Common

Six-Eye-Principle protects the body from Autoimmune diseases

So called dendritic cells patrol in our bodies 24/7 searching for indications for tumors or infections. As soon as they make a find, they activate Killer-T-Cells and thereby initiate an immune defense reaction. Researchers from the University of Bonn and their colleagues at the Universities of Düsseldorf, Hamburg, Utah (USA) and Melbourne (Australia) have now discovered how exactly this occurs: their findings could be of use for the development of better vaccines. They will be published in the next issue of the Nature Immunology journal (doi:10.1038/ni.1848).

One of the most important defense mechanisms against viruses, bacteria and cancer cells are cytotoxic T-cells. They are capable of inducing the death of infected somatic or cancer cells. Hence, they are also called Killer-T-cells.

Normally, Killer-T-cells are inactive. For good reason: Otherwise undesired autoimmune diseases like Diabetes mellitus or Multiple Sclerosis could result. They are activated by so-called dendritic cells patrolling the body continuously and searching for indications of tumors or infections. When making a find, they carry the information into the lymph nodes.

Within a human body, there are several million different Killer-T-cells. When an infection occurs, it is the dendritic cells’ task to only alarm the appropriate ones. Those will then divide several thousand times and swarm out to search for the disease agent and fight it. This has to happen very quickly for viruses multiply extremely fast.

“Scent trail” for Killer-Cells

So far it has remained unclear how exactly the patrollers manage to alarm the appropriate Killer-cells so quickly. “Now we have found out that two other types of T-cells play a decisive role” explains Professor Dr. Christian Kurts from the Insitutes for Molecular Medicine and Experimental Immunology at the University of Bonn.

He refers to the so called T helper cells and Natural killer T cells (NKT cells). Apparently, they detect dendritic cells that contain information about viruses or tumors. As a result, they produce certain messenger substances, so called Chemokines.
Killer T cells follow those messengers like dogs follow a trail.
This way they unerringly find those dendritic cells that can guide them to a hidden virus or tumor cell. “Hence, the Killer T cells do not have to inspect all of the body’s dendritic cells”, emphasizes Verena Semmling, who has counducted this study in the context of her doctorate thesis. “Thus, they can be activated more quickly.”

Immune System striving for consensus

This cooperation of different immune cells has the additional advantage, that it can prevent autoimmune diseases. The dendritic cell can only attract Killer T cells when either T helper cells or NKT cells have recognized the danger signal as well. Therefore, the dendritic cell gets a second opinion before it activates an immune response. This works particularly well if the T helper cells as well as the NKT cells agree. So if the dendritic cell gets a third confirmation, it is especially well capable of activating the Killer T cells.

“The clarification of these mechanisms is not only of interest for fundamental research” says Professor Dr. Irmgard Förster from the Environmental Health Research Institute at the University of Düsseldorf. “Once we understand how immune cells communicate among each other, we can make use of this knowledge in order to improve vaccines. The results at hand are showing that vaccines should work better if they activate T helper cells and NKT cells also.”

The recent papers were published in context of the Collaborative Research Center 704 located at the University of Bonn. With this, the German Research Foundation (DFG) promotes studying the immune defense.

Contact Information:
Professor Dr. Christian Kurts
Institute für Molekulare Medizin und Experimentelle Immunologie
Universität Bonn
Phone: +49 228/287-11031
E-Mail: ckurts@uni-bonn.de

Professor Dr. Irmgard Förster
Molekulare Immunologie,
Institut für Umweltmedizinische Forschung an der Universität Düsseldorf gGmbH
Phone: +49 211/3389-210
E-Mail: irmgard.foerster@uni-duesseldorf.de

Source: Rheinische Friedrich-Wilhelms-Universität Bonn

Thema: Biotechnology, Health and Medicine

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	Common Six-Eye-Principle protects the body from Autoimmune diseases So called dendritic cells patrol in our bodies 24/7 searching for indications for tumors or infections. As soon as they make a find, they activate Killer-T-Cells and thereby initiate an immune defense reaction. Researchers from the University of Bonn and their colleagues at the Universities of Düsseldorf, Hamburg, Utah (USA) and Melbourne (Australia) have now discovered how exactly this occurs: their findings could be of use for the development of better vaccines. They will be published in the next issue of the Nature Immunology journal (doi:10.1038/ni.1848). One of the most important defense mechanisms against viruses, bacteria and cancer cells are cytotoxic T-cells. They are capable of inducing the death of infected somatic or cancer cells. Hence, they are also called Killer-T-cells. Normally, Killer-T-cells are inactive. For good reason: Otherwise undesired autoimmune diseases like Diabetes mellitus or Multiple Sclerosis could result. They are activated by so-called dendritic cells patrolling the body continuously and searching for indications of tumors or infections. When making a find, they carry the information into the lymph nodes. Within a human body, there are several million different Killer-T-cells. When an infection occurs, it is the dendritic cells’ task to only alarm the appropriate ones. Those will then divide several thousand times and swarm out to search for the disease agent and fight it. This has to happen very quickly for viruses multiply extremely fast. “Scent trail” for Killer-Cells So far it has remained unclear how exactly the patrollers manage to alarm the appropriate Killer-cells so quickly. “Now we have found out that two other types of T-cells play a decisive role” explains Professor Dr. Christian Kurts from the Insitutes for Molecular Medicine and Experimental Immunology at the University of Bonn. He refers to the so called T helper cells and Natural killer T cells (NKT cells). Apparently, they detect dendritic cells that contain information about viruses or tumors. As a result, they produce certain messenger substances, so called Chemokines. Killer T cells follow those messengers like dogs follow a trail. This way they unerringly find those dendritic cells that can guide them to a hidden virus or tumor cell. “Hence, the Killer T cells do not have to inspect all of the body’s dendritic cells”, emphasizes Verena Semmling, who has counducted this study in the context of her doctorate thesis. “Thus, they can be activated more quickly.” Immune System striving for consensus This cooperation of different immune cells has the additional advantage, that it can prevent autoimmune diseases. The dendritic cell can only attract Killer T cells when either T helper cells or NKT cells have recognized the danger signal as well. Therefore, the dendritic cell gets a second opinion before it activates an immune response. This works particularly well if the T helper cells as well as the NKT cells agree. So if the dendritic cell gets a third confirmation, it is especially well capable of activating the Killer T cells. “The clarification of these mechanisms is not only of interest for fundamental research” says Professor Dr. Irmgard Förster from the Environmental Health Research Institute at the University of Düsseldorf. “Once we understand how immune cells communicate among each other, we can make use of this knowledge in order to improve vaccines. The results at hand are showing that vaccines should work better if they activate T helper cells and NKT cells also.” The recent papers were published in context of the Collaborative Research Center 704 located at the University of Bonn. With this, the German Research Foundation (DFG) promotes studying the immune defense. Contact Information: Professor Dr. Christian Kurts Institute für Molekulare Medizin und Experimentelle Immunologie Universität Bonn Phone: +49 228/287-11031 E-Mail: ckurts@uni-bonn.de Professor Dr. Irmgard Förster Molekulare Immunologie, Institut für Umweltmedizinische Forschung an der Universität Düsseldorf gGmbH Phone: +49 211/3389-210 E-Mail: irmgard.foerster@uni-duesseldorf.de Source: Rheinische Friedrich-Wilhelms-Universität Bonn Thema: Biotechnology, Health and Medicine	Drucken Zurück