Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

More Cancer-Fighting Power – Mouse with Highly Effective Components of the Human Immune System

09.08.2010
How to make the immune system more potent against cancer? Researchers of the Max Delbrück Center (MDC) and Charité Universitätsmedizin in Berlin, Germany, have dedicated ten years of research to modify T cell receptors (TCRs), the antenna-like structures of T cells, so that that they would no longer ignore cancer cells, but instead specifically track and recognize them. This modification is the precondition for the immune system to destroy cancer cells. The researchers developed a mouse with a whole repertoire of these human T cell receptors (Nature Medicine, doi: 10.1038/nm.2197)* with the aim of utilizing these receptors in the future for targeted immunotherapy in patients.

The T cells of the immune system possess receptors on their surface with which they can recognize bacteria, viruses, and fungi and which enable the immune system to fight against foreign invaders and destroy them. At the same time, however, T cells must differentiate between “self” and “foreign” – between the body’s own proteins and foreign proteins – so that the immune system tolerates the body’s own tissue. If the immune system is no longer able to make this differentiation, it attacks “self” structures, leading to autoimmune diseases such as type 1 diabetes or multiple sclerosis.

In cancer diseases, however, the immune system appears to be restricted in its response. Cancer cells originate from the body’s own tissue, which is why the immune system obviously has trouble recognizing them – and that, although cancer cells often have antigens (from the Greek word antigennan meaning “produce against”) which make them recognizable as tumor cells and pathologically altered cells.

Professor Thomas Blankenstein and his research team at the MDC and Charité want to break this tolerance towards cancer cells. In their research they utilized a process which in mammals automatically makes mature immune cells out of immature T cells. Immature T cells do not yet possess any T cell receptors and thus have to migrate from the bone marrow to the thymus. In this gland, which is part of the immune system, the T cell receptor genes, with which the T cell recognizes antigens, undergo random gene rearrangement.

Each of the millions of generated T cells expresses only one T cell receptor on the cell surface with which an antigen is recognized. In the thymus, however, all T cells which recognize “self” structures are deactivated. T cells which specifically target foreign antigens are spared from these tolerance mechanisms. The mouse, for example, does not develop any tolerance toward human cancer cell antigens.

“Probably no other transgenic mouse has that many human gene segments”
T cell receptors (TCR) consist of an alpha and a beta chain. Professor Blankenstein and his research team increased the DNA building blocks of humans for these chains with the aid of an artificial chromosome (YAC - yeast artificial chromosome) and then introduced them into embryonic stem cells of the mouse. Altogether there were approximately 2 million DNA building blocks, corresponding to 2 megabases or around 170 gene segments. “Probably no other transgenic mouse has that many human gene segments,” said Professor Blankenstein.
Transgenic mouse with human T cell receptors
In ten years of developmental work the researchers in Berlin used embryonic stem cells loaded with human DNA to breed transgenic mice, which possess all possible human T cell receptors on their T cells. “These human T cell receptors in the mouse recognize human antigens of human cancer cells. For the mice human tumor antigens are foreign,” Professor Blankenstein explained. “Such highly effective T cell receptors do not exist in humans. They are destroyed in humans in order to prevent them from attacking the body’s own structures. Only T cells remain with less effective T cell receptors,” he stressed.

The researchers aim to isolate these high-affinity human T cell receptors of the mouse, for which human cancer antigens are foreign, and to introduce them into the T cells of cancer patients. In this way the patients’ ineffective T cells shall be boosted in their effectiveness to destroy the cancer cells. In contrast to a bone marrow transplantation, in which many T cells of the transplant are activated in the recipient, which can lead to life-threatening destruction of healthy cells, this therapy approach is very selective. With this method the researchers hope to avoid an overreaction of the immune system.

Whether the highly upgraded human T cells from the mouse preserve their great effectiveness in humans remains to be seen. At present the researchers are preparing a first clinical trial, in which they will test the effectiveness and tolerance of these T cell receptors in cancer patients.

Professor Blankenstein is also spokesperson of the transregional collaborative research program “Principles and Applications of Adoptive T Cell Therapy” in Berlin and Munich. This program, funded by the German Research Foundation until 2014, explores new approaches to cancer treatment with the aid of the immune system. Participants in this program along with the MDC and the Charité in Berlin are the German Rheumatism Research Center Berlin and in Munich the Helmholtz Zentrum München – German Research Center for Environmental Health and two universities, Technische Universität München (TUM) and Ludwig-Maximilians-Universität (LMU).

A photo and graphics can be downloaded from the internet at:
http://www.mdc-berlin.de/de/index.html
*Transgenic mice with a diverse human T-cell antigen receptor repertoire
Liang-Ping Li1,2*, J. Christoph Lampert1,2*, Xiaojing Chen1,2, Catarina Leitao1,2, Jelena Popoviæ1,2, Werner Müller3 and Thomas Blankenstein1,2
1 Max Delbrück Center for Molecular Medicine, Robert-Rössle Strasse 10, 13092 Berlin, Germany
2 Institute of Immunology, Charité Campus Benjamin Franklin, Hindenburgdamm 30, 12200, Berlin, Germany

3 Bill Ford Chair in Cellular Immunology, University of Manchester, Faculty of Life Sciences, Oxford Road, Manchester, M13 9PT

*These authors contributed equally to this work

Barbara Bachtler
Press and Public Affairs
Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch
Robert-Rössle-Straße 10; 13125 Berlin; Germany
Phone: +49 (0) 30 94 06 - 38 96
Fax: +49 (0) 30 94 06 - 38 33
e-mail: presse@mdc-berlin.de
Claudia Peter
Stv. Leiterin Unternehmenskommunikation
Charité - Universitätsmedizin Berlin
Charitéplatz 1
10117 Berlin
Phone: +49-(0) 30 450 570 - 503
Fax: +49-(0) 30 450 570 - 940
e-mail: Claudia.Peter@charite.de

Barbara Bachtler | Max-Delbrück-Centrum
Further information:
http://www.charite.de/
http://www.mdc-berlin.de/
http://www.sfb-tr36.com/

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

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

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>