Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

500 million year reset for the immune system

21.08.2014

A single factor can reset the immune system of mice to a state likely similar to what it was 500 million years ago, when the first vertebrates emerged.

Scientists at the Max Planck Institute of Immunobiology and Epigenetics (MPI-IE) in Freiburg re-activated expression of an ancient gene, which is not normally expressed in the mammalian immune system, and found that the animals developed a fish-like thymus.


The normal mouse thymus (left) contains only a small fraction of B-cells (red). If the gene FOXN4 is activated, a fish-like thymus with many B-cells develops. This state is likely to have existed about 500 million years ago, at the time when the first vertebrates emerged.

© Max Planck Institute of Immunobiology & Epigenetics

To the researchers surprise, while the mammalian thymus is utilized exclusively for T cell maturation, the reset thymus produced not only T cells, but also served as a maturation site for B cells – a property normally seen only in the thymus of fish. Thus the model could provide an explanation of how the immune system had developed in the course of evolution. The study has been published in Cell Reports.

The adaptive immune response is unique to vertebrates. One of its core organs is the thymus, which exists in all vertebrate species. Epithelial cells in the thymus control the maturation of T-cells, which later fight degenerated or infected body cells.

The gene FOXN1 is responsible for the development of such T-cells in the mammalian thymus. Scientists led by Thomas Boehm, director at the MPI-IE and head of the department for developmental immunology, activated the evolutionary ancestor of FOXN1, called FOXN4, in the thymic epithelial cells of mice. FOXN4 is present in all vertebrates, but appears to play only a role in the maturation of immune cells of jawed fish, such as cat sharks and zebra fish.

“The simultanuous expression of FOXN4 and FOXN1 in the mouse led to a thymus that showed properties as in fish,” said first author Jeremy Swann. Together with earlier results this suggests that the development and function of thymic tissue was originally intitiated by FOXN4. Due to an evolutionary gene duplication, which led to FOXN1, transiently both genes, and finally only FOXN1 were active in the thymus.

To the researchers surprise not only T-cells developed in the thymus of the mice, but also B-cells. Mature B-cells are responsible for antibody production. In mammals, they normally do not mature in the thymus, but in other organs, such as the bone marrow.

“Our studies suggest a plausible scenario for the transition of a bipotent lymphopoietic tissue to a lymphoid organ supporting primarily T cell development,” said Boehm. Since B- and T-cell progenitors can not yet be distinguished, it remains unclear whether the B-cell development is based on the migration of dedicated B-cell precursors to the thymus, or to maturation from a shared T/B progenitor in the thymus itself.

Comparative studies often suggest that the origin of a particular evolutionary innovation must have occurred in an extinct species. „Here, the re-creation and functional analysis of presumed ancestral stages could provide essential insights into the course of such developments," explained Boehm the study approach.

Contact 

Dr. Thomas Boehm

Max Planck Institute of Immunobiology and Epigenetics, Freiburg

Phone: +49 761 5108-328
Fax: +49 761 5108-323

 

Johannes Faber

Press and Public relations

Max Planck Institute of Immunobiology and Epigenetics, Freiburg

Phone: +49 761 5108-368

 

Original publication

 
Swann JB, Weyn A, Nagakubo D, Bleul CC, Toyoda A, Happe C, Netuschil N, Hess I, Haas-Assenbaum A, Taniguchi Y, Schorpp M, Boehm T.
Cell Reports, 14 July 2014

Dr. Thomas Boehm | Max-Planck-Institute

Further reports about: B-cell B-cells Cell Epigenetics immune lymphoid mammalian organs species vertebrates

More articles from Life Sciences:

nachricht A Barcode For Shredding Junk RNA
28.08.2015 | Ruprecht-Karls-Universität Heidelberg

nachricht Researchers discover new mechanism in adrenal gland tumors
28.08.2015 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

Im Focus: Fraunhofer IPA develops prototype of intelligent care cart

It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.

Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

A Barcode For Shredding Junk RNA

28.08.2015 | Life Sciences

OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

28.08.2015 | Physics and Astronomy

Two satellites see newborn Tropical Storm Jimena consolidating

28.08.2015 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>