Exploration of the association between the single-nucleotide polymorphism of co-stimulatory system and rheumatoid arthritis

Abstract

IntroductionThe human leukocyte antigen (HLA) has been linked to the majority of autoimmune diseases (ADs). However, non-HLA genes may be risk factors for ADs. A number of genes encoding proteins involved in regulating T-cell and B-cell function have been identified as rheumatoid arthritis (RA) susceptibility genes.MethodsIn this study, we investigated the association between RA and single-nucleotide polymorphisms (SNPs) of co-stimulatory or co-inhibitory molecules in 124 RA cases and 100 healthy controls without immune-related diseases [including tumor necrosis factor superfamily member 4 (TNFSF4), CD28, cytotoxic T-lymphocyte–associated protein 4 (CTLA4), and programmed cell death protein 1 (PDCD1)].ResultsThe results showed that there were 13 SNPs associated with RA, including rs181758110 of TNFSF4 (CC vs. CT, p = 0.038); rs3181096 of CD28 (TT vs. CC + CT, p = 0.035; CC vs. TT, p = 0.047); rs11571315 (TT vs. CT, p = 0.045), rs733618 (CC vs. TT + CT, p = 0.043), rs4553808 (AA vs. AG vs. GG, p = 0.035), rs11571316 (GG vs. AG vs. AA, p = 0.048; GG vs. AG + AA, p = 0.026; GG vs. AG, p = 0.014), rs16840252 (CC vs. CT vs. TT, p = 0.007; CC vs. CT, p = 0.011), rs5742909 (CC vs. CT vs. TT, p = 0.040), and rs11571319 of CTLA4 (GG vs. AG vs. AA, p < 0.001; GG vs. AG + AA, p = 0.048; AA vs. GG + AG, p = 0.001; GG vs. AA, p = 0.008; GG vs. AG, p ≤ 0.001); and rs10204525 (TT vs. CT + CC, p = 0.024; TT vs. CT, p = 0.021), rs2227982 (AA vs. GG, p = 0.047), rs36084323 (TT vs. CT vs. CC, p = 0.022; TT vs. CT + CC, p = 0.013; CC vs. TT + CT, p = 0.048; TT vs. CC, p = 0.008), and rs5839828 of PDCD1 (DEL vs. DEL/G vs. GG, p = 0.014; DEL vs. DEL/G + GG, p = 0.014; GG vs. DEL + DEL/G, p = 0.025; DEL vs. GG, p = 0.007).DiscussionConsequently, these SNPs may play an important role in immune regulation, and further research into the role of these SNPs of immune regulatory genes in the pathogenesis of RA is required.

Finding the Common Single-Nucleotide Polymorphisms in Three Autoimmune Diseases and Exploring Their Bio-Function by Using a Reporter Assay

“…In this study, the sample size was increased to 40 GO cases and 40 healthy controls. In addition, the data about SLE and RA that were previously published [ 18 , 19 ] and the data on GO in this study were combined to find out the common SNPs among these three diseases.…”

“…rs733618 and rs4553808 were related and had a biological function in three autoimmune diseases at the same time, indicating that these two SNPs may play an important role in the mechanism of these autoimmune diseases, which could provide a new direction for their treatment. However, the allele frequencies of these common SNPs of CTLA4 had no statistical significance in RA but were only associated with RA in the heterozygous genotype [ 19 ], which could indicate that the pathogenesis of RA caused by CTLA4 SNPs may be different from that of SLE and GO. Moreover, the human leukocyte antigen (HLA) gene is one of the SNPs that is closely understood in a broad sense.…”

“…Previously, only the CTLA4 gene polymorphism and its correlation were analyzed in GO patients [ 20 ]. In this study, the GO sample size was increased, and we took the candidate SNPs in the previously published association study between SLE/RA and the genetic polymorphisms of the co-stimulatory system [ 18 , 19 ] as the candidate SNPs of GO, to explore the association between these SNPs and GO. Please refer to ref.…”

“…PCR was carried out in a total volume of 25 μL containing 50 ng of DNA, 7.5 µL of Hotstar Taq DNA Polymerase (Qiagen, Hilden, Germany) or 2X Tag polymerase, 1 µL each of forward and reverse primer (10 μΜ), and 14.5 µL of ddH 2 O. The primer pairs of each gene region and the PCR programs were the same as in the previous study [ 18 , 19 ]. After verifying the DNA fragments produced by PCR through gel electrophoresis, the Big Dye Terminator Cycle Sequencing kit (Thermo Fisher, Waltham, MA, USA) and the ABI PRISM genetic analyzer (Thermo Fisher, Waltham, MA, USA) were used for direct sequencing according to the manufacturer’s instructions.…”

“…Although the pathogenesis of SLE, RA, and GO is still unclear, genetic factors are considered to be the key query point. We previously studied the association between SNPs of the co-stimulation molecule genes and SLE [ 18 ] and RA [ 19 ]. In this study, we determine the common SNPs in these three autoimmune diseases by consolidating the SNP analysis data of SLE, RA, and GO and further verify the biological function of the SNP with statistical significance.…”