T cell receptor ‘photographed’ for the first time with atomic precision – Heilpraxis

First image of T-cell receptor reveals ‘big surprise’

In our immune system to play T cells a crucial role. They are like custom tools that are targeted cancer cells and pathogen eliminate various infectious diseases. Because the success of T cells is a receiver on the surface of immune cells is largely responsible. A German research team has just explained for the first time what this receiver looks like “down to the last atom”.

researchers of Goethe University Frankfurt am Main could, in cooperation with the University of Oxford and the Max Planck Institute for Biophysics using cryo-electron microscopy for the first time accurate imaging of the T cell receptor including bound antigen. Recording could make a fundamental contribution to the understanding of immune responses. The results were recently published in the renowned journal “Cell” present.

One of the most powerful weapons of the immune system

The main task of our immune system is to fend off pathogens that enter the body from outside and to kill degenerated cells inside the body. T cells are among the most powerful weapons available to the immune system

T cell receptor decides between friend and foe

The T lymphocytes belonging to the white blood cells carry on their surface a receiverthe antigens recognize them and relate to them. As the working group explains, antigens are “small protein fragments from bacteria, viruses, and infected or degenerated body cells”which are presented to T cells.

Of the T cell receptor therefore has an important task, since it is essentially responsible for distinguishing whether the presented antigen is endogenous or exogenous matter acts.

Binding to an antigen triggers an immune response

If the T cell receptor binds to an appropriate antigen, a signaling pathway is activated inside the T cell, which equips the T cell for its respective task. According to the researchers, it is still unclear exactly how this signaling pathway is activated.

Other receptors are known to alter their spatial structure after binding. This structural change triggers a cascade that causes the cell to behave in a certain way.

The image of the receiver revealed a big surprise

Until now, it has been assumed that the T-cell receptor also uses this mechanism. Images of the receiver that have now been released provide the first indication of reality activation mechanism.

The researchers were able to image the unbound receptor with atomic resolution and the receptor after it had bound to an antigen. One turned out big surprise: apparently occurs after antigen binding no significant change the spatial structure of the receiver. The structure remains practically the same with and without antigen.

First step towards the medical use of the T cell receptor

“Our structure is a model for future studies on T-cell activation”stress Robert Tampe from the Institute of Biochemistry of Goethe University. According to him, the study also provides an important impetus to make the T cell receptor usable in therapy, for example for the treatment of infections, cancer and autoimmune diseases. (vb)