PubMed Health⌕ Search

Biomedical subjects

Angelika Lueking

Publications and source records attributed to Angelika Lueking.

12 recordsLinked to original sources

Profiling humoral autoimmune repertoire of dilated cardiomyopathy (DCM) patients and development of a disease-associated protein chip.

Dilated cardiomyopathy (DCM) is a myocardial disease characterized by progressive depression of myocardial contractile function and ventricular dilatation. Thirty percent of DCM patients belong to the inherited genetic form; the rest may be idiopathic, viral, autoimmune, or immune-mediated associated with a viral infection. Disturbances in humoral and cellular immunity have been described in cases of myocarditis and DCM. A number of autoantibodies against cardiac cell proteins have been identified in DCM. In this study, we have profiled the autoantibody repertoire of plasma from DCM patients against a human protein array consisting of 37,200 redundant, recombinant human proteins and performed qualitative and quantitative validation of these putative autoantigens on protein microarrays to identify novel putative DCM specific autoantigens. In addition to analyzing the whole IgG autoantibody repertoire, we have also analyzed the IgG3 antibody repertoire in the plasma samples to study the characteristics of IgG3 subclass antibodies. By combining screening of a protein expression library with protein microarray technology, we have detected 26 proteins identified by the IgG antibody repertoire and 6 proteins bound by the IgG3 subclass. Several of these autoantibodies found in plasma of DCM patients, such as the autoantibody against the Kv channel-interacting protein, are associated with heart failure.

Amino Acid Sequence↗

New analytical tools for studying autoimmune diseases.

Protein microarrays with immobilised proteins on their surface are new analytical tools to overcome the current limits with respect to sample volume and throughput. They have a great potential as well with respect to multiplexing of complex samples, as a research tool and in diagnostics. Based on recent advances in this technology, new applications for protein microarrays in studying autoimmune diseases were described. Required tools for bioinformatical analysis of protein microarrays concerning normalisation, clustering and classification methods are discussed. The huge potential of this technology as well as future requirements such as protein microarray based diagnostics are presented.

Animals↗

Profiling of alopecia areata autoantigens based on protein microarray technology.

Protein biochips have a great potential in future parallel processing of complex samples as a research tool and in diagnostics. For the generation of protein biochips, highly automated technologies have been developed for cDNA expression library production, high throughput protein expression, large scale analysis of proteins, and protein microarray generation. Using this technology, we present here a strategy to identify potential autoantigens involved in the pathogenesis of alopecia areata, an often chronic disease leading to the rapid loss of scalp hair. Only little is known about the putative autoantigen(s) involved in this process. By combining protein microarray technology with the use of large cDNA expression libraries, we profiled the autoantibody repertoire of sera from alopecia areata patients against a human protein array consisting of 37,200 redundant, recombinant human proteins. The data sets obtained from incubations with patient sera were compared with control sera from clinically healthy persons and to background incubations with anti-human IgG antibodies. From these results, a smaller protein subset was generated and subjected to qualitative and quantitative validation on highly sensitive protein microarrays to identify novel alopecia areata-associated autoantigens. Eight autoantigens were identified by protein chip technology and were successfully confirmed by Western blot analysis. These autoantigens were arrayed on protein microarrays to generate a disease-associated protein chip. To confirm the specificity of the results obtained, sera from patients with psoriasis or hand and foot eczema as well as skin allergy were additionally examined on the disease-associated protein chip. By using alopecia areata as a model for an autoimmune disease, our investigations show that the protein microarray technology has potential for the identification and evaluation of autoantigens as well as in diagnosis such as to differentiate alopecia areata from other skin diseases.

Adult↗

Protein biochips: A new and versatile platform technology for molecular medicine.

The human genome has been sequenced and the challenges of understanding the function of the newly discovered genes have been addressed. High-throughput technologies such as DNA microarrays have been developed for the profiling of gene expression patterns in whole organisms or tissues. Protein arrays are emerging to follow DNA chips as possible screening tools. Here, we review the generation and application of microarray technology to obtain more information on the regulation of proteins, their biochemical functions and their potential interaction partners. Already, a large variety of assays based on antibody-antigen interactions exists. In addition, the medical relevance of protein arrays will be discussed.

Animals↗

Mouse protein arrays from a TH1 cell cDNA library for antibody screening and serum profiling.

The mouse is the premier genetic model organism for the study of disease and development. We describe the establishment of a mouse T helper cell type 1 (T(H)1) protein expression library that provides direct access to thousands of recombinant mouse proteins, in particular those associated with immune responses. The advantage of a system based on the combination of large cDNA expression libraries with microarray technology is the direct connection of the DNA sequence information from a particular clone to its recombinant, expressed protein. We have generated a mouse T(H)1 expression cDNA library and used protein arrays of this library to characterize the specificity and cross-reactivity of antibodies. Additionally, we have profiled the autoantibody repertoire in serum of a mouse model for systemic lupus erythematosus on these protein arrays and validated the putative autoantigens on highly sensitive protein microarrays.

Animals↗

Cell-free protein expression and functional assay in nanowell chip format.

The expression and characterization of large protein libraries requires high-throughput tools for rapid and cost-effective expression and screening. A promising tool to meet these requirements is miniaturized high-density plates in chip format, consisting of an array of wells with submicroliter volumes. Here, we show the combination of nanowell chip technology and cell-free transcription and translation of proteins. Using piezoelectric dispensers, we transferred proteins into nanowells down to volumes of 100 nL and successfully detected fluorescence using confocal laser scanning. Moreover, we showed cell-free expression of proteins on a nanoliter scale using commercially available coupled transcription and translation systems. To reduce costs, we demonstrated the feasibility of diluting the coupled in vitro transcription and translation mix prior to expression. Additionally, we present an enzymatic inhibition assay in nanowells to anticipate further applications, such as the high-throughput screening of drug candidates or the identification of novel enzymes for biotechnology.

Cell-Free System↗

A nonredundant human protein chip for antibody screening and serum profiling.

There is burgeoning interest in protein microarrays, but a source of thousands of nonredundant, purified proteins was not previously available. Here we show a glass chip containing 2413 nonredundant purified human fusion proteins on a polymer surface, where densities up to 1600 proteins/cm(2) on a microscope slide can be realized. In addition, the polymer coating of the glass slide enables screening of protein interactions under nondenaturing conditions. Such screenings require only 200-microl sample volumes, illustrating their potential for high-throughput applications. Here we demonstrate two applications: the characterization of antibody binding, specificity, and cross-reactivity; and profiling the antibody repertoire in body fluids, such as serum from patients with autoimmune diseases. For the first application, we have incubated these protein chips with anti-RGSHis(6), anti-GAPDH, and anti-HSP90beta antibodies. In an initial proof of principle study for the second application, we have screened serum from alopecia and arthritis patients. With analysis of large sample numbers, identification of disease-associated proteins to generate novel diagnostic markers may be possible.

Alopecia↗

Generation of minimal protein identifiers of proteins from two-dimensional gels and recombinant proteins.

We describe the technical feasibility and methodology to characterize a protein by a minimal set of structural information generated by matrix assisted laser desorption/ionization (MALDI)-mass spectrometry, termed a "minimal protein Identifier" (MPI). MPIs can be determined for proteins from two-dimensional gels and recombinant proteins and can be used to compare and identify proteins from these sources.

Brain↗

Protein array technology: the tool to bridge genomics and proteomics.

The generation of protein chips requires much more efforts than DNA microchips. While DNA is DNA and a variety of different DNA molecules behave stable in a hybridisation experiment, proteins are much more difficult to produce and to handle. Outside of a narrow range of environmental conditions, proteins will denature, lose their three-dimensional structure and a lot of their specificity and activity. The chapter describes the pitfalls and challenges in Protein Microarray technology to produce native and functional proteins and store them in a native and special environment for every single spot on an array, making applications like antibody profiling and serum screening possible not only on denatured arrays but also on native protein arrays.

Databases, Protein↗

High-throughput protein arrays: prospects for molecular diagnostics.

High-throughput protein arrays allow the miniaturized and parallel analysis of large numbers of diagnostic markers in complex samples. Using automated colony picking and gridding, cDNA or antibody libraries can be expressed and screened as clone arrays. Protein microarrays are constructed from recombinantly expressed, purified, and yet functional proteins, entailing a range of optimized expression systems. Antibody microarrays are becoming a robust format for expression profiling of whole genomes. Alternative systems, such as aptamer, PROfusion, nano- and microfluidic arrays are all at proof-of-concept stage. Differential protein profiles have been used as molecular diagnostics for cancer and autoimmune diseases and might ultimately be applied to screening of high-risk and general populations.

Animals↗

Large-scale plant proteomics.

Large-scale and high throughput approaches increasingly play an essential role in the study of biological systems, which are per se highly complex. Therefore, they need to be examined by these extensive methods to receive information about the large genomic and proteomic networks. In plant biology, this purpose has a strong support through the accessability of the complete genome sequence of the model plant Arabidopsis thaliana. This brief review intends to focus on the basics and the state-of-the-art of these high-throughput technologies and their application to plant proteomics. It describes protein microarrays, the use of antibodies, 2-DE and MS methods and the yeast two hybrid system, which are emerging as the major technologies for plant proteomics.

Arabidopsis↗