Role Of Tim-3 Research Articles

Investigation on the role of TIM4 in the pathogenesis of allergic rhinitis in mice

To investigate the role of TIM4 (T cell immunoglobulin and mucin domain molecule 4) in the pathogenesis of allergic rhinitis (AR) in mice, and to identify a novel therapeutic target for the treatment of AR. Twenty-one male BALB/C mice of clean grade were divided into three groups randomly (n = 7 per group) including control, AR and anti-TIM4 antibody treatment groups. In order to induce upper airway allergic inflammation, the mice from AR and anti-TIM4 antibody treatment groups were sensitized by intraperitoneal injection followed by intranasal challenge with ovalbumin. Before the ovalbumin challenge, a group of mice was treated with anti-TIM4 antibody. To assess the AR model, behavioral observation with immunological assessments and HE staining of nasal tissues were performed. The TIM4 expression in nasal tissues in different groups of mice were assessed by immunofluorescence and RT-PCR.SPSS18.0 software was used to analyze the data. The AR model in mice was successfully established as shown by behavioral observation and immunological evaluation. RT-PCR assays showed the relative expression of TIM4 mRNA in nasal mucosa of AR, control and anti-TIM4 antibody treatment mice was 16.29 ± 3.80, 0.51 ± 0.60, 1.64 ± 0.98, respectively. There was statistically significant differences mong three group (F = 46.56, P < 0.05). The expression of TIM4 in AR group was significantly higher than those in control group (t = 8.650, P < 0.05) and anti-TIM4 group (t = 8.027, P < 0.05). The expression of TIM4 was significantly reduced in the anti-TIM4 antibody group, as well as control group (t = -0.623, P > 0.05). More expression of TIM4 was detected in local nasal tissues of AR mice, mainly located below the pseudostratified ciliated columnar epithelium. TIM4 plays a crucial role in the pathogenesis of AR. Effective inhibition of TIM4 expression can partially reverse the pathological changes of AR.

Galectin-9 Signaling through TIM-3 Is Involved in Neutrophil-Mediated Gram-Negative Bacterial Killing: An Effect Abrogated within the Cystic Fibrosis Lung

The T cell Ig and mucin domain-containing molecule (TIM) family of receptors have emerged as potential therapeutic targets to correct abnormal immune function in chronic inflammatory conditions. TIM-3 serves as a functional receptor in structural cells of the airways and via the ligand galectin-9 (Gal-9) can modulate the inflammatory response. The aim of this study was to investigate TIM-3 expression and function in neutrophils, focusing on its potential role in cystic fibrosis (CF) lung disease. Results revealed that TIM-3 mRNA and protein expression values of circulating neutrophils were equal between healthy controls (n = 20) and people with CF (n = 26). TIM-3 was detected on resting neutrophil membranes by FACS analysis, and expression levels significantly increased post IL-8 or TNF-α exposure (p < 0.05). Our data suggest a novel role for TIM-3/Gal-9 signaling involving modulation of cytosolic calcium levels. Via TIM-3 interaction, Gal-9 induced neutrophil degranulation and primed the cell for enhanced NADPH oxidase activity. Killing of Pseudomonas aeruginosa was significantly increased upon bacterial opsonization with Gal-9 (p < 0.05), an effect abrogated by blockade of TIM-3 receptors. This mechanism appeared to be Gram-negative bacteria specific and mediated via Gal-9/ LPS binding. Additionally, we have demonstrated that neutrophil TIM-3/Gal-9 signaling is perturbed in the CF airways due to proteolytic degradation of the receptor. In conclusion, results suggest a novel neutrophil defect potentially contributing to the defective bacterial clearance observed in the CF airways and suggest that manipulation of the TIM-3 signaling pathway may be of therapeutic value in CF, preferably in conjunction with antiprotease treatment.

Effect of T cell immunoglobulin domain and mucin domain protein-3 gene interfered by short hairpin RNA on helper T lymphocytes 17 differentiation and proinflammatory capacity in asthmatic mice

Objective To investigate the effect of down-regulating of T cell immunoglobulin domain and mucin domain protein-3(Tim-3) gene in asthmatic mouse model by short hairpin RNA(shRNA) and explore the role of Tim-3 on the differentiation of helper T lymphocytes 17(Th17), airway inflammation, as well as airway hyperresponsiveness in pathogenesis of asthma. Methods An asthmatic murine model was established by way of ovalbumin(OVA) sensitization and challenge.Treating Tim-3 gene was intranasally administered with Tim-3-specific shRNA.Invasive pulmonary impedance method was adopted to detect mice airway resistance.Flow cytometry analysis was performed to determine the levels of Th17; enzyme linked immunosorbent assay was performed to determine the concentrations of IL-17 and transforming growth factor-beta(TGF-β) in supernatant. Results Asthmatic mice model was successfully established.By using Tim-3 shRNA silencing Tim-3, airway inflammation was reduced and airway hyperresponsiveness was declined in asthmatic group; the levels of Th17 cells in asthmatic group [(6.43±1.01)%] were significantly increased compared with normal controls[(1.75±0.02)%]. After using Tim-3 shRNA silencing Tim-3, the levels of Th17 cells [(2.36±0.28)%]were decreased (F=40.05, P<0.05); the level of IL-17 in asthmatic group[(118.8±16.5)ng/L] was significantly increased compared with normal controls[(72.5±13.6)ng/L], after using Tim-3 shRNA silencing Tim-3, the level of IL-17 [(73.6±12.5)ng/L]was decreased (F=32.80, P<0.05), while the expression of TGF-β did not change. Conclusions Down regulation of Tim-3 gene can decrease airway inflammation and airway hyperresponsiveness, which may be related to the change of Th17 cell differentiation. Key words: Asthma; T cell immunoglobulin domain and mucin domain protein-3; RNA interference; T hel-per cell

Role of T cell immunoglobulin domain and mucin domain 4 in immune response and disease

Background T cell immunoglobulin domain and mucin domain (TIM) molecules can regulate T cell immune responses.TIM4 is exclusively expressed in APCs.As a strong immune costimulatory molecule in T cell activation,it can regulate Th cell proliferation and differentiation.Objective Clarify the mechanism of T cell immune response regulated by TIM4 and its ligands,and explore the role of TIM4 in disease.Content To review the recent advance of TIM4 molecule and the role of TIM4 in diseases.Trend The role of TIM4 in T cell proliferation and inhibition depend on its ligand and the stage of T cell differentiation.TIM4 regulated immune responses are associated with many kinds of diseases,making TIM4 a new target for therapy. Key words: T cell immunoglobulin domain and mucin domain 4; Th cell activation; Antigen presenting cells; Anaphylaxis; Immune tolerance

T cell immunoglobulin domain and mucin domain-3 as an emerging target for immunotherapy in cancer management.

Cancer-induced immunosuppression significantly impacts tumors, rendering them the ability to acquire aggressive and treatment-resistant phenotypes. The recent clinical success of drugs targeting the immunosuppressive machinery of tumors highlights the importance of identifying novel drugs that effectively augment antitumor immunity and elicit clinical remission in advanced tumors. T cell immunoglobulin domain and mucin domain-3 (TIM-3) is a critical immunoregulatory molecule that links pattern recognition-mediated innate sensing with antigen-specific immune responses. Recent evidence has elucidated the potential utility of drugs targeting TIM-3 in inducing antitumor responses, particularly in synergy with conventional anticancer regimens. Herein, we provide a comprehensive overview, as well as future perspectives, regarding the role of TIM-3 as an emerging target that may improve clinical responses for cancer patients.

Tim-3 Expression Defines Regulatory T Cells in Human Tumors

Tim-3, a member of the novel Tim (T cell immunoglobulin and mucin domain) family, has been reported to negatively regulate the immune responses against viral infection and had implications for autoimmune disease. However, the nature and role of Tim-3+ CD4 T cells in human tumors remain largely unknown. In the present study, we characterized Tim-3+ CD4 T cells in 100 specimens from human hepatocellular, cervical, colorectal and ovarian carcinoma patients. Compared with peripheral blood and nontumor-infiltrating lymphocytes, the lymphocytes isolated from the corresponding tumor tissues of hepatocellular, cervical, colorectal and ovarian carcinoma patients contained significantly greater proportion of Tim-3+ CD4 T cells. The majority of tumor-derived Tim-3+ CD4 T cells exhibited an impaired capacity to produce IFN-γ and IL-2, but expressed higher levels of CD25, Foxp3, CTLA-4 and GITR than their Tim-3− CD4 T cell counterparts. In contrast, most Tim-3+ CD4 T cells isolated from the paired nontumor tissues and peripheral blood did not express these molecules. Moreover, tumor-derived Tim-3+ CD4 T cells, but not tumor-derived Tim-3− CD4 T cells, significantly suppressed the proliferation of autologous CD8+ T cells in vitro. Notably, multi-color immunofluorescence and confocal microscopy demonstrated that Tim-3+Foxp3+CD4+ cells were preferentially distributed in the tumor nest rather than the peritumoral stroma of hepatocellular carcinoma. Together, our data indicate that Tim-3-expressing CD4 T cells in human tumors could represent the functional regulatory T cells which contribute to the formation of the immune-suppressive tumor micromilieu.

Role of Tim-3 in pathogenesis of inflammatory diseases of the digestive system

Role of Tim-3 in pathogenesis of inflammatory diseases of the digestive system

Taming Dendritic Cells with TIM-3: Another Immunosuppressive Strategy Used by Tumors

Evaluation of: Chiba S, Baghdadi M, Akiba H et al. Tumor-infiltrating DCs suppress nucleic acid-mediated innate immune responses through interactions between the receptor TIM-3 and the alarmin HMGB1. Nat. Immunol. 13, 832-842 (2012). The identification of TIM-3 expression on tumor-associated dendritic cells (TADCs) provides insight into another aspect of tumor-mediated immunosuppression. The role of TIM-3 has been well characterized on tumor-infiltrating T cells; however, its role on TADCs was not previously known. The current paper demonstrated that TIM-3 was predominantly expressed by TADCs and its interaction with the nuclear protein HMGB1 suppressed nucleic acid-mediated activation of an effective antitumor immune response. The authors were able to show that TIM-3 interaction with HMGB1 prevented the localization of nucleic acids into endosomal vesicles. Furthermore, chemotherapy was found to be more effective in anti-TIM-3 monoclonal antibody-treated mice or mice depleted of all DCs, which indicated that a significant role is played by TADCs in inhibiting tumor regression. Taken together, these findings identify TIM-3 as a potential target for inducing antitumor immunity in conjunction with DNA vaccines and/or immunogenic chemotherapy in clinical settings.

Highly expression of Tim-3 on HIV-specific T cells associated with disease progression and T-cell exhaustion in HIV-1 infected Chinese

Methods 72 HIV-1 infected individuals with different disease outcomes were recruited in this study. Tim-3 expression and the profile of cellular immune response were measured by using Multicolor Intracellular Cytokine Staining (ICS) assay. Association between Tim-3 expression levels and disease progression was analyzed. And the potential role of Tim-3 on immune regulation during HIV-1 infection was investigated through assessment of CTL response with frequencies of Tim-3 expression and blocking effect.

Increased bovine Tim-3 and its ligand expressions during bovine leukemia virus infection

The immunoinhibitory receptor T cell immunoglobulin domain and mucin domain-3 (Tim-3) and its ligand, galectin-9 (Gal-9), are involved in the immune evasion mechanisms for several pathogens causing chronic infections. However, there is no report concerning the role of Tim-3 in diseases of domestic animals. In this study, cDNA encoding for bovine Tim-3 and Gal-9 were cloned and sequenced, and their expression and role in immune reactivation were analyzed in bovine leukemia virus (BLV)-infected cattle. Predicted amino acid sequences of Tim-3 and Gal-9 shared high homologies with human and mouse homologues. Functional domains, including tyrosine kinase phosphorylation motif in the intracellular domain of Tim-3 were highly conserved among cattle and other species. Quantitative real-time PCR analysis showed that bovine Tim-3 mRNA is mainly expressed in T cells such as CD4+ and CD8+ cells, while Gal-9 mRNA is mainly expressed in monocyte and T cells. Tim-3 mRNA expression in CD4+ and CD8+ cells was upregulated during disease progression of BLV infection. Interestingly, expression levels for Tim-3 and Gal-9 correlated positively with viral load in infected cattle. Furthermore, Tim-3 expression level closely correlated with up-regulation of IL-10 in infected cattle. The expression of IFN-γ and IL-2 mRNA was upregulated when PBMC from BLV-infected cattle were cultured with Cos-7 cells expressing Tim-3 to inhibit the Tim-3/Gal-9 pathway. Moreover, combined blockade of the Tim-3/Gal-9 and PD-1/PD-L1 pathways significantly promoted IFN-γ mRNA expression compared with blockade of the PD-1/PD-L1 pathway alone. These results suggest that Tim-3 is involved in the suppression of T cell function during BLV infection.

Tim-3 expression and function in natural killer cells from advanced melanoma patients.

8571 Background: The concept of CD8+ T cell exhaustion in the context of metastatic cancer has been reinforced by the recent success of immunotherapies targeting the exhaustion markers CTLA-4 and PD-1 in advanced melanoma. T-cell immunoglobulin 3 (Tim-3), another exhaustion marker, is also expressed in natural killer (NK) cells, however its role is still unknown. Recent reports have shown that NK cells, innate immune cells that eliminate tumors through cytotoxicity and IFN-g production, are functionally impaired in advanced melanoma patients, although no receptor has been linked with that phenotype so far. In this study, we characterize the role of Tim-3 in NK cells, particularly in the presence of its natural ligand, Galectin-9 (Gal-9), that is known to be expressed/secreted by some tumor cells including melanoma. Methods: We compared 20 advanced melanoma donors NK cells with 40 healthy donors NK cells as it relates to Tim-3 expression (by flow cytometry) and function (cytotoxicity, IFN-γ production and proliferation). NK cells cytotoxicity was measured by lamp-1 expression, and two different target cells were used: i) K562 cells (Gal-9-) and ii) Gmel Gal-9+ and Gmel Gal-9- sorted melanoma cells. Proliferation was quantified by CFSE after 6 days in the presence of rhIL-2. Recombinant rhGal9 effect was tested in cytotoxicity and IFN-γ production. Results: Melanoma patients NK cells express higher levels of Tim-3 compared to healthy donors NK cells (p&lt;0.05). Melanoma patients NK cells have a defect in cytotoxicity, proliferation and IFN-γ production. Tim-3 expression by itself (without engagement of specific ligands) does not negatively affect NK cell functions (p&lt;0.05). However, when rhGal9 is added to the system, a decrease in NK cell cytotoxicity and IFN-γ production (p&lt;0.05) was observed. Finally, the expression of Gal-9 by the target cells induces a defect in NK cell cytotoxicity (Gmel Gal-9+ vs Gmel Gal-9-). Conclusions: These data suggest that advanced melanoma patients NK cells are exhausted, although it still remains unclear if Tim-3 is involved in this phenotype. In addition,the expression/secretion of Galectin-9, immunosuppressive for NK cells, may be a possible mechanism for tumors to evade immune surveillance.

Abstract 5410: Tim-3 expression and function in natural killer cells from metastatic melanoma patients

Abstract BACKGROUND: Tim-3 (T-cell immunoglobulin domain and mucin domain 3) is a type-I glycoprotein receptor with pivotal roles in immune regulation and tolerance induction. Tim-3 has opposing roles in innate and adaptive immunity. It synergizes with TLR signaling in DCs inducing the production of inflammatory cytokines, while it acts as a negative regulator of Th1/Tc1 cell function by triggering T cell apoptosis upon interaction with its ligand, galectin-9. Tim-3 is also responsible for the functional exhaustion of T cells observed in some chronic infectious diseases and tumors, such as metastatic melanoma (MM). Natural Killer (NK) cells, innate immune cells which eliminate tumors and infected cells through cytotoxicity and IFNγ production, constitutively express Tim-3. Moreover, it has been described that some tumor cells (including melanoma cells) express and secrete galectin-9. However, little is known about the role of Tim-3 on NK cells, particularly in the presence of galectin-9, in healthy or melanoma patients. METHODS: Purified NK cells from PBMCs of 20 melanoma donors (MD) and 40 healthy donors (HD) were characterized according to the expression of Tim-3 by flow cytometry. Lamp-1 expression on NK cell surface was used to measure NK cell cytotoxicity against the following target cells: i) K562 cells which don't express Galectin-9 and ii) Gmel galectin-9+ and Gmel galectin-9- sorted melanoma cells. IFNγ production was assessed by intracellular staining after 4 hours culture in presence of IL-12. RESULTS: MD NK cells express higher levels of Tim-3 compared to HD NK cells (p&amp;lt;0.05). Moreover, MD NK cells have a defect in cytotoxicity, proliferation and IFNγ production, but it still remains unclear if Tim-3 is involved in this exhausted phenotype. So far, we found that Tim-3 expression by itself (without engagement of specific ligands) does not negatively affect NK cell cytotoxicity. However, the expression of Galectin-9 by the target cells induces a decrease in NK cell cytotoxicity (Gmel Gal-9+ vs Gmel Gal-9-). CONCLUSION: These data suggest that when engaged with Galectin-9, Tim-3 expression down-modulates NK cell cytotoxicity. Therefore, galectin-9 expression may be a possible mechanism for tumors to evade immune surveillance. Given that an increasing body of data supports an important role for Tim-3/Galectin-9 interaction in immune regulation in infectious diseases and cancer, deciphering the function of Tim-3 in different cell types will be critical for potentially targeting it therapeutically. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5410. doi:1538-7445.AM2012-5410

Tim-3 expression on peripheral T cell subsets correlates with disease progression in hepatitis B infection

Background and objectiveT-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3) represents a novel mechanism of T-cell dysfunction in chronic viral diseases. However, the role of Tim-3 in the pathogenesis of chronic hepatitis B (CHB) is not well understood. We investigated Tim-3 expression on peripheral T cell subsets and analyzed the relationship between Tim-3 expression and disease progression in HBV infection.Methodsperipheral blood samples were obtained from CHB patients (n = 40), including 23 patients with moderate CHB [MCHB] and 17 with severe CHB [SCHB]. Control samples were obtained from nine acute hepatitis B patients (AHB) and 26 age-matched healthy subjects. The expression of Tim-3 on T cells was determined by flow cytometry.ResultsTim-3 expression was elevated on peripheral CD4+ and CD8+ T cells from AHB and CHB patients compared to those from healthy controls. The percentage of Tim-3+ T cells was further increased in SCHB patients relative to MCHB patients and showed a positive correlation with conventional markers for liver injury (alanine aminotransferase (ALT), aspartate transaminase (AST), total bilirubin (TB) and international normalized ratio (INR) level). The frequency of Tim-3-expressing T cells was negatively correlated with T-bet mRNA expression and plasma interferon-gamma (INF-gamma) levels. Further, Tim-3 expression on CD4+ or CD8+ T cells was reduced in CHB patients with disease remission after antiviral treatment and in AHB patients during the convalescence phase.ConclusionsOur results suggest that over-expression of Tim-3 is involved in disease progression of CHB and that Tim-3 may participate in skewing of Th1/Tc1 response, which contributes to persistency of HBV infection.

Role of TIM-4 in innate or adaptive immune response.

Human being living in constant contact with microbes and pathogen and in the process has developed a recognition pattern of pathogenic structure in the immune cells. The gut lumen has high density of microbes thus the immune response is slightly tolerable to certain microbes, known as commensal flora. These microbes along with other innocuous agents do not cause any inflammation response normally, and are considered as harmless by the immune cells. In immune hypersensitivity condition, such as colitis or food allergy, this mechanism is disturbed. T cell immunoglobulin and mucin domain (TIM)-4 is a phosphatidylserine receptor expressed in mature antigen presenting cells. It is shown that TIM-4 and its ligand TIM-1 are associated in intestinal immune response. However the characteristic of TIM-4 sometimes seems to be two-faced and there is a possibility that TIM-4 also bind to other ligands.

The roles of Tim-3 and Th-17 in children with acute idiopathic thrombocytopenic purpura

Objective To investigate the expression and the role of Tim-3 and Th-17 in ITP patients and to research their clinical application. Methods Total 42 active ITP patients and 39 healthy donors were recruited in this research. The expressions of Th17 and CD4+ CD25+ Treg were measured with flow cytometer. IL-17, IFN-γ levels as well as IL-4 plasma levels were determined by ELISA. The mRNA expression of Tim-3, IFN-γ, IL-4 and T-bet were measured using RT-PCR in all samples. Results The expression of Th17 cells in ITP patients was (2.41 ± 1.43 )%, which was significantly higher than control group ( 1.08 ± 0.59)% ( t = 5.35, P 0.05). The level of IFN-γin plasma of ITP was (55.74 ± 15.25 ) ng/L, which was higher than control group (31.33 ± 12.99) ng/L (t = 7.72, P < 0.05 ). The level of IL-4 in the plasma of ITP was (7.42 ± 1.50) ng/L, which was lower than controls ( 18.17 ± 5.19) ng/L ( t = 12.87, P ＜ 0.05 ). Both IFN-γand T-bet mRNA levels were up-regulated in active ITP patients by the factor ( 8.57 ± 3.44 ) -fold and (3.34 ± 1.32)-fold than control group (t = 13.21,6.41 ,P <0.05). The decreases observed in IL-4 and Tim-3 were (0.25 ±0.15 )-fold and (0.29 ±0.15)-fold respectively in ITP patients compared with control group (t=10.02,9.61,P＜0.05 ). Conclusion The imbalance of Th17/Treg and the decrease of Tim-3 might be important determinants in the evolution of ITP. Key words: Purpura, thrombocytopenic, idiopathic; Membrane proteins; T-Lymphocytes,regulatory; Flow cytometry

Tim3 binding to galectin-9 stimulates antimicrobial immunity

T cell immunoglobulin and mucin domain 3 (Tim3) is a negative regulatory molecule that inhibits effector T(H)1-type responses. Such inhibitory signals prevent unintended tissue inflammation, but can be detrimental if they lead to premature T cell exhaustion. Although the role of Tim3 in autoimmunity has been extensively studied, whether Tim3 regulates antimicrobial immunity has not been explored. Here, we show that Tim3 expressed on T(H)1 cells interacts with its ligand, galectin-9 (Gal9), which is expressed by Mycobacterium tuberculosis-infected macrophages to restrict intracellular bacterial growth. Tim3-Gal9 interaction leads to macrophage activation and stimulates bactericidal activity by inducing caspase-1-dependent IL-1β secretion. We propose that the T(H)1 cell surface molecule Tim3 has evolved to inhibit growth of intracellular pathogens via its ligand Gal9, which in turn inhibits expansion of effector T(H)1 cells to prevent further tissue inflammation.

Comment on “Human Pregnancy Up-regulates Tim-3 in Innate Immune Cells for Systemic Immunity”

We read with interest the article by Zhao et al. ([1][1]), which provides encouraging data on the role of Tim-3 in systemic immunity. It lends support to our view that TIM-3 could be a potential therapeutic target for systemic lupus erythematosus (SLE) ([2][2]). To date, the etiology and

T cell immunoglobulin- and mucin-domain-containing molecule-3 (Tim-3) mediates natural killer cell suppression in chronic hepatitis B

T cell immunoglobulin- and mucin-domain-containing molecule-3 (Tim-3) has been shown to influence autoimmune diseases; however, its function in viral infection has not been well-defined. We therefore investigated the expression and regulatory function of Tim-3 in natural killer (NK) cells in chronic Hepatitis B (CHB) infection. Seventy-six CHB patients, 38 healthy controls, and 18 patients with fatty liver disease (FLD) were tested for Tim-3 expression on peripheral blood mononuclear cells (PBMCs) and in the liver tissue by flow cytometry and immunohistochemical stainning. The effects of HBV infection on Tim-3 expression in NK cells and the roles of Tim-3 in regulation of NK-cell function were also studied. There was a significant increase of Tim-3 expression in PBMCs, circulating NK cells and liver infiltrating lymphocytes (LILs) from CHB patients compared to that of healthy controls and FLD patients. Increased Tim-3 expression was also detected in NK92 cells that had been transfected with a HBV expression vector and NK cells isolated from the liver of HBV transgenic mice. Importantly, blockage of Tim-3 signaling with anti-Tim-3 antibodies or Tim-3-Fc fusion proteins resulted in an increased cytotoxicity for NK92 cells compared to HepG2 and HepG2.2.15 cells, as well as an elevated interferon-gamma (IFN-gamma) production. Similarly, enhanced cytotoxicity was also observed in PBMCs or NK cells from CHB patients treated with the Tim-3 blockade ex vivo. HBV infection can up-regulate Tim-3 expression in NK cells, which may in turn suppress NK-cell functions in CHB patients.

Expression of the Th1-Specific Cell-Surface Protein Tim-3 Increases in a Murine Model of Atopic Asthma

T-cell immunoglobulin- and mucin-domain-containing molecule-3 (Tim-3) is preferentially expressed on Th1-helper type T-cells and functions to repress the Th1-mediated immune response. However, the role of Tim-3 during the inflammatory pathogenesis of asthma remains unclear. This study determines the expression level of Tim-3 in CD4+ T-cells within the peripheral blood and bronchoalveolar lavage fluid (BALF) isolated from a murine model of atopic asthma and explores the potential role of Tim-3 during the inflammatory response. Mice were randomly divided into normal control, asthma day 1, and asthma day 7 groups, and peripheral blood T lymphocytes and BALF cells were collected. The ratio of Tim-3+/CD4+ cells among the total CD4+cell populations from peripheral blood and BALF was determined by flow cytometry, and the expression of the Tim-3 mRNA was determined by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). In contrast with the normal control group, the ratio of Tim-3+/CD4+:CD4+ cells and the level of Tim-3 mRNA in both the peripheral blood T lymphocytes and BALF cells among the asthma day 1 and asthma day 7 groups were significantly increased (p < 0.01), and those in the asthma day 7 group were higher than the asthma day 1 group (p < 0.05). There was also a positive correlation between the ratio of Tim-3+/CD4+:CD4+ detected in BALF and that the ratio detected in peripheral blood T lymphocytes (r = 0.84, p < 0.01). Therefore, the expression of Tim-3 is increased in CD4+ T-cells following airway challenge and likely affects asthma-induced inflammation by repressing the Th1-mediated immune response.

TIM‐3 is expressed on activated human CD4+ T cells and regulates Th1 and Th17 cytokines

TIM-3 is a molecule selectively expressed on a subset of murine IFN-gamma-secreting T helper 1 (Th1) cells but not Th2 cells, and regulates Th1 immunity and tolerance in vivo. At this time little is known about the role of TIM-3 on human T cells. To determine if TIM-3 similarly identifies and regulates Th1 cells in humans, we generated a panel of mAb specific for human TIM-3. We report that TIM-3 is expressed by a subset of activated CD4(+) cells, and that anti-CD3/anti-CD28 stimulation increases both the level of expression as well as the number of TIM-3(+) T cells. We also find that TIM-3 is expressed at high levels on in vitro polarized Th1 cells, and is expressed at lower levels on Th17 cells. In addition, human CD4(+) T cells secreted elevated levels of IFN-gamma, IL-17, IL-2, and IL-6, but not IL-10, IL-4, or TNF-alpha, when stimulated with anti-CD3/anti-CD28 in the presence of TIM-3-specific, putative antagonistic antibodies. This was not mediated by differences in proliferation or cell death, but rather by induction of cytokines at the transcriptional level. These results suggest that TIM-3 is a negative regulator of human T cells and regulates Th1 and Th17 cytokine secretion.