Posttranslationally modified peptides efficiently mimicking neoantigens: A challenge for theragnostics of autoimmune diseases

Abstract

We report the design, synthesis, and immunological evaluation of a series of glycopeptide analogues of the previously described antigenic probe CSF114(Glc), with the aim of understanding the importance of N-glycosylation on Asn residue in multiple sclerosis antibody recognition. The glucopeptide, characterized by a β-turn conformation which is fundamental for a correct presentation of the epitope, has been modified by introducing various natural glycoamino acids in position 7. The new glycopeptides were evaluated by measuring the IgG and IgM antibody titer in multiple sclerosis patients' and normal blood donors' sera. Moreover, we achieved the efficient synthetic strategy of new Asn derivative bearing N-acetylneuraminic acid (Neu5Ac), linked by an N-glycosidic bond, on the side chain of the Asn residue orthogonally protected for Fmoc/tBu SPPS.

Human recombinant domain antibodies against multiple sclerosis antigenic peptide CSF114(Glc)

“…Affinity measurements indicated that hV H -CSF114(Glc)6×His antibody establishes a very strong interaction with the CSF114 (Glc) peptide, with an equilibrium dissociation constant K D of 9.08 ± 0.13 × 10 À9 M. Another experimental aspect that confirmed the strength of the interaction between hV H -CSF114 (Glc)6×His antibody and CSF114(Glc) was the difficulty of regenerating the sensor chip after measurements. In fact, three consecutive regeneration steps were needed to completely detach the antibody from sensor chip surface instead of the one or two regenerations we usually used in similar experiments (Real-Fernández et al, 2012). The obtained results confirmed the specificity of hV H -CSF114(Glc)6×His to the sugar moiety in the glucopeptide sequence, fundamental in our goal of reproducing biological conditions.…”

Antibody Recognition in multiple sclerosis and rett syndrome using a collection of linear and cyclic N‐glucosylated antigenic probes

“…After defining the fundamental role of the sugar moiety in antibody recognition, 20 we focused our attention on the role of the glucosylated domain in the 21-mer sequence of the N-glucopeptide CSF114(Glc) to more precisely define the epitope when specifically bound to antibody of MS and RTT patients. Studies with the full-length peptide demonstrated that antibodies in MS sera recognized preferentially type I > type II 0 > type I 0 b-turn structures, with the N-glucosylated asparagine in position i 1 1 of the bturn.…”

Cross-Reactive Antibodies to Target Proteins are Dependent upon Oligomannose Glycosylated Epitopes in HTLV-1 Associated Neurological Disease

“…Interestingly, a recent paper showed that antibody immunoreactivity for target proteins in HIV infected patients was dependent upon the type of cell line as well as the type of glycosylation, including the ratio of high mannose to complex N-glycans (Raska et al, 2010). Further, recent data suggests that glycosylated epitopes of target proteins may assist in the diagnosis of MS and play a role in demyelination and oligodendrocyte pathology [53,54].…”