Research: Viral Trigger of Relapse

Laska MJ, Brudek T, Nissen KK, Christensen T, Anné ML, Petersen T, Nexø BA. Expression of HERV-Fc1, a human endogenous retrovirus, is increased in patients with active Multiple Sclerosis. J Virol. 2012 Jan.[Epub ahead of print]

Multiple Sclerosis (MS) is considered to be an autoimmune disease with unknown cause and with immune system dysregulation. Among environmental factors, viruses are most often connected with the aetiology of MS. Human Endogenous Retroviruses (HERVs) constitute 5-8% of human genomic DNA and have been detected as transcripts and proteins in the central nervous system (CNS) and peripheral blood, frequently in the context of neuroinflammation.

The HERV-Fc1, which belongs to the HERV-H/F family, has received our attention largely because of the genetic association with MS. The expression of a capsid (Gag) coat protein of HERV-H/F origin by flow cytometry in blood cells from healthy controls and from MS patients with non-active or active disease.

There was a significant increase in HERV-H/F Gag expression in CD4+ (P less than 0.001) and CD8+ T lymphocytes (P less than 0.001) and in monocytes (P=0.0356*) in the blood from MS patients with active disease. Furthermore, we have undertaken the first rigorous qualitative PCR (were you amplify the genes so that they can be detected and quantitated) to quantify extracellular HERV-Fc1 RNA viral loads in the plasma (blood fluid) from MS patients and healthy controls.

A 4 fold increase in extracellular HERV-Fc1 RNA titres in patients with active MS was found compared with healthy controls (P less than 0.001). These findings strengthen the link between HERV-Fc1 and the pathology of MS. The cause and biological consequences of these differential expressions will be the subject of further investigation. HERV-Fc1 biology could be a compelling area for understanding the pathology of MS and possibly other autoimmune disorders.

If you managed to attend the Research Day, you will have heard about the Charcot Project, which aims to try and tackle the possibility of a viral cause of MS.

As you will be aware Prof G has been investigating the link of MS with Epstein-Barr Virus, but Prof G Down Under has ideas about other viruses and these may be HERVs. There has been studies suggesting that HERVs may be more common in MSers. This current study suggests these endogenous retrovirus may become active during active disease in MS, so is this the trigger? Is there a link with EBV? There is one way to find out. That is deal with these viruses to stop them becomiing activated and see what happens in MS.

Please see previous posts

HERVS you heard it here
Is MS caused by a retro virus
Do human endogenous retroviruses play a role in MS