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Multiple sclerosis: Discovery of a mechanism responsible for chronic inflammation

Date:
May 10, 2019
Source:
Institut Pasteur
Summary:
Multiple sclerosis (MS) is an autoimmune disease. The defense system that usually protects patients from external aggression turns on its own cells and attacks them for reasons that are not yet known. Scientists have shown that ancient viruses are involved in the acute inflammatory defense response that may contribute to the disease.
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Multiple sclerosis (MS) is an autoimmune disease. The defense system that usually protects patients from external aggression turns on its own cells and attacks them for reasons that are not yet known. Scientists from the Institut Pasteur have shown that ancient viruses are involved in the acute inflammatory defense response that may contribute to the disease.

Multiple sclerosis (MS) is an incurable inflammatory autoimmune disease that leads to irreversible damage to the brain and spinal cord. This disease is also associated with the reactivation of ancient viruses, which were inserted in our DNA during the evolution of humankind. It was therefore long thought that multiple sclerosis was due to a viral infection.

"Our study shows that reactivation of ancient viruses does not correspond to an infectious phenomenon, but to a defense response of the body when faced with an acute inflammatory phenomenon" explains Christian Muchardt, Head of the Epigenetic Regulation Unit at the Institut Pasteur.

Viral sequences were neutralized during evolution and no longer represent a source of infection. But these sequences are a source of external DNA containing information about virus behavior. Cells have therefore been able to control these sequences to detect infections as quickly as possible and turn on their defense genes during an attack.

These viral sequences are, above all, used to control defense genes in stem cells. They lie dormant in adult cells and it is the more traditional sequences that become active. By examining samples from patients with MS, the scientists observed that regulatory sequences of viral origin emerged from their dormant state and were responsible for abnormal expression of several pro-inflammatory genes.

To conclude, in multiple sclerosis, activation of viral sequences does not correspond to an infectious phenomenon but to the unexpected use of regulatory sequences, leading to chronic excessive inflammation.

"The discovery of this mechanism, linked to epigenetic phenomena, may one day pave the way for management of MS using small molecules that inhibit chromatin modification enzymes" sums up Christian Muchardt.


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Materials provided by Institut Pasteur. Note: Content may be edited for style and length.


Journal Reference:

  1. Saliha Azébi, Eric Batsché, Frédérique Michel, Etienne Kornobis, Christian Muchardt. Expression of endogenous retroviruses reflects increased usage of atypical enhancers in T cells. The EMBO Journal, 2019; e101107 DOI: 10.15252/embj.2018101107

Cite This Page:

Institut Pasteur. "Multiple sclerosis: Discovery of a mechanism responsible for chronic inflammation." ScienceDaily. ScienceDaily, 10 May 2019. <www.sciencedaily.com/releases/2019/05/190510091354.htm>.
Institut Pasteur. (2019, May 10). Multiple sclerosis: Discovery of a mechanism responsible for chronic inflammation. ScienceDaily. Retrieved March 18, 2024 from www.sciencedaily.com/releases/2019/05/190510091354.htm
Institut Pasteur. "Multiple sclerosis: Discovery of a mechanism responsible for chronic inflammation." ScienceDaily. www.sciencedaily.com/releases/2019/05/190510091354.htm (accessed March 18, 2024).

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