Publications by David Hacker | EPFL Graph Search

Related publications (82)

Reduction of adenovirus E1A mRNA by RNAi results in enhanced recombinant protein expression in transiently transfected HEK293 cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Martin Bertschinger

Human embryonic kidney 293 (HEK293) cells, a widely used host for large-scale transient expression of recombinant proteins, are transformed with the adenovirus E1A and E1B genes. Because the E1A proteins function as transcriptional activators or repressors ...

2004

Role of non-specific DNA in reducing coding DNA requirement for transient gene expression with CHO and HEK-293E cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak

Transient gene expression (TGE) is a rapid method for the production of recombinant proteins in mammalian cells. While the TGE volumetric productivity has improved significantly over the past decade, the amount of plasmid DNA (pDNA) needed for transfection ...

2012

Disassembly of polyethylenimine-DNA particles in vitro: implications for polyethylenimine-mediated DNA delivery

Florian Maria Wurm, David Hacker, Martin Jordan, Martin Bertschinger, Gaurav Backliwal

Here a simple in vitro assay was used to investigate the disassembly of nanoparticles of polyethylenimine (PEI) and DNA. Particles were formed with various PEIs, allowed to mature for 10 min, and then exposed to different competitors (RNA, DNA, BSA or hepa ...

2006

A Nanoscaffolded Spike-RBD Vaccine Provides Protection against SARS-CoV-2 with Minimal Anti-Scaffold Response

Bruno Emanuel Ferreira De Sousa Correia, David Hacker, Florence Pojer, Kelvin Ka Ching Lau

The response of the adaptive immune system is augmented by multimeric presentation of a specific antigen, resembling viral particles. Several vaccines have been designed based on natural or designed protein scaffolds, which exhibited a potent adaptive immu ...

2021

The PiggyBac transposon enhances the frequency of CHO stable cell line generation and yields recombinant lines with superior productivity and stability

Florian Maria Wurm, David Hacker, Lucia Baldi Unser

Generating stable, high-producing mammalian cell lines is a major bottleneck in the manufacture of recombinant therapeutic proteins. Conventional gene transfer methods for cell line generation rely on random plasmid integration, resulting in unpredictable ...

Wiley-Blackwell2011

Multigene expression in stable CHO cell pools generated with the piggyBac transposon system

Florian Maria Wurm, David Hacker, Sowmya Balasubramanian

Heterogenous populations of recombinant cells (cell pools) stably expressing 1-4 transgenes were generated from Chinese hamster overy (CHO) cells with the piggyBac (PB) transposon system. The cell pools produced different combinations of three model protei ...

American Chemical Society2016

TubeSpin bioreactor 50 for the high-density cultivation of Sf-9 insect cells in suspension

Florian Maria Wurm, David Hacker, Lucia Baldi Unser

Here we present the TubeSpin bioreactor 50 (TubeSpins) as a simple and disposable culture system for Sf-9 insect cells in suspension. Sf-9 cells had substantially better growth in TubeSpins than in spinner flasks. After inoculation with 106 cells/ml, maxim ...

Springer Netherlands2011

Mild hypothermia improves transient gene expression yields several fold in Chinese hamster ovary cells

Florian Maria Wurm, David Hacker, Sarah Wulhfard

Large-scale transient gene expression (TGE) in mammalian cells is a rapid method to generate recombinant proteins, but the volumetric productivity for secreted proteins is still more than an order of magnitude lower than the yields typically achieved with ...

2008

Comparative Study on the In Vitro Cytotoxicity of Linear, Dendritic, and Hyperbranched Polylysine Analogues

Harm-Anton Klok, Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Zuzana Kadlecova

Lysine-based polycations are widely used as nonviral carriers for gene delivery. This manuscript reports the results of a comparative study on the in vitro cytotoxicity of a library of three structural polylysine variants, namely, linear polylysine (LPL), ...

American Chemical Society2012

Low-temperature pausing of cultivated mammalian cells

Florian Maria Wurm, David Hacker, Martin Jordan, Lisa Hunt, Frédéric Grosjean

There are currently two methods for maintaining cultured mammalian cells, continuous passage at 37 degrees C and freezing in small batches. We investigated a third approach, the "pausing" of cells for days or weeks at temperatures below 37 degrees C in a v ...

2005

Rapid recombinant protein production from piggyBac transposon-mediated stable CHO cell pools

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Zuzana Kadlecova, Sowmya Balasubramanian

Heterogeneous populations of stably transfected cells (cell pools) can serve for the rapid production of moderate amounts of recombinant proteins. Here, we propose the use of the piggyBac (PB) transposon system to improve the productivity and long-term sta ...

Elsevier2015

Poly(ethyleneimine)-Mediated Large-Scale Transient Gene Expression: Influence of Molecular Weight, Polydispersity and N-Propionyl Groups

Harm-Anton Klok, Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Zuzana Kadlecova

Three synthesis lots of linear poly(ethyleneimine) (PEI) are compared to a fully hydrolyzed linear PEI (commercially available as PEI Max) regarding structure, polyplex formation with plasmid DNA, and transfection of suspension-adapted HEK-293E cells. PEI ...

Wiley-Blackwell2012

Comparison of Three Transposons for the Generation of Highly Productive Recombinant CHO Cell Pools and Cell Lines

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Sowmya Balasubramanian

Several naturally occurring vertebrate transposable elements have been genetically modified to enable the transposition of recombinant genes in mammalian cells. We compared three transposonspiggyBac, Tol2, and Sleeping Beautyfor their ability to generate c ...

Wiley-Blackwell2016

Transcriptional and post-transcriptional limitations of high-yielding, PEI-mediated transient transfection with CHO and HEK-293E cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak

Transient gene expression (TGE) in human embryonic kidney (HEK-293) and Chinese hamster ovary (CHO) cells is a well-established technology for the rapid generation of recombinant proteins. Although the maximum TGE yields have reached 1 g/L or more, the amo ...

American Chemical Society2015

Changes in SARS-CoV-2 Spike versus Nucleoprotein Antibody Responses Impact the Estimates of Infections in Population-Based Seroprevalence Studies

Didier Trono, David Hacker, Florence Pojer, Kelvin Ka Ching Lau

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody responses to the spike (S) protein monomer, S protein native trimeric form, or the nucleocapsid (N) proteins were evaluated in cohorts of individuals with acute infection (n = 9 ...

American Society for Microbiology2021

New disposable tubes for rapid and precise biomass assessment for suspension cultures of mammalian cells

Florian Maria Wurm, David Hacker, Martin Jordan, Mathieu Benjamin Stettler

We present a new approach for biomass assessment in cell culture using a disposable microcentrifuge tube. The specially designed tube is fitted with an upper chamber for sample loading and a lower 5 microL capillary for cell collection during centrifugatio ...

2006

Highly efficient production of the Alzheimer's γ-Secretase integral membrane protease complex by a multi-gene stable integration approach

Florian Maria Wurm, David Hacker, Lorène Aeschbach, Patrick Fraering, Mitko Dimitrov, Sowmya Balasubramanian

Inefficient production of membrane-embedded multi-protein complexes by conventional methods has largely prevented the generation of high-resolution structural information and the performance of high-throughput drug discovery screens for this class of prote ...

2013

Population Variation and Genetic Control of Modular Chromatin Architecture in Humans

Bart Deplancke, David Hacker, Sebastian Martin Waszak, Sunil Kumar Raghav, Alisa Yurovsky, Gilles Udin

Chromatin state variation at gene regulatory elements is abundant across individuals, yet we understand little about the genetic basis of this variability. Here, we profiled several histone modifications, the transcription factor (TF) PU.1, RNA polymerase ...

Elsevier2015

Enhanced Plasmid DNA Utilization in Transiently Transfected CHO-DG44 Cells in the Presence of Polar Solvents

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak, Sowmya Balasubramanian

Although the protein yields from transient gene expression (TGE) with Chinese hamster ovary (CHO) cells have recently improved, the amount of plasmid DNA (pDNA) needed for transfection remains relatively high. We describe a strategy to reduce the pDNA amou ...

American Chemical Society2015

Production of active glycosylation-deficient gamma-secretase complex for crystallization studies

Florian Maria Wurm, David Hacker, Patrick Fraering, Mitko Dimitrov, Hermeto Gerber, Virginie Sandra Braman

Alzheimer's disease (AD)-associated gamma-secretase is a ubiquitously expressed multi-subunit protease complex embedded in the lipid bilayer of cellular compartments including endosomes and the plasma membrane. Although gamma-secretase is of crucial intere ...

Wiley-Blackwell2015