Comparing human respiratory adverse effects after acute exposure to particulate matter in conventional and particle-reduced swine building environments.

OBJECTIVES: To evaluate innate immunity responses, lung function and symptoms in volunteers acutely exposed to organic dust in swine buildings after installing particle separators aimed to reduce particulate matter exposure. METHODS: 11 healthy participants were exposed in 2 different facilities, with and without installed particle separators, in a cross-over design including 2-3 weeks wash-out between the 2 exposures. Size, distribution and composition of particulate matter and endotoxins in the air were measured. Lung function (spirometry), bronchial responsiveness, symptoms questionnaire and markers of innate immunity in blood and nasal lavage were measured before and after the 3-hour exposures. RESULTS: The number of particles, in particular fine particles sized 0.3-0.5 µm, was reduced in the particle-separated swine building environment (PSE) compared with that in the conventional building (CE). In the PSE, headache (p=0.03) and increased body temperature (p=0.016) were less pronounced than in the CE. The expression of toll-like receptors (TLR)2 and TLR4 on blood monocytes significantly increased (p=0.016 and 0.017, respectively) while cluster of differentiation (CD)14 on neutrophils decreased (p=0.05) after exposure in the CE, yet with no difference between the 2 exposures. Compared with the conventional environment, exposure to the PSE yielded lower interleukin (IL)-6 (p=0.02) and IL-8 (p=0.04) levels in the upper respiratory tract, as assessed by nasal lavage. CONCLUSIONS: Particulate matter and organic dust in the swine building were reduced after installing particle separators, which, in naïve never exposed volunteers, in turn reduced adverse health effects caused by acute exposure in swine buildings compared with exposure to the conventional swine building environment.

Long term effect and allergic sensitization in newly employed workers in laboratory animal facilities.

OBJECTIVE: The aim of this study was to identify targets predicting allergic sensitization to laboratory animals using shift in skin prick test to laboratory animals as primary outcome variable. METHODS: In a prospective longitudinal study, personnel who were employed to work with laboratory animals at a medical university were investigated before and 6, 12 and 24 month after the start of employment. Lung function, bronchial challenges, exhaled NO and nasal lavage were performed and blood samples were drawn at all visits. RESULTS: Seventy subjects attended all four visits and 13 (19%) became sensitized to laboratory animals during the two years of follow up. Lung function (VC and FEV1) deteriorated and blood levels of eosinophils and IL-2 producing lymphocytes increased after 24 months. An increased risk of developing laboratory animal allergy was significantly associated with female sex, atopy, symptoms associated with exposure to laboratory animals, low proportion of blood CD4+ cells, specific IgE to rat and mouse and high total IgE when starting to work with laboratory animals. CONCLUSIONS: A sensitization rate of 19% in 2 years, were demonstrated in laboratory animal workers. Atopy, increased total and specific IgE levels (rat and mouse) were the strongest predictors for laboratory animal sensitization. The progressive lung function impairment over time, observed in the whole study population may indicate that exposure in animal facilities induces harmful effects, irrespective to allergic sensitization.

Daily exposure to dust alters innate immunity.

Pig farmers are exposed to organic material in pig barns on a daily basis and have signs of an ongoing chronic airway inflammation and increased prevalence of chronic inflammatory airway diseases, predominantly chronic bronchitis. Interestingly, the inflammatory response to acute exposure to organic dust is attenuated in farmers. The aim of the study was to closer characterize innate immunity features in blood and airways in farmers and in naïve, non-exposed, controls. The expression of pattern recognition receptors (TLR2, TLR4 and CD14) whose ligands are abundant in pig barn dust and adhesion proteins (CD11b, CD62L and CD162L) on blood and sputum neutrophils in pig farmers and soluble TLR2 and CD14 (sTLR2 and sCD14) in blood and sputum were assessed in pig farmers and previously unexposed controls. The release of pro-inflammatory cytokines from blood cells stimulated with LPS ex vivo was measured in the absence and presence of anti-ST2. We also examined, in a separate study population, serum levels of soluble ST2 (sST2), before and after exposure in a pig barn and a bronchial LPS challenge. Farmers had signs of ongoing chronic inflammation with increased number of blood monocytes, and decreased expression of CD62L and CD162 on blood neutrophils. Farmers also had lower levels of sTLR2 and sCD14 in sputum and reduced expression of CD14 on sputum neutrophils than controls. Exposure to organic dust and LPS induced increase of serum sST2 in controls but not in farmers. In conclusion, farmers have signs of local and systemic inflammation associated with altered innate immunity characteristics.

Effect of formoterol and budesonide on chemokine release, chemokine receptor expression and chemotaxis in human neutrophils.

Severe persistent asthma and chronic obstructive pulmonary disease (COPD) are associated with neutrophil influx into the airways. It is not clear whether neutrophil chemotaxis is influenced by beta(2)-agonists and glucocorticoids, drugs commonly used in treatment of asthma and COPD. The effect of a long-acting beta(2)-agonist (formoterol), and a glucocorticosteroid (budesonide) on chemokine/cytokine release (CXCL8, CXCL1, IL-6), regulation of chemokine receptors (CXCR1, CXCR2), and migration were assessed in neutrophils from 10 non-allergic, healthy donors. Formoterol enhanced and budesonide inhibited IL-6, CXCL8 and CXCL1 release from LPS-stimulated neutrophils. Formoterol up-regulated both CXCR1 and CXCR2 expression, whereas budesonide up-regulated the expression of CXCR2 only. Despite the effects on chemokine release and drug-induced up-regulation of CXCR1 and CXCR2, no influence on neutrophil chemotaxis could be demonstrated. We conclude that a beta(2)-agonist and a glucocorticoid, commonly used in the treatment of obstructive lung diseases, influence chemokine release and receptor sensitivity but the functional consequences of these findings remain unclear.

Increased serum levels of soluble ST2 in birch pollen atopics and individuals working in laboratory animal facilities.

OBJECTIVE: To investigate toll-like receptors and CD14 expression on blood cells, cytokine profile of blood T-helper cells and serum levels of soluble suppression of tumorigenicity 2 (sST2) and sCD14 in 27 symptomatic laboratory animal (LA) workers with positive (n = 19) or negative (n = 8) skin-prick test to LA, 12 birch pollen atopics and 11 non-atopic controls not exposed to LA. METHODS: Surface markers and intracellular cytokines were measured with flow cytometry and sST2 and sCD14 with ELISA. RESULTS: The group who experienced symptoms when working with LA, with positive and negative skin-prick test to LA, had higher CD14 expression on monocytes compared with those allergic to birch and controls. Further, serum sST2 were elevated in birch atopics and in symptomatics non-allergic to LA compared with controls. CONCLUSION: Increased CD14 expression found in LA workers is most likely a response to non-allergic agent exposure whereas ST2 seems to react to acute allergen exposure and to non-allergic stimuli as pathogen-associated molecular patterns.

Altered innate immune response in farmers and smokers.

Pig farmers and cigarette smokers are continuously exposed to pathogen-associated molecular patterns (PAMPs) have an increased prevalence of respiratory disorders, such as chronic bronchitis and chronic obstructive pulmonary decease (COPD). We hypothesized that markers of innate immunity, T-helper (Th) cell cytokine profile and acute responses to pro-inflammatory stimuli differ between smokers and farmers, who are exposed to organic material on a daily basis and healthy non-exposed subjects. Eleven non-smoking pig farmers, 12 non-farming smokers and 12 controls underwent bronchial lipopolysaccharide (LPS) challenge and exposure in a pig barn during 3 h on separate days. Toll-like receptor 2 (TLR2), TLR4 and CD14 on blood monocytes and neutrophils and intracellular cytokine profile of Th cells were assessed before and 7 h after exposures. The same outcomes were analysed on peripheral blood and purified neutrophils from farmers and controls after stimulation ex vivo with dust from a pig barn and LPS. Circulating neutrophils and IL-13 and IL-4 producing Th cells were increased in smokers and farmers and TLR2 expression on blood monocytes was decreased in farmers compared with controls and smokers. After in vivo exposure, altered TLR expression was only observed in controls and the ex vivo stimulations showed an attenuated response in farmers compared to the control group. The inflammatory systemic response to pro-inflammatory stimuli is altered in farmers and smokers probably because of adaptive mechanisms arising from chronic exposure to organic material. This increased proportion of Th2 cells and reduced TLR2 expression may have health-related implications and may be related to the increased prevalence of respiratory disorders observed in these groups.

Microsomal glutathione transferase 1 in anticancer drug resistance.

Glutathione transferases (GSTs) are often upregulated in tumors and have been suggested to play an important role in multiple drug resistance in cancer chemotherapy. As a consequence GST-dependent pro-drugs and inhibitors are being developed. Little is known, however, on the potential role of membrane-bound GSTs in drug resistance despite the fact that detoxication of cytostatic drugs and upregulation in tumors has been demonstrated. Therefore, we have studied the involvement of membrane-bound microsomal GST1 (MGST1) in cellular resistance to anticancer drugs. As a tool we have developed a cell system utilizing MCF7 cells stably overexpressing MGST1. Here, we show for the first time that MGST1 can protect cells from several cytostatic drugs, chlorambucil, melphalan and cisplatin in an acute toxicity test (MTT assay) as well as a long-term colony forming efficiency cytotoxicity test. It is of note that these cells do not overexpress multidrug transporters, a prerequisite for protection with certain other GSTs investigated in this system. The cytostatic drugs used comprise both those that are known/predicted to be substrates as well as non-substrates. Thus, the mechanism most probably entails both direct detoxication and downstream protection of the cells from oxidative stress.

Effect of respirators equipped with particle or particle-and-gas filters during exposure in a pig confinement building.

OBJECTIVES: This study compared the protective effect of two respiratory protection devices during exposure in a pig confinement building. METHODS: Thirty-six healthy persons were exposed for 3 hours in the building, 12 without any protection, 12 with a particle-filter mask, and 12 with a mask filtering both particles and gases. Symptoms, body temperature, nasal lavage fluid, exhaled nitric oxide, and bronchial responsiveness to methacholine were assessed before and after the exposure. Pre- and postexposure urine and blood samples were collected. RESULTS: After the exposure, the participants with respirators reported fewer symptoms than those without. Wearing a mask also reduced the inflammatory response assessed with nasal lavage (cell concentration, interleukins 6 and 8) and peripheral blood (cell number). Lung function was significantly impaired only in the unprotected group; postexposure vital capacity and forced expiratory volume in 1 second showed a decrease of 3-4% from the preexposure levels (P=0.006 and P=0.002, respectively). Bronchial responsiveness (P<0.01) and body temperature (P<0.001) increased similarly in the three groups. Bronchial responsiveness to methacholine increased 2.7, 2.4, and 2.1 doubling concentration steps for those unprotected, those using a particle-filter mask, and those using a mask with particle and gas filters, respectively. The prostaglandin D2 metabolite, 9a, 11b-PGF2 increased significantly (P=0.003) only in those unprotected. CONCLUSIONS: Wearing a respirator in a pig confinement building reduces the inflammatory reaction but does not influence the increase in bronchial responsiveness, with no difference between the use of a particle-filter mask or a mask with a particle-gas filter combination.