Interleukin-23 Receptor Gene Polymorphism May Enhance Expression of the IL-23 Receptor, IL-17, TNF-α and IL-6 in Behcet’s Disease

PURPOSE: Recent studies identified an association between Behcet’s disease (BD) and the IL-23R gene polymorphism (rs17375018) in different populations. This study examined whether this IL-23R gene polymorphism is associated with enhanced inflammatory responses. METHODS: We recruited 27 BD patients and 32 controls with three genotypes. Peripheral blood mononuclear cells (PBMCs) were seeded with or without anti-CD3 and CD28. Cells were incubated for 24 hours, and then supernatants were collected and stored at −20◦C until analyzed. Levels of interferon (IFN)-γ, tissue necrosis factor (TNF)-α, interleukin (IL)-17 and IL-6 were detected by ELISA. IL-23R expression was assessed by quantitative real-time polymerase chain reaction (RT-PCR). RESULTS: The expression of IL-23R was significantly higher in both BD patients and healthy controls with the GG genotype compared to the AG and AA genotype with anti-CD3 and CD28 stimulation (all P-value < 0.05). Among the PBMCs cultured with anti-CD3 and CD28 stimulation, there was an elevated secretion of TNF-α, IL-6 and IL-17 in BD patients and healthy controls with the GG genotype. However, there was no significant change in secretion of IFN- γ in BD patients and healthy controls among the genotype of this IL-23R gene polymorphism. CONCLUSIONS: The results suggest that the GG genotype of the rs17375018 variant in the IL-23R gene enhances pro-inflammatory cytokine responses.