Carsten Zimmermann

I tag, you tag: translating tags for advanced user models

Collaborative tagging services (folksonomies) have been among the stars of the Web 2.0 era. They allow their users to label diverse resources with freely chosen keywords (tags). Our studies of two real-world folksonomies unveil that individual users develop highly personalized vocabularies of tags. While these meet individual needs and preferences, the considerable differences between personal tag vocabularies (personomies) impede services such as social search or customized tag recommendation. In this paper, we introduce a novel user-centric tag model that allows us to derive mappings between personal tag vocabularies and the corresponding folksonomies. Using these mappings, we can infer the meaning of user-assigned tags and can predict choices of tags a user may want to assign to new items. Furthermore, our translational approach helps in reducing common problems related to tag ambiguity, synonymous tags, or multilingualism. We evaluate the applicability of our method in tag recommendation and tag-based social search. Extensive experiments show that our translational model improves the prediction accuracy in both scenarios.

Challenges and opportunities for non-antibody scaffold drugs.

The first candidates from the promising class of small non-antibody protein scaffolds are now moving into clinical development and practice. Challenges remain, and scaffolds will need to be further tailored toward applications where they provide real advantages over established therapeutics to succeed in a rapidly evolving drug development landscape.

Transient expression of human antibodies in mammalian cells

Recombinant expression of antibody molecules in mammalian cells offers important advantages over traditionally utilized bacterial expression, including glycosylation required for antibody functionality and markedly reduced levels of endotoxin contamination. Advances in transient mammalian expression systems enable high yields (>100 mg/liter) that now allow for effective recombinant antibody production at a reasonable cost. Here, we provide step-by-step protocols for the design and recombinant expression of full-length IgG antibodies and antibody-derived constructs (including Fab, Fc-fusions and bispecifics) in mammalian cells. Antibody constructs are designed by combining antibody variable domains, generated by phage display or derived from human/humanized monoclonals, with constant regions. The constructs are then expressed from mammalian vectors, secreted into culture media, purified by affinity chromatography and characterized by biolayer interferometry. This article provides detailed protocols, sequences and strategies that allow the expression and purification of endotoxin-free antibody reagents suitable for testing in animal models within a 3-week time frame.