir J, Cormier Y, Duchaine C. Biological activities of respirable dust from Eastern Canadian peat moss factories. Toxicol In Vitro 2010; 24:1273-8. [PMID: 20398748 DOI: 10.1016/j.tiv.2010.03.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 03/19/2010] [Accepted: 03/31/2010] [Indexed: 11/26/2022]
Abstract
Bacteria, moulds, endotoxin and quartz from respirable dust of agricultural and industrial buildings are typically incriminated for the respiratory health decline of exposed workers despite that dust being an undefined mixture and quantification methods of aerosolized bacteria, moulds or endotoxin not being standardized yet. We developed an in vitro alveolar epithelial cell system in which biological activities of peat moss factories' dust might be correlated to bacteria, mould, endotoxin and quartz concentrations of the analyzed samples. Following exposure, interleukin-8 protein secretion, necrosis and apoptosis of the exposed A549 cells were monitored respectively with ELISA on cell supernatants, trypan blue exclusion and DNA fragmentation detection by flow cytometry. Respirable dust was collected with liquid impingers and respirable quartz with 10mm Dorr-Oliver cyclones. We quantified mesophilic bacteria, mesophilic moulds and endotoxins from liquid impinger samples. No correlation was observed between biological activities of dust and bacteria, mould, endotoxin or quartz concentrations under our experimental conditions. Our speculation is that simple measurements, such as dust concentrations, may not be adequate indicators of the human respiratory health hazard for a given environment.
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Affiliation(s)
- Valérie Létourneau
- Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 chemin Sainte-Foy, Québec, Canada G1V 4G5.
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Cesta MF, Ryman-Rasmussen JP, Wallace DG, Masinde T, Hurlburt G, Taylor AJ, Bonner JC. Bacterial lipopolysaccharide enhances PDGF signaling and pulmonary fibrosis in rats exposed to carbon nanotubes. Am J Respir Cell Mol Biol 2009; 43:142-51. [PMID: 19738159 DOI: 10.1165/rcmb.2009-0113oc] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Engineered multi-walled carbon nanotubes (MWCNT) represent a possible health risk for pulmonary fibrosis due to their fiber-like shape and potential for persistence in the lung. We postulated that bacterial lipopolysaccharide (LPS), a ubiquitous agent in the environment that causes lung inflammation, would enhance fibrosis caused by MWCNT. Rats were exposed to LPS and then intratracheally instilled with MWCNT or carbon black (CB) nanoparticles 24 hours later. Pulmonary fibrosis was observed 21 days after MWCNT exposure, but not with CB. LPS alone caused no fibrosis but enhanced MWCNT-induced fibrosis. LPS plus CB did not significantly increase fibrosis. MWCNT increased platelet-derived growth factor-AA (PDGF-AA), a major mediator of fibrosis. PDGF-AA production in response to MWCNT, but not CB, was synergistically enhanced by LPS. Immunostaining showed PDGF-AA in bronchiolar epithelial cells and macrophages. Since macrophages engulfed MWCNT, were positive for PDGF-AA, and mediate fibroblast responses, experiments were performed with rat lung macrophages (NR8383 cells) and rat lung fibroblasts in vitro. LPS exposure increased PDGF-A mRNA levels in NR8383 cells and enhanced MWCNT-induced PDGF-A mRNA levels. Moreover, LPS increased MWCNT- or CB-induced PDGF receptor-alpha (PDGF-Ralpha) mRNA in fibroblasts. Our data suggest that LPS exacerbates MWCNT-induced lung fibrosis by amplifying production of PDGF-AA in macrophages and epithelial cells, and by increasing PDGF-Ralpha on pulmonary fibroblasts. Our findings also suggest that individuals with pre-existing pulmonary inflammation are at greater risk for the potential adverse effects of MWCNT.
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Affiliation(s)
- Mark F Cesta
- Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, 27695-7633, USA
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Ferwerda B, McCall MB, Verheijen K, Kullberg BJ, van der Ven AJ, Van der Meer JW, Netea MG. Functional consequences of toll-like receptor 4 polymorphisms. Mol Med 2008; 14:346-52. [PMID: 18231573 DOI: 10.2119/2007-00135.ferwerda] [Citation(s) in RCA: 181] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 01/18/2008] [Indexed: 12/11/2022] Open
Abstract
Toll-like receptor 4 (TLR4) is an important pathogen recognition receptor that recognizes mainly lipopolysaccharide (LPS) of Gram-negative bacteria, but also structures from fungal and mycobacterial pathogens, as well as endogenous ligands. Two nonsynonymous polymorphisms of TLR4, Asp299Gly and Thr399Ile, have been suggested to alter the function of the receptor. Some, but not all, studies have proposed that these polymorphisms lead to reduced cytokine response and increased susceptibility to Gram-negative infections. In this review, we compare studies that assessed the effect of the Asp299Gly and Thr399Ile polymorphisms on susceptibility to Gram-negative infections and examine the phenotypic consequences of these polymorphisms. In addition, we review the geographical distribution of TLR4 polymorphisms and present a model for evolutionary pressures on the TLR4 genetic make-up.
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Affiliation(s)
- Bart Ferwerda
- Department of Internal Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
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Charavaryamath C, Juneau V, Suri SS, Janardhan KS, Townsend H, Singh B. Role of Toll-like receptor 4 in lung inflammation following exposure to swine barn air. Exp Lung Res 2008; 34:19-35. [PMID: 18205075 DOI: 10.1080/01902140701807779] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The authors tested a hypothesis that lung inflammation and airway hyperresponsiveness (AHR) induced following barn air exposure are dependent on Toll-like receptor 4 (TLR4) by exposing C3HeB/FeJ (intact TLR4, wild type [WT]) and C3H/HeJ (defective TLR4, mutant) mice either to the barn air (8 hours/day for 1, 5, or 20 days) or ambient air. Both strains of mice, compared to their respective controls, showed increased AHR following 5 exposures but dampened AHR after 20 exposures to show lack of effect of TLR4 on AHR. However, swine barn air induced lung inflammation with recruitment of inflammatory cells and cytokine expression was observed in WT but not in mutant mice. These data show different roles of TLR4 in lung inflammation and AHR in mice exposed to swine barn air.
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Affiliation(s)
- Chandrashekhar Charavaryamath
- Immunology Research Group, and Department of Veterinary Biomedical Sciences, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, Canada
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Marsik C, Jilma B, Joukhadar C, Mannhalter C, Wagner O, Endler G. The Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms influence the late inflammatory response in human endotoxemia. Clin Chem 2005; 51:2178-80. [PMID: 16244296 DOI: 10.1373/clinchem.2005.051649] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Claudia Marsik
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
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Vandenbulcke L, Bachert C, Van Cauwenberge P, Claeys S. The innate immune system and its role in allergic disorders. Int Arch Allergy Immunol 2005; 139:159-65. [PMID: 16388196 DOI: 10.1159/000090393] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND There has been an increasing prevalence of allergic diseases in the Western world over the last decades. The hygiene hypothesis has been proposed as a possible explanation for this epidemical trend in allergy. A key role in this theory is assigned to the reduced microbial stimulation of the Toll-like receptors (TLRs) in early life, which could lead to a weaker Th1 response and a stronger Th2 response to allergens. The individual immunological response is determined by the interplay between the dose and timing of exposure to endotoxins, other environmental factors and genetic predisposition. In the development and progression of allergic disorders, the innate immune system plays an important role. OBJECTIVE In this review, we discuss the paradoxical effects that may appear when the innate immune components are triggered. We review the influence of changes in the gene sequence and TLR expression in relation to the overall pattern of commensals and pathogens. We explored the possibility of alternative stimulations of the immune system by CpG oligodeoxynucleotides and probiotics as therapeutic devices against this endemic disease in Western society. METHODS Selection of papers was based on the importance of their contribution to the understanding of innate immunity and its implications. RESULTS AND CONCLUSION The innate immune system plays an important role in both the protection against and the enhancement of allergic disorders, but the mechanisms are still unclear. Nevertheless, gene polymorphisms and triggers of the innate immune system provide therapeutic targets for protection against and treatment of allergic disorders.
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Affiliation(s)
- Liesbet Vandenbulcke
- Upper Airways Research Laboratory, Department of Otorhinolaryngology, Ghent University, Ghent, Belgium.
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Spaan S, Wouters IM, Oosting I, Doekes G, Heederik D. Exposure to inhalable dust and endotoxins in agricultural industries. ACTA ACUST UNITED AC 2005; 8:63-72. [PMID: 16395461 DOI: 10.1039/b509838f] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Endotoxin is a well-known bacterial toxin that causes several health effects. Animal faeces and plant materials contaminated with bacteria have been identified as important determinants of organic dust related endotoxin exposure. Although high exposure to organic dust and endotoxins has been described regularly in agricultural industries, a detailed overview of levels of airborne exposure to endotoxins in the agricultural industry, as well as a systematic comparison between several specific branches using the same exposure assessment protocols are lacking. In this study, personal endotoxin exposure in a broad spectrum of agricultural industries was investigated and possible determinants of exposure were explored. 601 personal inhalable dust samples were taken in 46 companies of three agricultural industrial sectors: grains, seeds and legumes sector (GSL), horticulture sector (HC) and animal production sector (AP), with 350 participating employees. Dust and endotoxin levels were determined gravimetrically and by using the Limulus Amoebocyte Lysate (LAL) assay, respectively. Basic descriptive analysis and elaborate analysis of variance were performed. Mean exposure levels were high, with large differences between sectors and between companies within the sectors. Highest dust and endotoxin exposures were found in companies of the GSL sector. In all three sectors exposure was higher in the primary production part compared to the (industrial) products processing part of the sector. The Dutch proposed health based occupational exposure limit (50 EU m(-3)) and temporary legal limit (200 EU m(-3)) for endotoxin were often exceeded. Differences in exposure between workers were larger than the day-to-day variability. Identified determinants increasing exposure levels were company, dustiness of the product and contact with animals/faeces. 'Wet' processes resulted in less dusty working environments and thus lowered endotoxin exposure. Overall, exposure to endotoxins over the whole range of agricultural industries is high. A 10-1,000 fold reduction in exposure is needed to reduce endotoxin related health risks.
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Affiliation(s)
- Suzanne Spaan
- Division of Environmental and Occupational Health, Institute for Risk Assessment Sciences, University of Utrecht, PO Box 80176, 3508 TD Utrecht, The Netherlands.
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Gangloff SC, Guenounou M. Toll-like receptors and immune response in allergic disease. Clin Rev Allergy Immunol 2004; 26:115-25. [PMID: 15146108 DOI: 10.1007/s12016-004-0006-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Allergic reactions are dominated by the preferential development of specific Th2 responses against innocuous antigens in atopic individuals. This can reflect alterations in innate immune mechanisms. Toll-like receptors (TLRs) have evolved as key molecules in innate and adaptive immunity. Their activation by structurally distinct exogenous or endogenous ligands present at the cell microenvironment plays a critical role in antimicrobial defense. The global view is that TLR activation induces antigen-presenting cells to produce cytokines that favor Th1-type immune responses, suggesting that it might prevent the development of deleterious Th2 responses in allergy. On the basis of epidemiological studies and recent data, it has been established that TLRs play a role in the development of Th2 responses. However, more information is needed to fully understand the mechanism of TLR involvement and the implication of immune cells that express TLRs in the Th1/Th2 cytokine profiles. Several TLRs, such as TLR9, TLR7, and TLR8, can be considered as good target candidates. Some TLR ligands, such as CpG DNA, are effective adjuvants, strong inducers of both IL-5 and eosinophilia downregulation. They are also potential links to allergen epitopes that could provide new allergen-specific immunotherapy regimens for the treatment of allergic disorders.
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Affiliation(s)
- Sophie C Gangloff
- Department of Immunology and Microbiology, University of Reims Champagne-Ardenne, Reims, France.
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Punturieri A, Alviani RS, Polak T, Copper P, Sonstein J, Curtis JL. Specific engagement of TLR4 or TLR3 does not lead to IFN-beta-mediated innate signal amplification and STAT1 phosphorylation in resident murine alveolar macrophages. THE JOURNAL OF IMMUNOLOGY 2004; 173:1033-42. [PMID: 15240691 PMCID: PMC2701405 DOI: 10.4049/jimmunol.173.2.1033] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The innate immune response must be mobilized promptly yet judiciously via TLRs to protect the lungs against pathogens. Stimulation of murine peritoneal macrophage (PMphi) TLR4 or TLR3 by pathogen-associated molecular patterns (PAMPs) typically induces type I IFN-beta, leading to autocrine activation of the transcription factor STAT1. Because it is unknown whether STAT1 plays a similar role in the lungs, we studied the response of resident alveolar macrophages (AMphi) or control PMphi from normal C57BL/6 mice to stimulation by PAMPs derived from viruses (polyriboinosinic:polyribocytidylic acid, specific for TLR3) or bacteria (Pam(3)Cys, specific for TLR2, and repurified LPS, specific for TLR4). AMphi did not activate STAT1 by tyrosine phosphorylation on Y701 following stimulation of any of these three TLRs, but readily did so in response to exogenous IFN-beta. This unique AMphi response was not due to altered TLR expression, or defective immediate-early gene response, as measured by expression of TNF-alpha and three beta chemokines. Instead, AMphi differed from PMphi in not producing bioactive IFN-beta, as confirmed by ELISA and by the failure of supernatants from TLR-stimulated AMphi to induce STAT1 phosphorylation in PMphi. Consequently, AMphi did not produce the microbicidal effector molecule NO following TLR4 or TLR3 stimulation unless exogenous IFN-beta was also added. Thus, murine AMphi respond to bacterial or viral PAMPs by producing inflammatory cytokines and chemokines, but because they lack the feed-forward amplification typically mediated by autocrine IFN-beta secretion and STAT1 activation, require exogenous IFN to mount a second phase of host defense.
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Affiliation(s)
- Antonello Punturieri
- Pulmonary and Critical Care Medicine Section, and Research Service, Department of Veterans Affairs Medical Center, Ann Arbor, MI 48105, USA.
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Lorenz E, Patel DD, Hartung T, Schwartz DA. Toll-like receptor 4 (TLR4)-deficient murine macrophage cell line as an in vitro assay system to show TLR4-independent signaling of Bacteroides fragilis lipopolysaccharide. Infect Immun 2002; 70:4892-6. [PMID: 12183533 PMCID: PMC128243 DOI: 10.1128/iai.70.9.4892-4896.2002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial lipopolysaccharides (LPS) activate cells of innate immunity, such as macrophages, by stimulating signaling through toll-like receptor 4 (TLR4). We and others have hypothesized that LPS derived from different bacterial species may function through TLR4-independent mechanisms. To test this hypothesis, we have generated using a nonviral transformation procedure a bone marrow-derived macrophage cell line called 10ScNCr/23 from mouse strain C57BL/10ScNCr. This mouse strain has a deletion of the TLR4 locus, causing the mouse strain to be nonresponsive to stimulation by LPS from Escherichia coli while responding normally to other bacterial substrates, such as lipoteichoic acid (LTA) from Staphylococcus aureus, which signal TLR4 independently. Stimulation with LTA induces five- and sixfold increases in 10ScNCr/23 cell line tumor necrosis factor alpha and macrophage inflammatory protein-2 (MIP-2) secretion, but no increases in either cytokine were found when cells were stimulated with E. coli LPS. Bacteroides fragilis-derived LPS, however, can effectively stimulate MIP-2 expression in the absence of functional TLR4 in the 10ScNCr/23 cell line. This gives rise to the notion that LPS from some bacterial species will utilize alternative receptors to stimulate the innate immune response.
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Affiliation(s)
- Eva Lorenz
- Department of Internal Medicine, Section of Infectious Diseases, Wake Forest University Medical Center, Winston-Salem, NC, USA.
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