New Regulator of Immune Reaction Discovered
News Nov 30, 2016
Cells of the immune system can distinguish between protein molecules that are "self" and "non-self". For example, if we are exposed to pathogens such as bacteria or viruses that carry foreign molecules on their surface, the body reacts with an immune response. In contrast, cells are "tolerant" of the body's own molecules. This state of unresponsiveness, or anergy, is regulated by a cellular signal, a calcium-controlled switch that was known to control also many brain functions. Neuroscientists from Heidelberg University and immunologists of Heidelberg University Hospital identified this signal. The research results were published in the “Journal of Cell Biology”.
The research work was led by Prof. Dr Hilmar Bading from the Interdisciplinary Center for Neurosciences working together with the research group of Prof. Dr Yvonne Samstag, Director of the Molecular Immunology Section. The Heidelberg research team identified a calcium signal in the cell nucleus of human T lymphocytes as a decision-maker in the immune system. They showed that a nuclear calcium signal is required for the immune reaction that T-cells trigger after contact with molecules foreign to the body.
This study was inspired by previous work of Prof. Bading on the function of calcium in the cell nucleus. The neuroscientist demonstrated that the messenger calcium, after invading the cell nucleus, acts as a master switch in the nervous system. The nuclear calcium signal triggers genetic programmes that control virtually all of the brain's adaptive capabilities, including memory, chronic pain and neuroprotection – a process that prevents damaged nerve cells from dying.
"When we started our study, we thought that nuclear calcium may play a similar role in the immune system as in the brain by activating a specific immune reaction gene programme," says Prof. Bading. "But we were surprised to see that human T lymphocytes became tolerant, i.e. shifted towards an anergic state, as soon as we switched off the nuclear calcium signal." According to Hilmar Bading, this discovery has important implications for the development of novel types of immunosuppressive therapies.
After organ transplants, for example, it is common to use drugs that completely block the immune reaction. Based on this new research, it may be possible to redirect the immune reaction towards tolerance – described by the Heidelberg research team as "pro-tolerance immunosuppression". Prof. Bading indicates this may be possible to achieve by blocking nuclear calcium in activated immune cells.
Story from Universität Heidelberg. Please note: The content above may have been edited to ensure it is in keeping with Technology Networks’ style and length guidelines.
Monaco, S., Jahraus, B., Samstag, Y., & Bading, H. (2016). Nuclear calcium is required for human T cell activation. The Journal of Cell Biology, 215(2), 231–243. doi:10.1083/jcb.201602001
Study Reveals How MRSA Infection Compromises Lymphatic FunctionNews
Infections of the skin or other soft tissues with the hard-to-treat MRSA bacteria appear to permanently compromise the lymphatic system, which is crucial to immune system function. Investigators describe how MRSA infection impairs the ability of lymphatic vessels to pump lymphatic fluid to lymph nodes in mouse models, which may contribute to the frequent recurrences of MRSA infection experienced by patients.
Possible Biomarker to Identify Who Would Benefit from ImmunotherapyNews
While immunotherapy has made a big impact on cancer treatment, the fact remains that only about a quarter of patients respond to these treatments. In a new study, researchers examined tissue samples from melanoma and ovarian cancer patients treated with immunotherapies and found a link between the percentage of antigen-presenting cells expressing PD-L1 and an objective clinical response to treatment.READ MORE
Fight Against Cancer: Drug Combination Helps Kickstart the Immune SystemNews
Scientists from King's College London have found a way to boost the immune system to help it fight back against cancer.
The breakthrough involves the first ever use of a combination of chemotherapy and a drug being trialled as a treatment for neonatal jaundice, that together help kick start the body's natural defences.