Differential Expression of HERV-W in Peripheral Blood in Multiple Sclerosis and Healthy Patients in Two Different Ethnic Groups.

Rachael Tarlinton,Elena Morandi,Timur Khaiboullin,Bruno Gran,Ekatarina Martynova,Svetlana Khaiboullina,Albert Rizvanov,Belinda Wang

doi:10.3389/fphar.2019.01645

Abstract

Overexpression of the Human endogenous retrovirus W (HERV-W) group of inherited retroviruses has been consistently linked with Multiple Sclerosis (MS). However most of the studies on this link have focused on European genetic groups with a very high risk of MS and it is not clear that this relationship holds for all ethnic groups. This study examined via qPCR the RNA expression in peripheral blood of HERV-W (the multiple sclerosis associated retrovirus variant MSRV) of MS patients and healthy controls from two ethnic groups with very different risk rates of MS. Population one was derived from the UK with a Northern European genetic background and an MS risk rate of 108/100,000, population two was derived from the republic of Tatarstan, Russian Federation, with a mixed Russian (Eastern European) and Tartar (Turkic or Volga/Urals) population with an MS risk rate of 21-31/100,000. The Russian population displayed a significantly higher basal level of expression of MSRV in both healthy and MS individuals when compared to the British control population with a trend in the Russian population towards higher expression levels in MS patients than healthy patients.

Highlights

Multiple sclerosis (MS) is a chronic, progressive autoimmune neurological disease
While not statistically significant there is a clear trend in the Russian cohort towards a higher expression of Human endogenous retrovirus W (HERV-W) in MS patients than the healthy controls
The differences between the MS and healthy patients are in line with the reported increase in detection of HERV-W in Statistical analysis was performed using Graph Pad Prism 5, Kruskal Wallis test with Dunn’s multiple comparison test post hoc testing

Summary

Introduction

Multiple sclerosis (MS) is a chronic, progressive autoimmune neurological disease. The disease is often debilitating with few effective treatment options currently available. The underlying triggers for the disease are complex and be best summed up as: MS occurring in genetically susceptible individuals who are exposed to the “right” environmental triggers. A familial association is evident in some cases and some distinct restricted genetic groups (such as Sardinians) (Pugliatti et al, 2001) have a high risk. Extensive GWAS studies have demonstrated a compelling support for the HLA allele DRB1*15:01 as the most significant genetic risk factor for MS, with smaller effects. HERV-W in Two Different Ethnic Groups attributed to another 11 HLA alleles and 200 non HLA genes (Didonna and Oksenberg, 2017). Other risk factors for MS include gender (women are at higher risk than men), prior Epstein Barr Virus infection, Vitamin D levels (those with lower levels at higher risk)

Methods

Results

Conclusion