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

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>