Publications de David Hacker | EPFL Graph Search

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

David Hacker, Didier Trono, 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

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

David Hacker, Florence Pojer, Bruno Emanuel Ferreira De Sousa Correia, 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

Analysis of volumetric mass transfer coefficient (k(L)a) in small- (250 mL) to large-scale (2500 L) orbitally shaken bioreactors

Florian Maria Wurm, David Hacker, Likuan Zhu

In this study, the combination of dimensional analysis (DA) and analysis of variance (ANOVA) was used to predict the volumetric mass transfer coefficient (k(L)a) values under different operating conditions for orbitally shaken bioreactors (OSRs) with diffe ...

SPRINGER HEIDELBERG2020

Structural investigation of ACE2 dependent disassembly of the trimeric SARS-CoV-2 Spike glycoprotein

Henning Paul-Julius Stahlberg, David Hacker, Florence Pojer, Kelvin Ka Ching Lau, Dongchun Ni

The human membrane protein Angiotensin-converting enzyme 2 (hACE2) acts as the main receptor for host cells invasion of the new coronavirus SARS-CoV-2. The viral surface glycoprotein Spike binds to hACE2, which triggers virus entry into cells. As of today, ...

2020

Chromatin three-dimensional interactions mediate genetic effects on gene expression

Philipp Bucher, David Hacker, Giovanna Ambrosini, Sanjeev Kumar

Studying the genetic basis of gene expression and chromatin organization is key to characterizing the effect of genetic variability on the function and structure of the human genome. Here we unravel how genetic variation perturbs gene regulation using a da ...

American Association for the Advancement of Science2019

BRB-seq: ultra-affordable high-throughput transcriptomics enabled by bulk RNA barcoding and sequencing

David Hacker, Bastien Mangeat, Bart Deplancke, Antonio Carlos Alves Meireles Filho, Julie Marie Russeil, Daniel Alpern, Vincent Roland Julien Gardeux

Despite its widespread use, RNA-seq is still too laborious and expensive to replace RT-qPCR as the default gene expression analysis method. We present a novel approach, BRB-seq, which uses early multiplexing to produce 3 cDNA libraries for dozens of sample ...

2019

Chromatin 3D interactions mediate genetic effects on gene expression

Philipp Bucher, David Hacker, Giovanna Ambrosini

NATURE PUBLISHING GROUP2019

Improved process conditions for increasing expression of MHC class II protein from a stable Drosophila S2 cell line

Florian Maria Wurm, Lucia Baldi Unser, David Hacker, Xiao Shen

2018

Fluid dynamics of flow fields in a disposable 600-mL orbitally shaken bioreactor

Florian Maria Wurm, David Hacker, Dominique Terry Monteil Jr, Likuan Zhu

Orbitally shaken bioreactors (OSRs) are commonly used for the cultivation of mammalian cells in suspension. Here we conducted a three-dimensional computational fluid dynamics (CFD) simulation to characterize the fluid field in the disposable 600-mL orbital ...

Elsevier2018

Expression proteomics study to determine metallodrug targets and optimal drug combinations

Kai Johnsson, Paul Joseph Dyson, David Hacker, Claire Samantha Allardyce

The emerging technique termed functional identification of target by expression proteomics (FITExP) has been shown to identify the key protein targets of anti-cancer drugs. Here, we use this approach to elucidate the proteins involved in the mechanism of a ...

Nature Research2017

Studies on fluid dynamics of the flow field and gas transfer in orbitally shaken tubes

Florian Maria Wurm, David Hacker, Xiao Shen, Dominique Terry Monteil Jr, Likuan Zhu

Orbitally shaken cylindrical bioreactors [OrbShake bioreactors (OSRs)] without an impeller or sparger are increasingly being used for the suspension cultivation of mammalian cells. Among small volume OSRs, 50-mL tubes with a ventilated cap (OSR50), origina ...

American Chemical Society2017

Disposable orbitally shaken TubeSpin bioreactor 600 for Sf9 cell cultivation in suspension

Florian Maria Wurm, Lucia Baldi Unser, David Hacker, Xiao Shen, Dominique Terry Monteil Jr, Giulia Tontodonati

Disposable orbitally shaken TubeSpin bioreactor 600 tubes (TS600s) were recently developed for the bench-scale cultivation of animal cells in suspension. Here we compared batch cultures of Sf9 insect cells in TS600s, spinner flasks, and shake flasks. Super ...

Elsevier2016

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

Florian Maria Wurm, Lucia Baldi Unser, David Hacker, 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

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

Recombinant protein production from stable mammalian cell lines and pools

David Hacker, Sowmya Balasubramanian

We highlight recent developments for the production of recombinant proteins from suspension-adapted mammalian cell lines. We discuss the generation of stable cell lines using transposons and lentivirus vectors (non-targeted transgene integration) and site- ...

Elsevier2016

A comparison of orbitally-shaken and stirred-tank bioreactors: pH modulation and bioreactor type affect CHO cell growth and protein glycosylation

Florian Maria Wurm, Lucia Baldi Unser, David Hacker, Marc Moniatte, Valentin Juvet, Dominique Terry Monteil Jr

Orbitally shaken bioreactors (OSRs) support the suspension cultivation of animal cells at volumetric scales up to 200 L and are a potential alternative to stirred-tank bioreactors (STRs) due to their rapid and homogeneous mixing and high oxygen transfer ra ...

American Chemical Society2016

Population Variation and Genetic Control of Modular Chromatin Architecture in Humans

David Hacker, Gilles Udin, Nouria Hernandez, Bart Deplancke, Alisa Yurovsky, Sunil Kumar Raghav, Sarah Thurnheer, Sebastian Martin Waszak

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

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

Florian Maria Wurm, Lucia Baldi Unser, David Hacker, 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

A simple plasmid-based transient gene expression method using High Five cells

Florian Maria Wurm, Lucia Baldi Unser, David Hacker, Virginie Bachmann, Xiao Shen

The High Five (H5) cell line, derived from the lepidopteran Trichoplusia ni, is one of the major insect cell hosts for the production of recombinant proteins using the baculovirus expression vector system (BEVS). Here, we describe a simple polyethylenimine ...

Elsevier2015

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

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