Background
Dysregulation of T cells mediated immune responses is a hallmark in the development of systemic lupus erythematosus (SLE). Recent genome wide association study (GWAS) revealed the genetic contribution of variants located in the cytotoxic T lymphocyte-associated protein-4 (CTLA4)-inducible T cell co-stimulator (ICOS) intergenic region to SLE susceptibility. Our
Conclusions
The present study confirmed the functional role of rs17268364 in the CTLA4-ICOS intergenic region that increased SLE susceptibility in the Chinese population.
Methods
The genetic association
Results
A variant located in the CTLA4-ICOS intergenic region, rs17268364, was associated with susceptibility to SLE patients in Chinese populations (risk allele, pmeta = 7.02×10-11, OR 1.19, 95%CI 1.13-1.26). The bioinformatics suggested that rs17268364 might affect the expression of CTLA4, not ICOS. The rs17268364 risk G allele containing sequence reduced the expression of the reporter gene by binding transcriptional repressor Ewing sarcoma breakpoint region 1 (EWSR1). Following genotype-mRNA expression, the analysis also showed the risk allele of rs17268364 was associated with low CTLA4 expression in lupus nephritis (LN) patients. Healthy individuals carrying rs17268364 risk G allele was significantly correlated with higher levels of IFN-α signature including increased lymphocyte antigen 6E (LY6E) (p=0.031), interferon-stimulated gene 15 (ISG15) (p=0.038), interferon regulatory factor 9 (IRF9) (p=0.028), and interferon regulatory factor 5 (IRF5) (p=0.040) mRNA expression. Conclusions: The present study confirmed the functional role of rs17268364 in the CTLA4-ICOS intergenic region that increased SLE susceptibility in the Chinese population.