Background:The envelope protein from multiple sclerosis (MS) associated retroviral element (MSRV), a member of the Human Endogenous Retroviral family ‘W’ (HERV-W), induces dysimmunity and inflammation.Objective:The objective of this study was to confirm and specify the association between HERV-W/MSRV envelope (Env) expression and MS.Methods:103 MS, 199 healthy controls (HC) and controls with other neurological diseases (28), chronic infections (30) or autoimmunity (30) were analysed with an immunoassay detecting Env in serum. Env RNA or DNA copy numbers in peripheral blood mononuclear cells (PBMC) were determined by a quantitative polymerase chain reaction (PCR). Env was detected by immunohistology in the brains of patients with MS with three specific monoclonals.Results:Env antigen was detected in a serum of 73% of patients with MS with similar prevalence in all clinical forms, and not in chronic infection, systemic lupus, most other neurological diseases and healthy donors (p<0.01). Cases with chronic inflammatory demyelinating polyneuropathy (5/8) and rare HC (4/103) were positive. RNA expression in PBMC and DNA copy numbers were significantly elevated in patients with MS versus HC (p<0.001). In patients with MS, DNA copy numbers were significantly increased in chronic progressive MS (secondary progressive MS vs relapsing–remitting MS (RRMS) p<0.001; primary progressive MS vs RRMS –<0.02). Env protein was evidenced in macrophages within MS brain lesions with particular concentrations around vascular elements.Conclusion:The association between MS disease and the MSRV-type HERV-W element now appears quite strong, as evidenced ex-vivo from serum and PBMC with post-mortem confirmation in brain lesions. Chronic progressive MS, RRMS and clinically isolated syndrome show different ELISA (Enzyme-Linked Immunosorbent Assay) and/or PCR profiles suggestive of an increase with disease evolution, and amplicon sequencing confirms the association with particular HERV-W elements.

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Human apolipoprotein H (apo H)The hepatitis B virus (HBV) chronically infects more than 250 million people throughout the world, and is the most important etiologic agent responsible for diseases such as chronic hepatitis, cirrhosis, and hepatocellular carcinoma in endemic areas. 1 This DNA virus is a member of the Hepadnaviridae family 2 and mainly targets liver cells. The HBV envelope contains the hepatitis B surface antigen (HBsAg), which is a complex macromolecular aggregate with an M r of 3.5 ϫ 10 6 composed of proteins (75%), carbohydrates in glycoprotein form, and lipids from the host (25%). 3 HBsAg occurs in three molecular forms, named small (S), middle (M), and large (L) HBsAg. The SHBsAg contains 226 amino acid residues and the MHBsAg has an additional pre-S2 domain (55 amino acid residues), whereas the LHBsAg has the pre-S2 and pre-S1 extension (119 amino acid residues). During HBV infection, hepatocytes synthesize and secrete HBsAg mainly in the form of 20-nm diameter lipoproteic particles. 4 Phospholipids represent almost 70% of total lipids, with phosphatidylcholine being the most abundant component. 5 Two other types of virus-associated particles are present in the blood of HBV-infected subjects: Dane spherical particles with a diameter of about 42 nm, consisting of infectious complete virions and smaller quantities of filaments of variable length. The 20-nm HBsAg spheres are usually present in a 10,000-to 1,000,000-fold excess over Dane particles. 6 A variety of serum-derived proteins binds to HBV envelope glycoproteins. Altered human serum albumin, especially glutaraldehyde polymerized albumin (poly-HSA), has been the most studied. 7,8 The HBsAg receptor for poly-HSA has been localized within the pre-S2 domain, 9 and is more abundant in the hepatitis B e antigen (HBeAg) phase of HBV infection than in the anti-HBe phase. 10 A significant correlation was reported between poly-HSA binding activity on HBsAg particles and DNA polymerase, and further this poly-HSA binding activity was proposed as an active infection marker for a prognostic test for HBeAg-positive chronic hepatitis B. 11 This albumin polymers-HBsAg interaction is species specific, and some investigators found that only glutaraldehyde made albumin polymers bind HBsAg efficiently. 12 These controversial results and the fact that the albumin solutions previously used by these investigators were possibly not pure enough, led us to investigate the nature of possible albumin contaminants responsible for this binding activity. We thus purified, from human albumin, a 50-kd protein exhibiting HBsAg binding activity and preventing heat-induced formation of albumin polymers. The first 20 amino acids of the N-terminal region for this protein were determined by gas phase microsequencing: NH 2 -Gly-Arg-Thr-Cys-Pro-Lys-Pro-Asp-Asp-Leu-ProPhe-Ser-Thr-Val-Val-Pro-Leu-Lys-Thr-. A computer search of current database releases showed that this sequence is identical to the N-terminal sequence of the plasma protein apolipoprotein H (apo H), or ␤2-glycoprote...

BackgroundThe principle of a capture ELISA is binding of specific capture antibodies (polyclonal or monoclonal) to the surface of a suitable 96 well plate. These immobilized antibodies are capable of specifically binding a virus present in a clinical sample. Subsequently, the captured virus is detected using a specific detection antibody. The drawback of this method is that a capture ELISA can only function for a single virus captured by the primary antibody. Human Apolipoprotein H (ApoH) or β2-glycoprotein 1 is able to poly-specifically bind viral pathogens. Replacing specific capture antibodies by ApoH should allow poly-specific capture of different viruses that subsequently could be revealed using specific detection antibodies. Thus, using a single capture ELISA format different viruses could be analysed depending on the detection antibody that is applied. In order to demonstrate that this is a valid approach we show detection of group A rotaviruses from stool samples as a proof of principle for a new method of capture ELISA that should also be applicable to other viruses.ResultsStool samples of different circulating common human and potentially zoonotic group A rotavirus strains, which were pretested in commercial EIAs and genotyped by PCR, were tested in parallel in an ApoH-ELISA set-up and by quantitative real-time PCR (qPCR). Several control samples were included in the analysis. The ApoH-ELISA was suitable for the capture of rotavirus-particles and the detection down to 1,000 infectious units (TCID50/ml). Subsets of diagnostic samples of different G- and P-types were tested positive in the ApoH-ELISA in different dilutions. Compared to the qPCR results, the analysis showed high sensitivity, specificity and low cross-reactivity for the ApoH-ELISA, which was confirmed in receiver operating characteristics (ROC) analysis.ConclusionsIn this study the development of a highly sensitive and specific capture ELISA was demonstrated by combining a poly-specific ApoH capture step with specific detection antibodies using group A rotaviruses as an example.