Correlation Analysis of Th17/Treg Cells and PTPN22 Gene Polymorphism in HT Patients with Different Iodine Nutritional Status

Abstract

Background: The incidence of Hashimoto's thyroiditis (HT) may be related to environmental, immune, and genetic factors. Different iodine nutritional status can affect thyroid function. Th17/Treg cell imbalance is involved in the pathogenesis of autoimmune thyroid diseases, and PTPN22 is an important susceptibility gene related to autoimmune diseases. To study the relationship between Th17/Treg cells and cytokines and PTPN22 gene polymorphism in HT patients with different iodine nutritional status is to determine the role of immune and genetic factors in the pathogenesis of HT. Objective: To investigate the correlation between Th17/Treg cells and factors protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene-1123G>C site (rs2488457) polymorphism in peripheral blood mononuclear cells (PBMC) of Hashimoto's thyroiditis (HT) patients with different iodine nutritional status. Methods: 100 HT patients and 60 healthy subjects in Cang Zhou are selected from 2019 to 2020. Flow cytometry and real-time fluorescent quantitative PCR are used to detecting the proportion and ratio of Th17 and Treg cells in PBMC, as well as retinoic acid-related orphan receptor-γt (ROR-γt) and fork head/winged spiral transcription factor 3 (Foxp3) mRNA expression levels. Single allele-specific primer-polymerase chain reaction (SASP-PCR) technology is taken to sequence PTPN gene promoter-1123SNP leading to calculate the gene Type and allele frequency. Results: Th17 and Treg cells and factors in the PBMC of HT patients have a certain correlation with the-1123G>C locus of PTPN22 gene (rs2488457). The distribution frequency of rs2488457 genotype is consistent with Hardy Weinberg's law of genetic equilibrium. The distribution frequencies of various genotypes and alleles are significantly different between HT patients and the control group (P<0.05). PTPN22 gene-1123G>C site C/G, C/C genotype can increase of the risk of HT, while G/G genotype can decrease of the risk of HT. In Conclusion: The polymorphism of rs2488457 is related to susceptibility to HT. Carrying C/G and C/C genotypes may be risk factors for HT, and G/G genotypes may be protective factors for HT, but it has nothing to do with iodine nutrition status.