Brief Report: Functional Interaction of Endoplasmic Reticulum Aminopeptidase 2 and HLA-B27 Activates the Unfolded Protein Response.

Objective: The basic mechanisms underlying the pathogenesis of ankylosing spondylitis (AS) remain unresolved. We previously reported an association of the single-nucleotide polymorphism (SNP) rs2549782 in the endoplasmic reticulum aminopeptidase 2 gene (ERAP2) with AS. It is known that patients homozygous for the G allele (GG) of another ERAP2 SNP, rs2248374, lack expression of ERAP2 (ERAP2 null). The present study utilized this information to study the impact of ERAP2 deficiency on HLA–B27 expression in patients with AS, specifically focusing on the functional interaction of ERAP2 and HLA–B27 in peripheral blood mononuclear cells (PBMCs) from patients with AS and assessing the effects …