Novel reliable real-time PCR for differential detection of MSRVenv and syncytin-1 in RNA and DNA from patients with multiple sclerosis.
Two components of the HERV-W family of human endogenous retroviruses are activated during multiple sclerosis (MS) and proposed immunopathogenic co-factors: MSRV (MS-associated retrovirus), and ERVWE1 (whose env protein, syncytin-1, reaches the plasma membrane). MSRVenv and syncytin-1 are closely related, and difficult to distinguish each other. The sequences of extracellular MSRVenv and of syncytin-1 available in GenBank were compared with those found in MS patients and controls of the cohort under study. With respect to syncytin-1, MSRVenv sequences have a 12-nucleotide insertion in the trans-membrane moiety. Based on this insertion, discriminatory real-time PCR assays were developed, that can amplify selectively either MSRVenv or syncytin-1. The data of MS patients and controls indicated that MSRV and ERVWE1 are both expressed in the brain of MS patients, while only MSRV is present in the blood; MSRV was released in culture by PBMCs of MSRV-producer individuals. These cells expressed the complete MSRVenv gene in the absence of syncytin-1 expression, up to the final, fully glycosylated envelope protein product, since western blot staining with anti-HERV-Wenv antibody detected two bands of the same molecular weight (73 and 61kDa) of the fully glycosylated and partially glycosylated HERV-Wenv uncleaved proteins. Beyond MSRVenv DNA copy numbers were more abundant in MS patients than in healthy humans, while syncytin-1 were unchanged. These findings reinforce the link between MSRV and MS.
Mameli
Giuseppe
G
Section of Microbiology, Department of Biomedical Sciences, Centre of Excellence for Biotechnology Development and Biodiversity Research, University of Sassari, Viale San Pietro 43B, Sassari, Italy.
Poddighe
Luciana
L
Astone
Vito
V
Delogu
Giuseppe
G
Arru
Giannina
G
Sotgiu
Stefano
S
Serra
Caterina
C
Dolei
Antonina
A
D000328:Adult; D001483:Base Sequence; D001769:Blood / Q000821:virology; D001921:Brain / Q000821:virology; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D003937:Diagnosis, Differential; D020077:Endogenous Retroviruses / Q000145:classification* / Q000235:genetics*; D005260:Female; D015686:Gene Products, env / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009103:Multiple Sclerosis / Q000821:virology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011257:Pregnancy Proteins / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014759:Viral Envelope Proteins / Q000145:classification / Q000235:genetics*
D017931:DNA Primers; D004279:DNA, Viral; D015686:Gene Products, env; D011257:Pregnancy Proteins; D012367:RNA, Viral; D014759:Viral Envelope Proteins; C405335:syncytin