Vitamin D-Induced Promotor Dissociation of PU.1 and YY1 Results in FcεRI Reduction on Dendritic Cells in Atopic Dermatitis.

Atopic dermatitis (AD) is a severe inflammatory skin disease. Langerhans cells and inflammatory dendritic epidermal cells (IDEC) are located in the epidermis of AD patients and contribute to the inflammatory processes. Both express robustly the high-affinity receptor for IgE, FcεRI, and thereby sense allergens.

AhR mediates an anti-inflammatory feedback mechanism in human Langerhans cells involving FcεRI and IDO.

Background: Aryl hydrocarbon receptor (AhR), an important regulator of immune responses, is activated by UVB irradiation in the skin. Langerhans cells (LC) in the epidermis of patients with atopic dermatitis (AD) carry the high-affinity receptor for IgE, FcεRI, and are crucially involved in the pathogenesis of AD by inducing inflammatory responses and regulating tolerogenic processes.

Objectives: We investigated AhR and AhR repressor (AhRR) expression and functional consequences of AhR activation in human ex vivo skin cells and in in vitro-generated LC.

Among the S100 proteins, S100A12 is the most significant marker for psoriasis disease activity.

Background: Psoriasis is a chronic skin disease with deregulation of proteins in the immune system. These proteins include members of the heterogeneous S100 family, which have been discussed as potential biomarkers for disease severity.

Objective: The aim of this study was to evaluate the impact of S100A7, S100A8, S100A9 and S100A12 as possible markers for disease activity in patients with psoriasis skin disease.

Generation and functional analysis of human TNF-α/iNOS-producing dendritic cells (Tip-DC).

Background: A unique type of CD11c(pos) dendritic cells (DC) is abundant in inflamed tissue, for example, in chronic inflammatory skin diseases. Due to their remarkable production of tumor necrosis factor (TNF)-α and inducible NO synthase (iNOS), these cells have been referred to as TNF and iNOS-producing DC (Tip-DC). While Tip-DC have been mainly characterized in murine models of infection, functional data about their human counterpart are lacking.

TLR2 down-regulates FcεRI and its transcription factor PU.1 in human Langerhans cells.

Background: Epidermal Langerhans cells (LC) expressing the high-affinity receptor for IgE (FcεRI) play a key role in atopic dermatitis (AD). AD skin is highly colonized with Staphylococcus aureus (S.a.

Subpopulations of human dendritic cells display a distinct phenotype and bind differentially to proteins of the extracellular matrix.

CD1a(pos) dendritic cells (DCs) and Langerhans cells (LCs) are highly specialized antigen-presenting cells mainly localized in the skin. Various cells have been identified as precursors of cutaneous DCs, but the definitive precursor subpopulations remain to be defined and characterized in detail. In this study, DCs were generated in vitro from monocytes (monocyte-derived DCs, MoDCs) and from CD34(pos) stem cells (CD34(pos) cell-derived DCs, CD34DCs).

Migration and differentiation of Langerhans cell precursors.

Epidermal Langerhans cells (LC) are the first sentinels of the skin immune system. To study immigration of human LC precursor cells into the skin, we established a two-compartmental skin model consisting of a dermal matrix and an epidermal sheet of keratinocytes. We tested the individual components of the skin model for their influence on phenotype and function of LC precursors.

The analysis of tyrosinase-specific mRNA in blood samples of melanoma patients by RT-PCR is not a useful test for metastatic tumor progression.

Reverse transcription (RT) of the tyrosinase mRNA and specific cDNA amplification by nested polymerase chain reactin (PCR) have been reported to facilitate the early detection of circulating tumor cells in melanoma patients. The significance and practical value of this procedure for the diagnosis of tumor dissemination in melanoma patients are unclear. In the current study we analyzed peripheral blood samples of 65 melanoma patients of different clinical stages for the presence of tyrosinase mRNA by RT-PCR using nested oligonucleotide primers specific for tyrosinase cDNA.

The CD7- T cell subset represents the majority of IL-5-secreting cells within CD4+CD45RA- T cells.

Absence of CD7 is a stable phenotype in a subset of normal human T cells. Most circulating CD7- T cells express the CD4CD45RO+CD45RA- memory phenotype. We analysed CD4+CD45RA- peripheral blood lymphocytes that were separated into CD7+ and CD7- for their in vitro cytokine secretion in response to different stimuli.