The polymorphisms of Th1 cell surface gene Tim-3 are associated in a Korean population with rheumatoid arthritis

The role of immune regulatory molecules in rheumatoid arthritis: Implication for etiopathogenesis and prospective for treatment

Rheumatoid arthritis (RA) is considered an autoimmune chronic disorder and the most common inflammatory arthropathy. Disease progression in RA begins with asymptomatic autoimmune responses in cases with a genetic or environmental predisposition, that alters to arthralgia phase as autoantibodies reach the joints and subjects begin demonstrating nonspecific musculoskeletal presentations lacking any clinical symptoms of synovial inflammation. After that, patients' symptoms develop to undifferentiated arthritis (UA)/idiopathic arthritis (IA) whenever the subjects progress to clinical synovitis systemic comorbidities affecting the vasculature, metabolism, and bone, and eventually with augmented immune cell infiltration, IA/UA patients progress to clinically classifiable RA. RA is mainly correlated with different immune cells and each of them contributes variously to the pathogenesis of the disease. The pathogenesis of RA is altered by the contribution of both T and B cells in an autoimmune irregularity. Modulation of the immune responses occurs through regulatory and inhibitory molecules that control activation of the adaptive system as well as immune hemostasis. To confine the exorbitant T cell-associated inflammatory reactions, the immune system provides a system of inhibitory feedbacks, collectively named immune checkpoints. In this review, we aimed to discuss about inhibitory members of immune checkpoint molecules, including programmed cell death 1 (PD-1)/PD-L1, cytotoxic-T-lymphocyte-antigen-4, lymphocyte activation gene-3, T cell immunoglobulin-3, V-domain Ig suppressor of T cell activation, B- and T-lymphocyte attenuator, and T cell immunoglobulin and ITIM domain and their role in RA.

B7 immune checkpoint family members as putative therapeutics in autoimmune disease: An updated overview

Autoimmune diseases, especially among young people in the US, are one of the leading causes of morbidity and death. The immune responses are the fundamental pathogenicity of autoimmune disorders. The equilibrium between stimulatory and inhibitory signals is critical for the stimulation, migration, survival, and T cell-related immune responses. The B7 family can substantially regulate T cell-mediated immune responses. Nevertheless, recent breakthroughs in immune checkpoint blockade in cancer immunotherapy have facilitated autoimmune diseases, especially among the prone populations. In the current study, we tried to concisely review the role of the B7 family in regulating immune reactions and the influence of immune checkpoint inhibitors on autoimmunity development.

Genetic variants and expression of the TIM-3 gene are associated with clinical prognosis in patients with epithelial ovarian cancer

OBJECTIVE

Polymorphisms of T cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) were reported to be associated with cancer risk and patients' survival. This study aims to investigate the correlation of TIM-3 polymorphisms with susceptibility to epithelial ovarian cancer (EOC) and patients' outcomes.

METHODS

A total of 700 EOC patients and 710 healthy controls from North China were included. The polymorphisms (rs10053538, rs10515746 and rs1036199) were genotyped using the polymerase chain reaction/ligase detection reaction (PCR-LDR) method. Survival data were available for 339 patients after cytoreductive surgery. The expression level of TIM-3 was detected by real-time quantitative PCR (RT-qPCR). The prognostic value of TIM3 in EOC patients was assessed using the Kaplan-Meier plotter database.

RESULTS

The results showed that none of the TIM3 polymorphisms were associated with the risk of developing EOC. Patients with the rs10053538 CA + AA genotype had worse PFS and OS than those with the CC genotype (HR = 1.49, 95% CI = 1.05-2.09, P = 0.024 and HR = 1.57, 95%CI = 1.09-2.26, P = 0.017, respectively). The RT-qPCR results showed that the expression levels of TIM-3 mRNA in EOC tissues with the rs10053538CA + AA genotypes were significantly higher than those with the CC genotype (P = 0.006). Analysis using the Kaplan-Meier plotter database showed that high expression of TIM-3 mRNA was significantly associated with shorter PFS and OS in EOC patients (HR = 1.57, 95%CI = 1.29-1.91, P < 0.001 and HR = 1.31, 95% CI = 1.06-1.63, P = 0.013, respectively).

CONCLUSIONS

TIM-3 polymorphisms were not associated with risk of developing EOC. Both rs10053538 and the expression level of TIM-3 mRNA may be associated with its clinical outcome in EOC patients.

News on immune checkpoint inhibitors as immunotherapy strategies in adult and pediatric solid tumors

Immune checkpoint inhibitors (ICIs) have shown unprecedented benefits in various adult cancers, and this success has prompted the exploration of ICI therapy even in childhood malignances. Although the use of ICIs as individual agents has achieved disappointing response rates, combinational therapies are likely to promise better results. However, only a subset of patients experienced prolonged clinical effects, thus suggesting the need to identify robust bio-markers that predict individual clinical response or resistance to ICI therapy as the main challenge. In this review, we focus on how the use of ICIs in adult cancers can be translated into pediatric malignances. We discuss the physiological mechanism of action of each IC, including PD-1, PD-L1 and CTLA-4 and the new emerging ones, LAG-3, TIM-3, TIGIT, B7-H3, BTLA and IDO-1, and evaluate their prognostic value in both adult and childhood tumors. Furthermore, we offer an overview of preclinical models and clinical trials currently under investigation to improve the effectiveness of cancer immunotherapies in these patients. Finally, we outline the main predictive factors that influence the efficacy of ICIs, in order to lay the basis for the development of a pan-cancer immunogenomic model, able to direct young patients towards more specific immunotherapy.

Identification, characterization, expression profiles of OlHavcr2 in medaka (Oryzias latipes)

Hepatitis A virus cellular receptor2 (Havcr2) also named T-cell immunoglobulin and mucin domain containing-3 (Tim-3) was initially described as a T helper 1-specific cell surface protein, a member of Tim family implicated in the regulating process of adaptive and innate immune responses. Here, medaka (Oryzias latipes) Havcr2 (OlHavcr2) was isolated and characterized. Unlike other Havcr2 proteins, OlHavcr2 possesses two Ig-like domains but lacks cytoplasmic and transmembrane domains. RT-PCR results revealed that OlHavcr2 mRNA was expressed strongly in the liver, moderately in the intestine, heart and ovary, and weakly in the muscle, gill, brain, eye, spleen, and testis. OlHavcr2 expression begun from gastrula stage and was maintained until hatching. The signal of OlHavcr2 was mainly identified in the blood system in the yolk sac by in situ hybridization. These results indicated that OlHavcr2 is expressed ubiquitously in adult tissues, and is a zygotic gene expressed from gastrula onwards in embryogenesis. OlHavcr2 may play a significant role in the blood system of medaka. In the immune organs, OlHavcr2 expression was affected by the immune stimulants, lipopolysaccharide and poly I:C, suggesting that OlHavcr2 was involved in innate immunity and adaptive immunity in medaka.

TIM family gene polymorphism and susceptibility to rheumatoid arthritis: Systematic review and meta-analysis

BACKGROUND

TIM-family proteins are expressed on different immune cells such as dendritic cells, macrophages, type 1 and 2 T helper (Th) cells. Therefore, they have the ability to contribute to the various intracellular signals and immune responses, importantly the regulation of Th1 and Th17 cell differentiation, which plays a remarked role in fight against inflammatory and autoimmune diseases. Association of TIM family gene polymorphisms with rheumatoid arthritis (RA) has been frequently investigated. The findings however are not entirely consistent. Therefore, we carried out the present meta-analysis to examine the association between RA and the following TIM family gene polymorphisms: rs41297579, rs1036199, rs10515746, and rs7700944.

METHODS

A systematic search of Scopus, PubMed, and Web of Science databases was conducted through December 2018. Combined odds ratios (OR) with their corresponding 95% confidence intervals (CI) were calculated under different possible genetic models.

RESULTS

A total of eight case-control studies were included in the present meta-analysis. The results demonstrated significant association of RA with TIM-3 rs1036199 polymorphism under dominant (OR, 1.93, 95% CI, 1.43-2.61) and allelic models (OR, 1.74, 95% CI, 1.31-2.30). None of the other examined polymorphisms indicated significant association with RA.

CONCLUSIONS

The present meta-analysis revealed that the TIM-3 rs1036199 polymorphism might confer susceptibility to RA. Further studies are required to reassert our findings.

TIM-3 rs1036199 polymorphism increases susceptibility to autoimmune diseases: evidence based on 4200 subjects

Conflicting results have been reported regarding differing studies on the association between T-cell immunoglobulin and mucin domain 3 polymorphisms and autoimmune disease. The purpose of the present study was to evaluate the association of TIM-3 rs1036199 (4259 G/T) polymorphism with autoimmune disease susceptibility. A meta-analysis was performed to obtain a more precise evaluation of the association. Ten eligible studies were retrieved by searching PubMed, Embase and Web of Science databases, and statistical analyses were performed using STATA software. The pooled results indicated that TIM-3 rs1036199 polymorphism was significantly associated with an increased risk of overall autoimmune disease in allele comparison (G versus T: OR = 1.59, 95%CI: 1.17-2.17) and heterozygous comparison (GT versus TT: OR = 1.68, 95%CI: 1.37-2.06). Subgroup analyses based on disease type demonstrated that TIM-3 rs1036199 polymorphism was associated with an increased risk of rheumatic arthritis (G versus T: OR = 1.88, 95%CI: 1.45-2.44; GT versus TT: OR = 2.02, 95%CI: 1.53-2.65), especially in Asian populations.

Immune Checkpoints as Therapeutic Targets in Autoimmunity

Antibodies that block the immune checkpoint receptors PD1 and CTLA4 have revolutionized the treatment of melanoma and several other cancers, but in the process, a new class of drug side effect has emerged—immune related adverse events. The observation that therapeutic blockade of these inhibitory receptors is sufficient to break self-tolerance, highlights their crucial role in the physiological modulation of immune responses. Here, we discuss the rationale for targeting immune checkpoint receptors with agonistic agents in autoimmunity, to restore tolerance when it is lost. We review progress that has been made to date, using Fc-fusion proteins, monoclonal antibodies or other novel constructs to induce immunosuppressive signaling through these pathways. Finally, we explore potential mechanisms by which these receptors trigger and modulate immune cell function, and how understanding these processes might shape the design of more effective therapeutic agents in future.

Functional polymorphisms affecting Th1 differentiation are associated with the severity of autoimmune thyroid diseases

The prognosis for autoimmune thyroid diseases (AITDs), such as Hashimoto's disease (HD) and Graves' disease (GD), varies among patients. Interleukin (IL)-12 and IL-18 also induce Th1 differentiation, and SOCS1 (Suppressor of cytokine signaling 1) and TIM-3 (T cell immunoglobulin and mucin domain-3) are known to be negative regulators of Th1 cells. To clarify the association of functional polymorphisms in the IL12, IL12Rβ1, IL18, SOCS1 and TIM3 genes with the intractability and severity of autoimmune thyroid disease (AITD), we genotyped these polymorphisms in 151 GD patients, including 61 patients with intractable GD and 51 patients with GD in remission, in 140 HD patients, including 59 patients with severe HD and 55 patients with mild HD, and in 74 healthy controls. The frequency of the IL18 -607CC genotype which correlates with a high production of IL-18, was significantly higher in patients with GD in remission than in those with intractable GD (p=0.0178). The -607C allele was significantly higher in patients with severe HD than in those with mild HD (p=0.0050). The -607CC genotype in IL18 gene may be protective against the intractability of GD, and the -607C allele may enhance the severity of HD.

The Effect of Inhibitory Signals on the Priming of Drug Hapten-Specific T Cells That Express Distinct Vβ Receptors

Drug hypersensitivity involves the activation of T cells in an HLA allele-restricted manner. Because the majority of individuals who carry HLA risk alleles do not develop hypersensitivity, other parameters must control development of the drug-specific T cell response. Thus, we have used a T cell-priming assay and nitroso sulfamethoxazole (SMX-NO) as a model Ag to investigate the activation of specific TCR Vβ subtypes, the impact of programmed death -1 (PD-1), CTL-associated protein 4 (CTLA4), and T cell Ig and mucin domain protein-3 (TIM-3) coinhibitory signaling on activation of naive and memory T cells, and the ability of regulatory T cells (Tregs) to prevent responses. An expansion of the TCR repertoire was observed for nine Vβ subtypes, whereas spectratyping revealed that SMX-NO-specific T cell responses are controlled by public TCRs present in all individuals alongside private TCR repertoires specific to each individual. We proceeded to evaluate the extent to which the activation of these TCR Vβ-restricted Ag-specific T cell responses is governed by regulatory signals. Blockade of PD-L1/CTLA4 signaling dampened activation of SMX-NO-specific naive and memory T cells, whereas blockade of TIM-3 produced no effect. Programmed death-1, CTLA4, and TIM-3 displayed discrete expression profiles during drug-induced T cell activation, and expression of each receptor was enhanced on dividing T cells. Because these receptors are also expressed on Tregs, Treg-mediated suppression of SMX-NO-induced T cell activation was investigated. Tregs significantly dampened the priming of T cells. In conclusion, our findings demonstrate that distinct TCR Vβ subtypes, dysregulation of coinhibitory signaling pathways, and dysfunctional Tregs may influence predisposition to hypersensitivity.

Investigation of T-cell immunoglobulin- and mucin-domain-containing molecule-3 (TIM-3) polymorphisms in essential thrombocythaemia (ET)

OBJECTIVES

T-cell immunoglobulin- and mucin-domain-containing molecule-3 (TIM-3) is preferentially expressed on terminally differentiated Th1 cells and inhibits their IFN-γ production. It has been reported that chronic inflammation may be an important driving force for myeloproliferative neoplasms (MPNs). Therefore, we hypothesized that as an important inflammation regulator, TIM-3 may be involved in essential thrombocythaemia (ET). The goal of this study was to investigate whether the -1516G > T, -574G > T and +4259T > G single-nucleotide polymorphisms (SNPs) within the TIM-3 gene contribute to the genetic susceptibility of individuals to ET.

METHODS

Genotyping of the TIM-3 -1516G > T, -574G > T and + 4259T > G SNPs was performed in 175 patients with ET and in 151 controls via a polymerase chain reaction-restriction fragment length polymorphism assay. We also investigated the relationships between the genotypes of each SNP and the risk factors of ET such as routine blood indexes, age and JAK2 V617F mutation.

RESULTS

The genotype and allele frequencies of the -1516G > T SNP (p = 0.016 and 0.019, respectively), the -574G > T SNP (p = 0.035 and 0.038, respectively) and the +4259T > G SNP (p = 0.036 and 0.038, respectively) of the ET patients and the controls were significantly different. A haplotype analysis found that the GGT and TGT haplotypes had significantly different distributions between ET and controls (p = 0.041 and 0.041, respectively). However, no significant differences were detected between the genotypes of all SNPs and routine blood indexes, age and JAK2V617F mutation.

CONCLUSION

The -1516G > T, -574G > T and +4259T > G SNPs within TIM-3 gene might play an important role as a genetic risk factor in the pathogenesis of ET.

Expression of human T cell immunoglobulin domain and mucin-3 on kidney tissue from immunoglobulin A nephropathy patients

The aim of this study was to evaluate the expression of human T cell immunoglobulin domain and mucin-3 (Tim-3) in renal tissue from patients with immunoglobulin A nephropathy (IgAN) and without IgAN and to evaluate the difference in Tim-3 expression between them. A total of 71 patients with IgAN as IgA group and 13 patients without IgAN as control group were enrolled in the present study. Patients in IgAN accepted percutaneous renal biopsy. We examined the expression of Tim-3 in renal tissue and the serological parameters in serum from all enrolled cases. The expression of Tim-3 and serological parameters were compared between the different groups. Positive staining of Tim-3 protein was seen in 94.3 % patients with IgAN (67 out of 71), but only 15.4 % (2 out of 13) in the cases without IgAN were positive staining of Tim-3. There were significant differences between two groups in almost all serological markers, which reflect IgAN activity. There was a nearly positive correlation between pathological manifestations and expression degree of Tim-3. High immuno-reactivity of Tim-3 was found to be significantly correlated with serological grade (p < 0.001) in IgA group, but there was no such phenomenon in control group. The results showed that there was the expression of Tim-3 in renal tissue from the patients with IgAN, but rarely expression in cases without IgAN. Expression of Tim-3 was associated with the diseases' activity.

Characterization of the impairment of the uptake of apoptotic polymorphonuclear cells by monocyte subpopulations in systemic lupus erythematosus

Efficient removal of apoptotic polymorphonuclear leukocytes (PMNs) is an important step in the resolution of inflammation, which protects tissues from the noxious contents of dying cells. While the impairment of apoptotic PMNs removal has been demonstrated for macrophages in systemic lupus erythematosus (SLE), recent studies show that monocytes are also capable of such phagocytosis, although their involvement in SLE is not clear. Therefore, we characterized phagocytosis of apoptotic PMNs by monocytes in 22 patients with SLE and 22 healthy controls. Using flow cytometry we demonstrate that in SLE peripheral blood monocytes show impaired phagocytosis of autologous apoptotic PMNs, while they efficiently engulf apoptotic PMNs isolated from healthy subjects. Monocytes CD14highCD16+ and CD14dimCD16+ more efficiently interacted with apoptotic neutrophils than CD16– cells both in SLE and healthy subjects. Monocytes in SLE showed modestly decreased expression of CD35 and CD91 and increased expression of T Cell Ig- and mucin-domain-containing molecule-3 (TIM-3); however, these differences were evident mainly in selected subsets of monocytes (CD16+) while defects in phagocytosis were observed in all monocyte subsets. Apoptotic cell-dependent induction of lipopolysaccharide (LPS) stimulated production of anti-inflammatory cytokine IL-10 by peripheral blood mononuclear cells (PBMC) was blunted in SLE while the production of pro-inflammatory cytokine TNF-α was unchanged.

T-cell immunoglobulin- and mucin-domain-containing molecule 3 genetic variants and HIV+ non-Hodgkin lymphomas

T cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) has been established as a negative regulatory molecule and plays a critical role in inflammatory diseases such as rheumatoid arthritis, hepatitis B and C, and human immunodeficiency virus (HIV)-related inflammation. Recent studies have shown that chronic inflammation may greatly affect the pathogenesis of non-Hodgkin lymphomas (NHL). The aim of this study was to investigate whether polymorphisms in the TIM-3 gene were associated with susceptibility to non-NHL and HIV-related NHL. Three polymorphisms in TIM-3 gene (-1516G/T, -574G/T, and +4259T/G) were identified by polymerase chain reaction-restriction fragment length polymorphism in 434 NHL patients, 62 HIV-related NHL cases, and 512 healthy controls. Results showed that the prevalence of -574GT genotype and +4259TG genotype were significantly increased in the NHL cases than in controls (odds ratio (OR) = 2.72, 95% confidence interval (CI) = 1.50-4.92, p = 0.0006 and OR = 2.59, 95% CI = 1.49-4.49, p = 0.0005, respectively). The -1516G/T polymorphism did not reveal significant difference between patients and healthy controls. When analyzing the TIM-3 polymorphisms in HIV-related NHL patients, data showed that HIV+ NHL patients had higher prevalence of -574GT or +4259TG genotypes than those cases without HIV infection (OR = 3.48, 95% CI = 1.67-7.28, p = 0.0005 and OR = 2.92, 95% CI = 1.42-6.01, p = 0.0026, respectively). These results suggested polymorphisms in TIM-3 gene could be new risk factors for NHL as well as HIV-related NHL and suggested a possible role of the inflammatory factor in these diseases.

Expression of TIM-3 on CD4+ and CD8+ T cells in the peripheral blood and synovial fluid of rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by a chronic inflammatory process that targets the synovial lining of diarthrodial joints. TIM-3 plays a key role in the negative regulation of the immune response. In this study, we investigated the expression of TIM-3 on CD4+ and CD8+ T cells from systemic (peripheral blood) and local (synovial fluid) perspectives of RA. Level of TIM-3+ cells from peripheral blood and synovial fluid of patients as well as peripheral blood of healthy controls was measured by flow cytometry. Results showed that TIM-3 expression was significantly increased in both CD4+ and CD8+ T cells in the peripheral blood of RA (p < 0.001 and p < 0.001, respectively). Furthermore, patients revealed even higher expression of TIM-3 in CD4+ and CD8+ T cells in synovial fluid than in peripheral blood. When comparing TIM-3 level with the severity of RA, we identified that the percentage of TIM-3 on both peripheral CD4+ and peripheral CD8+ T cells was negatively correlated with disease activity score 28 (DAS28) of the patients. Similarly, TIM-3 on synovial fluid CD4+ and CD8+ T cells also revealed inverse correlation with DAS28 of the cases. Our data demonstrate a negative correlation between TIM-3 and the disease progression of RA.

Tim-3 on peripheral CD4⁺ and CD8⁺ T cells is involved in the development of glioma

Tim-3 acts as a negative regulatory molecule and plays a critical role in immune tolerance. The purpose of this study was to investigate the expression of Tim-3 on peripheral CD4⁺ and CD8⁺ T cells in glioma. A total of 30 newly diagnosed glioma patients and 30 healthy controls were recruited and leukocytes from peripheral blood mononuclear cells were analyzed for Tim-3 surface expression by flow cytometry. Plasma tumor necrosis factor-alpha (TNF-α) was also measured. Data showed that expression of Tim-3 was significantly increased in both CD4⁺ and CD8⁺ T cells in glioma patients than in controls (p<0.001 and p<0.001, respectively). Patients with a higher tumor grade revealed further elevated Tim-3 expression in CD8⁺ T cells compared with those with a lower tumor grade. Also, the Karnofsky score of patients was negatively correlated with the percentage of Tim-3⁺CD8⁺ T cells in glioma patients (p=0.007). In addition, an inverse correlation was observed between the plasma level of TNF-α and Tim-3⁺CD4⁺ T cells (p=0.005) or Tim-3⁺CD8⁺ T cells (p<0.001) in glioma patients. Our results suggested that Tim-3 may be involved in the development of glioma.

Expression of human T cell immunoglobulin domain and mucin-3 (TIM-3) on kidney tissue from systemic lupus erythematosus (SLE) patients

The aim of this study was to evaluate the expression of TIM-3 in renal tissue from patients with systemic lupus erythematosus (SLE) and patients without SLE, and to evaluate the difference of TIM-3 expression between them. A total of 272 patients with SLE as SLE group and 62 patients without SLE as control group were enrolled in the present study. Patients with SLE accepted percutaneous renal biopsy. We examined the expression of TIM-3 in renal tissue and the serological parameters in serum from all enrolled cases. The expression of TIM-3 and serological parameters were compared between the different groups. Positive staining of TIM-3 protein was seen in 97.1 % patients with SLE (264 out of 272), but 95.2 % negative staining in the cases without SLE (59 out of 62), only 3 out of 62 patients in control group were positive staining of TIM-3. There were significant differences between two groups in almost all serological markers which reflect SLE activity. There was a nearly positive correlation between pathological manifestations and expression degree of TIM-3. High immuno-reactivity of TIM-3 was found to be significantly correlated with serological grade (p < 0.001), but there was the phenomenon in control group. The results showed that there was the expression of TIM-3 in renal tissue from the patients with SLE, but rarely expression in cases without SLE. Expression of TIM-3 was associated with the diseases' activity.

Gene expression profiles in human and mouse primary cells provide new insights into the differential actions of vitamin D3 metabolites

1α,25-Dihydroxyvitamin D₃ (1α,25(OH)₂D₃) had earlier been regarded as the only active hormone. The newly identified actions of 25-hydroxyvitamin D₃ (25(OH)D₃) and 24R,25-dihydroxyvitamin D₃ (24R,25(OH)₂D₃) broadened the vitamin D₃ endocrine system, however, the current data are fragmented and a systematic understanding is lacking. Here we performed the first systematic study of global gene expression to clarify their similarities and differences. Three metabolites at physiologically comparable levels were utilized to treat human and mouse fibroblasts prior to DNA microarray analyses. Human primary prostate stromal P29SN cells (hP29SN), which convert 25(OH)D₃ into 1α,25(OH)₂D₃ by 1α-hydroxylase (encoded by the gene CYP27B1), displayed regulation of 164, 171, and 175 genes by treatment with 1α,25(OH)₂D₃, 25(OH)D₃, and 24R,25(OH)₂D₃, respectively. Mouse primary Cyp27b1 knockout fibroblasts (mCyp27b1^−/−), which lack 1α-hydroxylation, displayed regulation of 619, 469, and 66 genes using the same respective treatments. The number of shared genes regulated by two metabolites is much lower in hP29SN than in mCyp27b1^−/−. By using DAVID Functional Annotation Bioinformatics Microarray Analysis tools and Ingenuity Pathways Analysis, we identified the agonistic regulation of calcium homeostasis and bone remodeling between 1α,25(OH)₂D₃ and 25(OH)D₃ and unique non-classical actions of each metabolite in physiological and pathological processes, including cell cycle, keratinocyte differentiation, amyotrophic lateral sclerosis signaling, gene transcription, immunomodulation, epigenetics, cell differentiation, and membrane protein expression. In conclusion, there are three distinct vitamin D₃ hormones with clearly different biological activities. This study presents a new conceptual insight into the vitamin D₃ endocrine system, which may guide the strategic use of vitamin D₃ in disease prevention and treatment.

The expression of Tim-3 in peripheral blood of ovarian cancer

Ovarian cancer remains a challenging disease for which improved treatments are urgently needed. Tim-3 acts as a negative regulatory molecule and plays a critical role in immune tolerance. In the current study, we investigated the expression of Tim-3 on peripheral CD4+ T and CD8+ T cells in ovarian cancer. A total of 52 ovarian cancer patients and 56 healthy controls were recruited and leukocytes from peripheral blood mononuclear cells were analyzed for Tim-3 surface expression by flow cytometry. Data showed that expression of Tim-3 was significantly increased in both CD4+ and CD8+ T cells in ovarian cancer cases than in controls (p<0.0001 and p<0.0001, respectively). Patients who had recurrent ovarian cancer had a higher proportion of Tim-3+CD4+ T cells than when they were newly diagnosed (p=0.013). When analyzing Tim-3 expression with cancer progression, results revealed elevated Tim-3 expression in both CD4+ and CD8+ T cells in cases with advanced International Federation of Gynecology and Obstetrics (FIGO) staging (III/IV) than those with stage I and II (p=0.009 and p=0.037, respectively). We also tested Tim-3 with tumor grade, and observed that patients with a higher tumor grade (G3) demonstrated further augmented Tim-3 expression in CD4+ and CD8+ T cells compared to those with lower tumor grades (p=0.010 and p=0.042, respectively). Our study suggested that Tim-3 may participate in the development and progression of ovarian cancer by its negative regulation on various T-cell subsets, and Tim-3 expression in CD4+ T cells could serve as a predictive marker for anticancer therapies.

T-cell immunoglobulin- and mucin-domain-containing molecule 3 gene polymorphisms and prognosis of non-small-cell lung cancer

Lung cancer is the leading cause of death worldwide. Non-small-cell lung cancer (NSCLC) accounts for most of these cases. T-cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) has been established as a negative regulatory molecule and plays a critical role in immune tolerance. Studies have shown that polymorphisms in TIM-3 gene can be associated with various diseases. The aim of this study was to investigate whether polymorphisms in the TIM-3 gene were associated with susceptibility to NSCLC. Three polymorphisms in TIM-3 gene (-1516G/T, -574G/T, and +4259T/G) were identified by polymerase chain reaction-restriction fragment length polymorphism in 432 NSCLC patients and 466 healthy controls. Results showed that frequencies of TIM-3 +4259TG genotype for cases and controls were 10.9 and 4.1 %, respectively; subjects carrying the +4259TG genotype had a 2.81-fold increased risk of NSCLC compared to the wild-type genotype (P < 0.0001). The TIM-3 -1516G/T and -574G/T polymorphisms did not show any correlation with NSCLC. In addition, when analyzing the survival time of NSCLC patients with TIM-3 +4259T/G polymorphism, cases with +4259TG genotype had significantly shorter survival time compared to the wild-type patients (15.2 months vs. 26.7 months, P = 0.007). These results suggested polymorphism in TIM-3 gene is associated with increased susceptibility to NSCLC and could be used as prognostic factor for this malignancy.

Imbalanced expression of T-bet and T cell immunoglobulin mucin-3 in patients with aplastic anaemia

BACKGROUND

Activated T helper (Th)-1 CD4+ cells and their mediators are essential for pathogenesis processes in aplastic anaemia (AA). Recently, T-cell immunoglobulin and mucin domain 3 (Tim-3) molecules, a Th1-specific type 1 membrane protein, have been suggested to be important regulators of both Th1 proliferation and the development of tolerance. Moreover, T-box expressed in T cells (T-bet) is a major T cell transcription factor that regulates the expression of Th1 cytokine genes and plays a crucial role in T cell differentiation. The function of Tim-3 and its association with T-bet in the pathophysiology of AA remain unclear.

DESIGN AND METHODS

Plasma IL-18, IFN-γ and IL-4 levels were measured in patients with newly diagnosed AA (n = 29), AA in remission (n = 22) and healthy subjects (n = 30) via enzyme-linked immunosorbent assay (ELISA). CD4+ Tim-3+ cells were evaluated via flow cytometry and expressed as a percentage of the total number of CD4+ cells. Using real-time quantitative polymerase chain reaction (RT-PCR) and mRNA expression analysis the expression levels of Tim-3, IL-18, IFN-γ and T-box (T-bet) were examined in all subjects.

RESULTS

Tim-3 was expressed on CD4+T cells. The percentages of Tim-3 cells identified in newly diagnosed patients were significantly deceased compared with the controls. Meanwhile T-bet, IL-18 and IFN-γ levels were significantly elevated in patients, which resulted in an increased ratio of T-bet/Tim-3 expression levels in patients with active disease. During the remission stages, the levels of these cytokines were comparable with those observed in the healthy controls.

CONCLUSIONS

These results suggest that the imbalanced expression of Tim-3 and T-bet may play a role in the pathogenesis and course of AA, and the downregulation of T-bet/Tim-3 may represent a reasonable therapeutic strategy for AA treatment.

T cell immunoglobulin-3 as a new therapeutic target for rheumatoid arthritis

T cell immunoglobulin-3 (Tim-3) is a surface molecule expressed on various cell types of the immune system which plays a central role in immune regulation. Recently, identification of galectin-9 (Gal-9) as a ligand for Tim-3 has established the Tim-3-Gal-9 pathway as an important regulator of Th1 immunity and induction of tolerance. The interaction of Tim-3 with Gal-9 induces cell death; the in vivo blockade of this interaction results in exacerbated autoimmunity and abrogation of tolerance in experimental models, thus establishing Tim-3 as a negative regulatory molecule. A number of previous studies have demonstrated that Tim-3 influences chronic autoimmune diseases, such as multiple sclerosis and systemic lupus erythematosus. In addition, an association between Tim-3 polymorphisms and susceptibility to several autoimmune diseases has been identified in various autoimmune diseases, including rheumatoid arthritis (RA). Recent work has focused on the role of Tim-3 in RA, and the results indicate that Tim-3 may represent a novel target for the treatment of RA. In this article we will discuss the Tim-3 pathway and the therapeutic potential of modulating the Tim-3 pathway in RA.

Underexpression of TIM-3 and blunted galectin-9-induced apoptosis of CD4+ T cells in rheumatoid arthritis

The aim of this study is to compare the expression of TIM-3 from CD4+ T cells from rheumatoid arthritis (RA) patients and healthy controls and to evaluate the effect of galectin-9 (Gal-9) on apoptosis of CD4+ T cells in these patients. CD4+ T cells from RA patients and healthy controls were isolated from peripheral blood mononuclear cells and were activated. The expression of TIM-3 mRNA in CD4+ T cells was measured using real-time polymerase chain reaction. CD4+ T cells were activated in the presence of graded doses of Gal-9 or control, and Gal-9-induced cytotoxicity and apoptotic activity of CD4+ T cells were analyzed using MTT assays and annexin-V staining, respectively. TIM-3 mRNA expression was significantly lower in CD4+ T cells from RA patients compared with those in healthy controls (p = 0.028). CD4+ T cell survival as measured by MTT assay when incubated with Gal-9 (15 nM) was significantly higher in RA patients than in healthy controls (p = 0.002). Apoptotic activity of CD4+ T cells from healthy controls as measured by annexin staining increased with graded doses of Gal-9 (0 nM vs. 30 nM, 0 nM vs. 90 nM, p = 0.016 each). However, apoptotic activity of CD4+ T cells from RA patients did not change despite the stimulation with Gal-9. Gal-9-mediated apoptosis of CD4+ T cells is dysfunctional in RA patients. Blunted Gal-9-mediated apoptosis may be exerted through underexpression of TIM-3 that negatively regulates Th1 response. Our data suggest that TIM-3 and its interaction with Gal-9 may play an important role in the pathogenesis of RA and may represent a potential therapeutic target.

Polymorphisms of the T-cell immunoglobulin and mucin domain molecule-3 are not associated with autoimmune Graves' disease in a Chinese Han Population

OBJECTIVES

This study aimed to investigate the association between polymorphisms of T-cell immunoglobulin and mucin domain molecule-3 (TIM-3) and Graves' disease (GD) in a Chinese population.

DESIGN AND METHODS

Genomic DNA was extracted from peripheral blood cells of the 182 GD patients and 150 control subjects. The TIM-3 gene polymorphic sites were genotyped. We also analyzed the relationships between the genotypes of each SNP and serum specific clinical variables. To detect whether the variants were associated with the TIM-3 expression, we further studied 40 patients by using the method of real-time quantitative reverse-transcription polymerase chain reaction (real-time RT-PCR).

RESULTS

The genotype and allele frequency of each polymorphic site were not significantly different between GD and control individuals. Furthermore, it also showed no relationship between the variants and TIM-3 mRNA expression.

CONCLUSIONS

Our results demonstrated that the polymorphisms of TIM-3 gene may not contribute to GD susceptibility in the Chinese Han population.

T cell immunoglobulin- and mucin-domain-containing molecule 3 gene polymorphisms and susceptibility to pancreatic cancer

T cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) is a novel transmembrane protein that is involved in the regulation of T-helper 1 cell-mediated immunity. Studies have shown that polymorphisms in TIM-3 gene can be associated with various diseases. Here, we investigated the correlation of TIM-3 polymorphisms with susceptibility to pancreatic cancer in the Chinese population. Three polymorphisms in TIM-3 gene (-1516G/T, -574G/T, and +4259T/G) were identified by polymerase chain reaction-restriction fragment length polymorphism in 306 pancreatic patients and 408 healthy controls. Results showed that the prevalence of +4259TG genotype and +4259G allele were significantly increased in the pancreatic cancer cases than in controls [odds ratio (OR) = 2.82, 95 % confidence interval (CI), 1.45-5.48, p = 0.0015, and OR = 2.74, 95 % CI, 1.42-2.94, p = 0.0017]. In addition, when analyzing the TIM-3 polymorphisms with different clinical parameters in pancreatic cancer patients, the cases with vascular infiltration had higher numbers of +4259T/G polymorphism than those without vascular infiltration (OR = 3.07, 95 % CI, 1.41-6.68, p = 0.003). These results suggested polymorphisms in TIM-3 gene could be new risk factors for the development of pancreatic cancer.

Molecular characteristics of the porcine TIMD4 gene and its association analysis

As a member of the T cell immunoglobulin domain and mucin domain (TIM) gene family, TIMD4 plays an important role in the immune response. To understand its function more precisely, we isolated it and analyzed its subcellular localization, expression pattern, and associations. The porcine TIMD4 gene included nine exons and eight introns with an open reading frame of 1086 bp encoding 361 amino acids. It had relatively high levels in liver, lymph, and spleen. The fusion protein was localized mainly in the cytoplasm of pig kidney cells (PK15). The promoter region contained a TATA box and GATA3 consensus sites. A single nucleotide polymorphism was identified in intron 3 of the porcine TIMD4 gene, and analysis indicated that it had significant associations with the 17-day red blood cell count (p = 0.0106), hemoglobin (p = 0.0149), and hematocrit (p = 0.0063) and with 32-day hemoglobin (p = 0.0140).

Polymorphisms of the TIM-1 gene are associated with rheumatoid arthritis in the Chinese Hui minority ethnic population

The T-cell immunoglobulin and mucin domain 1 (TIM-1) is known to be associated with susceptibility to rheumatoid arthritis (RA). We investigated the association of four single-nucleotide polymorphisms (SNPs) in the promoter region of the TIM-1 gene with susceptibility to RA in a Chinese Hui ethnic minority group. Using RFLP or sequence specific primer-PCR, 118 RA patients and 118 non-arthritis control individuals were analyzed for the -1637A>G, -1454G>A, -416G>C, and -232A>G SNPs in the TIM-1 gene. The polymorphisms -232A>G and -1637A>G in the promoter region of TIM-1 were found to be associated with susceptibility to the RA gene in the Hui population, while -416G>C and -1454G>A SNPs were not. Of these, the polymorphism of -232A>G is inconsistent with that found in a Korean population, suggesting that genetic variations of the TIM-1 gene contribute to RA susceptibility in different ways among different populations. Based on haplotype analysis, individuals with haplotypes AGCA (Χ(2) = 22.0, P < 0.01, OR (95%CI) >1), AGCG (Χ(2) = 18.16, P < 0.01, OR (95%CI) >1) and AGGA (Χ(2) = 5.58, P < 0.05, OR (95%CI) >1) are at risk to develop RA in the Chinese Hui population; those with the GAGA (Χ(2) = 7.44, P < 0.01, OR (95%CI) <1) haplotype may have a decreased likelihood of RA. GGCA and GGCG are more common in both RA and non-RA subjects. We conclude that -1637A>G and -232A>G polymorphisms of TIM-1 are associated with susceptibility to RA in the Chinese Hui population.

TIM polymorphisms--genetics and function

The transmembrane immunoglobulin and mucin domain (TIM) family was identified more than a decade ago. Although the founding member of the family was first described in a rat model of ischemia-reperfusion injury, much of the recent interest in the TIM family members has focused on their potential roles in immunity. There are now a large number of genetic studies that have investigated the possible association of various TIM1 and TIM3 polymorphisms with different diseases. Here, we review this body of literature, and highlight some of the most interesting studies.

Association between polymorphisms of the T cell immunoglobulin musin-3 gene and outcome of hepatitis B virus infection

AIM: To investigate the relationship between single nucleotide polymorphisms (SNPs) of the T cell immunoglobulin musin-3 (Tim-3) gene and outcome of hepatitis B virus (HBV) infection in a Chinese Han population.

METHODS: Two tagSNPs of the Tim-3 gene (rs11741184 and rs13170556) were genotyped using the SNaPshot method in 996 patients with chronic HBV infection group and 301 patients with acute self-limiting HBV infection. The genotypes, allele frequencies and haplotypes of the two Tim-3 tagSNPs were compared between the two groups of patients.

RESULTS: The frequencies of CC, CG and GG genotypes at the rs11741184 locus were 84.39% (254/301), 15.28% (46/301) and 0.3% (1/301) in patients with acute self-limiting HBV infection, and 86.04% (857/996), 13.65% (136/996) and 0.3% (3/996) in patients with chronic HBV infection, respectively. There were no statistical differences in the genotype frequencies at the rs11741184 locus between the two groups of patients (all P > 0.05). The frequencies of AA, GA and GG genotypes at the rs13170556 locus were 68.77% (207/301), 28.57% (6/301) and 2.66% (8/301) in patients with acute self-limiting HBV infection, and 68.07% (678/996), 28.41% (283/996) and 3.51% (35/996) in patients with chronic HBV infection, respectively. There were also no statistical differences in the genotype frequencies at the rs13170556 locus between the two groups of patients (all P > 0.05). Three haplotypes for Tim-3 tagSNPs (C-A, C-G, G-A) were found in the Chinese Han population, and their haplotype frequencies were similar between patients with acute self-limiting HBV infection (75.08%, 16.94%, 7.97%) and those with chronic HBV infection (75.08% vs 75.15%, 16.94% vs 17.72%, 7.97% vs 7.13%, all P > 0.05).

CONCLUSION: The two Tim-3 tagSNPs may not be associated with outcome of HBV infection in Chinese Han population.

T-cell immunoglobulin and mucin domain 3 genetic polymorphisms are associated with rheumatoid arthritis independent of a shared epitope status

The aim of this study was to investigate T-cell immunoglobulin and mucin domain 3 (TIM3) genetic polymorphisms and rheumatoid arthritis (RA) according to the shared epitope (SE) status. Six single nucleotide polymorphisms (SNPs: rs11742259 [C/T], rs10515746 [C/A], rs35960726 [A/G], rs1036199 [A/C], rs4704846 [A/G], and rs11134551 [A/G]) in the TIM3 gene from 366 RA patients and 389 healthy controls were investigated using the real-time polymerase chain reaction method. Associations between these SNPs and clinical manifestations (including SE status) were investigated using the SPSS program and Haploview. Polymorphisms of rs35690726 (AG+ GG vs AA: 8.2% vs 1.8%, p(c) < 0.001) were significantly associated with RA with or without SE (p(c) < 0.001 or p(c) = 0.009, respectively). Polymorphisms of rs11742259 (p(c) = 0.003) and rs1036199 (p(c) = 0.012) were significantly different in RA patients with SE, but not in those without SE. In haplotype analysis with a permutation test for the first 4 SNPs (rs11742259, rs10515746, rs35690726, and, rs1036199), CCAA, CCGA, CCGC, and CAAA haplotypes were significantly associated with RA. The clinical characteristics of RA patients were not significantly associated with any TIM3 polymorphism. TIM3 genetic polymorphisms may have a role in the development of RA regardless of a shared epitope status.

Expression of human TIM-3 and its correlation with disease activity in rheumatoid arthritis

OBJECTIVE

T-cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) is a novel transmembrane protein that is involved in the regulation of T-helper 1 (Th1)-cell-mediated immunity. This study was undertaken to investigate the expressions of TIM-3 and its ligand galectin 9 (Gal-9) with respect to disease activity in rheumatoid arthritis (RA).

METHODS

Blood was collected from 39 RA patients and 31 healthy controls. Blood leucocyte TIM-3 and Gal-9 mRNA levels and RA disease activity were determined. Synovial tissue (ST) from five RA patients and five osteoarthritis (OA) patients were examined for TIM-3 mRNA expression and were also analysed for TIM-3 by immunohistology.

RESULTS

TIM-3 mRNA expression was significantly higher in the ST of RA patients than in the ST of OA patients. TIM-3 was expressed in the synovial sublining area in ST of RA patients but not in OA ST. TIM-3 mRNA expression from peripheral blood mononuclear cells (PBMCs) of RA patients was negatively correlated with the 28-joint Disease Activity Score (DAS28). Gal-9 mRNA level in PBMCs of RA patients was higher than in healthy controls, and was significantly higher in patients with low disease activity compared to those with moderate to high disease activity. Gal-9 mRNA expression in PBMCs of RA patients was positively correlated with forkhead box P3 (FoxP3) mRNA expression.

CONCLUSION

TIM-3 and its interaction with Gal-9 are closely associated with RA disease activity and may play an important role in the pathogenesis of RA. In addition to the negative regulatory effect of Gal-9 mediated through the TIM-3-Gal-9 pathway, Gal-9 may exert its suppressive effect on RA disease activity by modulation of regulatory T (Treg) cells.

Polymorphisms of the TIM-1 and TIM-3 genes are not associated with systemic lupus erythematosus in a Chinese population

Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune diseases, which affects multiple organ systems such as kidney. The imbalance of T-helper 1 (Th1)/Th2 cells is critical in the pathogenesis of SLE. The T-cell immunoglobulin mucin (TIM) proteins comprise a family of cell surface molecules expressed on T cells that regulate Th1- and Th2-cell-mediated immunity. Recent work has found increased expression of TIM-1 and TIM-3 ligand (galactin-9) mRNA in SLE patients and implied that TIM proteins might be involved in the pathogenesis of SLE. In this study, genotyping of single-nucleotide polymorphisms (SNPs) was performed for TIM-1 (rs1501909 and rs12522248) and TIM-3 (rs9313439 and rs10515746) in 202 SLE patients and 217 healthy individuals in a Chinese population. Results showed no significant differences existed between the patients with SLE and the controls as well as SLE patients with nephritis and those without nephritis, in all four SNPs. The findings suggest that the polymorphisms of TIM gene family might not contribute to SLE susceptibility in the Chinese population. However, it should be noted that the statistical power of our study is relatively low, which likely did not have adequate power to detect the actual correlation between the selected SNPs and SLE susceptibility; moreover, we cannot discard a possible association of other variants within the region covering TIM with SLE as a genetic risk factor, with larger samples in different populations.

Increased Tim-3 expression on peripheral lymphocytes from patients with rheumatoid arthritis negatively correlates with disease activity

Tim-3 has been reported as an important regulatory molecule and plays a pivotal role in several autoimmunity diseases. Here, we demonstrated the increased expression of Tim-3 on peripheral CD4(+) T, CD8(+) T, NKT cells and monocytes from RA patients compared to those from healthy controls. Percentage of Tim-3(+) cells in peripheral blood mononuclear cells (PBMCs) showed an inverse correlation with disease activity score 28 (DAS28) and plasma TNF-α level. Similar negative correlations were found between disease activity and Tim-3 levels on CD4(+) T, CD8(+) T and NKT cells. Consistently, Tim-3 expression on CD3(+) T cells was further increased in patients with disease remission after treatment. Tim-3 expression on CD8(+) T and NKT cells negatively correlates with plasma TNF-α. Our results suggest that Tim-3 might participate in the proceeding of RA by its negative regulation on various T cell subsets. Tim-3 might be a potential new marker for assessing severity of RA.

Molecular characterization of the porcine TIM-3 gene

TIM-3 is a member of the TIM (T-cell immunoglobulin domain and mucin domain) family, which plays an important role in TH1 responses and autoimmune diseases. In this study, we cloned and characterized the porcine TIM-3 gene. Real-time PCR showed little expression of porcine TIM-3 in muscle and stomach, low expression in kidney, brain, stomach and muscle, moderate expression in liver, small intestine and lymph, and high expression in spleen and lung. Transient transfection indicated that porcine TIM-3 fusion protein was found to localize on the cell membranes or cytoplasm. Association analysis indicated that the SNP AccI in exon2 was significantly associated (P < 0.05) with red blood cell count mean corpuscular haemoglobin, packed cell volume, Lymphocyte percentage and Lymphocyte modulus. In conclusion, our results provide some information for conducting further studies on the functions of porcine TIM-3 gene in type I diabetes and suggest that SNP AccI in exon2 may be utilized as a marker for molecular-assisted selection in animal breeding.