A Multiple <i>N</i>-Glucosylated Peptide Epitope Efficiently Detecting Antibodies in Multiple Sclerosis

oleh: Francesca Nuti, Feliciana Real Fernandez, Giuseppina Sabatino, Elisa Peroni, Barbara Mulinacci, Ilaria Paolini, Margherita Di Pisa, Caterina Tiberi, Francesco Lolli, Martina Petruzzo, Roberta Lanzillo, Vincenzo Brescia Morra, Paolo Rovero, Anna Maria Papini

Format: Article
Diterbitkan: MDPI AG 2020-07-01

Deskripsi

Diagnostics of Multiple Sclerosis (MS) are essentially based on the gold standard magnetic resonance imaging. Few alternative simple assays are available to follow up disease activity. Considering that the disease can remain elusive for years, identification of antibodies fluctuating in biological fluids as relevant biomarkers of immune response is a challenge. In previous studies, we reported that anti-<i>N</i>-glucosylated (<i>N</i>-Glc) peptide antibodies that can be easily detected in Solid-Phase Enzyme-Linked ImmunoSorbent Assays (SP-ELISA) on MS patients’ sera preferentially recognize hyperglucosylated adhesin of non-typeable <i>Haemophilus Influenzae</i>. Since multivalency can be useful for diagnostic purposes to allow an efficient coating in ELISA, we report herein the development of a collection of Multiple <i>N</i>-glucosylated Peptide Epitopes (<i>N</i>-Glc MEPs) to detect anti-<i>N</i>-Glc antibodies in MS. To this aim, a series of <i>N</i>-Glc peptide antigens to be represented in the <i>N</i>-GlcMEPs were tested in competitive ELISA. We confirmed that the epitope recognized by antibodies shall contain at least 5-mer sequences including the fundamental <i>N</i>-Glc moiety. Using a 4-branched dendrimeric lysine scaffold, we selected the <i>N</i>-Glc MEP <b>24</b>, carrying the minimal epitope Asn(Glc) anchored to a polyethylene glycol-based spacer (PEG) containing a 19-atoms chain, as an efficient multivalent probe to reveal specific and high affinity anti-<i>N</i>-Glc antibodies in MS.