T-cell receptor repertoire expression in workers with occupational asthma due to platinum salt

Mechanistic and Therapeutic Approaches to Occupational Exposure-Associated Allergic and Non-Allergic Asthmatic Disease

PURPOSE OF REVIEW

Occupational lung disease, including asthma, is a significant cause of disability worldwide. The dose, exposure frequency, and nature of the causal agent influence the inflammatory pathomechanisms that inform asthma disease phenotype and progression. While surveillance, systems engineering, and exposure mitigation strategies are essential preventative considerations, no targeted medical therapies are currently available to ameliorate lung injury post-exposure and prevent chronic airway disease development.

RECENT FINDINGS

This article reviews contemporary understanding of allergic and non-allergic occupational asthma mechanisms. In addition, we discuss the available therapeutic options, patient-specific susceptibility and prevention measures, and recent scientific advances in post-exposure treatment conception. The course of occupational lung disease that follows exposure is informed by individual predisposition, immunobiologic response, agent identity, overall environmental risk, and preventative workplace practices. When protective strategies fail, knowledge of underlying disease mechanisms is necessary to inform targeted therapy development to lessen occupational asthma disease severity and occurrence.

In vitro co-culture model of human monocyte-derived dendritic cells and T cells to evaluate the sensitization of dinitrochlorobenzene

Exposure to sensitizer has been suggested to be hazardous to human health, evaluation the sensitization of sensitizer is particularly important and urgently needed. Dendritic cells (DCs) exert an irreplaceable function in immunity, and the T cell receptor (TCR) repertoire is key to ensuring immune response to foreign antigens. We hypothesized that a co-culture model of human monocyte-derived dendritic cells (Mo-DCs) and T cells could be employed to evaluate the sensitization of DNCB. An experimental model of DNCB-induced sensitization in rat was employed to examine alterations of cluster of differentiation CD103⁺ DCs and T cells. A co-cultured model of Mo-DCs and T cells was developed in vitro to assess the sensitization of DNCB through the phenotypic and functional alterations of Mo-DCs, as well as the TCR repertoire. We found that the CD103⁺ DCs phenotype and T-helper (Th) cells polarization altered in sensitization rats. In vitro, phenotypic alteration of Mo-DCs caused by DNCB were consistent with in vivo results, antigen uptake capacity of Mo-DCs diminished and capacity of Mo-DCs to prime T cell increased. Clones of the TCR repertoire and the diversity of TCR repertoire were enhanced, changes were noted in the usage of variable, joining, and variable-joining gene combinations. DNCB exposure potentiated alterations and characteristics of Mo-DCs and the TCR repertoire in a co-culture model. Such changes provided innovative ideas for evaluating sensitization of DNCB.

Outpatient desensitization in selected patients with platinum hypersensitivity reactions

Platinum-based chemotherapies are a standard treatment for both initial and recurrent gynecologic cancers. Given this widespread use, it is important to be aware of the features of platinum hypersensitivity reactions and the subsequent treatment of these reactions. There is also increasing interest in the development of desensitization protocols to allow patients with a history of platinum hypersensitivity to receive further platinum based therapy. In this review, we describe the management of platinum hypersensitivity reactions and the desensitization protocols utilized at our institution. We also describe the clinical categorizations utilized to triage patients to appropriate desensitization protocols.

Thresholds in chemical respiratory sensitisation

There is a continuing interest in determining whether it is possible to identify thresholds for chemical allergy. Here allergic sensitisation of the respiratory tract by chemicals is considered in this context. This is an important occupational health problem, being associated with rhinitis and asthma, and in addition provides toxicologists and risk assessors with a number of challenges. In common with all forms of allergic disease chemical respiratory allergy develops in two phases. In the first (induction) phase exposure to a chemical allergen (by an appropriate route of exposure) causes immunological priming and sensitisation of the respiratory tract. The second (elicitation) phase is triggered if a sensitised subject is exposed subsequently to the same chemical allergen via inhalation. A secondary immune response will be provoked in the respiratory tract resulting in inflammation and the signs and symptoms of a respiratory hypersensitivity reaction. In this article attention has focused on the identification of threshold values during the acquisition of sensitisation. Current mechanistic understanding of allergy is such that it can be assumed that the development of sensitisation (and also the elicitation of an allergic reaction) is a threshold phenomenon; there will be levels of exposure below which sensitisation will not be acquired. That is, all immune responses, including allergic sensitisation, have threshold requirement for the availability of antigen/allergen, below which a response will fail to develop. The issue addressed here is whether there are methods available or clinical/epidemiological data that permit the identification of such thresholds. This document reviews briefly relevant human studies of occupational asthma, and experimental models that have been developed (or are being developed) for the identification and characterisation of chemical respiratory allergens. The main conclusion drawn is that although there is evidence that the acquisition of sensitisation to chemical respiratory allergens is a dose-related phenomenon, and that thresholds exist, it is frequently difficult to define accurate numerical values for threshold exposure levels. Nevertheless, based on occupational exposure data it may sometimes be possible to derive levels of exposure in the workplace, which are safe. An additional observation is the lack currently of suitable experimental methods for both routine hazard characterisation and the measurement of thresholds, and that such methods are still some way off. Given the current trajectory of toxicology, and the move towards the use of non-animal in vitro and/or in silico) methods, there is a need to consider the development of alternative approaches for the identification and characterisation of respiratory sensitisation hazards, and for risk assessment.

Antigen-specific T cell phenotyping microarrays using grating coupled surface plasmon resonance imaging and surface plasmon coupled emission

The circulating population of peripheral T lymphocytes obtained from a blood sample can provide a large amount of information about an individual's medical status and history. Recent evidence indicates that the detection and functional characterization of antigen-specific T cell subsets within the circulating population may provide a diagnostic indicator of disease and has the potential to predict an individual's response to therapy. In this report, a microarray detection platform that combines grating-coupled surface plasmon resonance imaging (GCSPRI) and grating-coupled surface plasmon coupled emission (SPCE) fluorescence detection modalities were used to detect and characterize CD4(+) T cells. The microspot regions of interest (ROIs) printed on the array consisted of immobilized antibodies or peptide loaded MHC monomers (p/MHC) as T cell capture ligands mixed with additional antibodies as cytokine capture ligands covalently bound to the surface of a corrugated gold sensor chip. Using optimized parameters, an unlabeled influenza peptide reactive T cell clone could be detected at a frequency of 0.1% in a mixed T cell sample using GCSPRI. Additionally, after cell binding was quantified, differential TH1 cytokine secretion patterns from a T cell clone cultured under TH1 or TH2 inducing conditions was detected using an SPCE fluorescence based assay. Differences in the secretion patterns of 3 cytokines, characteristic of the inducing conditions, indicated that differences were a consequence of the functional status of the captured cells. A dual mode GCSPRI/SPCE assay can provide a rapid, high content T cell screening/characterization tool that is useful for diagnosing disease, evaluating vaccination efficacy, or assessing responses to immunotherapeutics.

Lymphocyte subpopulations in human exposure to metals (IUPAC Technical Report)

Numerous species of metal ions cause immunosensitization in humans. Possible approaches to determine those occupational and environmental exposures to metals that result in immunological changes include lymphocyte transformation assay, cytokine profiling, and measurement of lymphocyte subpopulations. In two previous papers, we considered lymphocyte transformation assay [1] and cytokine profiling [2]. Here we review the effects of exposures to metals on lymphocyte subpopulations. Specific consideration is given to beryllium, chromium, cobalt, nickel, palladium and platinum, cadmium, gold, mercury, and lead. Analysis of the scientific literature shows that immunosensitizing metals may have influences on the lymphocyte subset composition, but only in a few instances does exposure to metals cause reproducible shifts of lymphocyte subpopulations. If lymphocyte subpopulations are analyzed, each diagnostic step, including indication, sample handling, analytic procedure, and data interpretation, should adhere to good quality assurance and quality control.

Proteomic analysis of peripheral T-lymphocytes in patients with asthma

BACKGROUND

Asthma is chronic airway inflammation that occurs together with reversible airway obstruction. T-lymphocytes play an important role in the pathogenesis of asthma. Proteomic technology has rapidly developed in the postgenomic era, and it is now widely accepted as a complementary technology to genetic profiling. We investigated the changes of proteins in T-lymphocytes of asthma patients by using standard proteome technology: two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and a database search.

METHODS

The proteins of CD3+ T-lymphocytes were isolated from whole blood of six steroid-naive asthmatic patients and of six healthy volunteers. 2D-PAGE was performed and the silver-stained protein spots were comparatively analyzed between the asthma and control groups using an image analyzer. Some differentially expressed spots were identified by MALDI-TOF-MS and database search. The messenger RNA expressions of some identified proteins were examined by real-time polymerase chain reaction (RT-PCR).

RESULTS

Thirteen protein spots in the T-lymphocytes of the asthmatic patients were increased and 12 spots were decreased compared to those of the normal subjects. Among the identified proteins, the increased expression of the messenger RNA of phosphodiesterase 4C and thioredoxin-2 and the decreased expression of the messenger RNA of glutathione S-transferase M3 were confirmed by RT-PCR in the asthmatic patients.

CONCLUSIONS

Proteomic examination of the peripheral T-lymphocytes revealed some differentially expressed proteins in the asthmatic patients. The possibility of using the differentially expressed proteins as important biomarkers and therapeutic targets in asthma patients warrants further studies.

Evaluation of the incidence of carboplatin hypersensitivity reactions in cancer patients

OBJECTIVES

Although the reported incidence of carboplatin hypersensitivity is low, its occurrence is important to characterize because of potential fatal complications. The purpose of this study was to determine the current incidence of carboplatin hypersensitivity in the ovarian cancer patients compared to other oncology patients and identify potential risk factors that may contribute to development of carboplatin hypersensitivity reactions.

METHODS

This was a retrospective chart review analyzing all hospital records at an academic tertiary oncology center between July 2002 and September 2003. Data collected included patient demographics, past medical histories, and detailed carboplatin administration information. Patients that had received carboplatin were identified from pharmacy dispensing records. Positive carboplatin hypersensitivity reactions were identified from the documentation provided in the patient medical record.

RESULTS

The incidence of carboplatin hypersensitivity for all cancer patients compared to ovarian cancer patients receiving carboplatin at our institution was 2.6% and 7.9%, respectively. Statistically significant risk factors (P < 0.05) included prior carboplatin exposure and history of drug allergies. There was also a trend to suggest premedication with histamine1 (H1) and histamine(2) (H2) blocker decreases the risk of developing carboplatin hypersensitivity reactions.

CONCLUSION

This study confirmed a similar incidence of carboplatin hypersensitivity reactions to previous reports. However, we found that the higher incidence associated with ovarian cancer patients can be attributed to the prolonged carboplatin exposure or history of drug allergies. This is the first study to observe that the administration of H1 and H2 antagonists is associated with a decrease risk of carboplatin hypersensitivity reaction.

Neutrophils potentiate platinum-mediated injury to human ciliated epithelium in vitro

Exposure to platinum salts, such as may occur in the platinum refining industry, can be associated with the development of airway disorders such as asthma. However, there have been no studies investigating the direct effects of platinum salts on human ciliated epithelium. We have investigated the effects of platinic chloride on human ciliated epithelium, obtained by brushing the inferior nasal turbinate of healthy human volunteers. Ciliary beat frequency was measured using a phototransistor technique, and damage to the structural integrity of the epithelium was measured using a visual scoring index. Platinic chloride at concentrations between 0.25 and 25 microM caused a dose-dependent slowing of ciliary beating and damage to the structural integrity of the epithelium. These direct injurious effects were not affected by catalase, but were almost completely attenuated by preincubation of the epithelium with cysteine. The effects of platinic chloride on ciliary beating and structural integrity were enhanced by the presence of neutrophils and were partially attenuated by preincubation of the epithelial strips with catalase, suggesting that the direct effects of the metal were enhanced in this experimental system by reactive oxidants produced by activated neutrophils. This study documents that platinum salts have an injurious effect on human ciliated epithelium in vitro. If such effects also occur in vivo they may play a role, at least partly, in the pathogenesis of airway disorders that may manifest in exposed workers.

Effects of platinum and palladium ions on the production and reactivity of neutrophil-derived reactive oxygen species

This study was designed to investigate the effects of platinum, as hydrogen hexachloroplatinate (Pt; 0.0025-25 microM), on the production of reactive oxygen species (ROS) by human neutrophils in vitro. ROS were measured by lucigenin-enhanced chemiluminescence (LECL). Addition of Pt to neutrophils was accompanied by a lag phase of about 1 min, followed by a linear dose-related increase in LECL, which peaked at around 4 min and achieved statistical significance at concentrations of 0.025 microM Pt and higher. Interestingly, Pt-mediated enhancement of LECL was not associated with meaningful alterations in neutrophil oxygen consumption, assembly of NADPH oxidase, or cytosolic Ca2+ and was completely attenuated by superoxide dismutase and inhibitors of NADPH oxidase, but not by catalase or scavengers of hydroxyl radical, and was undetectable with cells from individuals with chronic granulomatous disease. Exposure of alpha1-proteinase inhibitor to Pt-treated neutrophils resulted in inactivation of elastase-inhibitory capacity, underscoring the potential toxicity of neutrophil/Pt interactions. The pro-oxidative actions of Pt were mimicked by palladium (Pd), but not by cisplatin or rhodium. These observations demonstrate that Pt and Pd potentiate the reactivity, as opposed to the generation of neutrophil-derived oxidants, an activity that may contribute to airway inflammation in occupationally and possibly environmentally exposed individuals.

Does IL-4 play a role in the expansion of V beta 8a T cell receptor-bearing cells?

BACKGROUND

Peripheral blood mononuclear cells (PBMC) of subjects allergic to the insect-derived allergen Chi t 1--9 are characterized by an allergen-induced pronounced proliferation and increased expression of activation markers (CD25, HLA-DR, CD23). T cell lines showed an elevated percentage of V beta 8a-positive cells following stimulation by Chi t 1--9.

OBJECTIVE

The aim of the present study was to investigate whether V beta 8a dominance plays an important role in PBMC short-term cultures (24 h) as well. The role of exogenous added cytokines, especially IL-4, has been determined.

METHODS

The T cell receptor repertoire was measured with 16 monoclonal antibodies to epitopes on the variable region of the beta chain by flow cytometry. Patients allergic to Chi t 1--9 were compared to nonallergic subjects as well as to subjects with other occupational allergies. In addition, cytokines were determined intracellulary by flow cytometry. Studies were performed with PBMC cultured for 24 h.

RESULTS

After cultivation for 24 h without or with different stimuli (cytokines, allergen, phytohaemagglutinin), changes in the T cell receptor profile and the cytokine profile were measurable compared to the baseline value (without cultivation). Stimulation with IL-4 revealed increased percentages of V beta 8a-expressing cells in Chi t 1--9-sensitized patients. This IL-4-induced V beta 8a increase did not occur in PBMC from the two control subject groups (non-allergic and allergic to other allergens than Chi t 1--9). CONCLUSION In conclusion, the dominance of certain T cell receptor types seems to arise due to the exposure to specific allergens and cytokine production. Some T cell receptors are often affected, for example V beta 8a, whereas others only show minor variations. V beta 8a expression obviously plays an important role in Chi t 1-9 allergy.