Increased accumulation of dendritic cells in celiac disease associates with increased expression of autophagy protein LC3

Abstract

Background: Celiac disease (CD) an immune-mediated disorder associates with accumulation of dendritic cell (DC) in duodenal mucosa. Autophagy has recently been implicated in autoantigen formation. However, its role in CD is still unknown. Aim: To examine role of autophagic protein LC3 expressed by activated DC in CD. Materials and Methods : Thirty CD patients were analyzed at initial presentation and after 6 months of gluten-free diet (GFD). Duodenal biopsies were studied for histological changes and CD11c, CD86, and MAP1LC3A expressions by double immunohistochemistry (IHC). Masson′s trichrome (MT) staining was used to assess basement membrane (BM) thickness and Oil Red O (ORO) staining for mucosal lipid deposit. Polymerase chain reaction (PCR) was performed for HLA-DQ system. Statistical analysis was done using paired and unpaired t test, chi-square test, Fisher′s exact test, and McNemar-Bowker test. A P-value <0.05 was considered statistically significant. Results: HLA-DQ2 and HLA-DQ8 alleles were present in all studied patients. Increased BM thickness was observed in 63% and 73% had ORO-positive lipid in surface lining epithelium. Pre-treatment biopsies showed increased DCs expressing LC3, which were significantly less in follow-up biopsies. The follow-up biopsies had shown significant reduction in BM thickness and ORO. Conclusion : Histological improvement in duodenal biopsies was associated with reduction in activated DCs expressing autophagic protein, which probably play important role in pathogenesis of an autoimmune disorder like CD.

Keywords

• Autophagy
• celiac disease
• dendritic cells
• HLA-DQ
• mucosal lipid