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Poole JA, Zamora-Sifuentes JL, De Las Vecillas L, Quirce S. Respiratory Diseases Associated With Organic Dust Exposure. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2024:S2213-2198(24)00196-X. [PMID: 38423290 DOI: 10.1016/j.jaip.2024.02.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 03/02/2024]
Abstract
Organic dusts are complex bioaerosol mixtures comprised of dust and par ticulate matter of organic origin. These include components from bacteria, fungi, pollen, and viruses to fragments of animals and plants commonplace to several environmental/occupational settings encompassing agriculture/farming, grain processing, waste/recycling, textile, cotton, woodworking, bird breeding, and more. Organic dust exposures are linked to development of chronic bronchitis, chronic obstructive pulmonary disease, asthma, asthma-like syndrome, byssinosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis. Risk factors of disease development include cumulative dust exposure, smoking, atopy, timing/duration, and nutritional factors. The immunopathogenesis predominantly involves Toll-like receptor signaling cascade, T-helper 1/T-helper 17 lymphocyte responses, neutrophil influx, and potentiation of manifestations associated with allergy. The true prevalence of airway disease directly attributed to organic dust, especially in a workplace setting, remains challenging. Diagnostic confirmation can be difficult and complicated by hesitancy from workers to seek medical care, driven by fears of potential labor-related consequence. Clinical respiratory and systemic presentations coupled with allergy testing, lung function patterns of obstructive versus restrictive disease, and radiological characteristics are typically utilized to delineate these various organic dust-associated respiratory diseases. Prevention, risk reduction, and management primarily focus on reducing exposure to the offending dust, managing symptoms, and preventing disease progression.
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Affiliation(s)
- Jill A Poole
- Division of Allergy & Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Neb.
| | - Jose L Zamora-Sifuentes
- Division of Allergy & Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Neb
| | | | - Santiago Quirce
- Department of Allergy, La Paz University of Hospital, IdiPAZ, Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
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Plombon S, Henneberger PK, Humann MJ, Liang X, Doney BC, Kelly KM, Cox-Ganser JM. The association of chronic bronchitis and airflow obstruction with lifetime and current farm activities in a sample of rural adults in Iowa. Int Arch Occup Environ Health 2022; 95:1741-1754. [PMID: 35482110 PMCID: PMC10424266 DOI: 10.1007/s00420-022-01866-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/04/2022] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Farmers have an increased risk for chronic bronchitis and airflow obstruction. The objective of this study was to investigate the association of these health outcomes with farm activities. METHODS We evaluated the Keokuk County Rural Health Study (KCRHS) enrollment data for farm activities and the two health outcomes chronic bronchitis based on self-reported symptoms and airflow obstruction based on spirometry. We used logistic regression to model the health outcomes, yielding an odds ratio (OR) and 95% confidence interval (95% CI) for farm activities while adjusting for potential confounders and other risk factors. RESULTS Of the 1234 farmers, 104 (8.4%) had chronic bronchitis, 75 (6.1%) fulfilled the criteria for airflow obstruction, and the two outcomes overlapped by 18 participants. Chronic bronchitis without airflow obstruction (n = 86) had a statistically significant association with crop storage insecticides (OR 3.1, 95% CI 1.6, 6.1) and a low number of years (≤ 3) worked with turkeys (OR 3.3, 95% CI 1.2, 9.4). The latter result should be interpreted with caution because it is based on a small number of cases (n = 5). Airflow obstruction with or without chronic bronchitis (n = 75) was significantly associated with ever working in a hog or chicken confinement setting (OR 2.2, 95% CI 1.0, 4.5). CONCLUSIONS These results suggest that work with crop storage insecticides or turkeys may increase the risk for chronic bronchitis and work in hog or chicken confinement may increase the risk for airflow obstruction.
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Affiliation(s)
- Savanna Plombon
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS H2900, 1000 Frederick Lane, Morgantown, WV, 26508, USA
| | - Paul K Henneberger
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS H2900, 1000 Frederick Lane, Morgantown, WV, 26508, USA.
| | - Michael J Humann
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS H2900, 1000 Frederick Lane, Morgantown, WV, 26508, USA
| | - Xiaoming Liang
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS H2900, 1000 Frederick Lane, Morgantown, WV, 26508, USA
| | - Brent C Doney
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS H2900, 1000 Frederick Lane, Morgantown, WV, 26508, USA
| | - Kevin M Kelly
- Department of Occupational and Environmental Health, The University of Iowa, Iowa City, IA, USA
| | - Jean M Cox-Ganser
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS H2900, 1000 Frederick Lane, Morgantown, WV, 26508, USA
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Korytina GF, Akhmadishina LZ, Kochetova OV, Aznabaeva YG, Izmailova SM, Zagidullin SZ, Victorova TV. Association of CRP, CD14, Pro-Inflammatory Cytokines and Their Receptors (TNFA, LTA, TNFRSF1A, TNFRSF1B, IL1B, and IL6) Genes with Chronic Obstructive Pulmonary Disease Development. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420080086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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LeVan TD, Smith LM, Heires AJ, Mikuls TR, Meza JL, Weissenburger-Moser LA, Romberger DJ. Interaction of CD14 haplotypes and soluble CD14 on pulmonary function in agricultural workers. Respir Res 2017; 18:49. [PMID: 28302109 PMCID: PMC5353891 DOI: 10.1186/s12931-017-0532-y] [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: 01/28/2017] [Accepted: 03/07/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Agricultural environments are contaminated with organic dusts containing bacterial components. Chronic inhalation of organic dusts is implicated in respiratory diseases. CD14 is a critical receptor for gram-negative lipopolysaccharide; however, its association with respiratory disease among agricultural workers is unknown. The objective of this study was to determine if serum soluble CD14 (sCD14) levels are associated with lung function among agricultural workers and if this association is modified by genetic variants in CD14. METHODS This cross-sectional study included 584 veterans with >2 years of farming experience and that were between the ages of 40 and 80 years. Participants underwent spirometry and were genotyped for four tagging CD14 polymorphisms (CD14/-2838, rs2569193; CD14/-1720, rs2915863; CD14/-651, rs5744455; and CD14/-260, rs2569190). Serum sCD14 was assayed by ELISA. RESULTS Subjects were 98% white males with a mean age 64.5 years. High soluble CD14 levels (> median sCD14) were associated decreased lung function (FEV1/FVC, p = 0.011; % predicted FEV1, p = 0.03). When stratified by COPD (yes/no) and smoking status (ever/never), high sCD14 levels (> median sCD14) were associated with low lung function among ever smokers with COPD (% predicted FEV1, padj = 0.0008; FEV1/FVC, padj = 0.0002). A similar trend was observed for never smokers with COPD; however, results did not reach statistical significance due to small sample size. There was a significant sCD14 x COPD/smoking interaction with lung function (% predicted FEV1, pinter = 0.0498; FEV1/FVC, pinter = 0.011). Regression models were adjusted for age, body mass index, education, sex, race and years worked on a farm. No association was found between CD14 polymorphisms/haplotypes (CD14/-2838; CD14/-1720; CD14/-651; CD14/-260) and sCD14 levels. The final model included the variables sCD14 and haplotypes and a haplotype x sCD14 interaction term. Individuals with the GTTG haplotype (CD14/-2838 → CD14/-260) and high sCD14 levels (> median sCD14) had on average 6.94 lower % predicted FEV1 than individuals with the GCCA haplotype and low sCD14 levels (≤ median sCD14, padj = 0.03). CONCLUSION CD14 haplotypes and sCD14 are important mediators of lung function among those with COPD in this occupationally-exposed population.
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Affiliation(s)
- Tricia D LeVan
- Department of Epidemiology, University of Nebraska Medical Center, 985910, Omaha, NE, 68198-5910, USA. .,Department of Internal Medicine and Veterans Nebraska Western Iowa Healthcare System, Omaha, NE, USA.
| | - Lynette M Smith
- Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE, USA
| | - Art J Heires
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ted R Mikuls
- Department of Internal Medicine and Veterans Nebraska Western Iowa Healthcare System, Omaha, NE, USA
| | - Jane L Meza
- Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Debra J Romberger
- Department of Internal Medicine and Veterans Nebraska Western Iowa Healthcare System, Omaha, NE, USA
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Makamure MT, Reddy P, Chuturgoon A, Naidoo RN, Mentz G, Batterman S, Robins TG. Interaction between ambient pollutant exposure, CD14 (-159) polymorphism and respiratory outcomes among children in Kwazulu-Natal, Durban. Hum Exp Toxicol 2016; 36:238-246. [PMID: 27142357 DOI: 10.1177/0960327116646620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The objective of this study was to determine if the association between exposure to ambient air pollutants such as sulfur dioxide, nitrogen dioxde (NO2), nitrous oxide (NO), and PM10, and variation in lung function measures was modified by genotype. A validated questionnaire was administered to 71 African children to evaluate prevalence of respiratory symptoms. Atopy was evaluated by skin-prick testing and bihourly measures of lung function (spirometry) were collected. Gaseous air pollutant concentrations were monitored continuously. CD14 polymorphism was genotyped and plasma CD14 levels were measured. There was no statistically significant association between the CD14 (159) CT+TT polymorphism with any asthma-related phenotype. There was a significant association between lung function (forced expiratory volume in 1 second intraday variability) and NO2 and NO among participants carrying the CD14 CT/TT genotype for lags 1, 2, and the 5-day average. Similarly, statistically significant gene-pollutant interactions ( p < 0.05) were found with NO and CD14 CT/TT at lag 2 and for the 5-day average. While there was no association with any respiratory phenotype (as determined by symptoms), the CD14 CT/TT genotype appeared to be protective to increased exposure to NO2 and NO.
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Affiliation(s)
- M T Makamure
- 1 Department of Community Health Studies, Durban University of Technology, Durban, South Africa
| | - P Reddy
- 1 Department of Community Health Studies, Durban University of Technology, Durban, South Africa
| | - A Chuturgoon
- 2 Discipline of Medical Biochemistry, School of Laboratory Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - R N Naidoo
- 3 Discipline of Occupational and Environmental Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - G Mentz
- 4 Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI, USA
| | - S Batterman
- 4 Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI, USA
| | - T G Robins
- 4 Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI, USA
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Moghadampour M, Eskandari-Nasab E, Shabani F. Relationship between CD14-159C/T gene polymorphism and acute brucellosis risk. ASIAN PAC J TROP MED 2016; 9:247-51. [PMID: 26972395 PMCID: PMC7104939 DOI: 10.1016/j.apjtm.2016.01.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 12/20/2015] [Accepted: 12/30/2015] [Indexed: 12/19/2022] Open
Abstract
Objective To investigate the association between the cluster of differentiation 14 (CD14)-159C/T (rs2569190) gene polymorphism and susceptibility to acute brucellosis in an Iranian population. Methods The study included 153 Iranian patients with active brucellosis and 128 healthy individuals as the control group. Genotyping of the CD14 variant was performed using an amplification refractory mutation system-polymerase chain reaction method. Results The prevalence of CD14-159 TT and CT genotypes were associated with increased risk of brucellosis [odds ratio (OR) = 1.993, 95% confidence interval (95% CI) = 1.07–3.71, P = 0.03 for CT; OR = 3.869, 95% CI = 1.91–7.84, P = 0.01 for TT genotype. Additionally, the minor allele (T) was significantly more frequently present in brucellosis patients than in controls (61% vs. 45%, respectively), and was a risk factor for brucellosis (OR = 3.058, 95% CI = 1.507–6.315, P = 0.01). Conclusions The findings provided suggestive evidence of association of the CD14-159C/T gene polymorphism with susceptibility to acute brucellosis in the Iranian population.
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Affiliation(s)
- Mehdi Moghadampour
- Department of Microbiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran; Infectious Diseases and Tropical Medicine Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Ebrahim Eskandari-Nasab
- Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran; Genetic of Non-Communicable Disease Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
| | - Fatemeh Shabani
- School of Medicine, Jiroft University of Medical Sciences, Jiroft, Kerman, Iran
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Basinas I, Sigsgaard T, Kromhout H, Heederik D, Wouters IM, Schlünssen V. A comprehensive review of levels and determinants of personal exposure to dust and endotoxin in livestock farming. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2015; 25:123-37. [PMID: 24280684 DOI: 10.1038/jes.2013.83] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 06/24/2013] [Indexed: 05/21/2023]
Abstract
The respiratory health effects of livestock farming have been on debate for more than three decades. Endotoxin-contaminated organic dusts are considered as the most important respiratory hazards within livestock environments. A comprehensive review of the knowledge from studies assessing the exposure status of livestock farmers is still to be published. The present study reviews research published within the last 30 years on personal exposure of livestock farmers to organic dust and endotoxin, focusing on studies on pig, poultry and cattle farmers. Applied measurement methods and reported levels of personal exposure for the total, inhalable and respirable fractions are summarized and discussed, with emphasis on the intensity of exposure and the size and distribution of the reported exposure variability. In addition, available evidence on potential determinants of personal exposure to dust and endotoxin among these farmers are documented and discussed, taking results from exposure determinant studies using stationary sampling approaches into consideration. Research needs are addressed from an epidemiological and industrial hygiene perspective. Published studies have been heterogeneous in design, and applied methodologies and results were frequently inadequately reported. Despite these limitations and the presence of an enormous variability in personal exposure to dust and endotoxin, no clear downward trends in exposure with time were observed, suggesting that working environments within stables remains largely uncontrolled. Exposure control and prevention strategies for livestock farmers are urgently required. These should focus on the development of novel and improved methods of controlling dust and endotoxin exposure within stables based on the currently available knowledge on determinants of exposure.
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Affiliation(s)
- Ioannis Basinas
- Section for Environment, Occupation and Health, Department of Public Health, Danish Ramazzini Center, Aarhus University, Aarhus, Denmark
| | - Torben Sigsgaard
- Section for Environment, Occupation and Health, Department of Public Health, Danish Ramazzini Center, Aarhus University, Aarhus, Denmark
| | - Hans Kromhout
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| | - Dick Heederik
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| | - Inge M Wouters
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| | - Vivi Schlünssen
- Section for Environment, Occupation and Health, Department of Public Health, Danish Ramazzini Center, Aarhus University, Aarhus, Denmark
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Baatjies R, Meijster T, Heederik D, Jeebhay MF. Exposure-response relationships for inhalant wheat allergen exposure and asthma. Occup Environ Med 2014; 72:200-7. [PMID: 25535033 DOI: 10.1136/oemed-2013-101853] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND A few studies have investigated exposure-response relationships for sensitisation to wheat, work-related symptoms and wheat allergen exposure. IgG4 is suggested to protect against the development of allergic sensitisation. The main aim of this current study was to explore the nature of exposure-response relationships for a range of clinically relevant endpoints among bakery workers, and to investigate the role of IgG4 in these relationships. METHODS A cross-sectional study of 517 supermarket bakery workers in 31 bakeries used a questionnaire, serum-specific IgE and IgG4 to wheat, and methacholine challenge testing. Exposure models were developed previously using job, bakery size, tasks and specific ingredients used. These models were used to predict average personal exposure to wheat allergens. RESULTS The exposure-response relationships for average exposure followed a linear relationship for sensitisation, but a bell-shaped curve for allergic symptoms and probable occupational asthma, increasing up to 10-15 µg/m(3) wheat allergen concentration after which they plateau off and decrease at higher exposure concentrations. This relationship was modified by atopic status. IgG4 levels were strongly exposure related: a clear increase in prevalence of higher IgG4 with increase in wheat allergen exposure was observed among those sensitised and non-sensitised to wheat, with IgG4 even more strongly associated with exposure than IgE to wheat. CONCLUSIONS The bell-shaped exposure-response relationship in the current study is consistent with the findings of previous studies. IgG4 showed no protective effect for sensitisation, confirming the findings of previous studies, suggesting that the pattern is probably related to a healthy worker effect.
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Affiliation(s)
- R Baatjies
- Faculty of Applied Sciences, Department of Environmental and Occupational Studies, Cape Peninsula University of Technology, Cape Town, Western Cape, South Africa Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, Western Cape, South Africa
| | - T Meijster
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - D Heederik
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - M F Jeebhay
- Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, Western Cape, South Africa
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Wells AD, Poole JA, Romberger DJ. Influence of farming exposure on the development of asthma and asthma-like symptoms. Int Immunopharmacol 2014; 23:356-63. [PMID: 25086344 DOI: 10.1016/j.intimp.2014.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/09/2014] [Accepted: 07/11/2014] [Indexed: 12/24/2022]
Abstract
Based upon age and type of farming exposures, a wide range of studies demonstrate either protective or deleterious effects of the farming environment on asthma. In this review, we highlight key studies supporting the concept that farming exposure protects children from asthma and atopy based on studies performed largely in European pediatric cohorts. Various types of farming in certain regions appear to have a greater effect on asthma protection, as does the consumption of unpasteurized milk. In the United State, where concentrated animal feeding operations (CAFOs) are more common, asthma is increased in children exposed especially to swine CAFOs; whereas, rates of atopy and allergy are lower in these children. We also review studies evaluating the role of farming exposures both as a child and/or as an adult on asthma seen in adults. The importance of microbes in farming environments and the contribution of various components of the innate immune system including toll-like receptors to the underlying mechanisms of asthma related to farming exposures are also reviewed.
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Affiliation(s)
- Adam D Wells
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Jill A Poole
- Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Debra J Romberger
- VA Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE 68105, USA; Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198-5990, USA
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Smit LAM. Respiratory health effects in agricultural workers: are some more susceptible than others? Expert Rev Respir Med 2014; 6:7-10. [DOI: 10.1586/ers.11.86] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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CD14 gene variants and their importance for childhood croup, atopy, and asthma. DISEASE MARKERS 2013; 35:765-71. [PMID: 24347797 PMCID: PMC3856132 DOI: 10.1155/2013/434920] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 10/01/2013] [Accepted: 10/09/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND The CD14 gene has an important role in the detection of inflammatory provoking pathogens and in the ensuing signaling of the innate immune response. We assessed the role of CD14 C-159T, G-1359T in the expression of asthma, croup, and allergy in Canadian school children of ages 6 to 14 years. METHODS Children attending schools in a rural community participated in a cross-sectional survey of respiratory health. Following consent, we conducted clinical assessments to collect buccal swabs for genotyping and perform skin prick testing (SPT) to determine atopic status. Genotyping and SPT results were available for 533 and 499 children, respectively. Separate multivariable analyses that included both polymorphisms were conducted for each phenotype. RESULTS The prevalence of asthma, allergy, and croup was 18.6%, 22.4%, and 6.6%, respectively. Children with the T/T variant of CD14 G-1359T were more likely to have physician diagnosed asthma (26.8%). Children with C/C variant of CD14 C-159T had a significantly lower prevalence of croup (2.6%). Haplotype analyses of the two CD14 polymorphisms showed that individuals with the T|T haplotype combination were significantly more likely to have asthma (P = 0.014). CONCLUSIONS In this study, CD14 variants are important for the expression of croup and asthma but not atopy.
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Pulmonary function reductions among potentially susceptible subgroups of agricultural workers in Colorado and Nebraska. J Occup Environ Med 2012; 54:632-41. [PMID: 22576462 DOI: 10.1097/jom.0b013e31824d2e1c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Organic dust inhalation has been associated with adverse respiratory responses among agricultural workers. We evaluated factors that may confer increased susceptibility to these health effects. METHODS We quantified personal work shift exposures to inhalable dust, endotoxin, and its 3-hydroxy fatty acid constituents, and evaluated changes in pulmonary function among 137 grain elevator, cattle feedlot, dairy, and corn farm workers. RESULTS Increased dust exposure was associated with work shift reductions in lung function. Although interpretation is limited because of small samples, a suggestion of stronger exposure-response relationships was observed among smokers, as well as workers reporting pesticide/herbicide application, asthma, or allergies, and those with genetic polymorphisms (TLR4) (Pinteraction ≤ 0.05). CONCLUSIONS A better understanding of factors leading to increased susceptibility of adverse respiratory outcomes is needed to optimize exposure reduction strategies and develop more comprehensive wellness programs.
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Poole JA. Farming-associated environmental exposures and effect on atopic diseases. Ann Allergy Asthma Immunol 2012; 109:93-8. [PMID: 22840248 DOI: 10.1016/j.anai.2011.12.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 12/22/2022]
Affiliation(s)
- Jill A Poole
- Pulmonary, Critical Care, Sleep, and Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198-5300, USA.
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Abstract
A genetic contribution to develop chronic obstructive pulmonary disease (COPD) is well established. However, the specific genes responsible for enhanced risk or host differences in susceptibility to smoke exposure remain poorly understood. The goal of this review is to provide a comprehensive literature overview on the genetics of COPD, highlight the most promising findings during the last few years, and ultimately provide an updated COPD gene list. Candidate gene studies on COPD and related phenotypes indexed in PubMed before January 5, 2012 are tabulated. An exhaustive list of publications for any given gene was looked for. This well-documented COPD candidate-gene list is expected to serve many purposes for future replication studies and meta-analyses as well as for reanalyzing collected genomic data in the field. In addition, this review summarizes recent genetic loci identified by genome-wide association studies on COPD, lung function, and related complications. Assembling resources, integrative genomic approaches, and large sample sizes of well-phenotyped subjects is part of the path forward to elucidate the genetic basis of this debilitating disease.
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Affiliation(s)
- Yohan Bossé
- Centre de recherche Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, Canada.
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Xue Y, Zhao ZQ, Chen F, Zhang L, Li GD, Ma KW, Bai XF, Zuo YJ. Polymorphisms in the promoter of the CD14 gene and their associations with susceptibility to pulmonary tuberculosis. ACTA ACUST UNITED AC 2012; 80:437-43. [PMID: 22937756 DOI: 10.1111/j.1399-0039.2012.01958.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/12/2012] [Accepted: 08/13/2012] [Indexed: 10/27/2022]
Abstract
Although the role of CD14 in recognizing Mycobacterium tuberculosis is well-understood, the possible role of polymorphisms in susceptibility to develop tuberculosis remains unclear. This study evaluates whether there is an association of polymorphisms within the promoter of the CD14 gene with susceptibility to pulmonary tuberculosis. In a case-control study, we genotyped the eight known single nucleotide polymorphisms SNPs within the promoter of the CD14 gene of 698 Han Chinese subjects. Statistically significant differences between tuberculosis patients and healthy controls were found for G-1619A, T-1359G, A-1145G, and C-159T. The haplotype-GGGT, composed of these four SNPs, exhibited a significant association with the disease. Furthermore, expression levels of soluble CD14 were significantly higher in tuberculosis patients with the GGGT haplotype than with other haplotypes, while IgE expression levels were significantly reduced. Our results suggest that these four SNPs within the promoter of the CD14 gene are associated with susceptibility to pulmonary tuberculosis.
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Affiliation(s)
- Y Xue
- Laboratory of Medical Engineering, College of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, Henan, China
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Abstract
PURPOSE OF REVIEW Agriculture represents a major industry worldwide, and despite protection against the development of IgE-mediated diseases, chronic exposure to agriculture-related organic dusts is associated with an increased risk of developing respiratory disease. This article will review the literature regarding new knowledge of important etiologic agents in the dusts and focus on the immunologic responses following acute and repetitive organic dust exposures. RECENT FINDINGS Although endotoxin remains important, there is an emerging role of nonendotoxin components such as peptidoglycans from Gram-positive bacteria. Pattern recognition receptors including Toll-like receptor 4 (TLR4), TLR2 and intracellular nucleotide oligomerization domain-like receptors are partially responsible for mediating the inflammatory consequences. Repeated organic dust exposures modulate innate and adaptive immune function with a resultant adaptation-like response. However, repetitive exposures cause lung parenchymal inflammation, chronic disease, and lung function decline over time. SUMMARY The immunological consequences of organic dust exposure in the farming industry are likely explained by the diversity of microbial motifs in dust that can elicit differing innate immune receptor signaling pathways. Whereas initial activation results in a robust inflammatory response, repetitive dust exposures modulate immunity. This can result in low-grade, chronic inflammation, and/or protection against allergic disease.
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Different implications of paternal and maternal atopy for perinatal IgE production and asthma development. Clin Dev Immunol 2012; 2012:132142. [PMID: 22272211 PMCID: PMC3261469 DOI: 10.1155/2012/132142] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/03/2011] [Indexed: 12/16/2022]
Abstract
Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-beta are associated with lung function and allergic sensitization, respectively. In IgE production and asthma development, the maternal influence on gene-environment interaction is greater than paternal influence. Maternal, paternal, and/or postnatal environmental modulation of allergic responses have been linked to epigenetic mechanisms, which may be good targets for early prevention of asthma.
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May S, Romberger DJ, Poole JA. Respiratory health effects of large animal farming environments. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2012; 15:524-41. [PMID: 23199220 PMCID: PMC4001716 DOI: 10.1080/10937404.2012.744288] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
With increases in large animal-feeding operations to meet consumer demand, adverse upper and lower respiratory health effects in exposed agriculture workers are a concern. The aim of this study was to review large animal confinement feeding operational exposures associated with respiratory disease with a focus on recent advances in the knowledge of causative factors and cellular and immunological mechanisms. A PubMed search was conducted with the keywords airway, farm, swine, dairy, horse, cattle inflammation, organic dust, endotoxin, and peptidoglycan, among items were published between 1980 and now. Articles were selected based on their relevance to environmental exposure and reference to airway diseases. Airway diseases included rhinitis, sinusitis, mucus membrane inflammation syndrome, asthma, chronic bronchitis, chronic obstructive pulmonary disease, hypersensitivity pneumonitis, and organic dust toxic syndrome. There is lower prevalence of immunoglobulin (Ig) E-mediated asthma and atopy in farmers and their children, but organic dust worsens existing asthma. Multiple etiologic factors are linked to disease, including allergens, organic dusts, endotoxins, peptidoglycans, and gases. Large animal confinement feeding operations contain a wide diversity of microbes with increasing focus on gram-positive bacteria and archaebacteria as opposed to gram-negative bacteria in mediating disease. Toll-like receptors (TLR) and nucleotide oligomerization domain (NOD)-like innate immune pathways respond to these exposures. Finally, a chronic inflammatory adaptation, tolerance-like response in chronically exposed workers occurs. Large animal confinement farming exposures produce a wide spectrum of upper and lower respiratory tract diseases due to the complex diversity of organic dust, particulates, microbial cell wall components, and gases and resultant activation of various innate immune receptor signaling pathways.
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Affiliation(s)
- Sara May
- Pulmonary, Critical Care, Sleep & Allergy Division; Department of Internal Medicine,; University of Nebraska Medical Center, 985300 The Nebraska Medical Center, Omaha, NE 68198-5300
| | - Debra J. Romberger
- Pulmonary, Critical Care, Sleep & Allergy Division; Department of Internal Medicine,; University of Nebraska Medical Center, 985300 The Nebraska Medical Center, Omaha, NE 68198-5300
- Veterans Administration Nebraska Western Iowa Healthcare System, Omaha, NE, 4101 Woolworth Ave., 68105
| | - Jill A. Poole
- Pulmonary, Critical Care, Sleep & Allergy Division; Department of Internal Medicine,; University of Nebraska Medical Center, 985300 The Nebraska Medical Center, Omaha, NE 68198-5300
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Sutoluk Z, Kekec Z, Daglioglu N, Hant I. Association of chronic pesticide exposure with serum cholinesterase levels and pulmonary functions. ARCHIVES OF ENVIRONMENTAL & OCCUPATIONAL HEALTH 2011; 66:95-99. [PMID: 24484366 DOI: 10.1080/19338244.2010.506496] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The present study focused on the analysis of serum cholinesterase levels and the pulmonary function tests in seasonal farm workers who were chronically exposed to pesticides, mostly organophosphorus, in comparison with non-farm workers in the farming areas of Cukurova region, Turkey. Serum cholinesterase levels and pulmonary function tests using spyrometer in 50 male seasonal farm workers (study group) were compared to 50 male non-farm workers (control group) in this cross-sectional study. The mean serum cholinesterase enzyme level in the farm worker group (7095.5 ± 1699.4 U/L) was significantly lower than those of the control group (9716.4 ± 1484.4 U/L) (p < .001). There was no significant difference between pulmonary function tests of 2 groups (p > .05). These results show that chronic environmental organophosphorus exposure caused a decrease in the serum cholinesterase enzyme levels in farm workers, emphasizing the importance of primary prevention.
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Affiliation(s)
- Zeynel Sutoluk
- a Department of Public Health , Cukurova University Adana Turkey
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Mehta AJ, Malloy EJ, Applebaum KM, Schwartz J, Christiani DC, Eisen EA. Reduced lung cancer mortality and exposure to synthetic fluids and biocide in the auto manufacturing industry. Scand J Work Environ Health 2010; 36:499-508. [PMID: 20835688 PMCID: PMC4108426 DOI: 10.5271/sjweh.3088] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVES Water-based soluble and synthetic metalworking fluids (MWF) used in auto manufacturing may be contaminated by endotoxin from Gram-negative bacteria, a possible anticarcinogen via increased immuno-surveillance. The effectiveness of biocide, generally added to limit bacterial growth is unknown. We investigated whether an inverse relationship between lung cancer and synthetic MWF and biocide - as surrogates of endotoxin exposure - persisted in an extended follow-up of autoworkers. METHODS A nested case-control analysis was performed within a retrospective cohort study of 46 399 auto manufacturing workers. Follow-up began in 1941 and was extended from 1985-1995. Mortality rate ratios (MRR) were estimated in Cox regression models for lung cancer as discrete and smoothed functions of cumulative exposure to synthetic MWF (mg/m (3)per year) and years exposed to biocide with both synthetic and soluble MWF. The analysis was also restricted to the subcohort hired on or after 1941 and stratified by follow-up period. RESULTS The splines suggested a non-linear inverse exposure-response for lung cancer mortality with increasing endotoxin exposure. Overall, the greatest reduction in mortality was observed among those with the highest exposure [MRR 0.63, 95% confidence interval (95% CI) 0.39-0.98] at the 99 (th)percentile of exposure (15.8 mg/m (3)per year). Evidence for an inverse effect was limited to the earlier follow-up period. Effect modification by biocide was marginally significant (P=0.07); the protective effect of synthetic MWF was observed only for those who were co-exposed. CONCLUSIONS The protective effect of synthetic MWF against lung cancer mortality persisted through the extended period of follow-up, although attenuated, and was observed only among workers with co-exposure to biocide and synthetic MWF.
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Affiliation(s)
- Amar J Mehta
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Switzerland.
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Pacheco KA, Rose CS, Silveira LJ, Van Dyke MV, Goelz K, MacPhail K, Maier LA. Gene-environment interactions influence airways function in laboratory animal workers. J Allergy Clin Immunol 2010; 126:232-40. [PMID: 20579716 DOI: 10.1016/j.jaci.2010.04.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 03/27/2010] [Accepted: 04/22/2010] [Indexed: 11/16/2022]
Abstract
BACKGROUND Most diseases, including asthma, result from the interaction between environmental exposures and genetic variants. Functional variants of CD14 negatively affect lung function in farm workers and children exposed to animal allergens and endotoxin. OBJECTIVE We hypothesized that CD14 polymorphisms interact with inhaled endotoxin, mouse allergen, or both to decrease airways function in laboratory animal workers. METHODS Three hundred sixty-nine Caucasian workers completed a symptom and work exposure questionnaire, skin prick testing, and spirometry. Individual exposure estimates for endotoxin and murine allergen were calculated by weighting task-based breathing zone concentrations by time reported for each task and length of time in the current job. Real-time PCR was used to assess CD14/-1619, -550, and -159 alleles. Multiple linear regression predicting airways function included an interaction term between genotype and exposure. RESULTS Workers at the highest quartile of the natural log-transformed cumulative endotoxin exposure and with the endotoxin-responsive CD14/-1619 G allele had significantly lower FEV(1) and forced expiratory flow, midexpiratory phase (FEF(25-75)) percent predicted compared with workers with an AA genotype, with no significant differences noted at lower endotoxin levels for either genotype. The gene-environment effect was marked for atopic workers. Laboratory animal allergy, murine allergen exposure, CD14/-159 or -550 genotype, and a gene-exposure interaction term for these genotypes and exposures did not predict changes in lung function. CONCLUSIONS A significant gene-environment interaction affects airways function in laboratory animal workers. More highly endotoxin-exposed workers with CD14/-1619G alleles have significantly lower FEV(1) and FEF(25-75) percent predicted than those with CD14/-1619AA alleles. Atopic workers are particularly affected by cumulative endotoxin exposures.
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Affiliation(s)
- Karin A Pacheco
- Department of Medicine, Division of Environmental and Occupational Health Sciences, National Jewish Health, Denver, CO 80206, USA.
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Munthe-Kaas MC, Torjussen TM, Gervin K, Lødrup Carlsen KC, Carlsen KH, Granum B, Hjorthaug HS, Undlien D, Lyle R. CD14 polymorphisms and serum CD14 levels through childhood: a role for gene methylation? J Allergy Clin Immunol 2010; 125:1361-8. [PMID: 20398919 DOI: 10.1016/j.jaci.2010.02.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Revised: 01/18/2010] [Accepted: 02/04/2010] [Indexed: 11/19/2022]
Abstract
BACKGROUND CD14 is a pattern-recognition receptor for environmental LPS, and engagement of the CD14-LPS complex activates innate host defense mechanisms. Single nucleotide polymorphisms (SNPs) in the CD14 gene have been associated with soluble CD14 (sCD14) levels, but inconsistencies between studies suggest the presence of regulatory mechanisms hitherto not well understood. OBJECTIVE We sought to investigate possible associations between CD14 SNPs and sCD14 levels at different time points in childhood (at birth [cord blood] and 2 and 10 years) and to explore whether these associations were related to CD14 gene methylation. METHODS Four SNPs, rs2569191 (-1145GA), rs5744455 (-550CT or -651CT), rs2569190 (-159CT or -260CT), and rs4914 in CD14 were genotyped in 762 children from the Environmental and Childhood Asthma study. Genotype frequencies were analyzed for association with sCD14 levels in 660 babies, 346 children at age 2 years, and 360 children at age 10 years. In a subgroup of 157 children with DNA available at both 2 and 10 years of age, CD14 methylation patterns were determined and analyzed against detected CD14 gene-sCD14 associations. RESULTS rs2569191, rs5744455, and rs2569190 were associated with sCD14 levels at birth and 2 years, but only rs5744455 was associated with sCD14 levels at 10 years. CD14 methylation increased significantly from age 2 to 10 years, and the level of methylation was inversely correlated with sCD14 levels at 10 years. CONCLUSION The reduced effect of CD14 polymorphisms on sCD14 levels from early to late childhood paralleled a small but significant increase in CD14 methylation during the same period.
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Anas A, van der Poll T, de Vos AF. Role of CD14 in lung inflammation and infection. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:209. [PMID: 20236452 PMCID: PMC2887102 DOI: 10.1186/cc8850] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855.
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Affiliation(s)
- Adam Anas
- Center for Experimental and Molecular Medicine, Center of Infection and Immunity, Academic Medical Center, Meibergdreef 9, Amsterdam, Netherlands
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Anas A, Van Der Poll T, De Vas AF. Role of CD14 in Lung Inflammation and Infection. Intensive Care Med 2010. [PMCID: PMC7120299 DOI: 10.1007/978-1-4419-5562-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Toll-like receptors (TLR) on the surface of cells of the respiratory tract play an essential role in sensing the presence of microorganisms in the airways and lungs. These receptors trigger inflammatory responses, activate innate immune responses, and prime adaptive immune responses to eradicate invading microbes [1]. TLR are members of a family of pattern-recognition receptors, which recognize molecular structures of bacteria, viruses, fungi and protozoa (pathogen-associated molecular patterns or PAMPs), as well as endogenous structures and proteins released during inflammation (damage/danger-associated molecular patterns or DAMPs). To date, ten different TLR have been identified in humans and twelve in mice. TLR are expressed on all cells of the immune system, but also on parenchymal cells of many organs and tissues. The binding of a PAMP to a TLR results in cellular activation and initiates a variety of effector functions, including cytokine secretion, proliferation’ co-stimulation or phagocyte maturation. To facilitate microbial recognition and to amplify cellular responses, certain TLR require additional proteins, such as lipopolysaccharide (LPS) binding protein (LBP), CD14, CD36 and high mobility group box-l protein (HMGB-l). In this chapter, the role of CD14 as an accessory receptor for TLR in lung inflammation and infection is discussed. The central role of CD14 in the recognition of various PAMPs and amplification of immune and inflammatory responses in the lung is depicted in Fig. 1. Central role of CD14 in pathogen- and pathogen-associated molecular pattern (PAMP)-induced responses in the lung. CD14, which lacks an intracellular domain for signal transduction, is expressed on the surface of alveolar macrophages, infiltrating monocytes and neutrophils, and at lower levels also on epithelial and endothelial cells in the lung. CD14 recognizes and binds various structures from invading microbes, such as lipopolysaccharide (LPS) from Gram-negative bacteria, lipoteichoic acid (LTA) from Gram-positive bacteria, lipoarabinomannan (LAM) from mycobacteria, viral double stranded (ds) RNA and F glycoprotein (F-gp) from respiratory syncytial virus (RSV). CD14 subsequently transfers these bound components to Toll-like receptors (TLR) which than trigger cell activation. Binding of LPS to CD14 is regulated by additional accessory receptors in the lung, including LPS-binding protein (LBP) and a number of surfactant proteins (SP). Furthermore, soluble CD14 (sCD14) enhances LPS-induced activation of cells with low CD14 expression. Depending on the microbe and the PAMPs it expresses, CD14-amplified responses can either be beneficial to the host by induction of an adequate inflammatory and immune response to eradicate the invading microbe, or detrimental to the host by excessive inflammation and/or dissemination of the pathogen. ![]()
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Role of CD14 in Lung Inflammation and Infection. YEARBOOK OF INTENSIVE CARE AND EMERGENCY MEDICINE 2010. [PMCID: PMC7124092 DOI: 10.1007/978-3-642-10286-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Toll-like receptors (TLR) on the surface of cells of the respiratory tract play an essential role in sensing the presence of microorganisms in the airways and lungs. These receptors trigger inflammatory responses, activate innate immune responses, and prime adaptive immune responses to eradicate invading microbes [1]. TLR are members of a family of pattern-recognition receptors, which recognize molecular structures of bacteria, viruses, fungi and protozoa (pathogen-associated molecular patterns or PAMPs), as well as endogenous structures and proteins released during inflammation (damage/danger-associated molecular patterns or DAMPs). To date, ten different TLR have been identified in humans and twelve in mice. TLR are expressed on all cells of the immune system, but also on parenchymal cells of many organs and tissues. The binding of a PAMP to a TLR results in cellular activation and initiates a variety of effector functions, including cytokine secretion, proliferation, co-stimulation or phagocyte maturation. To facilitate microbial recognition and to amplify cellular responses, certain TLR require additional proteins, such as lipopolysaccharide (LPS) binding protein (LBP), CD14, CD36 and high mobility group box-1 protein (HMGB-1). In this chapter, the role of CD14 as an accessory receptor for TLR in lung inflammation and infection is discussed. The central role of CD14 in the recognition of various PAMPs and amplification of immune and inflammatory responses in the lung is depicted in Figure 1.
Central role of CD14 in pathogen- and pathogen-associated molecular pattern (PAMP)-induced responses in the lung. CD14, which lacks an intracellular domain for signal transduction, is expressed on the surface of alveolar macrophages, infiltrating monocytes and neutrophils, and at lower levels also on epithelial and endothelial cells in the lung. CD14 recognizes and binds various structures from invading microbes, such as lipopolysaccharide (LPS) from Gram-negative bacteria, lipoteichoic acid (LTA) from Grampositive bacteria, lipoarabinomannan (LAM) from mycobacteria, viral double stranded (ds) RNA and F glycoprotein (F-gp) from respiratory syncytial virus (RSV). CD14 subsequently transfers these bound components to Toll-like receptors (TLR) which than trigger cell activation. Binding of LPS to CD14 is regulated by additional accessory receptors in the lung, including LPS-binding protein (LBP) and a number of surfactant proteins (SP). Furthermore, soluble CD14 (sCD14) enhances LPS-induced activation of cells with low CD14 expression. Depending on the microbe and the PAMPs it expresses, CD14-amplified responses can either be beneficial to the host by induction of an adequate inflammatory and immune response to eradicate the invading microbe, or detrimental to the host by excessive inflammation and/or dissemination of the pathogen. ![]()
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Pahwa P, Karunanayake CP, Rennie DC, Chen Y, Schwartz DA, Dosman JA. Association of the TLR4 Asp299Gly polymorphism with lung function in relation to body mass index. BMC Pulm Med 2009; 9:46. [PMID: 19772581 PMCID: PMC2759902 DOI: 10.1186/1471-2466-9-46] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Accepted: 09/21/2009] [Indexed: 12/20/2022] Open
Abstract
Background Previous studies have shown conflicting results for the association between TLR4 polymorphism (Asp299Gly) and lung function. We investigated the influence of TLR4 Asp299Gly, a polymorphism, on lung function in a community population. Methods In 2003, a cross-sectional survey was conducted to assess the respiratory health of residents living in and around the town of Humboldt, Saskatchewan, Canada. There were 2090 adults age 18-79 years who completed a questionnaire that included a medical and smoking history, as well as socio-economic and lifestyle variables. Genetic information and lung function test measurements were available on 1725 subjects (754 males and 971 females) of the 2090 respondents. These subjects were selected for further analysis to investigate the association between TLR4 Asp299Gly genotype and forced expiratory volume in the first second in liters (FEV1), forced vital capacity in liters (FVC), FEV1/FVC ratio, and forced expiratory flow rate in liters/second (FEF25-75). Multivariable linear regression analysis was used to investigate associations. Results Adjusted mean values of FEV1 and FVC were significantly different between TLR4 wild type and TLR4 variant groups [Mean ± S.E.: (TLR4 wild type - FEV1: 3.18 ± 0.02, FVC: 3.95 ± 0.03; TLR4 variant - FEV1: 3.31 ± 0.06, FVC: 4.14 ± 0.07)]. Based on multivariable regression analysis, we observed that body mass index (BMI) was associated with decreased FEV1/FVC ratio and FEF25-75 in TLR4 variant group but not in wild type group. Conclusion BMI may modify the associations of TLR4 Asp299Gly polymorphism with FEV1/FVC ratio and FEF25-75.
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Affiliation(s)
- Punam Pahwa
- Canadian Centre for Health and Safety in Agriculture, R.U.H., Saskatchewan, Canada.
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Zhou H, Alexis NE, Almond M, Donohue J, LaForce C, Bromberg PA, Peden DB. Influence of C-159T SNP of the CD14 gene promoter on lung function in smokers. Respir Med 2009; 103:1358-65. [PMID: 19361972 DOI: 10.1016/j.rmed.2009.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Revised: 03/10/2009] [Accepted: 03/12/2009] [Indexed: 12/31/2022]
Abstract
CD14, a co-receptor for endotoxin, plays a significant role in regulating the inflammatory response to this agent. The C-159T single nucleotide polymorphism (SNP) in the CD14 gene promoter is an important regulator of CD14 expression, with TT homozygotes having increased expression of CD14. This SNP has been linked to pathogenesis of asthma and with cardiovascular diseases in smokers. We hypothesize that CD14 also plays a role in the pathophysiology of COPD in smokers who are exposed to endotoxin contained in cigarette smoke as well as endotoxin derived from Gram-negative microbes colonizing their airways. To assess the effect of the C-159T SNP of the CD14 gene promoter on lung function, we recruited 246 smokers 40 years of age or older with a range of 10-156 pack-year smoking exposures. The TT genotype was associated with lower lung function in smokers with a moderate smoking history. However, the CC genotype was associated with decreased lung function in heavy smokers (>56 pack years). The effect of CC genotype on severity of COPD is analogous with the effect of this genotype in risk for asthma. CD14 may be a factor in the pathophysiology of COPD, as it is in asthma and smoking-related cardiovascular diseases.
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Affiliation(s)
- Haibo Zhou
- The Center for Environmental Medicine, Asthma and Lung Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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Maestrelli P, Boschetto P, Fabbri LM, Mapp CE. Mechanisms of occupational asthma. J Allergy Clin Immunol 2009; 123:531-42; quiz 543-4. [DOI: 10.1016/j.jaci.2009.01.057] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 01/23/2009] [Accepted: 01/26/2009] [Indexed: 11/29/2022]
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Abstract
PURPOSE OF REVIEW This review examines the relationship between exposure to workplace allergens and the risk of developing occupational allergy. RECENT FINDINGS Evidence suggests that the risk of developing occupational allergy increases with allergen exposure; however, with some occupational allergens, this exposure-response relationship is more complex. In laboratory animal workers, the risk of developing occupational allergy increases with exposure, except at high allergen exposure when there is a reduction in sensitization. This attenuation of specific immunoglobulin E antibody is associated with increased specific immunoglobulin G4 antibodies, which are likely to play a protective role, leading to a form of natural tolerance. Exposure-response relationships are also very dependent on the genetic susceptibility of the individual. The interaction between genes, occupational allergens and other cofactors in the environment, such as endotoxin, are also important risk factors in the development of sensitization and asthma. SUMMARY Occupational allergy provides a good opportunity to understand the complex relationships between exposure to allergens in the workplace, interaction with genes and the coexposures with other factors in the working environment and the increased risk of developing occupational allergy.
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BROPHY DF, BUKAVECKAS BL, FERREIRA-GONZALEZ A, ARCHER KJ, MARTIN EJ, GEHR TW. A pilot study of genetic polymorphisms and hemodialysis vascular access thrombosis. Hemodial Int 2009; 13:19-26. [DOI: 10.1111/j.1542-4758.2009.00334.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Innate microbial sensors and their relevance to allergy. J Allergy Clin Immunol 2008; 122:846-58; quiz 858-60. [PMID: 19000576 DOI: 10.1016/j.jaci.2008.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 10/02/2008] [Accepted: 10/02/2008] [Indexed: 01/01/2023]
Abstract
The innate immune system oversees the gateway to immunity with its microbial sensors. Innate microbial sensors are germ line-encoded receptors with genetically predetermined specificities for microbes. The readiness and effectiveness of the innate immune system to provide immediate and appropriate responses at the host-environment interface is dependent on its sensitive and comprehensive microbial detection systems. The purpose of this review is to provide an overview of innate microbial sensors, our growing understanding of their diverse repertoire, and their elegant structural and functional approaches to microbial recognition. Their relevance to allergic disease is also discussed: the potential recognition and uptake of allergens by some of these receptors, inhibited expression of other microbial sensors by allergic immune responses and inflammation, and their upregulation by microbial exposures in early life that may help to protect against the development of allergic immune responses and disease.
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Abstract
This review considers the data from studies analysing associations between the CD14C-159T single nucleotide polymorphism (SNP) and asthmatic phenotypes and discusses the variability of the conclusions. By searching PubMed and EMBASE for articles on CD14C-159T -related population or family-based association studies, 47 were identified up till September 2007. Collectively, the studies reviewed herein consistently showed population differences in frequencies of the alleles of the SNP, with African descent having the highest C allele frequencies, followed by Caucasians and Asians. The T allele of the SNP was associated with increased sCD14 in some studies but not in others. Inconsistently, the C allele, or even occasionally the T allele, was associated with atopic phenotypes in a population subgroup. There are several explanations for these inconsistencies, including lack of power, linkage disequilibrium, gene-gene interactions, population admixture and gene-environment interactions. If the SNP was associated with functional changes to the coded protein and thus modulating susceptibility to allergic disease, its effect may be modest and dependent on other co-existent, ethnicity-specific, genetic or environmental risk factors.
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Affiliation(s)
- G Zhang
- School of Paediatrics and Child Health, University of Western Australia, Perth, WA, Australia
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Lipopolysaccharide-induced immune responses in relation to the TLR4(Asp299Gly) gene polymorphism. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:1878-83. [PMID: 18927069 DOI: 10.1128/cvi.00241-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Altered microbial exposure is a possible explanation for the increase of allergies in the Western world. However, genetic factors influence microbially induced immune responses. We have investigated the TLR4(Asp299Gly) gene polymorphism and its possible association with receptor expression of circulating peripheral blood monocytes and the in vitro cytokine responses and phosphorylation of intracellular signaling proteins in peripheral blood mononuclear cells (PBMC) stimulated with lipopolysaccharide (LPS) from Escherichia coli and Salmonella enterica serotype Typhimurium. We studied 34 of the predominant haplotype TLR4 Asp299 (AA) and 8 heterozygote Asp299Gly (AG) individuals. TLR4 expression levels were similar in the two genotype groups. Serovar Typhimurium LPS induced interleukin-12p70 from PBMC, and the degree of phosphorylation of the intracellular signaling protein IkappaBalpha in PBMC was lower in the AG than the AA group (P=0.03 and P=0.04, respectively). These results were not seen, however, when PMBC were stimulated with E. coli-derived LPS. Based on these results, we propose that TLR4(Asp299Gly) gene polymorphism and the bacterial origin of LPS should be considered when environmental LPS exposure is evaluated in disease risk or protection.
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Germolec D, Burns-Naas L, Gerberick G, Ladics G, Ryan C, Pruett S, Yucesoy B, Luebke R. Immunotoxicogenomics. Genomics 2008. [DOI: 10.3109/9781420067064-12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
Occupational exposures can cause a new onset of asthma in a subset of susceptible workers on the basis of sensitization to a specific work agent or a high-level irritant exposure. Epidemiologic studies give insight into the natural history of occupational asthma, including host factors and environmental factors leading to the development of occupational asthma, the progression, and the potential role of preventive measures. Work-exacerbated asthma has been a focus of studies only recently but is recognized as common among asthmatic workers and is a potential cause of significant morbidity and socioeconomic impact.
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Affiliation(s)
- Susan M Tarlo
- University of Toronto and University Health Network, Toronto Western Hospital, Toronto, Ontario M5T 2S8, Canada.
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Functional significance of CD14 promoter polymorphisms and their clinical relevance in a Chinese Han population*. Crit Care Med 2008; 36:2274-80. [DOI: 10.1097/ccm.0b013e318180b1ed] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
Asthma risk has a clear hereditary component but, unexpectedly, the majority of reported associations between genetic variants and asthma have not been consistently replicated across studies. Methodological flaws have been indicated as a possible explanation for these inconsistencies. However, an alternative explanation is that the effects of genetic variants depend on other factors whose frequency and distribution vary, both across individuals and across populations. Within this framework, we review recent advances in asthma genetics and conclude that a paradigm shift is needed, because a static model in which the DNA sequence is associated with disease risk in a linear fashion fails to consider the interdependence of the diverse components of asthma risk. We propose an integrated approach, linking sequence variation to specific phenotypic manifestations of the disease by taking into account concurrent influences from biological systems and environmental factors that interact within specific developmental windows of opportunity.
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Affiliation(s)
- Stefano Guerra
- Arizona Respiratory Center, University of Arizona, Tucson, Arizona 85724, USA.
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Miller RL, Ho SM. Environmental epigenetics and asthma: current concepts and call for studies. Am J Respir Crit Care Med 2008; 177:567-73. [PMID: 18187692 DOI: 10.1164/rccm.200710-1511pp] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Recent studies suggest that epigenetic regulation (heritable changes in gene expression that occur in the absence of alterations in DNA sequences) may in part mediate the complex gene-by-environment interactions that can lead to asthma. The variable natural history of asthma (i.e., incidence and remission of symptoms) may be a result of epigenetic changes, such as DNA methylation, covalent histone modifications, microRNA changes, and chromatin alterations, after early or later environmental exposures. Findings from multiple epidemiologic and experimental studies indicate that asthma risk may be modified by epigenetic regulation. One study suggested that the transmission of asthma risk may occur across multiple generations. Experimental studies provide substantial in vitro data indicating that DNA methylation of genes critical to T-helper cell differentiation may induce polarization toward or away from an allergic phenotype. Despite this initial progress, fundamental questions remain that need to be addressed by well-designed research studies. Data generated from controlled experiments using in vivo models and/or clinical specimens collected after environmental exposure monitoring are limited. Importantly, cohort-driven epigenetic research has the potential to address key questions, such as those concerning the influence of timing of exposure, dose of exposure, diet, and ethnicity on susceptibility to asthma development. There is immense promise that the study of environmental epigenetics will help us understand a theoretically preventable environmental disease.
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Affiliation(s)
- Rachel L Miller
- PH8E, 630 W. 168th Street, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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Hoppin JA, Valcin M, Henneberger PK, Kullman GJ, Umbach DM, London SJ, Alavanja MCR, Sandler DP. Pesticide use and chronic bronchitis among farmers in the Agricultural Health Study. Am J Ind Med 2007; 50:969-79. [PMID: 17975796 PMCID: PMC2806052 DOI: 10.1002/ajim.20523] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Farmers have increased risk for chronic bronchitis. Few investigators have considered pesticides. METHODS We evaluated pesticides as risk factors for chronic bronchitis using the Agricultural Health Study enrollment data on lifetime pesticide use and history of doctor-diagnosed chronic bronchitis from 20,908 private pesticide applicators, primarily farmers. RESULTS A total of 654 farmers (3%) reported chronic bronchitis diagnosed after age 19. After adjustment for correlated pesticides as well as confounders, 11 pesticides were significantly associated with chronic bronchitis. Heptachlor use had the highest odds ratio (OR=1.50, 95% Confidence Interval (CI)=1.19, 1.89). Increased prevalence for chronic bronchitis was also seen for individuals who had a history of a high pesticide exposure event (OR=1.85, 95% CI=1.51, 2.25) and for those who also applied pesticides in off-farm jobs (OR=1.40, 95% CI=1.04, 1.88). Co-morbid asthma and current farm activities did not explain these results. CONCLUSIONS These results provide preliminary evidence that pesticide use may increase chronic bronchitis prevalence.
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Affiliation(s)
- Jane A Hoppin
- Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina 27709-2233, USA.
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Smit LAM, Bongers SIM, Ruven HJT, Rijkers GT, Wouters IM, Heederik D, Omland Ø, Sigsgaard T. Atopy and new-onset asthma in young Danish farmers and CD14, TLR2, and TLR4 genetic polymorphisms: a nested case-control study. Clin Exp Allergy 2007; 37:1602-8. [PMID: 17877764 DOI: 10.1111/j.1365-2222.2007.02831.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Evidence exists that exposure to high levels of microbial agents such as endotoxin in the farm environment decreases the risk of atopic sensitization. Genetic variation in innate immunity genes may modulate the response to microbial agents and thus influence susceptibility to asthma and atopy. OBJECTIVE To study potential associations between single nucleotide polymorphisms (SNPs) in CD14, Toll-like receptor 2 (TLR2), and TLR4 genes, and atopy and new-onset asthma in young farmers. METHODS A nested case-control study was conducted within a cohort of 1901 young Danish farmers. We genotyped 100 new-onset asthma cases and 88 control subjects for three CD14 SNPs, three TLR2 SNPs, and two TLR4 SNPs. Atopy at baseline (defined as a positive skin prick test to one or more common inhalant allergens) was found in 17 asthma cases (17.0%) and in 17 controls (19.3%). RESULTS The CD14/-260T allele was significantly associated with less atopy [odds ratio (OR) 0.39; 95% confidence interval (CI) 0.21-0.72, additive genetic model], whereas the CD14/-651T allele was positively associated with atopy (OR 2.53; 95% CI 1.33-4.80). Similar results were obtained by haplotype analysis. Stratified analysis by farm childhood showed stronger effects of both CD14 SNPs on atopy among farmers who were born and raised on a farm, although no significant interaction was found. No associations between CD14, TLR2, or TLR4 genotypes and new-onset asthma were found. CONCLUSION The CD14/-260 and CD14/-651 promoter polymorphisms are associated with atopy prevalence among young adults exposed to farm environments.
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Affiliation(s)
- L A M Smit
- Division Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
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Gu W, Shan YA, Zhou J, Jiang DP, Zhang L, Du DY, Wang ZG, Jiang JX. Functional significance of gene polymorphisms in the promoter of myeloid differentiation-2. Ann Surg 2007; 246:151-8. [PMID: 17592304 PMCID: PMC1899213 DOI: 10.1097/01.sla.0000262788.67171.3f] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the functional significance of the reported single nucleotide polymorphisms (SNPs) in the promoter of the myeloid differentiation-2 (MD-2) gene. SUMMARY BACKGROUND DATA Functional gene polymorphisms of innate immune receptors have been shown to be critical determinants of the immune inflammatory response. MD-2 is an important signaling enhancer protein in the endotoxin (LPS) receptor complex. Although a total of 156 SNPs have been identified within the whole MD-2 gene, little is known about the functional significance of these SNPs. METHODS : The possible biosignificance of 8 reported SNPs was analyzed using on-line software tools. The selected SNPs were then genotyped using a restriction fragment length polymorphism method applied to 711 healthy Chinese volunteers. Their functional effects were assessed by the observation of transcription activity, MD-2 mRNA expression, and leukocyte response to ex vitro LPS stimulation. Moreover, the clinical relevance of these SNPs was investigated in 105 patients with major trauma. RESULTS Three SNPs (C-1625G, A-1064G, and A-475T) in the MD-2 promoter were selected based on bio-informatic analysis. Both -1625 and -1064 SNPs, rather than -475, were seen in the Chinese population, with frequencies of 19.8% (-1625G) and 34.7% (-1064G). But only the -1625 polymorphism was found to affect MD-2 promoter activity. Moreover, the expression of MD-2 mRNA and the production of TNF-alpha in whole blood leukocytes, in response to LPS stimulation, were significantly increased in subjects with the -1625 G allele. Patients who possessed the -1625 G allele were more likely to experience complications with organ dysfunction and sepsis after major trauma. All these associations were in allele-dose dependent effect. CONCLUSIONS The MD-2/-1625 polymorphism is an important functional variant.
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Affiliation(s)
- Wei Gu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Chongqing, China
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Yang IA, Savarimuthu S, Kim ST, Holloway JW, Bell SC, Fong KM. Gene-environmental interaction in asthma. Curr Opin Allergy Clin Immunol 2007; 7:75-82. [PMID: 17218815 DOI: 10.1097/aci.0b013e328012ce39] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE OF REVIEW Asthma is likely to result from the effects of environmental stimuli in genetically susceptible individuals. This review summarizes recent studies of gene-environmental interaction in the pathogenesis of asthma, focusing on study designs. RECENT FINDINGS Studies using genetic epidemiology, in-vitro and ex-vivo models and in-vivo model organisms demonstrate that gene-environmental interaction in involved in the development of asthma. Genetic association studies show a reduced risk of asthma and atopy with early life exposure to farming environments and house dust endotoxin, and increased risk with environmental tobacco smoke. These associations are modified by CD14 genotype. In people with a specific genotype, high environmental exposure may have the opposite effect of low exposure, possibly explaining some of the inconsistencies in previous studies. In-vitro and ex-vivo cell culture experiments show gene-environmental interactions with Toll-like receptor agonists, viruses and tobacco smoke. Interactions between innate immunity genes and exposure to endotoxin and air pollution have been observed in in-vivo mouse models. SUMMARY The expanding evidence for gene-environmental interaction in asthma indicates the importance of measuring environmental factors in genetic studies of asthma. Understanding gene-environmental interaction would facilitate risk prognostication, improve preventive strategies and develop targeted interventions in people with asthma.
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Affiliation(s)
- Ian A Yang
- Department of Thoracic Medicine, The Prince Charles Hospital, Brisbane, Australia.
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Palmer SM, Klimecki W, Yu L, Reinsmoen NL, Snyder LD, Ganous TM, Burch L, Schwartz DA. Genetic regulation of rejection and survival following human lung transplantation by the innate immune receptor CD14. Am J Transplant 2007; 7:693-9. [PMID: 17217435 DOI: 10.1111/j.1600-6143.2007.01669.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have developed the hypothesis that genetic polymorphisms which alter the expression or function of innate immune receptors contribute to the marked interindividual differences in the onset and severity of lung transplant rejection. In this analysis, we considered the effects of a common promotor polymorphism of the lipopolysaccharide receptor CD14 associated with increased transcriptional activity upon the development of posttransplant rejection and graft survival. Genotyping was performed in 226 lung transplant recipients well characterized with regards to clinical outcomes. An earlier onset of acute rejection, bronchiolitis obliterans syndrome (BOS) and worse posttransplant graft survival due to greater BOS related deaths was evident in patients with the CD14 -159 TT genotype (TT). The adverse effect upon graft survival of the TT genotype remained significant in a multivariate Cox model (Hazard Ratio 1.65, 95% CI, 1.03-2.64, p-value = 0.04) after adjusting for other important covariates. Furthermore, TT patients have significantly greater sCD14, TNF-alpha and IFN-gamma in the peripheral blood implying a heightened state of innate immune activation drives the development of increased post-transplant rejection. Inhibition of innate immune activation through CD14 represents a novel and potentially important therapeutic target to prevent post-transplant rejection and improve outcomes after human lung transplantation.
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Affiliation(s)
- S M Palmer
- Departments of Medicine, University of Arizona, Tucson, AZ, USA.
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James JA, Poulton KV, Haworth SE, Payne D, McKay IJ, Clarke FM, Hughes FJ, Linden GJ. Polymorphisms of TLR4 but not CD14 are associated with a decreased risk of aggressive periodontitis. J Clin Periodontol 2007; 34:111-7. [PMID: 17309585 DOI: 10.1111/j.1600-051x.2006.01030.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To study whether there is an association between the frequency of functional polymorphisms in the toll-like receptor 4 (TLR4) and cluster differentiation 14 (CD14) genes and periodontitis. METHODOLOGY Genotyping for the TLR4 single-nucleotide polymorphisms (SNPs) Asp299Gly, Thr399Ile and the CD14 SNPs -159 and -1359 was completed for subjects with periodontal disease compared with control subjects. Two disease populations were investigated: 73 subjects with aggressive periodontitis (AgP; 28 males, 45 females) and 95 males with chronic periodontitis (CP). The TLR4 and CD14 polymorphisms were determined using SNaPshot primer extension with capillary electrophoresis. Comparison of allele and genotype frequencies for each polymorphism was by Fisher's exact test or chi2 analysis. RESULTS The TLR4 Asp299Gly genotype was present in a significantly (p=0.026) lower proportion of AgP subjects (5.5%) compared with control subjects (16.3%). The unadjusted odds ratio for the Asp299Gly genotype to be associated with AgP was 0.30, 95% confidence interval 0.10-0.91. No differences were found in the prevalence of the TLR4 Asp299Gly genotype in men with CP (18.9%) compared with an age-matched control group with no evidence of periodontitis (17%). In addition, there was no difference in the distribution of the CD14 polymorphisms in either the AgP or CP populations studied compared with controls. CONCLUSION It is concluded that in West European Caucasians, the Asp299Gly TLR4 gene polymorphism is associated with a decreased risk of AgP but not CP. Promoter polymorphisms of the CD14 gene, however, did not influence susceptibility to inflammatory periodontitis in the population cohorts studied.
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Affiliation(s)
- Jacqueline A James
- Centre for Cancer Research and Cell Biology, Queens University, Belfast, UK.
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Yucesoy B, Luster MI. Genetic susceptibility in pneumoconiosis. Toxicol Lett 2007; 168:249-54. [PMID: 17161563 DOI: 10.1016/j.toxlet.2006.10.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Accepted: 10/09/2006] [Indexed: 11/24/2022]
Abstract
A large number of cellular mediators such as cytokines, antioxidants and growth factors have been implicated in the pathogenesis of chronic inflammatory and fibrotic diseases. Common functional polymorphisms in these genes have been shown to influence individual susceptibility to these diseases. Silicosis, coal worker pneumoconiosis, progressive massive fibrosis and berylliosis are examples of fibrotic pneumoconiosis and are characterized by irreversible fibrotic lesions in the lung resulting from chronic dust inhalation. Although the materials are the major contributory factors of the disease pathogenesis, not all individuals exposed to similar levels develop disease. This suggests that there is a genetic predisposition to their development. Therefore, an understanding of genetic variability and the interaction between genetic and environmental factors is crucial to the identification of high-risk individuals and prevention and treatment of these diseases.
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Affiliation(s)
- Berran Yucesoy
- Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA.
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Vallyathan V, Pack D, Leonard S, Lawson R, Schenker M, Castranova V. Comparative in vitro toxicity of grape- and citrus-farm dusts. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:95-106. [PMID: 17365569 DOI: 10.1080/15287390600747825] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Agricultural workers are exposed to a variety of airborne dusts, including crystalline silica and other inorganic minerals. This study was designed to characterize the organic and inorganic components of agricultural dusts in California grape- and citrus-farm fields and to compare their cytotoxicity using in vitro toxicity bioassays as predictors of pathogenicity. Aerosolized dusts collected from farm fields were characterized by scanning-electron-microscopic energy-dispersive x-ray analysis, x-ray diffraction, trace metal analysis by plasma emission spectroscopy, and surface area measurements. As indicators of cytotoxicity, cell viability, release of alveolar enzymes activities (lactate dehydrogenase, N-acetyl glucosaminidase), production of reactive oxygen species (ROS), such as H2O2 and hydroxyl radical (OH), and lipid peroxidation were monitored after exposure of cells to grape- and citrus-farm dusts or inorganic components of these dusts. In addition, activation of nuclear factor kappa B and activator protein-1 were evaluated at the peak time for response of 36 h postexposure. All toxicity studies were done in comparison with crystalline silica of similar particle size and diameter using the same mass concentrations as farm dusts. The results showed that inorganic minerals in the aerosolized farm dust fractions were mostly composed of aluminum silicates, crystalline silica, and free iron. Crystalline silica used in these studies was more cytotoxic than grape- and citrus-farm dusts. However, in general, citrus farm dust exhibited the greatest ability to generate ROS and induce lipid peroxidation. These results support human epidemiologic studies, reporting an increased incidence of pulmonary fibrosis in farm workers, by documenting the potential of farm dusts to induce oxidative stress and initiate disease development.
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Affiliation(s)
- Val Vallyathan
- Pathology and Physiology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
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Yang IA, Fong KM, Holgate ST, Holloway JW. The role of Toll-like receptors and related receptors of the innate immune system in asthma. Curr Opin Allergy Clin Immunol 2006; 6:23-8. [PMID: 16505608 DOI: 10.1097/01.all.0000200503.77295.bb] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE OF REVIEW The biology of the innate immunity receptors is of central importance in the host response to the environment. Identifying genetic variants that alter the innate immune response is highly relevant to understanding asthma pathogenesis. This review summarizes recent studies of the role of innate immunity receptors, including Toll-like receptors and CD14, in the pathogenesis of asthma. RECENT FINDINGS The majority of studies published since 2004 have been genetic association studies in various clinical settings, which have found positive associations of single nucleotide polymorphisms in TLR2, TLR4, TLR6 and TLR10 with asthma or atopy, although the number of studies is small and the results not yet replicated. The designs for CD14 genetic studies have been more sophisticated and have included gene-environment interaction. The results of CD14 gene associations with asthma and atopy are suggestive but have not been fully replicated. Potential reasons for non-replication of TLR and CD14 association studies include insufficient power, type I error, population heterogeneity and different phenotypes studied. In addition, there may be differences in CD14 genetic effects between childhood and adulthood, and between levels of endotoxin exposure. SUMMARY The evidence is still being accumulated for the role of Toll-like receptor polymorphisms in the pathogenesis of asthma. There is emerging evidence for the role of CD14 polymorphisms in the development of asthma and atopy. Further studies of innate immunity in asthma and allergy are required, using rigorous study design, measurement of environmental exposure and intermediate phenotypes to demonstrate single nucleotide polymorphism functionality.
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Affiliation(s)
- Ian A Yang
- Department of Thoracic Medicine, The Prince Charles Hospital, Brisbane, Queensland, Australia.
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Nawrot T, Nemmar A, Nemery B. Update in environmental and occupational medicine 2005. Am J Respir Crit Care Med 2006; 173:948-52. [PMID: 16632634 DOI: 10.1164/rccm.2601010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Tim Nawrot
- Eenheid voor Longtoxicologie Herestraat 49, O and N 706, B-3000 Leuven, Belgium
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Current World Literature. Curr Opin Allergy Clin Immunol 2006; 6:67-9. [PMID: 16505615 DOI: 10.1097/01.all.0000202355.95779.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Campos J, Gude F, Quinteiro C, Vidal C, Gonzalez-Quintela A. Gene by Environment Interaction: The -159C/T Polymorphism in the Promoter Region of the CD14 Gene Modifies the Effect of Alcohol Consumption on Serum IgE Levels. Alcohol Clin Exp Res 2006; 30:7-14. [PMID: 16433727 DOI: 10.1111/j.1530-0277.2006.00007.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Serum IgE is increased in heavy drinkers. Endotoxin mediates most of the immunological alterations associated with heavy drinking. The -159C/T polymorphism in the promoter region of the gene encoding CD14 (an endotoxin receptor) is associated with serum IgE levels in different populations. AIM To investigate the possible interaction between alcohol intake and the -159C/T polymorphism in the promoter region of the CD14 gene for serum IgE levels. METHODS A total of 415 individuals (51.6% males, median age 50 years, range 18-92 years) were studied. A total of 140 individuals were alcohol abstainers, 112 were moderate drinkers (1-280 g/week), and 163 were heavy drinkers (>280 g/week). Main determinations included the CD14/-159C/T genotype, a panel of skin prick tests, total serum IgE, and specific serum IgE against common aeroallergens (Phadiatop test). RESULTS Heavy drinking was associated with increased total serum IgE values and with positive specific serum IgE to common aeroallergens, but the association was stronger in carriers of the CD14/-159C allele (either CC homozygotes or CT heterozygotes) than in CD14/-159TT homozygotes. Both additive and multiplicative interactions between heavy drinking and the CD14/-159C allele for total and specific serum IgE values was still present after adjusting for potential confounders. Neither alcohol consumption nor the CD14/-159 genotype was associated with skin prick test positivity. CONCLUSIONS The CD14/-159C/T polymorphism modifies the effect of alcohol consumption on serum IgE levels.
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Affiliation(s)
- Joaquin Campos
- Department of Internal Medicine, Hospital Clinico Universitario, Santiago de Compostela, Spain
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