Identification and molecular characterization of oat peptides implicated on coeliac immune response

Comino, Isabel et al.
[Background] Oats provide important nutritional and pharmacological properties, although their safety in coeliac patients remains controversial. Previous studies have confirmed that the reactivity of the anti-33-mer monoclonal antibody with different oat varieties is proportional to the immune responses in terms of T-cell proliferation. Although the impact of these varieties on the adaptive response has been studied, the role of the dendritic cells (DC) is still poorly understood. The aim of this study is to characterize different oat fractions and to study their effect on DC from coeliac patients.
[Methods and results] Protein fractions were isolated from oat grains and analyzed by SDS–PAGE. Several proteins were characterized in the prolamin fraction using immunological and proteomic tools, and by Nano-LC-MS/MS. These proteins, analogous to α- and γ-gliadin-like, showed reactive sequences to anti-33-mer antibody suggesting their immunogenic potential. That was further confirmed as some of the newly identified oat peptides had a differential stimulatory capacity on circulating DC from coeliac patients compared with healthy controls.
[Conclusions] This is the first time, to our knowledge, where newly identified oat peptides have been shown to elicit a differential stimulatory capacity on circulating DC obtained from coeliac patients, potentially identifying immunogenic properties of these oat peptides.
This study was supported by a grant (Project AGR172) from the Junta de Andalucía. IC was supported by the Contrato de Acceso al Sistema Español de Ciencia, Tecnología e Innovación para el Desarrollo del Programa Propio de I + D+i from the Universidad de Sevilla and the EMBO short-term fellowship. DB and SCK were supported by the Biotechnology and Biological Sciences Research Council (BBSRC) Institute Strategic Programme for Gut Health and Food Safety BB/J004529/1.