Projects / Diagnostics to detect antibodies in patient sera / Peptide based diagnostics
Design and synthesis of cross-linked peptide probes for the development of an in vitro diagnostics for Coeliac Disease
- Anna Maria PAPINI
- Mario CHELLI
- Paolo ROVERO
- Giuseppina SABATINO
In collaboration with:
Antonino Salvatore Calabrò and Daniela Renzi
Dipartimento di Scienze Biomediche, Sperimentali e Cliniche "Mario Serio"
Coeliac Disease (CD) is an autoimmune enteropathic condition triggered in genetically susceptible individuals, by the gliadin fraction of wheat gluten and similar alcohol soluble proteins (prolamines). The main autoantigen is the Ca2+-dependent intracellular enzyme tissue Transglutaminase (tTG) . This enzyme promotes in its active site protein crosslinks via transamidation reaction and can recognise gliadin peptide epitopes. Untreated CD patients have high levels of circulating IgAs and IgGs anti-tTG, anti-gliadin, anti-tTGgliadin adducts, and anti-endomysium. Transamidation can be considered an aberrant post-translational modification triggering autoantibodies in Coeliac Disease. Therefore, cross-linked peptides between Lys- and Glu side-chains of tTG and α-Gliadin peptide epitopes could be innovative tools to develop peptide-based in vitro diagnostics for Coeliac Disease. In this context Following our Chemical Reverse Approach, three tTG peptide epitopes and three α-Gliadin peptide epitopes have been selected: e.g., tTG(I), tTG(II), and tTG(III), αGlia(61-69), αGlia(63-71), and αGlia(68-76), previously identified as autoantigens in CD4+ T cell extracts. Nine peptides containing cross-links between Lys- and Glu side-chains in tTG and αGlia linear fragments respectively, were synthesized by Fmoc/tBu SPPS.The cross-linked peptide probes were tested in direct ELISA on sera of newly diagnosed coeliac patients to evaluate IgA and IgG antibody titre in 24 CD sera and 18 healthy blood donors (DS) as controls.
Epitope Mapping of the N-terminal Portion of Tissue Transglutaminase Protein Antigen to Identify Linear Epitopes in Celiac Disease.
M. Di Pisa, P. Buccato, G. Sabatino, F. Real Fernández, B. Berti, F. Cocola, A.M. Papini, and P. Rovero. J.Pept.Sci. (2014) 20(9), 689-695.
Synthetic Peptides Reproducing Tissue Transglutaminase-Gliadin Complex Neo-epitopes as Probes for Antibody Detection in Celiac Disease Patients’ Sera.
M. Di Pisa, S. Pascarella, M. Scrima, G. Sabatino, F. Real Fernández, M. Chelli, D. Renzi, A. Calabrò, A.M. D'Ursi, A.M. Papini, and P. Rovero. J.Med.Chem. (2015) 58 (3), 1390–1399.