Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flexibility, rather than perfection, helps in the fight against pathogens

19.02.2016

Flexibility may be a crucial advantage in the defence against pathogens

When a foreign substance invades a body, the body produces antibodies that recognise and fight the intruder by means of antibodies that bind to a specific portion of the intruder - the antigen. Memory cells are then formed in the course of the defence reaction.


Mesenteric lymph node of a Confetti mouse infected with Friend retrovirus. The clusters of colored cells are germinal centers showing different levels of color dominance

© Gabriel D. Victora

These cells make sure that the body can respond more quickly and more strongly to any recurring attack of the same pathogen. According to a study just published in "Science" by scientists of the Whitehead Institute for Biomedical Research, Cambridge, USA, and the Helmholtz Centre for Infection Research (HZI) in Braunschweig, Germany, the common notion, i.e. that the body produces antibodies with a perfectly fitting key-lock design for a specific antigen exclusively, is not true.

Antibodies are produced by a certain type of white blood cells called B-cells or B-leukocytes which patrol our lymph nodes in search of pathogens every day. When a B-cell binds to an antigen by means of its receptor, the B-cell either produces a reasonably well-fitting antibody directly or it gets involved in the formation of a germinal centre. Germinal centres are antibody training sites:

The B-cells proliferate in them, diversify their antibodies through mutation and optimise them through selection. "In the course of time, the affinity of the antibodies for the antigens increases. Basically, only the most effective antibodies persist. This evolutionary process is called affinity maturation," says Michael Meyer-Hermann, who is the director of the "System Immunology" department at the HZI.

Meyer-Hermann and his colleague, Gabriel Victora, from the Whitehead Institute for Biomedical Research aimed to test this theory in the scope of a project funded by the Human Frontiers Science Program in order to find out more about the process of affinity maturation. For this purpose, the researchers combined single-cell sequencing with brainbow experiments, a technique that is common in brain and developmental research. In this technique, mother cells are stained with random fluorescent proteins, which they then pass on to their daughter cells.

"This allows us to recognise exactly which lineage the cells have come from, and which founder cells dominate the germinal centre," says Meyer-Hermann. "According to what was known, we presumed that only a few cells established the germinal centre and that the strong selection pressure would lead to uni-coloured germinal centres."

The results of the sequencing were astounding: "According to common belief, there are on the order of three to five founder cells per germinal centre. We just showed that the number is closer to 100," says Meyer-Hermann. The brainbow experiments showed that the germinal centres do not become as uni-coloured as expected. While some centres turned uni-coloured in the course of the antibody selection process, there were others which consisted of different colours even after a long period of time.

This means that there is not one definite dominant antibody, but that many different antibodies coexist.
Perhaps it is not always of advantage to adapt perfectly to a pathogen. After all, the pathogens keep developing too. "The more specific the antibodies are, the more difficult it may be for them to respond to mutations in the pathogens," says Meyer-Hermann. "Accordingly, a certain degree of variability and flexibility could be crucial for keeping up with the constantly changing pathogens."

In the long term, these insights might help in the development of new vaccines, since antibodies are the fundamental basis of vaccines. "Once we know what affects the ratio of dominant-clone versus diverse germinal centres, we can specifically adapt the diversity of the induced antibodies to the mutation rate of the pathogen in the vaccination protocols we use," says Meyer-Hermann.

Weitere Informationen:

http://www.helmholtz-hzi.de/en/news_events/news/view/article/complete/flexibilit... - Press release

Susanne Thiele | Helmholtz-Zentrum für Infektionsforschung

Further reports about: B-cell B-cells Biomedical HZI Helmholtz-Zentrum pathogens

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>