PTK 2015 Banner 
2015 Peptalk M Banner 

Overcoming Challenges with Solutions  


Many of the proteins required for therapeutics and diagnostics pose problems in that they may be difficult to express in existing hosts, or have problems with folding, solubility, glycosylation, etc.  Some may even be toxic to the host.  This conference will address the newest developments in these protein science fields and provide insights and solutions for conquering these issues. 

Day 1 | Day 2 | Download Brochure  

THURSDAY, JANUARY 12 

1:00 pm Conference Registration 

  

Glycosylation and Glycoprotein Expression  

1:45 Chairperson's Remarks 


» 1:50 KEYNOTE PRESENTATION  

Recombinant Protein Production by Large Scale Transfection:  HEK293 or CHO Cells? 

Yves Durocher, Ph.D., Research Officer, Biotechnology Research Institute, National Research Council Canada 

Large-scale transfection of HEK293 cells has proven itself as a powerful technology for the fast production of r-proteins. Many would prefer using CHO cells in order to minimize post-translational modification dissimilarities between transiently and stably expressed genes. However, CHO cells have traditionally been shown to provide lower levels of transient gene expression compared to 293 cells. We developed a simple and robust large-scale CHO transfection process providing r-protein titres closely matching those obtained in 293 cells, questioning the necessity to sustain or not two transfection platforms. Here, we provide some evidences that using two expression hosts increases the likelihood of successful target expression. 

2:20 Effects of Cell Culture Conditions on Antibody N-linked Glycosylation-What Affects High Mannose 5 Glycoform? 

Efren Pacis, Oceanside Pharma Technical Development, Biologics Pharma Technical Development, Genentech, Inc. 

The glycosylation profile of therapeutic antibodies is routinely analyzed throughout development to monitor the impact of process parameters and to ensure consistency, efficacy, and safety for clinical and commercial batches of therapeutic products. In this study, unusually high levels of the mannose-5 (Man5) glycoform were observed during the early development of a therapeutic antibody produced from a Chinese hamster ovary (CHO) cell line, model cell line A. Follow up studies indicated that the antibody Man5 level was increased throughout the course of cell culture production as a result of increasing cell culture medium osmolality levels and extending culture duration. 

2:50 Optimization of IgGs in Glycoengineered Yeast: Glycoengineered Pichia Produced Anti-Her2 Comparable to Trastuzumab in Pre-Clinical Study 

Dongxing Zha, Ph.D., Research Fellow, Group Leader, Antibody Development, GlycoFi, Inc., a wholly owned subsidiary of Merck & Co. Inc. 

Humanization of yeast glycosylation pathway allows it expressing glycoprotein with human glycan profile. This not only offers an alternative IgGs production platform similar to mammalian hosts but it also provides more homogenous product and better efficacy. In this case study, glycoengineered Pichia produced anti-Her2 is comparable to CHO produced trastuzumab with enhanced in vitro ADCC in pre-clinical study. 

Sponsored by
CEVEC
3:20 CAP: A Protein and Vaccine Production Platform based on Immortalized Human Amniocytes 

Hartmut Tintrup, Ph.D., Director Marketing & Business Development, CEVEC Pharmaceuticals GmbHHuman CAP and CAP-T (CEVEC‘s Amniocyte Production) cells allow for stable and transient high yield production of recombinant proteins with excellent therapeutic efficacy as a result of authentic posttranslational modification. This talk will highlight recent progress in terms of producing various difficult to express proteins, antibodies and also viruses on the CAP technology platform. 

3:35 Networking Refreshment Break in the Exhibit Hall with Poster Viewing 

  

Solutions for Solubility, Stability and Folding  

4:30 Expression of Soluble Proteins by Linkage with Acidic Tags 

Richard Discipio, Ph.D., Research Scientist, Torrey Pines Institute for Molecular Studies 

An expression method has been developed to produce soluble cationic polypeptides in Escherichia coli while avoiding inclusion body deposition. For this technique the recombinant product is linked through a thrombin or factor Xa susceptible bond to the amino-terminal domain of the precursor of eosinophil major basic protein (MBP). This N-terminal domain is strongly acidic and is apparently able to shield eosinophils from the potentially injurious activities of MBP. It was reasoned that constructs of this acidic domain with small heterologous cationic proteins expressed in E. coli could result in soluble expression while preventing trafficking and packaging into insoluble inclusion bodies.  Using two different expression plasmids, we were able to produce several bioactive polypeptides in a soluble form using this chimera construction method. 

5:00 Screening of Genetic Parameters for Soluble Protein Expression in Escherichia coli 

Erik Vernet, Ph.D., The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen 

Although soluble protein expression is influenced by numerous factors, a thorough investigation is usually not feasible in high-throughput efforts. Here we present a screening strategy in Escherichia coli using engineered strains and vectors. Used for soluble production of > 20 biomedical targets, including full-length variants of human cytokines and growth factors, this rapid screening approach has proven valuable for hard-to-get targets. 

5:30 Optimization of Protein Folding in the Cell 

James C. Bardwell, Ph.D., Associate Professor, Howard Hughes Medical Investigator, Department of Molecular Cellular Developmental Biology, Program in Cellular Molecular Biology, Department of Biophysics, University of Michigan 

We want to understand why proteins are often so unstable and how proteins fold within the cell. Thus we have devised folding biosensors that link protein folding to antibiotic resistance. Under antibiotic selection, only stabilized variants grow, making the biosensors an extremely powerful selection for stabilizing proteins, for optimizing in vivo folding and for discovering new chaperones. 

6:00 Close of Day 


Day 1 | Day 2 | Download Brochure
  


Links to Companion Meetings

Pipeline 4  

Engineering Genes, Vectors, Constructs and Clones  

Choosing, Designing and Optimizing Hosts and Platforms