Factors Affecting SARS-CoV-2 IgG Production after Vaccination and/or Disease: A Large-Scale Seroprevalence Study.

This study aimed at identifying factors influencing SARS-CoV-2-specific IgG antibody levels after vaccination and/or infection. Between January 2022 and March 2023, 2000 adults (≥18 years, Salzburg, Austria) participated in this population-based seroprevalence study by providing 3 mL of blood to detect SARS-CoV-2-specific IgG antibodies using an anti-SARS-CoV-2 IgG quantitative assay and by completing a self-designed questionnaire including anthropometric factors, vaccination information, and medical history. For 77 of the participants, a time-course study up to 24 weeks post vaccination or quarantine end was performed. Convalescent-only subjects had the lowest median antibody titer (65.6 BAU/mL) compared to vaccinated and hybrid immunized subjects (p-value < 0.0001) The type of vaccine as well as vaccine combinations significantly influenced the levels of SARS-CoV-2 spike-protein-specific IgG, ranging from a median antibody level of 770.5 BAU/mL in subjects who were vaccinated only to 3020.0 BAU/mL in hybrid immunized subjects (p-value < 0.0001). Over time, a significant decline in the levels of neutralizing antibodies was found. Depending on the subpopulation analyzed, further significant influencing factors included sex assigned at birth, disease severity, chronic diseases, and medication. A hybrid immunization resulted in more robust immune responses. Nevertheless, there were multiple other factors impacting these responses. This knowledge should be included in future vaccination strategies and serve as a guide in the development of personalized medicine.

Antioxidative and Antimicrobial Evaluation of Bark Extracts from Common European Trees in Light of Dermal Applications.

Plant species have developed effective defense strategies for colonizing diverse habitats and protecting themselves from numerous attacks from a wide range of organisms, including insects, vertebrates, fungi, and bacteria. The bark of trees in particular constitutes a number of components that protect against unwanted intruders. This review focuses on the antioxidative, dermal immunomodulatory, and antimicrobial properties of bark extracts from European common temperate trees in light of various skin pathogens, wound healing, and the maintenance of skin health. The sustainability aspect, achieved by utilizing the bark, which is considered a byproduct in the forest industry, is addressed, as are various extraction methods applied to retrieve extracts from bark.

Antimicrobial Activity and Wound-Healing Capacity of Birch, Beech and Larch Bark Extracts.

Bark is a major by-product of woodworking industries. The contents of several wood species are known to harbor antimicrobial, antiviral, anti-inflammatory and wound-healing capacities. The aim of this work was to identify beneficial properties of Austrian larch, birch and beech bark extracts for their potential usage as additives or active ingredients in dermatological applications. Bacterial agar diffusion assay and resazurin-based broth microdilution assay were used to evaluate anti-bacterial activity. To gain more insight into the cellular response to bark extracts, viability-, scratch-assays and ELISAs were performed. Birch and beech extracts showed strong antimicrobial activities against Gram-positive bacteria, including Cutibacterium acnes, Staphylococcus epidermidis and MRSA. Wound closure was enhanced with birch and beech extracts as compared to controls in the scratch-assays. Whereas beneficial properties of birch bark components have previously been described, the similar effects of beech extracts are novel. The combined positive effect on wound-healing and antimicrobial activity has great potential for the treatment of various skin diseases, including acne in future dermal applications.

On the Acceptance of "Fake" Histopathology: A Study on Frozen Sections Optimized with Deep Learning.

BACKGROUND: The fast acquisition process of frozen sections allows surgeons to wait for histological findings during the interventions to base intrasurgical decisions on the outcome of the histology. Compared with paraffin sections, however, the quality of frozen sections is often strongly reduced, leading to a lower diagnostic accuracy. Deep neural networks are capable of modifying specific characteristics of digital histological images. Particularly, generative adversarial networks proved to be effective tools to learn about translation between two modalities, based on two unconnected data sets only. The positive effects of such deep learning-based image optimization on computer-aided diagnosis have already been shown. However, since fully automated diagnosis is controversial, the application of enhanced images for visual clinical assessment is currently probably of even higher relevance. METHODS: Three different deep learning-based generative adversarial networks were investigated. The methods were used to translate frozen sections into virtual paraffin sections. Overall, 40 frozen sections were processed. For training, 40 further paraffin sections were available. We investigated how pathologists assess the quality of the different image translation approaches and whether experts are able to distinguish between virtual and real digital pathology. RESULTS: Pathologists' detection accuracy of virtual paraffin sections (from pairs consisting of a frozen and a paraffin section) was between 0.62 and 0.97. Overall, in 59% of images, the virtual section was assessed as more appropriate for a diagnosis. In 53% of images, the deep learning approach was preferred to conventional stain normalization (SN). CONCLUSION: Overall, expert assessment indicated slightly improved visual properties of converted images and a high similarity to real paraffin sections. The observed high variability showed clear differences in personal preferences.

Comparative analysis of high CRP-levels in human blood using point-of-care and laboratory-based methods.

OBJECTIVES: The use of point-of-care (POC) methods and the measurements of C-reactive protein (CRP) as a diagnostic marker have both increased over the past years. This has led to an increase in POC-methods analysing CRP. High CRP levels are often seen as an indication for the subscription of antibiotics. The quality of POC-systems compared to routine diagnostic measurements for the analysis of CRP is thereby of main importance, since many small practises will use POC-methods. This study compared high-level CRP concentrations (above 100 mg/L) using an i-CHROMATM with 2 routinely used laboratory-based systems (Architect and ABX). DESIGN: and Methods: A total of 199 patient samples with a CRP concentration above 100 mg/L were analysed with the i-CHROMATM POC system and the turbidimetric routine methods using the Architect and ABX equipment. RESULTS: The results of the i-CHROMATM device showed a significant decrease in the CRP levels compared to those obtained with the Architect and the ABX (i-CHROMATM vs. Architect: y â€‹= â€‹0.6792x + 94.701; R2 = 0.4980, i-CHROMATM vs. ABX: y â€‹= â€‹0.3674x + 118.05; R2 â€‹= â€‹0.3964, Architect vs. ABX: y â€‹= â€‹0.7657x + 36.337; R2 = 0.9311). Furthermore, data analysis showed a partition of the i-CHROMATM measurements in two defined clouds, which could not be explained with any of the available sample information. CONCLUSIONS: This analysis showed the limitations of the i-CHROMATM CRP analyser. In addition, it illustrates the need for strict regulations on the information and output provided by companies regarding the boundaries of novel and existing diagnostic methods.

The protein corona suppresses the cytotoxic and pro-inflammatory response in lung epithelial cells and macrophages upon exposure to nanosilica.

Engineered amorphous silica nanoparticles (nanosilica) are one of the most abundant nanomaterials and are widely used in industry. Furthermore, novel nanosilica materials are promising theranostic tools for biomedicine. However, hazardous effects of nanosilica especially after inhalation into the lung have been documented. Therefore, the safe development of nanosilica materials urgently requires predictive assays to monitor toxicity. Here, we further investigate the impact of the protein corona on the biological activity of two different types of nanosilica (colloidal and pyrogenic) in lung cells. As previously described, adsorption of serum proteins to the nanosilica surface suppresses cytotoxicity in macrophages and lung epithelial cells. As the increase of pro-inflammatory mediators is a hallmark of inflammation in the lung upon nanosilica exposure, we studied the potential coupling of the cytotoxic and pro-inflammatory response in A549 human lung epithelial cells and RAW264.7 mouse macrophages. Indeed, cytotoxicity precedes the onset of pro-inflammatory gene expression and cytokine release as exemplified for IL-8 in A549 cells and TNF-alpha in RAW264.7 macrophages after exposure to 0-100 µg/mL nanosilica in medium without serum. Formation of a protein corona not only inhibited cellular toxicity, but also the pro-inflammatory response. Of note, uptake of nanosilica into cells was negligible in the absence, but enhanced in the presence of a protein corona. Hence, the prevailing explanation that the protein corona simply interferes with cellular uptake thus preventing adverse effects needs to be revisited. In conclusion, for the reliable prediction of adverse effects of nanosilica in the lung, in vitro assays should be performed in media not complemented with complete serum. However, in case of different exposure routes, e.g., injection into the blood stream as intended for biomedicine, the protein corona prevents acute toxic actions of nanosilica.

Mobile Phone-Supported Physiotherapy for Frozen Shoulder: Feasibility Assessment Based on a Usability Study.

BACKGROUND: Patients with frozen shoulder show limited shoulder mobility often accompanied by pain. Common treatment methods include physiotherapy, pain medication, administration of corticosteroids, and surgical capsulotomy. Frozen shoulder often lasts from months to years and mostly affects persons in the age group of 40 to 70 years. It severely reduces the quality of life and the ability to work. OBJECTIVE: The objective of this study was to evaluate the feasibility of a mobile health (mHealth) intervention that supports patients affected by "stage two" frozen shoulder. Patients were supported with app-based exercise instructions and tools to monitor their training compliance and progress. These training compliance and progress data supplement the patients' oral reports to the physiotherapists and physicians and can assist them in therapy adjustment. METHODS: In order to assess the feasibility of the mHealth intervention, a pilot study of a newly developed app for frozen shoulder patients was conducted with 5 patients for 3 weeks. The main function of the app was the instruction for exercising at home. Standardized questionnaires on usability such as System Usability Scale (SUS) and USE (Usefulness, Satisfaction, and Ease of use), and Technology Acceptance Model-2 (TAM-2) were completed by the study participants at the end of the study. Additionally, a nonstandardized questionnaire was completed by all patients. The correctness of the exercises as conducted by the patients was assessed by a physiotherapist at the end of the study. The mobility of the shoulder and pain in shoulder movement was assessed by a physiotherapist at the start and the end of the study. RESULTS: The pilot study was successfully conducted, and the app was evaluated by the patients after 3 weeks. The results of the standardized questionnaires showed high acceptance (TAM-2) and high usability (SUS) of the developed app. The overall usability of the system as assessed by the SUS questionnaire was very good (an average score of 88 out of 100). The average score of the TAM-2 questionnaire on the intention to further use the app was 4.2 out of 5, which indicated that most patients would use the app if further available. The results of the USE questionnaires highlighted that the patients learned how to use the app easily (an average score of 4.2 out of 5) and were satisfied with the app (an average score of 4.7 out of 5). The frequency of app usage and training was very high based on patient reports and verified by analysis of the usage data. The patients conducted the exercises almost flawlessly. CONCLUSIONS: Our results indicate the feasibility of the mHealth intervention, as the app was easy to use and frequently used by the patients. The app supported the patients' physiotherapy by providing clear exercising instructions.

The oxidative potential of differently charged silver and gold nanoparticles on three human lung epithelial cell types.

BACKGROUND: Nanoparticle (NPs) functionalization has been shown to affect their cellular toxicity. To study this, differently functionalized silver (Ag) and gold (Au) NPs were synthesised, characterised and tested using lung epithelial cell systems. METHODS: Monodispersed Ag and Au NPs with a size range of 7 to 10 nm were coated with either sodium citrate or chitosan resulting in surface charges from -50 mV to +70 mV. NP-induced cytotoxicity and oxidative stress were determined using A549 cells, BEAS-2B cells and primary lung epithelial cells (NHBE cells). TEER measurements and immunofluorescence staining of tight junctions were performed to test the growth characteristics of the cells. Cytotoxicity was measured by means of the CellTiter-Blue ® and the lactate dehydrogenase assay and cellular and cell-free reactive oxygen species (ROS) production was measured using the DCFH-DA assay. RESULTS: Different growth characteristics were shown in the three cell types used. A549 cells grew into a confluent mono-layer, BEAS-2B cells grew into a multilayer and NHBE cells did not form a confluent layer. A549 cells were least susceptible towards NPs, irrespective of the NP functionalization. Cytotoxicity in BEAS-2B cells increased when exposed to high positive charged (+65-75 mV) Au NPs. The greatest cytotoxicity was observed in NHBE cells, where both Ag and Au NPs with a charge above +40 mV induced cytotoxicity. ROS production was most prominent in A549 cells where Au NPs (+65-75 mV) induced the highest amount of ROS. In addition, cell-free ROS measurements showed a significant increase in ROS production with an increase in chitosan coating. CONCLUSIONS: Chitosan functionalization of NPs, with resultant high surface charges plays an important role in NP-toxicity. Au NPs, which have been shown to be inert and often non-cytotoxic, can become toxic upon coating with certain charged molecules. Notably, these effects are dependent on the core material of the particle, the cell type used for testing and the growth characteristics of these cell culture model systems.

Differential pro-inflammatory effects of metal oxide nanoparticles and their soluble ions in vitro and in vivo; zinc and copper nanoparticles, but not their ions, recruit eosinophils to the lungs.

Abstract Nickel, zinc, and copper oxide nanoparticles (NiONP, ZnONP, and CuONP) and their aqueous extracts (AEs) were applied to A549 lung epithelial cells to determine the cytotoxicity, IL-8 production, and activation of transcription factors. Nanoparticles (NPs) and their AEs were also instilled into rat lungs to evaluate acute and chronic inflammatory effects. In vitro AEs had specific effects; for example NiOAE had no effect and ZnOAE affected all parameters measured. NPs themselves all had cytotoxic effects but only ZnONP and CuONP impacted pro-inflammatory endpoints. The inflammatory cells in the BAL were also different from AEs and NPs with ZnONP and CuONP recruiting eosinophils and neutrophils whilst ZnOAE and CuOAE elicited only mild neutrophilic inflammation that had resolved by four weeks. NiONP recruited neutrophils only whilst NiOAE did not cause any inflammation. Understanding differences in the toxic role of the ionic components of metal oxide NPs will contribute to full hazard identification and characterisation.

Nitration of the egg-allergen ovalbumin enhances protein allergenicity but reduces the risk for oral sensitization in a murine model of food allergy.

BACKGROUND: Nitration of proteins on tyrosine residues, which can occur due to polluted air under "summer smog" conditions, has been shown to increase the allergic potential of allergens. Since nitration of tyrosine residues is also observed during inflammatory responses, this modification could directly influence protein immunogenicity and might therefore contribute to food allergy induction. In the current study we have analyzed the impact of protein nitration on sensitization via the oral route. METHODOLOGY/PRINCIPAL FINDINGS: BALB/c mice were immunized intragastrically by feeding untreated ovalbumin (OVA), sham-nitrated ovalbumin (snOVA) or nitrated ovalbumin (nOVA) with or without concomitant acid-suppression. To analyze the impact of the sensitization route, the allergens were also injected intraperitoneally. Animals being fed OVA or snOVA under acid-suppressive medication developed significantly elevated levels of IgE, and increased titers of specific IgG1 and IgG2a antibodies. Interestingly, oral immunizations of nOVA under anti-acid treatment did not result in IgG and IgE formation. In contrast, intraperitoneal immunization induced high levels of OVA specific IgE, which were significantly increased in the group that received nOVA by injection. Furthermore, nOVA triggered significantly enhanced mediator release from RBL cells passively sensitized with sera from allergic mice. Gastric digestion experiments demonstrated protein nitration to interfere with protein stability as nOVA was easily degraded, whereas OVA and snOVA remained stable up to 120 min. Additionally, HPLC-chip-MS/MS analysis showed that one tyrosine residue (Y(107)) being very efficiently nitrated is part of an ovalbumin epitope recognized exclusively after oral sensitization. CONCLUSIONS/SIGNIFICANCE: These data indicated that despite the enhanced triggering capacity in existing allergy, nitration of OVA may be associated with a reduced de novo sensitizing capability via the oral route due to enhanced protein digestibility and/or changes in antibody epitopes.

Time evolution of the nanoparticle protein corona.

In this work, we explore the formation of the protein corona after exposure of metallic Au nanoparticles (NPs), with sizes ranging from 4 to 40 nm, to cell culture media containing 10% of fetal bovine serum. Under in vitro cell culture conditions, zeta potential measurements, UV-vis spectroscopy, dynamic light scattering and transmission electron microscope analysis were used to monitor the time evolution of the inorganic NP-protein corona formation and to characterize the stability of the NPs and their surface state at every stage of the experiment. As expected, the red-shift of the surface plasmon resonance peak, as well as the drop of surface charge and the increase of the hydrodynamic diameter indicated the conjugation of proteins to NPs. Remarkably, an evolution from a loosely attached toward an irreversible attached protein corona over time was observed. Mass spectrometry of the digested protein corona revealed albumin as the most abundant component which suggests an improved biocompatibility.

Interactions between effects of environmental chemicals and natural stressors: a review.

Ecotoxicological effect studies often expose test organisms under optimal environmental conditions. However, organisms in their natural settings rarely experience optimal conditions. On the contrary, during most of their lifetime they are forced to cope with sub-optimal conditions and occasionally with severe environmental stress. Interactions between the effects of a natural stressor and a toxicant can sometimes result in greater effects than expected from either of the stress types alone. The aim of the present review is to provide a synthesis of existing knowledge on the interactions between effects of "natural" and chemical (anthropogenic) stressors. More than 150 studies were evaluated covering stressors including heat, cold, desiccation, oxygen depletion, pathogens and immunomodulatory factors combined with a variety of environmental pollutants. This evaluation revealed that synergistic interactions between the effects of various natural stressors and toxicants are not uncommon phenomena. Thus, synergistic interactions were reported in more than 50% of the available studies on these interactions. Antagonistic interactions were also detected, but in fewer cases. Interestingly, about 70% of the tested chemicals were found to compromise the immune system of humans as judged from studies on human cell lines. The challenge for future studies will therefore be to include aspects of combined stressors in effect and risk assessment of chemicals in the environment.

The cytotoxic effects of the organophosphates chlorpyrifos and diazinon differ from their immunomodulating effects.

Some organophosphate insecticides have immunomodulating capacities, but it is unknown whether different compounds within this class affect the immune system to the same extent. In this in vitro study, human immortalized T-lymphocytes or bronchial epithelial cells were treated with diazinon or chlorpyrifos in the absence or presence of cellular stress factors, thereby mimicking a stimulated immune system. Cytotoxicity was determined and cytokine release or cytokine-promoter studies were performed to study immunomodulatory effects of these chemicals, whereby the same concentrations of chlorpyrifos and diazinon were used. Results showed that chlor- pyrifos was cytotoxic at concentrations >/= 250 muM, whereas diazinon was not toxic at concentrations up to 1 mM. The immunomodulatory effects of these two compounds were similar for most cytokine promoters tested and induction of cellular stress enhanced these effects. The results were compared to data obtained with blood mononuclear cells, which confirmed the results of stably transfected cell lines, but refer to a higher sensitivity of primary cells. In conclusion, these two pesticides act in a different manner on cell viability and on some immune parameters, but cell viability was not linked to immunomodulation. The results also imply that healthy and diseased individuals are differentially affected by these pollutants.

Dispersion medium modulates oxidative stress response of human lung epithelial cells upon exposure to carbon nanomaterial samples.

Due to their large specific surface area, the potential of nanoparticles to be highly reactive and to induce oxidative stress is particularly high. In addition, some types of nanoparticles contain transition metals as trace impurities which are known to generate reactive oxygen species (ROS) in biological systems. This study investigates the potential of two types of single-walled carbon nanotube samples, nanoparticulate carbon black and crocidolite asbestos to induce ROS in lung epithelial cells in vitro. Carbon nanotube and carbon black samples were used as produced, without further purification or processing, in order to best mimic occupational exposure by inhalation of airborne dust particles derived from carbon nanomaterial production. Intracellular ROS were measured following short-term exposure of primary bronchial epithelial cells (NHBE) and A549 alveolar epithelial carcinoma cells using the redox sensitive probe carboxydichlorofluorescin (carboxy-DCFDA). The oxidative potential of agglomerated nanomaterial samples was compared following dispersion in cell culture medium with and without foetal calf serum (FCS) supplement. In addition, samples were dispersed in dipalmitoylphosphatidylcholine (DPPC), the major component of lung surfactant. It could be illustrated that in vitro exposure of lung epithelial cells to carbon nanomaterial samples results only in moderate or low oxidative stress under the exposure conditions employed. However, cell responses are strongly dependent on the vehicle used for dispersion. Whereas the presence of DPPC increased intracellular ROS formation, FCS seemed to protect the cells from oxidative insult.

SWCNT suppress inflammatory mediator responses in human lung epithelium in vitro.

Single-walled carbon nanotubes have gained enormous popularity due to a variety of potential applications which will ultimately lead to increased human and environmental exposure to these nanoparticles. This study was carried out in order to evaluate the inflammatory response of immortalised and primary human lung epithelial cells (A549 and NHBE) to single-walled carbon nanotube samples (SWCNT). Special focus was placed on the mediating role of lung surfactant on particle toxicity. The toxicity of SWCNT dispersed in cell culture medium was compared to that of nanotubes dispersed in dipalmitoylphosphatidylcholine (DPPC, the main component of lung lining fluid). Exposure was carried out for 6 to 48 h with the latter time-point showing the most significant responses. Moreover, exposure was performed in the presence of the pro-inflammatory stimulus tumour necrosis factor-alpha (TNF-alpha) in order to mimic exposure of stimulated cells, as would occur during infection. Endpoints evaluated included cell viability, proliferation and the analysis of inflammatory mediators such as interleukin (IL)-8, IL-6, TNF-alpha and macrophage chemoattractant protein-1 (MCP-1). Crocidolite asbestos was included as a well characterised, toxic fibre control. The results of this study showed that HiPco SWCNT samples suppress inflammatory responses of A549 and NHBE cells. This was also true for TNF-alpha stimulated cells. The use of DPPC improved the degree of SWCNT dispersion in A549 medium and in turn, leads to increased particle toxicity, however, it was not shown to modify NHBE cell responses.

Chlorobenzene induces the NF-kappa B and p38 MAP kinase pathways in lung epithelial cells.

Chlorobenzene is a volatile organic compound that is used as a solvent in many industrial settings and has been shown to be related with irritations of the respiratory tract. Exposure to chlorobenzene induces the release of monocyte chemoattractant protein 1 (MCP-1) by lung epithelial cells, a chemokine involved in inflammatory reactions. To characterize the underlying mechanisms we investigated the influence of chlorobenzene on the activation of two intracellular signalling pathways: the nuclear factor-kappa B (NF-kappa B) and the p38 mitogen-activated protein kinase (MAPK) pathways. Human lung epithelial cells (A549) were stimulated with tumor necrosis factor (TNF)-alpha in the presence or absence of specific inhibitors of NF-kappaB or the p38 MAP kinase and exposed to chlorobenzene using an air-liquid cell culture system. Exposure of lung epithelial cells to chlorobenzene resulted in an activation of NF-kappa B and p38 MAP kinase and a release of the chemokine MCP-1. In the presence of IKK-NBD, a specific NF-kappa B inhibitor, or the inhibitors of the p38 MAP kinase SB 203580 and SB 202190, the chlorobenzene-related MCP-1 release was suppressed, suggesting an involvement of both pathways in the chlorobenzene induced expression of MCP-1. Our data show that the release of MCP-1 following chlorobenzene exposure is dependent on the NF-kappa B and MAPK pathways.

Styrene induces an inflammatory response in human lung epithelial cells via oxidative stress and NF-kappaB activation.

Styrene is a volatile organic compound (VOC) that is widely used as a solvent in many industrial settings. Chronic exposure to styrene can result in irritation of the mucosa of the upper respiratory tract. Contact of styrene with epithelial cells stimulates the expression of a variety of inflammatory mediators, including the chemotactic cytokine monocyte chemoattractant protein-1 (MCP-1). To characterise the underlying mechanisms of the induction of inflammatory signals by styrene, we investigated the influence of this compound on the induction of oxidative stress and the activation of the nuclear factor-kappa B (NF-kappaB) signalling pathway in human lung epithelial cells (A549). The results demonstrate that styrene-induced MCP-1 expression, as well as the expression of the oxidative stress marker glutathione S-transferase (GST), is associated with a concentration dependent pattern of NF-kappaB activity. An inhibitor of NF-kappaB, IKK-NBD, and the anti-inflammatory antioxidant N-acetylcysteine (NAC) were both effective in suppressing styrene-induced MCP-1 secretion. In addition, NAC was capable of inhibiting the upregulation of GST expression. Our findings suggest that the activation of the NF-kappaB signalling pathway by styrene is mediated via a redox-sensitive mechanism.

A high-throughput screening method based on stably transformed human cells was used to determine the immunotoxic effects of fluoranthene and other PAHs.

Exogenous substances may compromise the human immune system, but immunotoxic effects of many pollutants have not been sufficiently determined thus far. It is often unknown which parameters should be taken into consideration when the immunotoxicity of a pollutant is analysed. Moreover, certain substances might only affect a primed immune system, but have no effect on healthy individuals. In order to analyse immunological responses caused by exposure to pollutants, a screening method has been established in our laboratory that uses a panel of stably transfected human cell lines containing promoter regions for different cytokines and chemokines. The luciferase sequence present at the 3' end of the promoter allows for the analysis of enzymatic luciferase activity. Four polycyclic aromatic hydrocarbons were used to evaluate this screening assay. Moreover, we compared promoter induction with cytokine production and tested the effect of fluoranthene on primary lung epithelial cells. The results showed that the regulation of different promoter genes is pollutant specific and differs between individual PAHs, and that the regulation is affected by the presence of a pro-inflammatory stimulator. The use of a panel of human cell lines stably transfected with different cytokine promoters is an easy-to-use tool for screening in immunotoxicological studies and might decrease the number of animal tests for such studies.

Patulin influences the expression of Th1/Th2 cytokines by activated peripheral blood mononuclear cells and T cells through depletion of intracellular glutathione.

Patulin is a mold toxin secreted mainly by fungi of the Penicillium species. Exposure generally results from consumption of moldy fruits and fruit products. Since recent studies identified mold exposure as a risk factor for allergic diseases, we examined the effects of patulin on human peripheral blood mononuclear cells (PBMC) prepared from buffy coats of healthy donors. Cells were stimulated with CD3- and CD28-specific antibodies in the presence or absence of patulin. Effects of patulin on PBMCs were evaluated by proliferation, viability assays, and cytokine ELISAs. The presence of 50 ng/mL patulin strongly decreased the amounts of several cytokines in the supernatant of stimulated PBMCs. This decrease in cytokine secretion was not due to cytotoxic effects of patulin. Moreover, the extent of the reduction of cytokine amounts was cytokine specific, affecting some (IL-4, IL-13, IFNgamma, and IL-10), but not others (IL-8, IL-5). We show that all effects could be abolished by adding thiol containing compounds. A depletion of intracellular GSH could be measured after incubation of cells with patulin. Taken together, our data indicate that patulin modulates the functional activation of PBMCs with respect to proliferation and cytokine secretion patterns by depletion of intracellular GSH. The depletion of intracellular glutathione may influence the balance between Th1 and Th2 cells and have implications for allergic diseases.