The CD11a Binding Site of Efalizumab in Psoriatic Skin Tissue as Analyzed by Multi-Epitope Ligand Cartography Robot Technology

Current knowledge on psoriasis and autoimmune diseases

Psoriasis is a prevalent, chronic inflammatory disease of the skin, mediated by crosstalk between epidermal keratinocytes, dermal vascular cells, and immunocytes such as antigen presenting cells (APCs) and T cells. Exclusive cellular “responsibility” for the induction and maintenance of psoriatic plaques has not been clearly defined. Increased proliferation of keratinocytes and endothelial cells in conjunction with APC/T cell/monocyte/macrophage inflammation leads to the distinct epidermal and vascular hyperplasia that is characteristic of lesional psoriatic skin. Despite the identification of numerous susceptibility loci, no single genetic determinant has been identified as responsible for the induction of psoriasis. Thus, numerous other triggers of disease, such as environmental, microbial and complex cellular interactions must also be considered as participants in the development of this multifactorial disease. Recent advances in therapeutics, especially systemic so-called “biologics” have provided new hope for identifying the critical cellular targets that drive psoriasis pathogenesis. Recent recognition of the numerous co-morbidities and other autoimmune disorders associated with psoriasis, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus suggest common signaling elements and cellular mediators may direct disease pathogenesis. In this review, we discuss common cellular pathways and participants that mediate psoriasis and other autoimmune disorders that share these cellular signaling pathways.

Advances in toponomics drug discovery: Imaging cycler microscopy correctly predicts a therapy method of amyotrophic lateral sclerosis

An imaging cycler microscope (ICM) is a fully automated (epi)fluorescence microscope which overcomes the spectral resolution limit resulting in parameter- and dimension-unlimited fluorescence imaging. This enables the spatial resolution of large molecular systems with their emergent topological properties (toponome) in morphologically intact cells and tissues displaying thousands of multi protein assemblies at a time. The resulting combinatorial geometry of these systems has been shown to be key for in-vivo/in-situ detection of lead proteins controlling protein network topology and (dys)function: If lead proteins are blocked or downregulated the corresponding disease protein network disassembles. Here, correct therapeutic predictions are exemplified for ALS. ICM drug target studies have discovered an 18-dimensional cell surface molecular system in ALS-PBMC with a lead drug target protein, whose therapeutic downregulation is now reported to show statistically significant effect with stop of disease progression in one third of the ALS patients. Together, this clinical and the earlier experimental validations of the ICM approach indicate that ICM readily discovers in vivo robustness nodes of disease with lead proteins controlling them. Breaking in vivo robustness nodes using drugs against their lead proteins is likely to overcome current high drug attrition rates. © 2015 The Author. Published by Wiley Periodicals, Inc, on behalf of ISAC.

Systematic, spatial imaging of large multimolecular assemblies and the emerging principles of supramolecular order in biological systems

Understanding biological systems at the level of their relational (emergent) molecular properties in functional protein networks relies on imaging methods, able to spatially resolve a tissue or a cell as a giant, non-random, topologically defined collection of interacting supermolecules executing myriads of subcellular mechanisms. Here, the development and findings of parameter-unlimited functional super-resolution microscopy are described-a technology based on the fluorescence imaging cycler (IC) principle capable of co-mapping thousands of distinct biomolecular assemblies at high spatial resolution and differentiation (<40 nm distances). It is shown that the subcellular and transcellular features of such supermolecules can be described at the compositional and constitutional levels; that the spatial connection, relational stoichiometry, and topology of supermolecules generate hitherto unrecognized functional self-segmentation of biological tissues; that hierarchical features, common to thousands of simultaneously imaged supermolecules, can be identified; and how the resulting supramolecular order relates to spatial coding of cellular functionalities in biological systems. A large body of observations with IC molecular systems microscopy collected over 20 years have disclosed principles governed by a law of supramolecular segregation of cellular functionalities. This pervades phenomena, such as exceptional orderliness, functional selectivity, combinatorial and spatial periodicity, and hierarchical organization of large molecular systems, across all species investigated so far. This insight is based on the high degree of specificity, selectivity, and sensitivity of molecular recognition processes for fluorescence imaging beyond the spectral resolution limit, using probe libraries controlled by ICs.

Combined multi-gene analysis at the RNA and protein levels in single FFPE tissue sections

Novel approaches of individualized medicine require rapid analyses of comprehensive multi-gene expression patterns both at the RNA and protein levels. Optimally these analyses are achieved with minimal amounts of tissues, which are derived from routine procedures of clinical diagnostics. We demonstrate the parallel analyses of gene expression of six different genes at the RNA and protein levels in two consecutive sections of routinely processed FFPE tissues. This was achieved by combination of multi-epitope-ligand cartography (MELC) and fully automatically magnetic bead-based RNA extraction and subsequent qRT-PCR analysis. Our work provides proof-of-principle that comprehensive analyses of multi-gene expression patterns can be achieved by the combination of these two high content technologies. This may provide new perspectives for the determination of pathogenic gene expression in the framework of individualized medicine.

Bodilisant-a novel fluorescent, highly affine histamine h3 receptor ligand

A piperidine-based lead structure for the human histamine H3 receptor (hH3R) was coupled with the BODIPY fluorophore and resulted in a strong green fluorescent (quantum yield, 0.92) hH3R ligand with affinity in the nanomolar concentration range (K i hH3R = 6.51 ± 3.31 nM), named Bodilisant. Screening for affinities at histamine and dopamine receptor subtypes showed high hH3R preference. Bodilisant was used for visualization of hH3R in hH3R overexpressing HEK-293 cells with fluorescence confocal laser scanning microscopy. In addition, in native human brain tissues, Bodilisant showed clear and displaceable images of labeled hH3R.

Murine whole-organ immune cell populations revealed by multi-epitope-ligand cartography

Multi-epitope-ligand cartography (MELC) is an innovative high-throughput fluorescence microscopy-based method. A tissue section is analyzed through a repeated cycling of (1) incubation with a fluorophore-labeled antibody, (2) fluorescence imaging, and (3) soft bleaching. This method allows staining of the same tissue section with up to 100 fluorescent markers and to analyze their toponomic expression using further image processing and pixel-precise overlay of the corresponding images. In this study, we adapted this method to identify a large panel of murine leukocyte subpopulations in a whole frozen section of a peripheral lymph node. Using the resulting antibody library, we examined non-inflamed versus inflamed tissues of brain and spinal cord in the experimental autoimmune encephalomyelitis (EAE) model. The presence and activity of specific leukocyte subpopulations (different T cell subpopulations, dendritic cells, macrophages, etc.) could be assessed and the cellular localizations and the corresponding activation status in situ were investigated. The results were then correlated with quantitative RT-PCR.

Proteome technologies in studying the pathogenesisof psoriasis

Psoriasis is one of the most prevalent inflammatory dermatoses. At the same time, its pathogenesis has not been studied in full. Proteome profiling is currently a promising method to study the biological mechanisms of developing different diseases. Proteome technologies make it possible to detect changes in the skin protein profile in psoriatic patients and identify the revealed proteins. The proteins serve as potential targets for drugs or biomarkers for assessing the patients individual drug response. The article describes the key achievements in the field of studying the pathogenesis of psoriasis using proteome technologies (two-dimensional electrophoresis and mass spectrometry) set out in the latest literature sources, and also analyzes the results of the authors studies aimed at detecting proteins being markers of the patients response to the infliximab therapy.

Toponomics: studying protein-protein interactions and protein networks in intact tissue

The function of a protein is determined on several levels including the genome, transcriptome, proteome, and the recently introduced toponome. The toponome describes the topology of all proteins, protein complexes and protein networks which constitute and influence the microenvironment of a given protein. It has long been known that cellular function or dysfunction of proteins strongly depends on their microenvironment and even small changes in protein arrangements can dramatically alter their activity/function. Thus, deciphering the topology of the multi-dimensional networks which control normal and disease-related pathways will give a better understanding of the mechanisms underlying disease development. While various powerful proteomic tools allow simultaneous quantification of proteins, only a limited number of techniques are available to visualize protein networks in intact cells and tissues. This review discusses a novel approach to map and decipher functional molecular networks of proteins in intact cells or tissues. Multi-epitope-ligand-cartography (MELC) is an imaging technology that identifies and quantifies protein networks at the subcellular level of morphologically-intact specimens. This immunohistochemistry-based method allows serial visualization and biomathematical analysis of up to 100 cellular components using fluorescence-labelled tags. The resulting toponome maps, simultaneously ranging from the subcellular to the supracellular scale, have the potential to provide the basis for a mathematical description of the dynamic topology of protein networks, and will complement current proteomic data to enhance the understanding of physiological and pathophysiological cell functions.

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.

Topo-Proteomic in situ Analysis of Psoriatic Plaque under Efalizumab Treatment

In a pilot study 6 psoriasis patients were treated over 12 weeks with efalizumab targeting the CD11a subunit of LFA-1. The treatment was well tolerated. Five of these patients proved to be responders with an average decrease in psoriasis area and severity index (PASI) from 21.3 +/- 5.4 (day 0) to 3.9 +/- 0.6 (week 12). The nonresponder was subsequently successfully treated with cyclosporin. Skin biopsies were taken before and after efalizumab treatment and subjected to Multi-Epitope Ligand Cartography (MELC) robot microscopy. A MELC library of 46 antibodies including FITC-labeled efalizumab was chosen focusing upon inflammatory epitopes. Quantification of marker expression was performed using a special adaptation to the needs of skin tissue in terms of pixel events normalized to a standardized horizontal skin width of 100 mum. The before-versus-after comparison for the responders revealed at the 'single epitope level' of MELC analysis a significant decrease (p < 0.05) in epidermal thickness (represented by pan-cytokeratin, CD71, CD138), of the expression of common leukocyte antigen (CD45), T-cell markers (CD2, CD4, CD8, CD45R0), CD11a, efalizumab binding site (EfaBS), and CD58. At the 'EfaBS-centered, double colocation level' a corresponding decrease was observed for CD2, CD3, CD4, CD8, CD11a, CD13, CD26, CD44, CD45, CD45R0, CD54, CD62L, HLA-DR, and TIA-1. MELC analysis at the 'multicombinatorial level' revealed predominant combinatorial molecular phenotype (CMP) motifs, which showed an efalizumab treatment-dependent significant decrease. These CMP motifs were defined as toponomic combinations of lead markers for (i) leukocytes in general (CD45), (ii) T cells (CD2, CD3, CD4, CD45R0, CD45RA), (iii) macrophages (CD68), (iv) cell activation (CD13, CD26, HLA-DR), and (v) cell adhesion (CD11a, EfaBS). Thirty-five of the most relevant 50 CMP motifs were directly related to the T-cell type. A descriptive statistical analysis of the nonresponder before treatment showed a below-responder range degree of expression for CD4, CD8, CD44 (H-CAM), CD56, CD62L, HLA-DQ, and also for these epitopes in colocation with EfaBS. In the nonresponder and before treatment we observed an above-responder range degree of expression for CD54 (ICAM-1) as LFA-1 ligand. In conclusion, the topo-proteomic data provide new diversified insights into the pleiotropic cellular dynamics in psoriatic skin lesions under effective efalizumab treatment. Moreover, the data may be relevant to the future development of possible strategies for individual prediction of efalizumab treatment response or nonresponse.