Soo-Cheon Chae

Carbon Monoxide Produced by Heme Oxygenase-1 Suppresses T Cell Proliferation via Inhibition of IL-2 Production

Heme oxygenase-1 (HO-1) catabolizes heme into CO, biliverdin, and free iron and serves as a protective enzyme by virtue of its anti-inflammatory, antiapoptotic, and antiproliferative actions. Previously, we have demonstrated that human CD4+ T cells express HO-1 and that HO-1-overexpressing Jurkat T cells tend to display lower proliferative response. The aim of this study is to elucidate the mechanism(s) by which HO-1 can mediate its antiproliferative effect on CD4+ T cells. Among the three HO-1 byproducts, only CO showed suppressive effect on T cell proliferation in response to anti-CD3 plus anti-CD28 Abs, mimicking the antiproliferative action of HO-1. CO blocked the cell cycle entry of T cells, which was independent of the guanylate cyclase/cGMP pathway. CO also suppressed the secretion of IL-2, and this suppressive effect of CO on IL-2 secretion mediated the antiproliferative action of CO. CO selectively inhibited the extracellular signal-regulated kinase pathway, which could explain the suppressive effects of CO on T cell proliferation and IL-2 secretion. Based on these findings, we suggest that HO-1/CO suppresses T cell proliferation and IL-2 secretion, possibly via its inhibition of extracellular signal-regulated kinase activation.

Identification of polymorphisms in human interleukin-27 and their association with asthma in a Korean population

AbstractInterleukin 27 (IL-27) acts as a versatile cytokine in the early regulation of Th1 initiation and in the negative regulation of the Th2 factor GATA-3. IL-27, which was discovered as a novel heterodimeric cytokine of the IL-12 family, consists of two subunits, the Epstein-Barr virus-induced gene 3 (EBI3) and p28. The IL-27 cytokine is mediated by one of the receptor chains (WSX-1) of the IL-27 receptor that is highly expressed on CD4+ T lymphocytes and NK cells. Although signaling of IL-27/WSX-1 interactions have been recognized in the down-regulation of airway hyper-reactivity and in lung inflammation during the development of allergic asthma, little is known about the role of single nucleotide polymorphisms (SNPs) of IL-27 and individual susceptibility to asthma. To address this question, we have examined the five exons and the boundary intron sequences of IL-27P28, including the promoter regions, with the aim of identifying sites of variation that may be useful for understanding the genetic influences of this gene. We identified four SNPs, g.-964A > G, g.2905T > G, g.4603G > A and g.4730T > C, and analyzed the genotype and allele frequencies between asthma patients and healthy controls. Our results strongly suggest that the g.-964A > G polymorphism of IL-27p28 is most likely associated with susceptibility to asthma. Moreover, we elucidate the haplotype frequencies of g.2905T > G, g.4603G > A and g.4730T > C in terms of their relative correlation with asthma patients and healthy controls.

Differential expressions of heme oxygenase-1 gene in CD25- and CD25+ subsets of human CD4+ T cells.

Growing evidence suggests that the immunomodulatory heme oxygenase-1 (HO-1) may have an important role in regulating T-cell responses. In this study, we investigated whether CD4(+)CD25(-) and CD4(+)CD25(+) T cells of human CD4(+) subpopulation could differentially express HO-1. Our results obtained from qualitative reverse transcriptase-polymerase chain reaction and quantitative flow cytometry analyses revealed that the CD4(+)CD25(+) T cells constitutively express HO-1 and that T cell stimulation with plate-bound anti-CD3 in combination with soluble anti-CD28 not only induced HO-1 gene expression in the CD4(+)CD25(-) T cells but also up-regulated HO-1 gene expression in the CD4(+)CD25(+) T cells. Our further studies showed that CD28 signal alone was enough to induce HO-1 expression and CD3 signal, of which signal alone did not induce HO-1 expression, was required at least for full HO-1 expression in both CD25(-) and CD25(+) subsets of human CD4(+) T cells. In addition, transfection of human Jurkat T cells with HO-1 suppressed the cellular proliferation, and this effect was reversed by zinc protoporphyrin, a specific HO competitive inhibitor. Taken together, we have first reported that human CD4(+)CD25(+) regulatory T cells constitutively express HO-1 and that HO-1 inhibits Jurkat T cell proliferation.

Interleukin-27 polymorphisms are associated with inflammatory bowel diseases in a Korean population

Background and Aims:  The cytokine interleukin (IL)‐27 is composed of two subunits, Epstein–Barr virus‐induced gene 3 (EBI3) and p28, and IL‐27 is a novel IL‐12 family member that mediates between the innate and adaptive immune systems. We previously identified four polymorphisms in the human IL‐27 gene and we suggested that the polymorphism of IL‐27 is associated with the susceptibility to asthma. IL‐27 transcripts are significantly elevated in active Crohns disease (CD) but not in ulcerative colitis (UC). To determine whether these IL‐27 single nucleotide polymorphisms are associated with the susceptibility to inflammatory bowel disease (IBD), the genotype and allelic frequencies of the IL‐27 polymorphisms were analyzed between the IBD patients and the healthy controls.

The polymorphisms of Tim-1 promoter region are associated with rheumatoid arthritis in a Korean population

It has been determined that the family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is expressed on T cells. A member of the TIM family, TIM-1, is considered to be a membrane protein associated with the development of Th2-biased immune responses and selectively expressed on Th2 cells. We previously showed that the exon 4 variations of Tim-1 are associated with susceptibility to allergic diseases, as well as autoimmune diseases such as rheumatoid arthritis (RA). In this study, we assessed the association between genotype and allele frequencies of the Tim-1 gene promoter region, in both RA patients and the controls without RA, using polymerase chain reaction-restriction fragment length polymorphism and single-base extension methods. We further investigated the relationships among the genotypes of each polymorphism and C-reactive protein or rheumatoid factor levels in RA patients. The genotype and allele frequencies of the −1637A>G polymorphism in RA patients are significantly different from those in the non-RA controls (P=0.0004 and P=0.001, respectively). Our results strongly suggest that polymorphism in the Tim-1 promoter region might be associated with susceptibility to RA.

Molecular variations in Th1-specific cell surface gene Tim-3

The family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is identified to be expressed on T cells. A member of Tim family, Tim-3 (T cell immunoglobulin mucin 3) is selectively expressed on the surface of differentiated Th1 cells. Tim-3 might have an important role in the induction of autoimmune diseases by regulating macrophage activation and interacts with Tim-3 ligand to regulate Th1 responses. To determine the variation sites in the coding and promoter region of human Tim-3 gene, we performed variation scanning by direct sequencing using the genomic DNA isolated from the patients with asthma or allergic rhinitis and healthy controls without asthma and allergic rhinitis. We identified four single nucleotide polymorphisms (SNPs) including one novel SNPs (-1541C>T) and two variation sites (-1292_-1289delTAAA and -1282_-1278dupTAAAA) in the coding and promoter region of human Tim-3 gene in both the patients and healthy groups.

Relationship between the Glutathione-S-Transferase P1, M1, and T1 Genotypes and Prostate Cancer Risk in Korean Subjects

Purpose The glutathione-S-transferase (GST)P1, GSTM1, and GSTT1 genotypes have been associated with an increased risk of prostate, bladder, and lung cancers. The aim of this study was to investigate the association between the GSTP1, GSTM1, and GSTT1 genotypes and the risk of prostate cancer in Korean men. Materials and Methods The study group consisted of 166 patients with histologically confirmed prostate cancer. The control group consisted of 327 healthy, cancer-free individuals. The diagnosis of prostate cancer was made by transrectal ultrasound-guided biopsy. Patients with prostatic adenocarcinoma were divided into organ-confined (≤pT2) and non-organ-confined (≥pT3) subgroups. The histological grades were subdivided according to the Gleason score. The GSTP1, GSTM1, and GSTT1 genotypes were determined by using polymerase chain reaction-based methods. The relationship among GSTP1, GSTM1, and GSTT1 polymorphisms and prostate cancer in a case-control study was investigated. Results The frequency of the GSTM1 null genotype in the prostate cancer group (54.2%) was higher than in the control group (odds ratio=1.53, 95% confidence interval=1.20-1.96). The comparison of the GSTP1, GSTM1, and GSTT1 genotypes and cancer prognostic factors, such as staging and grading, showed no statistical significance. Conclusions An increased risk for prostate cancer may be associated with the GSTM1 null genotype in Korean men, but no association was found with the GSTT1 or GSTP1 genotypes.

The suggestive association of eotaxin-2 and eotaxin-3 gene polymorphisms in Korean population with allergic rhinitis

The eotaxin gene family (eotaxin, eotaxin-2 and eotaxin-3) has been implicated in the recruitment of eosinophils, basophiles and Th2 lymphocytes that are central aspects of allergic diseases. To determine whether single-nucleotide polymorphisms (SNPs) of the eotaxin-2 and eotaxin-3 genes are associated with susceptibility to allergic rhinitis, we scanned 178 allergic rhinitis patients and 281 controls without allergic rhinitis using the direct sequencing and single-base extension (SBE) methods. We also calculated the haplotype frequencies between +179T>C and +275C>T of eotaxin-2 and +2497T>G of eotaxin-3 in both controls and allergic rhinitis patients. The haplotype frequency between controls and allergic rhinitis patients was suggestively associated (P=0.0001). The genotype frequencies of eotaxin-3 +2497T>G in allergic rhinitis patients were suggestively different from those in non-allergic rhinitis controls (P=<0.0007). Our results strongly suggest that the SNP of eotaxin-3 might be associated with susceptibility to allergic rhinitis.

Identification of single nucleotide polymorphisms in FOXJ1 and their association with allergic rhinitis

AbstractForkhead-box J1 (FOXJ1) is a presumed transcription factor that can suppress T cell activity, at least partially, through the repression of NFκB activity. Thus, dysregulation of FOXJ1 is thought to be associated with autoimmune diseases and/or other inflammatory diseases. To investigate the association between single nucleotide polymorphisms (SNPs) of human FOXJ1 and allergic rhinitis, we scanned the whole human FOXJ1 gene, including the promoter region, by direct sequencing of DNA from 32 individuals. We identified seven SNPs, three of which (g.-460C>T, g.1805G>T, and g.3375G>C) were chosen for large sample size genotyping (n=713), and to assess the genotype frequencies of these SNPs between controls and allergic rhinitis patients. We also investigated the relationships of each genotype with serum total IgE levels in allergic rhinitis patients, and compared the frequencies of haplotypes constructed by these SNPs between the two groups. Our results suggest that the SNPs g.-460C>T, g.1805G>T and g.3375G>C in the human FOXJ1 gene might be associated with susceptibility to allergic rhinitis (P=0.0184, 0.0076, and 0.0143, respectively). The main haplotype, CGG, also revealed a significant association with allergic rhinitis (P=0.000018). However, no significant association was found between serum total IgE levels and the genotypes of these polymorphisms.

Association of TBX21 polymorphisms in a Korean population with rheumatoid arthritis

TBX21 (T-bet) is a member of the T-box family of transcriptional factors that contain a conserved DNA binding domain. TBX21 is a critical regulator of the commitment to the Th1 lineage and IFN-γ production. Th1 and Th2 cells cross-regulate the differentiation of each other, and in this way TBX21 could be an attractive candidate gene for treating autoimmune disease such as rheumatoid arthritis (RA). In present study, we analyzed the genotypic frequencies of six polymorphisms of the TBX21 gene between the 367 RA patients and the 572 healthy controls. We showed that the g.-1514T>C and c.99C>G polymorphisms are suggestively associated with RA susceptibility. It is interesting that the genotypic frequencies of the TBX21 polymorphisms (g.-1514T>C and c.2103A>C) in the male RA patients were significantly different from the male control group (P = 0.0016 and 0.045, respectively). We also found that the g.-1514T>C and c.2103A>C polymorphisms of the TBX21 gene in the male RA patients have significant association with the levels of anti-CCP (P = 0.05) and rheumatoid factor (P = 0.03), respectively. These results suggest that the polymorphisms of the TBX21 gene might be associated with the susceptibility to male RA patients.