Effects of Gliadin on Autoimmune Responses of Central Nervous System of C57BL/6 Mice

Gluten sensitivity contributes to various degrees of neurological manifestations and neurodegenerative immunological changes. We investigated the experimental features of anti-gliadin immune responses in the central nervous system (CNS) of mice. Female C57BL6 mice were divided into three groups. Mice immunized with complete Freund's adjuvant (CFA) or gliadin emulsified in CFA, and the control group received phosphate-buffered saline (PBS). Immunohistochemistry, hematoxylin-eosin, and Luxol fast blue staining were performed on the sections. The serum levels of interleukin (IL)-17 and interferon-gamma (IFN-γ) were measured using enzyme-linked immunosorbent assay (ELISA). Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the mRNA levels of chemokine (C-X-C motif) ligand-2 (CXCL-2), C-C motif chemokine ligand-2 (CCL-2), and CXCL-10.  In gliadin+CFA immunized mice, the microscopic lesions included perivascular edema, focal-microgliosis, and acute neuronal necrosis in the cortex, subcortical, Purkinje cell layer, and ventral horn of the spinal cord. While extravasation of anti-IgG antibodies and selective targeting of Purkinje cells were observed in gliadin+CFA immunized mice. A significant increase in serum IL-17 and IFN-g levels (p<0.05), as well as expression of CXCL-2, CCL-2, and CXCL-10 in mice immunized with gliadin+CFA, were monitored versus controls. Our findings indicated that the immune responses directed against gliadin peptides might contribute to blood-brain barrier breakdown, extravasation of serum anti-IgG, gliosis, and acute neuronal necrosis in the cortex and cerebellar Purkinje cells. Anti-IgG antibodies may cause extravasation of blood-born anti-gliadin antibodies and selective targeting of Purkinje cells observed in mice immunized with peptide tryptic (pt) -gliadin in CFA.