Comparative in situ topoproteome analysis reveals differences in patch test-induced eczema: cytotoxicity-dominated nickel versus pleiotrope pollen reaction.

A subgroup of patients with atopic eczema develops acute eczematous reactions to type I allergy-inducing agents such as pollen that clinically resemble type IV allergies induced by haptens like metal ions. To clarify the underlying immunologic mechanisms, this study was designed to map the inflammatory in situ topoproteome of eczematous responses to grass/birch pollen and nickel by using atopy patch test (APT) and nickel patch test (NPT) as an appropriate clinical model, respectively. Biopsies from NPT (n = 6) and APT (n = 6) with positive reactions at 72 h were analysed by multiple epitope ligand cartography (MELC), which enabled to investigate coexpression of 49 different epitopes immunohistochemically in a single given tissue section. Colocalisation of IgE and FcepsilonRI was investigated by confocal microscopy. Compared with APT responses, NPT reactions were dominated by cytotoxic TIA-1 + and CD8 + T cells. In contrast, the immune response in APT reactions appeared more pleiotrope - as detected by colocalisation analysis. Multiple combinatorial molecular phenotype (CMP) motifs containing naive, early maturation and memory T cell (CD45RA, CD7, CD44, CD45R0), and general activation markers (CLA, HLA-DR, CD13, CD29, CD58, CD71, CD138) were significantly higher expressed in APT when compared with NPT reactions. APT response was confirmed to be accompanied by IgE bound to FcepsilonRI. In summary, our results demonstrate that the NPT reaction is clearly dominated by cytotoxic events, while the APT reaction to pollen grains is more heterogeneous and elicits a combined humoral and cellular immune reaction.

In-situ-topoproteome analysis of cutaneous lymphomas: perspectives of assistance for dermatohistologic diagnostics by Multi Epitope Ligand Cartography (MELC).

BACKGROUND: Immunophenotyping is essential for diagnostics of cutaneous lymphomas. In this regard we present a skin tissue-adapted application platform of MELC technology. PATIENTS AND METHODS: This topoproteome analysis allows the subcellular colocalization of at least n = 100 epitopes in situ. For this purpose the specimen is processed by a Toponome Imaging Cycler for a n-fold repetition of the following cycle: 1) staining with a fluorophore-labeld antibody, 2) fluorescence-imaging, and 3) photobleaching. Overlay and binarization of fluorescence images lead to combinatorial molecular phenotypes (CMP), which relate to a pixel or microtopographic unit (450 x 450 nm2, 20x objective). Skin biopsies were derived from patients with mycosis fungoides (patch/plaque lesions), psoriasis, atopic eczema and from healthy skin donors. RESULTS: In orientation to the WHO-EORTC-classification of cutaneous lymphomas a MELC-library of 23 markers was established. According to an inaugurative detailed procedure the CMP frequency was determined in a normalization to 100 microm horizontal skin width. By a TopoMiner strategy mycosis fungoides could be separated from the other states with a maximum of significance (p < or = 0.03) by at least 10-fold overexpression of the following tumor cell-representative CMP-motif: CD3+/CD4+/CD1a-/CD7-/CD8-/CD45R0+/CD45RA-/CD11a+. CONCLUSIONS: The skin tissue-adapted MELC-application-platform extends substantially conventional lymphoma diagnostics by an unprecedented dimension of in-situ-analysis of marker combinatorics including its exact quantification and visualization.

UVB irradiation-induced impairment of keratinocytes and adaptive responses to oxidative stress.

UVB irradiation of human skin is known to induce pathophysiological processes as oxidative stress and inflammation. HaCaT keratinocytes represent a well-established in vitro model system to investigate the influence of UVB irradiation on cell cultures. It was the aim of these investigations to study the effects of moderate UVB doses on cellular and mitochondrial integrity of HaCaT keratinocytes, biomarkers of oxidative stress and antioxidant protection by superoxide dismutases. F(2)-isoprostane concentrations were UVB dose-dependently enhanced reaching a plateau at 50 mJ/cm(2). Cell viability was reduced and apoptosis was enhanced with increasing UVB doses. The activities of the respiratory chain complexes were practically not altered at lower UVB doses, up to 50 mJ/cm(2), whereas remarkable decreases, also for the levels of cardiolipin species, were seen at 100 mJ/cm(2). As an adaptive response to the enhanced oxidative stress, protein levels of MnSOD increased about 3-fold at 50 mJ/cm(2) and decreased at higher doses. From the data it can be concluded that keratinocytes are sufficiently protected at low UVB doses, whereas higher doses lead to irreversible cell damage.

Analyzing proteome topology and function by automated multidimensional fluorescence microscopy.

Temporal and spatial regulation of proteins contributes to function. We describe a multidimensional microscopic robot technology for high-throughput protein colocalization studies that runs cycles of fluorescence tagging, imaging and bleaching in situ. This technology combines three advances: a fluorescence technique capable of mapping hundreds of different proteins in one tissue section or cell sample; a method selecting the most prominent combinatorial molecular patterns by representing the data as binary vectors; and a system for imaging the distribution of these protein clusters in a so-called toponome map. By analyzing many cell and tissue types, we show that this approach reveals rules of hierarchical protein network organization, in which the frequency distribution of different protein clusters obeys Zipf's law, and state-specific lead proteins appear to control protein network topology and function. The technology may facilitate the development of diagnostics and targeted therapies.

Profiling lymphocyte subpopulations in peripheral blood under efalizumab treatment of psoriasis by multi epitope ligand cartography (MELC) robot microscopy.

CD11a-blocking efalizumab has recently been approved as a systemic treatment of moderate to severe chronic plaque psoriasis. When treating 6 psoriasis patients with efalizumab over 12 weeks in the present study, we observed an overall good tolerability and 5 treatment responders characterized by a decrease of PASI from 21.3 +/- 5.4 to 3.9 +/- 0.6. The accompanying significant increase of peripheral blood lymphocytes from 1.9 +/- 0.7 to 4.3 +/- 1.0 x 10(9)/L (p < 0.05) was analyzed by multi epitope ligand cartography (MELC) robot microscopy. Thereby a high-dimension simultaneous multiplex immunophenotyping was pursued using 39 fluorophore-labeled antibodies including labeled efalizumab and 3 other affinity reagents such as lectins. Due to efalizumab treatment there was a substantial decrease of the cellular expression of CD11a (detected by mab clone 25.3.1) and efalizumab binding sites (EfaBSs). This was paralleled by an increase of the number of EfaBS- and EfaBS+ lymphocytes by a factor of 2.4x and 2.2x, respectively. The latter effect was mainly derived from a subpopulation showing a low degree of EfaBS expression. Efalizumab treatment led furthermore to an increase of the numbers of CD3+, CD4+, CD8+, CD44+, CD45+, CD45R0+, CD45 RA+, CD52+, CD58+, CD247+, HLA-DR+ and Sambucus nigra lectin-reactive lymphocytes (by factors from 2.0 to 3.3x). In terms of a combinatorial molecular phenotype we identified a CD3+/CD4+/CD44+/CD52+ lymphocyte subpopulation which accumulated most predominantly from 0.824 +/- 0.270 x 10(9)/L up to 1.616 +/- 0.152 x 10(9)/L under efalizumab treatment (p < 0.01). Thus, the current study extends the knowledge of efalizumab-dependent perturbations of recirculating blood lymphocyte subpopulations in psoriasis patients.