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Author

Steffen Goletz

Other affiliations: Humboldt State University, Charité
Bio: Steffen Goletz is an academic researcher from Max Delbrück Center for Molecular Medicine. The author has contributed to research in topics: Antigen & Epitope. The author has an hindex of 23, co-authored 114 publications receiving 1902 citations. Previous affiliations of Steffen Goletz include Humboldt State University & Charité.
Topics: Antigen, Epitope, Antibody, Glycosylation, MUC1


Papers
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TL;DR: In this article, a mass spectrometric sequencing strategy was developed to identify in vivo O-glycosylation sites on mucin-derived glycopeptides, where the mass of C- or N-terminal fragments registered for the mono-to pentasubstituted PAP20 indicated that GalNAc was linked to the peptide at Ser5,Thr6 (GSTA) and Thr14(VTSA) but contrary to previous in vitro glycosylations studies also at Thr19 and Ser15 located within the PDTR or

149 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe a fast and reliable technique for generating large diversities of anti-iotypic single chain antibody fragments from non-immunized phagemid libraries using phage display.

140 citations

Journal ArticleDOI
TL;DR: PankoMab is a novel antibody, which binds specifically to this epitope and was designed to show the highest glycosylation dependency and the strongest additive binding effect when compared to other MUC1 antibodies, which renders it a superior antibody for in vivo diagnostics and various immunotherapeutic approaches.
Abstract: Recently, we described a new carbohydrate-induced conformational tumour-epitope on mucin-1 (MUC1) with the potential for improvement of immunotherapies [29, 30]. PankoMab is a novel antibody, which binds specifically to this epitope and was designed to show the highest glycosylation dependency and the strongest additive binding effect when compared to other MUC1 antibodies. This enables PankoMab to differentiate between tumour MUC1 and non-tumour MUC1 epitopes. It has a high-affinity towards tumour cells (e.g. K D [M] of 0.9 and 3×10−9 towards NM-D4 and ZR75-1, respectively) and detects a very large number of binding sites (e.g. 1.0 and 2.4×106 for NM-D4 and ZR75-1, respectively). PankoMab is rapidly internalised, and after toxin coupling is able to induce very effectively toxin-mediated antigen-specific tumour cell killing. PankoMab reveals a potent tumour-specific antibody-dependent cell cytotoxicity (ADCC). PankoMab is, therefore, distinguished by a combination of advantages compared to other MUC1 antibodies in clinical development, including higher tumour specificity, higher affinity, a higher number of binding sites, largely reduced binding to shed MUC1 from colon and pancreatic carcinoma patients, no binding to mononucleated cells from peripheral blood (except ~7% of activated T cells), stronger ADCC activity and rapid internalisation as required for toxin-mediated cell killing. This renders it a superior antibody for in vivo diagnostics and various immunotherapeutic approaches.

123 citations

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TL;DR: A hypothesis is proposed which might help to solve the problem of tumor specificity in at least a subgroup of stem cell markers, and Glycosylation may provide the key.
Abstract: Since the cancer stem cell concept has been widely accepted, several strategies have been proposed to attack cancer stem cells (CSC). Accordingly, stem cell markers are now preferred therapeutic targets. However, the problem of tumor specificity has not disappeared but shifted to another question: how can cancer stem cells be distinguished from normal stem cells, or more specifically, how do CSC markers differ from normal stem cell markers? A hypothesis is proposed which might help to solve this problem in at least a subgroup of stem cell markers. Glycosylation may provide the key.

119 citations

Journal Article
TL;DR: Evidence is presented that the antigenicity of the single repeat toward a considerable number of antibodies to the DTR motif is greatly enhanced if it is glycosylated within this motif, and only in this position, and several lines of evidence suggest that Glycosylation with N-acetylgalactosamine is sufficient for the observed enhancement effect.
Abstract: The epithelial mucin MUC1 is an important tumor marker of breast cancer and other carcinomas. Its immunodominant DTR motif, which is the principal target for immunotherapeutic approaches, has been assumed until recently not to be glycosylated in both normal and tumor MUC1 and to acquire its immunogenic conformation by virtue of a certain number of tandem repeats. We present evidence that the antigenicity of the single repeat toward a considerable number of antibodies to the DTR motif is greatly enhanced if it is glycosylated within this motif, and only in this position. Twenty-eight monoclonal anti-MUC1 antibodies with DTR specificity were tested for binding to synthetic 21-mer (AHG21) or 20-mer (HGV20) tandem repeat peptides O-glycosylated with galactose beta1-3N-acetylgalactosamine alpha or N-acetylgalactosamine alpha at defined Thr or Ser positions. Binding was measured in ELISA experiments using the glycopeptides as plate-immobilized antigens or as inhibitors in solution. At least 12 antibodies revealed significantly enhanced binding to the peptides glycosylated at the DTR motif (Thr-10) as compared to positional isomers glycosylated at Thr-5, Ser-6, Ser-16, or Thr-17 and to the nonglycosylated peptides. Six antibodies (VU-3-C6, A76-A/C7, Ma552, VU-11-D1, VU-12-E1, and VU-11-E2) that were unreactive with the monomeric repeat peptide did bind to the DTR-glycosylated peptide. Several lines of evidence suggest that glycosylation with N-acetylgalactosamine is sufficient for the observed enhancement effect. Our results are of special interest in conjunction with the recent observation that the DTR motif of lactation-associated MUC1 is O-glycosylated in vivo (Muller et al., J. Biol. Chem., 272: 24780-24793, 1997). They may have consequences for the design of efficient tumor vaccines.

115 citations


Cited by
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Journal ArticleDOI
TL;DR: There is tremendous potential for all antibody fragments either as robust diagnostic reagents, or as nonimmunogenic in vivo biopharmaceuticals with superior biodistribution and blood clearance properties.
Abstract: With 18 monoclonal antibody (mAb) products currently on the market and more than 100 in clinical trials, it is clear that engineered antibodies have come of age as biopharmaceuticals. In fact, by 2008, engineered antibodies are predicted to account for >30% of all revenues in the biotechnology market. Smaller recombinant antibody fragments (for example, classic monovalent antibody fragments (Fab, scFv)) and engineered variants (diabodies, triabodies, minibodies and single-domain antibodies) are now emerging as credible alternatives. These fragments retain the targeting specificity of whole mAbs but can be produced more economically and possess other unique and superior properties for a range of diagnostic and therapeutic applications. Antibody fragments have been forged into multivalent and multispecific reagents, linked to therapeutic payloads (such as radionuclides, toxins, enzymes, liposomes and viruses) and engineered for enhanced therapeutic efficacy. Recently, single antibody domains have been engineered and selected as targeting reagents against hitherto immunosilent cavities in enzymes, receptors and infectious agents. Single-domain antibodies are anticipated to significantly expand the repertoire of antibody-based reagents against the vast range of novel biomarkers being discovered through proteomics. As this review aims to show, there is tremendous potential for all antibody fragments either as robust diagnostic reagents (for example in biosensors), or as nonimmunogenic in vivo biopharmaceuticals with superior biodistribution and blood clearance properties.

2,167 citations

Journal ArticleDOI
TL;DR: The targeting schemes explored for many of the reported nanoparticle systems suggest the great potential of targeted delivery to revolutionize cancer treatment.

1,521 citations

Journal ArticleDOI
TL;DR: Various studies on different cationic antimicrobial peptides that exhibit cytotoxic activity against cancer cells are reviewed and the suitability of cancer cell-targeting AMPs as cancer therapeutics is discussed.

1,114 citations

Journal ArticleDOI
TL;DR: Through specific interactions with a variety of intra- and extracellular proteins galectin-3 affects numerous biological processes and seems to be involved in different physiological and pathophysiological conditions, such as development, immune reactions, and neoplastic transformation and metastasis.

1,003 citations

Journal ArticleDOI
TL;DR: An update on the latest advances in the clinical development of treatment strategies targeting cancer stem cells with rational combinations of agents to inhibit possible compensatory escape mechanisms is provided.
Abstract: During the past decade, cancer stem cells (CSCs) have been increasingly identified in many malignancies Although the origin and plasticity of these cells remain controversial, tumour heterogeneity and the presence of small populations of cells with stem-like characteristics is established in most malignancies CSCs display many features of embryonic or tissue stem cells, and typically demonstrate persistent activation of one or more highly conserved signal transduction pathways involved in development and tissue homeostasis, including the Notch, Hedgehog (HH), and Wnt pathways CSCs generally have slow growth rates and are resistant to chemotherapy and/or radiotherapy Thus, new treatment strategies targeting these pathways to control stem-cell replication, survival and differentiation are under development Herein, we provide an update on the latest advances in the clinical development of such approaches, and discuss strategies for overcoming CSC-associated primary or acquired resistance to cancer treatment Given the crosstalk between the different embryonic developmental signalling pathways, as well as other pathways, designing clinical trials that target CSCs with rational combinations of agents to inhibit possible compensatory escape mechanisms could be of particular importance We also share our views on the future directions for targeting CSCs to advance the clinical development of these classes of agents

976 citations