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Science In asthma, certain helper cells become disease triggers
Although asthma is relatively easy to control in the symptoms, it can not yet be cured on the basis of available treatment approaches. The causes of the disease remain unclear. However, in a recent study, researchers have identified the molecular mechanism that causes a type of immune cell that is involved in allergic diseases, such as asthma.
The scientists around Professor Dr. Magdalena Huber from Philipps-Universität Marburg showed in her research that certain proteins involved in the development of immune cells lead to an imbalance in the provision of immune cells. Under the influence of the proteins, possibly excessively special immune cells are produced which are related to the development of autoimmune diseases such as asthma. The researchers published their results in the journal "Nature Communications".
In asthma, an imbalance of certain proteins causes the formation of Th9 immune cells. (Image: bubutu / fotolia.com) Control of cell differentiation
In analyzing the molecular processes that lead to the differentiation of the so-called T-helper cells, the scientists were able to gain some groundbreaking findings. T-helper cells usually contribute to the body's immune defense, for example against worm infestations and cancers, but they are also involved in autoimmune diseases and asthma, the experts explain. These immune cells arise from immature progenitors and specialize in certain services when external stimuli stimulate their maturation, the researchers continue. This process is called cell differentiation.
Interplay of two proteins studied
Which cells develop in cell differentiation, according to the researchers controlled by the network-like interaction of genes that turn on or off each other. "In order to combat allergic diseases effectively, it is important to find out how the differentiation of T helper cells is genetically controlled," said Prof. Huber. The research team has therefore investigated the interaction of two proteins that have a significant influence on the differentiation of T helper cells. They analyzed the effect of the so-called "interferon-regulating factors" IRF1 and IRF4.
Opposing effect of the two proteins studied
The scientists found that the two proteins work against each other when a specific type of helper T-cell develops, the Th9 cells. These Th9 cells are characterized by the production of the protein interleukin 9 (IL-9) and the experiments have shown that IRF1 suppresses the production of IL-9, the researchers report. The protein IRF4, however, promoted IL-9 production. This observation suggested that IRF1 and IRF4 compete for coupling to a gene that contains the blueprint for IL-9, reports the Philipps-Universität Marburg.
Effects on the development of asthma
In the mouse model, the researchers investigated the consequences of the opposing activities of IRF1 and IRF4 on the development of asthma. Here they could prove that IRF1 limits the pathogenic effects of Th9 cells. This suggests that "asthmatics have a disturbed balance of the two factors and therefore produce more asthma-promoting IL-9," explains first author Lucia Campos Carrascosa of the Philipps University of Marburg.
New ways of treatment
"Our study shows that the molecular ratio between IRF1 and IRF4 influences the fate of Th9 cells," concludes Prof. Huber. This also opens up new possibilities for the treatment of allergic diseases such as asthma. Researchers from the University Hospital Mainz, the Universities of Würzburg and Munich (LMU) as well as Japanese researchers from Osaka were involved in the study in addition to the scientists from Marburg. (Fp)