Protein-Peptide Arrays for Detection of Specific Anti-Hepatitis D Virus (HDV) Genotype 1, 6, and 8 Antibodies among HDV-Infected Patients by Surface Plasmon Resonance Imaging

Abstract

iLiver diseases linked to hepatitis B-hepatitis D virus co-or superinfections are more severe than those during hepatitis B virus (HBV) monoinfection. The diagnosis of hepatitis D virus (HDV) infection therefore remains crucial in monitoring patients but is often overlooked. To integrate HDV markers into high-throughput viral hepatitis diagnostics, we studied the binding of anti-HDV antibodies (Abs) using surface plasmon resonance imaging (SPRi). We focused on the ubiquitous HDV genotype 1 (HDV1) and the more uncommon African-HDV6 and HDV8 genotypes to define an array with recombinant proteins or peptides. Fulllength and truncated small hepatitis D antigen (S-HDAg) recombinant proteins of HDV genotype 1 (HDV1) and 11 HDV peptides of HDV1, 6, and 8, representing various portions of the delta antigen were grafted onto biochips, allowing SPRi measurements to be made. Sixteen to 17 serum samples from patients infected with different HDV genotypes were injected onto protein and peptide chips. In all, Abs against HDV proteins and/or peptides were detected in 16 out of 17 infected patients (94.12%), although the amplitude of the SPR signal varied. The amino-terminal part of the protein was poorly immunogenic, while epitope 65-80, exposed on the viral ribonucleoprotein, may be immunodominant, as 9 patient samples led to a specific SPR signal on peptide 65 type 1 (65#1), independently of the infecting genotype. In this pilot study, we confirmed that HDV infection screening based on the reactivity of patient Abs against carefully chosen HDV peptides and/or proteins can be included in a syndromebased viral hepatitis diagnostic assay. The preliminary results indicated that SPRi studying direct physical HDAg-anti-HDV Ab interactions was more convenient using linear peptide epitopes than full-length S-HDAg proteins, due to the regeneration process, and may represent an innovative approach for a hepatitis syndrome-viral etiology-exploring array.

Biotechnological and Immunological Platforms Based on PGL-I Carbohydrate-Like Peptide of Mycobacterium leprae for Antibodies Detection Among Leprosy Clinical Forms

“…Interestingly, the binding affinity of PGLI-M3 to serum antibodies measured by SPR was almost 30-fold lower than that measured by a solution binding assay (ELISA), in which the SPR technology was able to detect antibodies with just as few as 0.03 µg of the peptide, while ELISA required 1 µg per reaction. It is important to note that the versatility of the SPR platform has allowed not only the evaluation of peptide ligands to mycobacteria (Ngubane et al, 2013), but also has been used as immunosensors for hepatitis (Villiers et al, 2015) or for detection of salivary proteins (Musso et al, 2015), and also for characterization of binding affinity of human proteins to M. leprae glycoproteins (Kim et al, 2015). Another advantage of this platform is the possibility to transform angular variations in absolute values, which present greater application in clinical practice.…”

Synthetic biology and biomimetic chemistry as converging technologies fostering a new generation of smart biosensors

“…For example, Enander et al (2008) This clinical potential was also demonstrated by Villiers et al (2015). This group projected a protein/peptide array to detect, by surface plasmon resonance imaging, anti-Delta genotype 1, 6, 8 specific antibodies among Hepatitis D Virus infected patients.…”

Réplication du génome du virus de l’hépatite delta : un rôle pour la petite protéine delta S-HDAg

“…L'analyse en microscopie électronique de la RNP d'HDV révèle une structure sphérique d'environ 19 nm de diamètre. Le signal de localisation nucléaire (ou NLS) de S-HDAg, accessible à la surface de la RNP [14,15], permet la translocation de la protéine vers le noyau. On ne sait si L-HDAg est encore présente dans la RNP lors de la transcription des différents ARN d'HDV.…”

“…Elles présentent donc une activité d'autoclivage qui hydrolyse les ARN linéaires néo-synthétisés en monomères, qui sont eux-mêmes circularisés de façon covalente, probablement par une ligase cellulaire. Un seul gène porté par l'ARN HDV de polarité antigénomique code les deux isoformes de la protéine qui sont successivement synthétisées pendant le cycle viral : non ramifiée qui associe des régions parfaitement bicaténaires à de petites protubérances et des boucles internes, lui conférant une configuration flexible [14].…”