| Based on the method of TaqMan Real time PCR,we have established a new way to determine the alleles of transporter associated with antigen processing gene TAP1 and TAP2 and performed the population genetics study in the first part of the study.TAP1 and TAP2 gene polymorphisms in Chinese Hans were investigated,gene frequencies were caculated,haplotypes distribution of TAP1-TAP2,TAP1-DRB1,TAP2-DRB1 and TAP1-TAP2-DRB1 were analyzed,and the difference of TAP polymorphisms between Chinese Hans and other populations were also compared.The aim of the second part of work was to perform desease association analyse between TAP and ankylosing spondylitis(AS) through researching the TAP polymorphisms and single nucleotide polymorphisms(SNPs) haplotypes in HLA-B27 positive AS patients,HLA-B27 positive controls and HLA-B27 negative controls of genetically homogenous Chinese Han population.In the first part of work,we detected five TAP1 alleles(TAP1*0101,TAP1*020101,TAP1* 020102,TAP1*0301,TAP1*0401) and four TAP2 alleles(TAP2*0101,TAP2*0102,TAP2*0103,TAP2*0201).All the loci conform to the Hardy-Weinberg expectations(P＞0.05).The most frequent alleles in Chinese Hans were TAP1*0101 (79.79%) and TAP2*0101(82.74%).The two-locus haplotype analysis showed highly significant positive linkage disequilibrium for one TAP1-TAP2 haplotype (TAP1*020101-TAP2*0102),three TAP1-DRB1 haplotypes(TAP1*020101-DRB1*03, TAP1*020102-DRB1*13,and TAP1*0301-DRB1*16),and three TAP2-DRB1 haplotypes(TAP2*0102-DRB1*09,TAP2*0103-DRB1*04,and TAP2*0201-DRB1*01)(χ~2＞10.83).The three-locus haplotype analysis showed highly significant positive linkage disequilibrium for TAP1*0101-TAP2*0101-DRB1*07,TAP1*0101-TAP2 *0103-DRB1*04,TAP1*020101-TAP2*0101-DRB1*03,and TAP1*020101-TAP2* 0102-DRB1*13(D'＞0.5).Comparison of the allele frequencies with those of other populations showed that the TAP1 allele distribution was very similar in all the groups, except for the Guarani,Kaingang,and Anatolian populations(P＞0.05),but TAP2 distribution was significantly different from that of the other populations(P＜0.05).The new TaqMan method provides relatively accurate,highresolution,simple,and fast assays for TAP genotyping.Human leukocyte antigen(HLA)-B27 is strongly associated with the autoimmune disease ankylosing spondylitis(AS).Other autoimmune disease-associated genes,such as TAP genes,could also influence AS susceptibility.TAP complex plays a key role in adapt immune response process.It would affect the way of antigens to be chosen,processed and displayed when SNP changed in code genes,result in some auto immune deseases happened.Hence,the main purpose of the second part of work was to study whether TAP (TAP1 and TAP2) SNPs were associated with B27~+ AS disease,and the role of TAP played in the AS pathology.Six TAP1 single nucleotide polymorphisms(SNPs) and three TAP2 SNPs sites were analyzed in B27-positive AS cases,healthy B27-negative controls, and healthy B27-positive controls.In the allele and genotype analysis,the results indicated that TAP1 site 1910 allele G,genotype AG and TAP2 site 1693 genotype AA were associated with increased AS risk in a case-B27 negative control(P＜0.05).In the haplotype analysis,TAP1 SNP haplotype(GGGGGG,TAP1*020101) and TAP1-TAP2 SNP haplotypes(GGGGGG-GGG,TAP1*020101-TAP2*0101,and GGAAGGGAG, TAP1*0101-TAP2*0102) increased AS risk in case-B27 negative control(P＜0.05).In contrast,TAP1-TAP2 SNP haplotype GGGGGG-GAG(TAP1*020101-TAP2*0102) was less common in cases than in B27-negative controls(P＜0.05).Moreover,TAP1-TAP2 SNP haplotype GGGAGG-GGG(TAP1*0301-TAP2*0101) was less common in cases than in B27-positive controls.The two haplotypes appeared to confer protection in AS (P＜0.05).These results suggest a potential mechanism of altered antigen-peptide selection and transport in AS pathogenesis.
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