Major differences between human atopic dermatitis and murine models, as determined by using global transcriptomic profiling.

Background: Atopic dermatitis (AD) is caused by a complex interplay between immune and barrier abnormalities. Murine models of AD are essential for preclinical assessments of new treatments. Although many models have been used to simulate AD, their transcriptomic profiles are not fully understood, and a comparison of these models with the human AD transcriptomic fingerprint is lacking.

A proteomics approach to the identification of biomarkers for psoriasis utilising keratome biopsy.

Unlabelled: The discovery of plasma biomarkers for psoriasis vulgaris may aid clinicians in disease grading and monitoring of treatment response. We have therefore developed a proteomics/mass spectrometry based workflow which enables biomarker discovery from psoriasis patient samples. We have utilised keratome skin biopsy, which results in reduced cellular complexity compared to punch biopsy.

The histone deacetylase inhibitor Trichostatin A modulates CD4+ T cell responses.

Background: Histone deacetylase inhibitors (HDACIs) induce hyperacetylation of core histones modulating chromatin structure and affecting gene expression. These compounds are also able to induce growth arrest, cell differentiation, and apoptotic cell death of tumor cells in vitro as well as in vivo. Even though several genes modulated by HDAC inhibition have been identified, those genes clearly responsible for the biological effects of these drugs have remained elusive.

Superantigen-induced regulatory T cells display different suppressive functions in the presence or absence of natural CD4+CD25+ regulatory T cells in vivo.

Repeated exposures to both microbial and innocuous Ags in vivo have been reported to both eliminate and tolerize T cells after their initial activation and expansion. The remaining tolerant T cells have been shown to suppress the response of naive T cells in vitro. This feature is reminiscent of natural CD4(+)CD25(+) regulatory T cells.

Role of the CTLA-4 receptor in T cell activation and immunity. Physiologic function of the CTLA-4 receptor.

Costimulatory molecules of the B7 family regulate the activation of T lymphocytes. T cell activation is promoted by binding of B7 molecules to CD28 and inhibited by binding to CTLA-4 (CD152). The balance between positive signals through CD28 and negative signals through CTLA-4 is critical for the fate of the T cell and is subject to tight regulation.

Fas-independent death of activated CD4(+) T lymphocytes induced by CTLA-4 crosslinking.

The CTLA-4 receptor is a critical inhibitory regulator of T cell proliferation and effector function. However, the mechanisms through which CTLA-4 modulates the activation of T cells remain uncertain. Initial studies, using activated human T cells, have suggested that CTLA-4 crosslinking may induce apoptosis.

Role of ADP-ribosylation in activated monocytes/macrophages.

Stimulating monocytes/macrophages with bacterial lipopolysaccharide (LPS) results in TNF-alpha, IL-1, IL-6 and nitrite (NO2-) formation. Inhibitors of poly(ADP-ribose)polymerase inhibit release of these mediators by preventing mRNA expression indicating that ADP-ribosylation plays a crucial role in the synthesis of these mediators. Furthermore we present evidence that ADP-ribosylation is involved in modifying cellular proteins.

Drug targeting and metabolic investigations of cryoprepared tumor cells with analytical electron energy loss spectroscopy.

Analytical electron microscopy is an ideal tool for holistic data acquisition on biological systems. The use of analytical electron microscopy for both, the investigation of micropharmacokinetic problems and metabolic studies, is becoming more and more important. Depending on the mode of investigation, it is possible to localize drugs and xenobiotics precisely in situ under optical control or to quantify their uptake and distribution in the corresponding target cells without disintegrating the cell or tissue material.

Lipopolysaccharide-induced change of ADP-ribosylation of a cytosolic protein in bone-marrow-derived macrophages.

Treatment of bone-marrow-derived macrophages with nanogram quantities of bacterial lipopolysaccharide (LPS) or with the synthetic bacterial lipopeptide analogue N-palmitoyl-(S)-[2,3-bis(palmitoyloxy)-(2RS)-propyl] (Pam3)Cys-Ala-Gly results in a change of ADP-ribosylation of a cytosolic 33 kDa protein. The immunostimulant-induced change is both dose- and time-dependent. It is not observed in macrophages from an LPS-unresponsive C3H/HeJ mouse strain upon treatment with LPS.

Engagement of major histocompatibility complex class II molecules leads to nitrite production in bone marrow-derived macrophages.

The present study was designed to examine whether engagement of major histocompatibility complex (MHC) class II molecules can lead to induction of NO synthase in bone marrow-derived macrophages. We treated the macrophages with toxic shock syndrome toxin 1 (TSST-1), a superantigen which activates T cells in an MHC class II-dependent manner. Upon addition of syngeneic spleen cells as a source of mature T cells to the TSST-1-treated macrophage culture.

Induction of nitric oxide synthase in L929 cells by tumour-necrosis factor alpha is prevented by inhibitors of poly(ADP-ribose) polymerase.

The fibroblast cell line L929 contains a constitutively expressed NO synthase (EC 1.14.29.

Reduced chemical and radioactive liquid waste during electrophoresis using polymerized electrode gels.

Using polyacrylamide electrode gels during horizontal sodium lauryl sulfate-polyacrylamide electrophoresis of radiolabeled proteins instead of electrode papers reaching into electrode buffer reservoirs, silver staining is improved and we reduce chemical and radioactive liquid waste during electrophoresis.

Inhibitors of poly (ADP-ribose) polymerase suppress lipopolysaccharide-induced nitrite formation in macrophages.

Stimulating bone marrow derived macrophages with LPS results in the induction of NO-synthase as measured by NO2- formation. Inhibitors of poly(ADP-ribose)polymerase, namely nicotinamide, 3-aminobenzamide and 3-methoxybenzamide, prevented NO2- formation in a dose dependent manner. Inhibition was most effective if the inhibitors were added at the same time as LPS.