Functional Polymorphisms of CTLA4 Associated with Aggressive Periodontitis in the Chinese Han Population.

ABSTRACT

BACKGROUND/AIMS: CTLA4 has been identified functioning as a protein receptor which functions as an immune checkpoint, downregulating the immune system. Susceptibility to aggressive periodontitis (AgP) is influenced by gene polymorphisms related to the immune response. In this study, we focused on SNPs in the 3'-UTR of CTLA4 among Chinese AgP patients, and investigated any further relationships between the SNPs and miRNAs. METHODS: This case-control study included 120 AgP patients and 150 healthy controls. Genotyping was used to detect allele distribution. Cell transfection and the dual luciferase reporter assay were performed to investigate the potential functions of SNPs located in the 3'UTR of CTLA4. RESULTS: The data show that patients with a history of smoking were more susceptible compared to controls, exhibiting deeper probing depth, greater attachment loss and more sites of bleeding on probing. The results of genotyping analysis revealed that individuals with the GA and AA genotypes, and with the A carrier had a decreased risk (P = 0.015, P = 0.03). Furthermore, patients with the G allele might be regulated by miR-105, which caused a down-regulation of CTLA4. The carriers of the GG genotype exhibited the worst results of attachment loss and bleeding on probing. CONCLUSION: These findings show that rs56102377 in the 3'-UTR of CTLA4 may act as a protective factor by disrupting the regulatory role of miR-105 in CTLA4 expression. Thus, our study highlighted a potential role of these polymorphisms as genetic susceptibility biomarkers of periodontitis in Chinese Han populations.