Eavesdropping on the Immune System
Communicating immune cells
Communicating immune cells
When disaster strikes, the police, fire department and rescue services must work together to coordinate their actions. In the same way, immune reactions in the body must be closely coordinated to enable a targeted defense against infections. Felix Meissner and his research group “Experimental Systems Immunology” are seeking to find out how the defense forces of the immune system work together and communicate at the molecular level.
In a previous study, Meissner and his colleagues succeeded in implementing a first major eavesdropping operation. The objects of their surveillance were macrophages (literally “big eaters” in Greek) because they can engulf and devour pathogens. Together with dendritic cells, macrophages form the first line of defense of the immune system and significantly determine the further course of the immune response. They regulate whether and which other players are called into action.
Macrophages can attract a variety of other immune cells by secreting different messenger proteins and instructing them to fight off threats or to initiate healing processes. The modes of action of some of these molecules have already been studied. For example, certain cytokines transmit biological messages between sometimes very distant cellular transmitters and receivers. Research approaches that focus on selected messenger proteins provide important insights into the body’s defense mechanisms – but nonetheless are not comprehensive enough. They represent only a few voices in the cacophony of messages that are sent and received from different cells.
Mass spectrometry enables the identification of hundreds or even thousands of different proteins in a mixture of molecules. Thus, for the first time, Meissner and his team were able to analyze the entirety of the messenger proteins secreted by the immune cells. In addition to the exact quantities of hundreds of proteins with communication functions, they identified novel immune signals that transmit messages between cells. In their future research, he and his team will continue to focus on the first line of defense of the immune system. Many questions are still open. For example, it remains unclear how microbes are classified as friend or enemy and how inflammatory reactions can be inactivated.
Answers to these questions could provide infection researchers with starting points for new therapy approaches. Other medical areas would also benefit from these findings: Cellular communication plays a role in all inflammatory responses in the body – for instance in sepsis, rheumatism, atherosclerosis, neurodegeneration, diabetes and many other diseases.