Antibodies protect the body against diseases – but can also harm their own organism if the reactions are misdirected. Researchers from the University of Zurich have now discovered that a particular sugar in the antibodies determines whether one of the body’s own cells is destroyed or not. This result could lead to new treatment possibilities for patients with autoimmune diseases.
The immune system is our biological defense shield. Antibodies protect the organism against invading pathogens such as viruses or bacteria. In the case of certain autoimmune diseases, however, this defense behavior is misdirected: The antibodies don’t just target foreign substances; they also attack the body’s own cells. Once the antibody binds to the cell surface, they can activate specific proteins, so-called complement factors, which can damage the cell membrane and thus kill the cell.
Antikörper sind Y-förmig gebaute Moleküle. Zuckerstrukturen (rot), die an das Antikörperprotein gekoppelt sind, spielen eine wichtige Rolle für die Funktion von Antikörpern. Das Vorhandensein von Sialinsäure an dem Zucker führt dazu, dass Antikörper weniger stark ihre Zielzellen angreifen und zerstören. (Bild: UZH)
Sialic acid protects from antibody-induced cell killing
A team of researchers headed by Professor Jan Lünemann from the Institute of Experimental Immunology at the University of Zurich has now discovered that a particular sugar structure in the antibody plays a key role in the complement-dependent destruction of the body’s own tissue. Antibodies consist of protein and coupled sugar groups. Earlier studies revealed that antibodies with the sugar structure sialic acid are detectable more rarely in patients suffering from autoimmune diseases than in healthy people.
“We observed that patients suffering from an autoimmune disease felt better the more sialic-acid-carrying antibodies they had in their blood,” reports Isaak Quast, a doctoral student in Lünemann’s group and the study’s first author. Different versions of antibody-coupled sugar structures were produced in the lab. “We managed to demonstrate that antibodies containing the sugar sialic acid only destroy the body’s own cells to a very limited extent. Our data indicates that the coupling of sialic acid to antibodies might be a potential strategy in treating patients with autoimmune diseases,” summarizes Lünemann.
Isaak Quast et al.. Sialylation of lgG Fc domain impairs complement-dependent cytotoxicity. The Journal of Clinical Investigation, 2015, October 5. DOI: 10.1172/JCI82695.
Melanie Nyfeler | Universität Zürich
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine