Toll-like Receptor Confers Susceptibility To Uveitis Disease In A Chinese Han Population

Purpose: Accumulating evidences showed that Toll-like receptors(TLRs) play an important role in many autoimmune diseases includingrheumatoid arthritis (RA), systemic sclerosis (SS), Behcet’s disease (BD),systemic lupus erythematosus (SLE). TLRs, together with RLRs and NLRs,are members of the family of pattern recognition receptors (PRRs), whichconsist of main innate immune sensors. Thirteen distinct mammalian TLRs,so far, have been identified10of which are functional in humans(TLR1-10). Among the10TLRs, TLR2,4,7and9genes polymorphismswere found to have association with autoimmune diseases and a TLR8gene polymorphism was found to have relation with Acquired ImmuneDeficiency Syndrome (AIDS), an acquired immune function deficiencydisease. In view of the fact that TLRs play an important role in the processof many autoimmune diseases, we therefore evaluated the genetic effects ofthem with the association of BD, VKH syndrome, AAU, AS and PU in theChinese Han patients.Methods: A two-stage case-control association studies was performed.The first stage studied group comprised400ocular BD patients,400VKH syndrome patients,400AAU±AS patients,400PU patients and600healthy subjects. The second stage included a total438BD patients and1000healthy controls. Direct sequencing was also performed by MajorbioBiotechnology Company (Shanghai, China) using randomly selectedsubjects (5%of all samples) to validate the result of the PCR-RFLP methodused in our study. For rs3764880, genotype was determined by TaqMan SNP Genotyping Assay on the Applied Biosysterms7500Real-Time PCRsystem，all the operation followed the manual, and negative controls wereincluded in each plates. The analysis was performed in TaqMan Genotyper Software.Results: A total of400BD patients and600healthy controls weregenotyped for five SNPS: one SNP (rs2289318) of TLR2, one SNP(rs7037117) of TLR4and three SNPs (rs187084, rs352139, rs352140) ofTLR9. A total of400BD patients (male: female=225:175) and600(male:female=300:300) healthy controls were genotyped for one SNP(rs3764880) of TLR8. These six SNPs were successfully genotyped andconformed to Hardy-Weinberg expectation in controls. Frequencies of thers2289318/TLR2genotype CC and C allele were significantly higher in BDpatients (pc=0.036, OR=1.537,95%CI1.175to2.011; pc=0.018, OR=1.489,95%CI1.180to1.878, respectively) compared with controls. Thecorrected P values of the rs2289318/TLR2genotype GG or CG were lostsignificance. After extending the number of BD cases (n=838) and healthy controls (n=1600), we confirmed the association with the rs2289318/TLR2genotype CC, GG and C allele (pc=0.001, OR=1.462,95%CI1.223to1.747; pc=1.55E-05, OR=1.470,95%CI1.260to1.714, respectively)and found the corrected P value genotype GG was significant (pc=0.001,OR=0.363,95%CI0.220to0.601). No significant differences were foundbetween BD patients and controls concerning the frequencies of the otherfive SNPs.We also studied the association of polymorphisms of the four geneswith the clinical features of BD entities, using stratified analysis. Asignificantly higher frequency of CC genotype and C allele ofrs2289318/TLR2was noticed in BD patients with genital ulcer. Nosignificant statistical association was found for the other five SNPsgenotypes and clinical manifestations in BD.A total of400VKH patients,400AAU±AS patients,400PUpatients and600healthy controls were genotyped for five SNPS: one SNP(rs2289318) of TLR2, one SNP (rs7037117) of TLR4and three SNPs(rs187084, rs352139, rs352140) of TLR9. A total of400VKH patients(male: female=214:186)，400AAU±AS patients (male: female=193:207)，400PU patients (male: female=199:201)，and600(male:female=300:300) healthy controls were genotyped for one SNP(rs3764880) of TLR8. The six SNPs were successfully genotyped andconformed to Hardy-Weinberg expectation in controls. There were no differences concerning the genotype or allelefrequencies of the six SNPs between VKH syndrome, AAU±AS, PU andhealthy controls by Bonferroni correction.Conclusions: In this study, we investigated the association of genepolymorphisms of TLRs2,4,8and9with the risk of developing ocularBD, VKH syndrome, AAU±AS and PU in a Chinese Han populationand found a association of TLR2gene rs2289318with the susceptibility toocular BD. Stratification analysis also showed an association of certainclinical features of ocular BD with the tested SNP of TLR2(rs2289318).We did not find an association of the TLR2,4,8and9SNP withsusceptibility to VKH, AAU±AS and PU.