Immunity system complexity: T cell reaction controls (Introduction)

by David Turell , Monday, July 20, 2020, 20:03 (1586 days ago) @ David Turell

Molecular controls revealed:

https://medicalxpress.com/news/2020-07-immune-cells-killer-mode.html

"Now research groups led by Dr. Susana Minguet and Prof. Dr. Wolfgang Schamel from the University of Freiburg's signaling research Clusters of Excellence BIOSS and CIBSS have succeeded in demonstrating how this identification mechanism activates T cells to switch to attack mode. In a study published in the journal Nature Immunology, they describe a previously undiscovered domain of the T-cell receptor and demonstrate that this so-called RK motif improves immune therapies against cancer in pre-clinical studies.

"The T-cell receptor is a tiny machine made up of many individual proteins. When it recognizes an infected or a tumor cell in the body, a so-called lymphocyte specific kinase binds to the T-cell receptor at the newly discovered RK motif. This binding switch on the T-cell receptor activating the T cell to become a killer cell and thus, eliminate the threat.. "We were astounded that this RK motive has never been described before," say Minguet and Schamel of the discovery: "Immunologists have been studying the T-cell receptor for more than 30 years now."

"The findings serve to build a bridge between the perception of a threat and the activation of the immune response at the molecular level, shedding light on an essential operating principle of the immune system. T cells fulfill various functions: Cytotoxic T cells, so-called killer cells, are particularly responsible for destroying the body's own cells when they pose a threat to it—because they have been infected by bacteria or viruses or because they have changed into cancer cells. The T cells identify antigens exclusively on cells and then release toxic substances to destroy these target cells.

"The scientists discovered the RK motif with a combination of biochemistry, synthetic biology, and immunology. They demonstrated that the RK motif is normally hidden to prevent un-desired T cell activation and it is exposed only after binding to the antigen, this may explain why it has remained undetected until now. This unique combination of disciplines is a product of the integrative approach at the Cluster of Excellence CIBSS. The biochemical analyses enable a detailed understanding of the molecular signals, while their immunological understanding and medical application explain their function in the body." (my bold)

Comment: See my bold. A carefully designed system to protect the body's own cells from unnecessary attacks, but autoimmune diseases do occur. Mistakes happen as discussed before.