Chemical sensitization and allergotoxicology.

Chemical sensitization remains an important environmental and occupational health issue. A wide range of substances have been shown to possess the ability to induce skin sensitization or respiratory sensitization. As a consequence, there is a need to have appropriate methods to identify sensitizing agents.

Biomonitoring and biomarkers to unravel the risks from prenatal environmental exposures for later health outcomes.

An increasing number of studies have addressed the concern that environmental pollutants may contribute to the early origin of diseases. Epidemiologic studies suggest that prenatal exposure to air pollutants, several food contaminants, and chemicals present in consumer products are associated with nongenetically transmitted adverse health effects, which manifest after birth. Changes in neurobehavior, sexual development, the prevalence of asthma and allergy, and growth curves have been shown to be associated with pollutant exposure at early life stages.

Microarray analyses in dendritic cells reveal potential biomarkers for chemical-induced skin sensitization.

The assessment of the skin sensitising capacity of chemicals is up to now investigated using in vivo animal tests. However there has been an increasing public and governmental concern regarding the use of animals for chemical screening. This has raised the need for the development of validated in vitro alternatives.

Gene expression signatures in CD34+-progenitor-derived dendritic cells exposed to the chemical contact allergen nickel sulfate.

The detection of the sensitizing potential of chemicals is of great importance to industry. A promising in vitro alternative to the currently applied animal assays for sensitization testing makes use of dendritic cells (DCs) that have the capability to process and present antigens to naive T cells and induce their proliferation. Here, we studied changes in gene expression profiles after exposing DCs to the contact allergen nickel sulfate.

Capacity of CD34+ progenitor-derived dendritic cells to distinguish between sensitizers and irritants.

In an attempt to develop an in vitro test to identify contact sensitizers, mostly dendritic cells (DCs) derived from monocytes (Mo-DC) have been used. Less is known about the potency of DC derived from CD34+ progenitors (CD34-DC) for in vitro allergen testing. CD34+ progenitor derived DC were exposed to nine well-known allergens (one weak, three moderate and five strong allergens) and two irritants.

Cytokine transcript profiling in CD34+-progenitor derived dendritic cells exposed to contact allergens and irritants.

We here investigated wether genes encoding the interleukins IL-1beta, IL-6 and IL-8, and the chemokines CCL2, CCL3, CCL3L1 and CCL4 are useful markers for sensitization testing in CD34+-progenitor derived dendritic cells (CD34-DC). CD34-DC from at least three donors were exposed during 0.5 up to 24h to the chemical sensitizers nickel sulphate, oxazolone, 2,4-dinitrochlorobenzene (DNCB) and eugenol, and to the irritants sodium dodecyl sulphate (SDS) and benzalkonium sulphate (BC).

Immunologic biomarkers in relation to exposure markers of PCBs and dioxins in Flemish adolescents (Belgium).

In this study, we investigated 17- to 18-year-old boys and girls to determine whether changes in humoral or cellular immunity or respiratory complaints were related to blood serum levels of polychlorinated biphenyls (PCBs) and dioxin-like compounds after lifetime exposure in Flanders (Belgium). We obtained blood samples from and administered questionnaires to 200 adolescents recruited from a rural area and two urban suburbs. Physicians recorded medical history and respiratory diseases.

Phenotypic alterations and IL-1beta production in CD34(+) progenitor- and monocyte-derived dendritic cells after exposure to allergens: a comparative analysis.

Dendritic cells (DC) have been shown to capture and process antigens and play an initiating role in contact sensitization. Cells with dendritic morphology can be generated in vitro either from CD34(+) cord blood cells or from CD14(+) peripheral monocytes. The aim of this study was to determine the state of maturation/activation of both populations after exposure to several concentrations of four well-established model allergens (nickel sulfate, eugenol, alpha-hexylcinnamaldehyde and 2,4,6-trinitrobenzene sulfonic acid) or the irritant sodium dodecyl sulfate.