Publications by authors named "Hisaya Akiba"

94 Publications

Chitin induces steroid-resistant airway inflammation and airway hyperresponsiveness in mice.

Allergol Int 2021 Feb 24. Epub 2021 Feb 24.

Department of Respiratory Medicine, Juntendo University Faculty of Medicine and Graduate School of Medicine, Tokyo, Japan; Research Institute for Diseases of Old Ages, Juntendo University Faculty of Medicine and Graduate School of Medicine, Tokyo, Japan.

Background: Previous reports have shown that pathogen-associated patterns (PAMPs) induce the production of interleukin (IL)-1β in macrophages. Moreover, studies using mouse models also suggest that chitin, which acts as a PAMP, induces adjuvant effects and eosinophilic infiltration in the lung. Thus, we investigated the effects of inhaled chitin in mouse models.

Methods: We developed mouse models of inhaled chitin particle-induced airway inflammation and steroid-resistant ovalbumin (OVA)-induced airway inflammation. Some experimental groups of mice were treated additionally with dexamethasone (DEX). Murine alveolar macrophages (AMs), which were purified from bronchoalveolar lavage (BAL) fluids, were incubated with chitin, and treated with or without DEX.

Results: The numbers of total cells, AMs, lymphocytes, eosinophils, and neutrophils among BAL-derived cells, as well as the IL-1β levels in BAL fluids and the numbers of IL-1β-positive cells in lung, were significantly increased by chitin stimulation. Airway hyperresponsiveness (AHR) was aggravated in mice of the chitin inflammation model compared to control animals. The production of IL-1β was significantly increased in murine AMs by chitin treatment, but DEX administration did not inhibit this chitin-induced IL-1β production. Furthermore, in mouse models, DEX treatment inhibited the OVA-induced airway inflammation and AHR but not the airway inflammation and AHR induced by chitin or the combination of OVA and chitin.

Conclusions: These results suggest that inhaled chitin induces airway inflammation, AHR, and the production of IL-1β. Furthermore, our findings demonstrate for the first time that inhaled chitin induces steroid-resistant airway inflammation and AHR. Inhaled chitin may contribute to features of steroid-resistant asthma.
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http://dx.doi.org/10.1016/j.alit.2020.12.004DOI Listing
February 2021

Tim4 recognizes carbon nanotubes and mediates phagocytosis leading to granuloma formation.

Cell Rep 2021 Feb;34(6):108734

Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan; Laboratory of Immunology and Microbiology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Japan; PRESTO, JST, Kawaguchi, Japan. Electronic address:

Macrophage recognition and phagocytosis of crystals is critical for the associated fibrosis and cancer. Of note, multi-walled carbon nanotubes (MWCNTs), the highly representative products of nanotechnology, induce macrophage NLRP3 inflammasome activation and cause asbestosis-like pathogenesis. However, it remains largely unknown how macrophages efficiently recognize MWCNTs on their cell surfaces. Here, we identify by a targeted screening of phagocyte receptors the phosphatidylserine receptors T cell immunoglobulin mucin 4 (Tim4) and Tim1 as the pattern-recognition receptors for carbon crystals. Docking simulation studies reveal spatiotemporally stable interfaces between aromatic residues in the extracellular IgV domain of Tim4 and one-dimensional carbon crystals. Further, CRISPR-Cas9-mediated deletion of Tim4 and Tim1 reveals that Tim4, but not Tim1, critically contributes to the recognition of MWCNTs by peritoneal macrophages and to granuloma development in a mouse model of direct mesothelium exposure to MWCNTs. These results suggest that Tim4 recognizes MWCNTs through aromatic interactions and mediates phagocytosis leading to granulomas.
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http://dx.doi.org/10.1016/j.celrep.2021.108734DOI Listing
February 2021

Blockade of costimulatory CD27/CD70 pathway promotes corneal allograft survival.

Exp Eye Res 2020 10 14;199:108190. Epub 2020 Aug 14.

Department of Ophthalmology, Tokyo Medical University, 6-7-1 Nishi-shinjuku, Shinjuku-ku, Tokyo, 160-0023, Japan.

Purpose: To determine whether the CD27/CD70 pathway plays a significant role in corneal allograft rejection by investigating the effect of blocking the CD27/CD70 pathway by anti-CD70 antibody on corneal allograft survival.

Methods: Orthotopic penetrating keratoplasty was performed using C57BL/6 donor grafts and BALB/c recipients. Expression of CD27 and CD70 on rejected cornea was examined by immunohistochemistry. Corneal transplant recipients received intraperitoneal injection of anti-CD70 antibody (FR70) or control rat IgG. Alloreactivity was measured by mixed lymphoid reaction (MLR) in recipients administered control rat IgG and those administered anti-CD70 antibody. Corneal expression of IFN-γ and IL-12 was also examined in both groups. Graft opacity was assessed over an 8-week period and graft survival was evaluated using Kaplan-Meier survival curves. Proportion of CD4CD44 memory T cells in lymph nodes was measured by flow cytometry.

Results: CD4CD27 cells and CD11cCD70 cells were present in rejected cornea. Anti-CD70 antibody administration suppressed alloreactivity in corneal allograft recipients, and inhibited IFN-γ expression in recipient cornea (p < 0.05). Anti-CD70 antibody suppressed opacity score of recipient cornea and prolonged corneal allograft survival (p < 0.05). Proportion of CD4CD44 memory T cells in recipient lymph nodes was reduced by anti-CD70 antibody treatment.

Conclusion: The CD27/CD70 pathway plays a significant role in corneal allograft rejection by initiating alloreactive Th1 cells and preserving memory T cells. Anti-CD70 antibody administration prolongs corneal allograft survival indicating the potential therapeutic effect of CD27/CD70 pathway blockade on corneal allograft rejection.
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http://dx.doi.org/10.1016/j.exer.2020.108190DOI Listing
October 2020

Combination of TWEAK and TGF-β1 induces the production of TSLP, RANTES, and TARC in BEAS-2B human bronchial epithelial cells during epithelial-mesenchymal transition.

Exp Lung Res 2018 09 24;44(7):332-343. Epub 2019 Jan 24.

a Department of Respiratory Medicine, Faculty of Medicine , Graduate School of Medicine, Juntendo University , Tokyo , Japan.

Aim Of The Study: In patients with asthma, chronic inflammatory processes and the subsequent remodeling of the airways contribute to the symptoms and the pathophysiological changes. Epithelial-mesenchymal transition (EMT) is thought to play an important role in tissue remodeling. Previous reports show that tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a cytokine of the TNF superfamily, exerts pro-inflammatory effects, and enhances transforming growth factor (TGF)-β-induced EMT in bronchial epithelial cells. In this study, we investigated the TWEAK-induced cytokine and chemokine production in the human bronchial epithelial cell line BEAS-2B during EMT.

Materials And Methods: Quantitative real-time RT-PCR, enzyme-linked immunosorbent assays, western blotting, and immunohistochemistry were used to define the production of cytokines and chemokines.

Results: We found that TWEAK increases mRNA and protein levels of thymic stromal lymphopoietin (TSLP), monocyte chemoattractant protein -1 (MCP-1), regulated upon activation normal T cell express sequence (RANTES), and IL-8 in BEAS-2B bronchial epithelial cells. Moreover, co-treatment with TWEAK and TGF-β1 induces not only features of EMT but also enhances the production of TSLP and RANTES. Thymus- and activation-regulated chemokines (TARC) production is induced by the co-treatment of TWEAK and TGF-β1 but not by TWEAK or TGF-β1 stimulation alone. Furthermore, the increased mRNA expression of TSLP and RANTES after co-treatment with TWEAK and TGF-β1 is prevented by inhibitors of Smad-independent signaling pathways.

Conclusions: In the present study, we have revealed a novel mechanism for the production of asthma-related cytokines and chemokines in EMT driven by the co-stimulation with TWEAK and TGF-β1. We conclude that cellular EMT processes caused by TWEAK and TGF-β1 may contribute to chronic airway inflammation and remodeling.
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http://dx.doi.org/10.1080/01902148.2018.1522558DOI Listing
September 2018

Characterization of tenascin-C as a novel biomarker for asthma: utility of tenascin-C in combination with periostin or immunoglobulin E.

Allergy Asthma Clin Immunol 2018 19;14:72. Epub 2018 Nov 19.

1Department of Respiratory Medicine, Juntendo University Faculty of Medicine and Graduate School of Medicine, 3-1-3 Hongo, Bunkyo-ku, Tokyo, 113-8431 Japan.

Background: Extracellular matrix proteins tenascin-C (TNC) and periostin, which were identified as T-helper cell type 2 cytokine-induced genes in human bronchial epithelial cells, accumulate in the airway basement membrane of asthmatic patients. Although serum periostin has been accepted as a type 2 biomarker, serum TNC has not been evaluated as a systemic biomarker in asthma. Therefore, the objective of this study was to evaluate whether serum TNC can serve as a novel biomarker for asthma.

Methods: We evaluated 126 adult patients with mild to severe asthma. Serum TNC, periostin, and total IgE concentrations were quantified using enzyme-linked immunosorbent assays.

Results: Serum TNC levels were significantly higher in patients with severe asthma and high serum total IgE levels. Patients with both high serum TNC (> 37.16 ng/mL) and high serum periostin (> 95 ng/mL) levels (n = 20) or patients with both high serum TNC and high serum total IgE (> 100 IU/mL) levels (n = 36) presented higher disease severity and more severe airflow limitation than patients in other subpopulations.

Conclusions: To our knowledge, this is the first study to show that serum TNC levels in asthmatic patients are associated with clinical features of asthma and that the combination of serum TNC and periostin levels or combination of serum TNC and total IgE levels were more useful for asthma than each single marker, suggesting that serum TNC can serve as a novel biomarker for asthma.
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http://dx.doi.org/10.1186/s13223-018-0300-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6241046PMC
November 2018

Cutting Edge: Anti-TIM-3 Treatment Exacerbates Pulmonary Inflammation and Fibrosis in Mice.

J Immunol 2017 12 23;199(11):3733-3737. Epub 2017 Oct 23.

Department of Immunology, Juntendo University School of Medicine, Tokyo 113-8421, Japan.

Promising results of immune checkpoint inhibitors have indicated the use of immunotherapy against malignant tumors. However, they cause serious side effects, including autoimmune diseases and pneumonitis. T cell Ig and mucin domain (TIM)-3 is a new candidate immune checkpoint molecule; however, the potential toxicity associated with anti-TIM-3 treatment is unknown. In this study, we investigated the pathological contribution of anti-TIM-3 mAb in a bleomycin-induced lung inflammation and fibrosis model. Anti-TIM-3-treated mice showed more severe inflammation and peribronchiolar fibrosis compared with control IgG-treated mice. Anti-TIM-3 mAb was associated with increased numbers of myofibroblasts, collagen deposition, and TGF-β1 production in lungs. TIM-3 expression was only detected on alveolar macrophages that protect against fibrosis by apoptotic cell clearance. Treatment with anti-TIM-3 mAb inhibited the phagocytic ability of alveolar macrophages in vivo, resulting in the defective clearance of apoptotic cells in lungs. In summary, anti-TIM-3 mAb treatment might cause pneumonitis and it should be used with caution in clinical settings.
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http://dx.doi.org/10.4049/jimmunol.1700059DOI Listing
December 2017

Protective Role of ICOS and ICOS Ligand in Corneal Transplantation and in Maintenance of Immune Privilege.

Invest Ophthalmol Vis Sci 2016 12;57(15):6815-6823

Department of Ophthalmology, Nippon Medical School, Tokyo, Japan.

Purpose: The interaction between the inducible costimulatory molecule (ICOS) and ICOS ligand (ICOSL) has been implicated in the differentiation and functions of T cells. The purpose of the present study was to determine the role of ICOS-ICOSL in the immune privilege of corneal allografts.

Methods: Expression of ICOS and ICOSL mRNA from mouse eyes was assessed by RT-PCR. Corneas of C57BL/6 mice were orthotopically transplanted into the eyes of ICOS-/- BALB/c recipients and BALB/c wild-type (WT) recipients treated with anti-ICOSL mAb, and graft survival was assessed. A separate set of WT and ICOS-/- BALB/c mice received an anterior chamber injection of C57BL/6 splenocytes, and induction of allospecific anterior chamber-associated immune deviation (ACAID) was assessed. In vitro, cornea was incubated with T cells from WT and ICOS-/- BALB/c mice, and destruction of corneal endothelial cells (CECs) and the population of Foxp3+ CD25+ CD4+ T cells was assessed.

Results: Inducible costimulatory molecule ligand mRNA was constitutively expressed in the cornea, iris-ciliary body, and retina. Allograft survival in ICOS-/- recipients and WT recipients treated with anti-ICOSL mAb was significantly shorter than in control recipients. Anterior chamber-associated immune deviation was induced less efficiently in ICOS-/- mice. Destruction of CECs by alloreactive ICOS-/- T cells was enhanced compared with WT T cells. After coincubation with allogeneic corneal tissue, the proportion of regulatory T cells was significantly greater among WT T cells than in ICOS-/- T cells.

Conclusions: The expression of ICOSL in the cornea and the ICOS-mediated induction of Foxp3+ CD4+ regulatory T cells may contribute to successful corneal allograft survival.
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http://dx.doi.org/10.1167/iovs.16-20644DOI Listing
December 2016

OX40L blockade protects against inflammation-driven fibrosis.

Proc Natl Acad Sci U S A 2016 07 13;113(27):E3901-10. Epub 2016 Jun 13.

INSERM, U1016 UMR8104, Cochin Institute, Paris Descartes University, Sorbonne Paris Cite, 75014 Paris, France; Rheumatology A Department, Cochin Hospital, Paris Descartes University, 75014 Paris, France;

Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40-OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease, we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation.
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http://dx.doi.org/10.1073/pnas.1523512113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941508PMC
July 2016

Characteristics of alveolar macrophages from murine models of OVA-induced allergic airway inflammation and LPS-induced acute airway inflammation.

Exp Lung Res 2015 ;41(7):370-82

a 1 Department of Respiratory Medicine , Juntendo University Faculty of Medicine and Graduate School of Medicine , Tokyo, Japan.

Background:  Macrophages include the classically activated pro-inflammatory M1 macrophages (M1s) and alternatively activated anti-inflammatory M2 macrophages (M2s). The M1s are activated by both interferon-γ and Toll-like receptor ligands, including lipopolysaccharide (LPS), and have potent pro-inflammatory activity. In contrast, Th2 cytokines activate the M2s, which are involved in the immune response to parasites, promotion of tissue remodeling, and immune regulatory functions. Although alveolar macrophages (AMs) play an essential role in the pulmonary immune system, little is known about their phenotypes.

Methods:  Quantitative reverse transcription polymerase chain reaction and flow cytometry were used to define the characteristics of alveolar macrophages derived from untreated naïve mice and from murine models of both ovalbumin (OVA)-induced allergic airway inflammation and LPS-induced acute airway inflammation. AMs were co-cultured with CD4(+) T cells and were pulsed with tritiated thymidine to assess proliferative responses.

Results:  We characterized in detail murine AMs and found that these cells were not completely consistent with the current M1 versus M2-polarization model. OVA-induced allergic and LPS-induced acute airway inflammation promoted the polarization of AMs towards the current M2-skewed and M1-skewed phenotypes, respectively. Moreover, our data also show that CD11c(+) CD11b(+) AMs from the LPS-treated mice play a regulatory role in antigen-specific T-cell proliferation in vitro.

Conclusions:  These characteristics of AMs depend on the incoming pathogens they encounter and on the phase of inflammation and do not correspond to the current M1 versus M2-polarization model. These findings may facilitate an understanding of their contributions to the pulmonary immune system in airway inflammation.
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http://dx.doi.org/10.3109/01902148.2015.1044137DOI Listing
June 2016

ICOS promotes group 2 innate lymphoid cell activation in lungs.

Biochem Biophys Res Commun 2015 Aug 4;463(4):739-45. Epub 2015 Jun 4.

Department of Immunology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.

Group 2 innate lymphoid cells (ILC2s) are newly identified, potent producers of type 2 cytokines, such as IL-5 and IL-13, and contribute to the development of allergic lung inflammation induced by cysteine proteases. Although it has been shown that inducible costimulator (ICOS), a costimulatory molecule, is expressed on ILC2s, the role of ICOS in ILC2 responses is largely unknown. In the present study, we investigated whether the interaction of ICOS with its ligand B7-related protein-1 (B7RP-1) can promote ILC2 activation. Cytokine production in ILC2s purified from mouse lungs was significantly increased by coculture with B7RP-1-transfected cells, and increased cytokine production was inhibited by monoclonal antibody-mediated blocking of the ICOS/B7RP-1 interaction. ILC2 expansion and eosinophil influx induced by papain, a cysteine protease antigen, in mouse lungs were significantly abrogated by blocking the ICOS/B7RP-1 interaction. Dendritic cells (DCs) in the lungs expressed B7RP-1 and the number of DCs markedly increased with papain administration. B7RP-1 expression on lung DCs was reduced after papain administration. This downregulation of B7RP-1 expression may be an indication of ICOS/B7RP-1 binding. These results indicate that ILC2s might interact with B7RP-1-expressing DCs in allergic inflammatory lung, and ICOS signaling can positively regulate the protease allergen-induced ILC2 activation followed by eosinophil infiltration into the lungs.
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http://dx.doi.org/10.1016/j.bbrc.2015.06.005DOI Listing
August 2015

Effect of TIM-3 Blockade on the Immunophenotype and Cytokine Profile of Murine Uterine NK Cells.

PLoS One 2015 21;10(4):e0123439. Epub 2015 Apr 21.

Children's Hospital Boston, Renal Division, Harvard Medical School, Boston, Massachusetts, United States of America.

NK cells are the most abundant lymphocyte population in the feto-maternal interface during gestation. The uterine NK cells (uNK) are transient, have a unique immunophenotype and produce a number of cytokines. These cytokines play an important role in establishment and maintenance of vascular remodeling and tolerance associated with successful pregnancy. The uNK cells also express TIM-3 during gestation and blockade of TIM-3 expression results in fetal loss in mice. In this study we determined the effect of TIM-3 blockade on uNK cells. Specifically we observed surface receptor phenotype and cytokine production by uNK cells following TIM-3 blockade. Our results show that TIM-3 plays a role in regulating the uNK cells and contributes to the maintenance of tolerance at the feto-maternal interface.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0123439PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4405344PMC
April 2016

Endogenous Tim-1 promotes severe systemic autoimmunity and renal disease MRL-Fas(lpr) mice.

Am J Physiol Renal Physiol 2014 May 12;306(10):F1210-21. Epub 2014 Mar 12.

Department of Hematology and Rheumatology, Kinki University School of Medicine, Osaka, Japan;

The T-cell immunoglobulin mucin 1, also known as kidney injury molecule-1, modulates CD4+ T-cell responses and is also expressed by damaged proximal tubules within the kidney. Both Th subset imbalance (Th1/Th2/Th17) and regulatory T-cell and B-cell alterations contribute to the pathogenesis of autoimmune disease. This study investigated the effects of an inhibitory anti-T-cell immunoglobulin mucin 1 antibody (RMT1-10) in lupus-prone MRL-Fas(lpr) mice. MRL-Fas(lpr) mice were treated with RMT1-10 or a control antibody intraperitoneally twice weekly from 3 mo of age for 16 wk. RMT1-10 treatment significantly improved survival, limited the development of lymphadenopathy and skin lesions, preserved renal function and decreased proteinuria, reduced serum anti-DNA antibody levels, and attenuated renal leukocyte accumulation. Th1 and Th17 cellular responses systemically and intrarenally were reduced, but regulatory T and B cells were increased. RMT1-10 treatment also reduced glomerular immunoglobulin and C3 deposition and suppressed cellular proliferation and apoptosis. Urinary excretion and renal expression of kidney injury molecule-1 was reduced, reflecting diminished interstitial injury. As RMT1-10 attenuated established lupus nephritis, manipulating immune system T-cell immunoglobulin mucin 1 may represent a therapeutic strategy in autoimmune diseases affecting the kidney.
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http://dx.doi.org/10.1152/ajprenal.00570.2013DOI Listing
May 2014

The TIM-3 pathway ameliorates Theiler's murine encephalomyelitis virus-induced demyelinating disease.

Int Immunol 2014 Jul 31;26(7):369-81. Epub 2014 Jan 31.

Department of Biomedical Laboratory Sciences, Graduate School of Medicine, Shinshu University, Matsumoto, Nagano 390-8621, Japan

Infection by Theiler's murine encephalomyelitis virus (TMEV) in the central nervous system (CNS) induces an immune-mediated demyelinating disease in susceptible mouse strains and serves as a relevant infection model for human multiple sclerosis. T-cell immunoglobulin and mucin domain-3 (TIM-3) has been demonstrated to play a crucial role in the maintenance of peripheral tolerance. In this study, we examined the regulatory role of the TIM-3 pathway in the development of TMEV-induced demyelinating disease (TMEV-IDD). The expression of TIM-3 was increased at both protein and mRNA levels in the spinal cords of mice with TMEV-IDD compared with naive controls. In addition, by utilizing a blocking mAb, we demonstrate that TIM-3 negatively regulates TMEV-specific ex vivo production of IFN-γ and IL-10 by CD4(+) T cells and IFN-γ by CD8(+) T cells from the CNS of mice with TMEV-IDD at 36 days post-infection (dpi). In vivo blockade of TIM-3 by using the anti-TIM-3 mAb resulted in significant exacerbation of the development of TMEV-IDD both clinically and histologically. The number of infiltrating mononuclear cells in the CNS was also increased in mice administered with anti-TIM-3 mAb both at the induction phase (10 dpi) and at the effector phase (36 dpi). Flow cytometric analysis of intracellular cytokines revealed that the number of CD4(+) T cells producing TNF, IL-4, IL-10 and IL-17 was significantly increased at the effector phase in the CNS of anti-TIM-3 mAb-treated mice. These results suggest that the TIM-3 pathway plays a critical role in the regulation of TMEV-IDD.
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http://dx.doi.org/10.1093/intimm/dxt056DOI Listing
July 2014

OX40 ligand regulates splenic CD8⁻ dendritic cell-induced Th2 responses in vivo.

Biochem Biophys Res Commun 2014 Feb 22;444(2):235-40. Epub 2014 Jan 22.

Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. Electronic address:

In mice, splenic conventional dendritic cells (cDCs) can be separated, based on their expression of CD8α into CD8(-) and CD8(+) cDCs. Although previous experiments demonstrated that injection of antigen (Ag)-pulsed CD8(-) cDCs into mice induced CD4 T cell differentiation toward Th2 cells, the mechanism involved is unclear. In the current study, we investigated whether OX40 ligand (OX40L) on CD8(-) cDCs contributes to the induction of Th2 responses by Ag-pulsed CD8(-) cDCs in vivo, because OX40-OX40L interactions may play a preferential role in Th2 cell development. When unseparated Ag-pulsed OX40L-deficient cDCs were injected into syngeneic BALB/c mice, Th2 cytokine (IL-4, IL-5, and IL-10) production in lymph node cells was significantly reduced. Splenic cDCs were separated to CD8(-) and CD8(+) cDCs. OX40L expression was not observed on freshly isolated CD8(-) cDCs, but was induced by anti-CD40 mAb stimulation for 24 h. Administration of neutralizing anti-OX40L mAb significantly inhibited IL-4, IL-5, and IL-10 production induced by Ag-pulsed CD8(-) cDC injection. Moreover, administration of anti-OX40L mAb with Ag-pulsed CD8(-) cDCs during a secondary response also significantly inhibited Th2 cytokine production. Thus, OX40L on CD8(-) cDCs physiologically contributes to the development of Th2 cells and secondary Th2 responses induced by Ag-pulsed CD8(-) cDCs in vivo.
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http://dx.doi.org/10.1016/j.bbrc.2014.01.060DOI Listing
February 2014

TIM-4 glycoprotein-mediated degradation of dying tumor cells by autophagy leads to reduced antigen presentation and increased immune tolerance.

Immunity 2013 Dec 5;39(6):1070-81. Epub 2013 Dec 5.

Research Center for Infection-Associated Cancer, Institute for Genetic Medicine, Hokkaido University, Sapporo, 060-0815, Japan. Electronic address:

Phagocytosis of apoptotic cells by myeloid cells has been implicated in the maintenance of immune homeostasis. In this study, we found that T cell immunoglobulin- and mucin domain-containing molecule-4 (TIM-4) repressed tumor-specific immunity triggered by chemotherapy-induced tumor cell death. TIM-4 was found to be highly expressed on tumor-associated myeloid cells such as macrophages (TAMs) and dendritic cells (TADCs) and danger-associated molecular patterns (DAMPs) released from chemotherapy-damaged tumor cells induced TIM-4 on tumor-associated myeloid cells recruited from bone marrow-derived precursors. TIM-4 directly interacted with AMPKα1 and activated autophagy-mediated degradation of ingested tumors, leading to reduced antigen presentation and impaired CTL responses. Consistently, blockade of the TIM-4-AMPKα1-autophagy pathway augmented the antitumor effect of chemotherapeutics by enhancing tumor-specific CTL responses. Our finding provides insight into the immune tolerance mediated by phagocytosis of dying cells, and targeting of the TIM-4-AMPKα1 interaction constitutes a unique strategy for augmenting antitumor immunity and improving cancer chemotherapy.
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http://dx.doi.org/10.1016/j.immuni.2013.09.014DOI Listing
December 2013

TIM-4 has dual function in the induction and effector phases of murine arthritis.

J Immunol 2013 Nov 25;191(9):4562-72. Epub 2013 Sep 25.

Department of Immunology, Juntendo University School of Medicine, Tokyo 113-8421, Japan;

T cell Ig and mucin domain (TIM)-4 is involved in immune regulation. However, the pathological function of TIM-4 has not been understood and remains to be clarified in various disease models. In this study, DBA/1 mice were treated with anti-TIM-4 mAb during the induction or effector phase of collagen-induced arthritis (CIA). Anti-TIM-4 treatment in the induction phase exacerbated the development of CIA. In vitro experiments suggest that CD4 T cells bind to TIM-4 on APCs, which induces inhibitory effect to CD4 T cells. In contrast, therapeutic treatment with anti-TIM-4 mAb just before or after the onset or even at later stage of CIA significantly suppressed the development and progression by reducing proinflammatory cytokines in the ankle joints without affecting T or B cell responses. Consistently, clinical arthritis scores of collagen Ab-induced arthritis, which is not mediated by T or B cells, were significantly reduced in anti-TIM-4-treated mice with a concomitant decrease of proinflammatory cytokines in the joints. In vitro, macrophages secreted proinflammatory cytokines in response to TIM-4-Ig protein and LPS, which were reduced by the anti-TIM-4 mAb. The anti-TIM-4 mAb also inhibited the differentiation and bone-resorbing activity of osteoclasts. These results indicate that TIM-4 has two distinct functions depending on the stage of arthritis. The therapeutic effect of anti-TIM-4 mAb on arthritis is mediated by the inhibition of proinflammatory cytokine production by inflammatory cells, osteoclast differentiation, and bone resorption, suggesting that TIM-4 might be an appropriate target for the therapeutic treatment of arthritis.
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http://dx.doi.org/10.4049/jimmunol.1203035DOI Listing
November 2013

Interruption of dendritic cell-mediated TIM-4 signaling induces regulatory T cells and promotes skin allograft survival.

J Immunol 2013 Oct 13;191(8):4447-55. Epub 2013 Sep 13.

Transplantation Research Center, Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02445;

Dendritic cells (DCs) are the central architects of the immune response, inducing inflammatory or tolerogenic immunity, dependent on their activation status. As such, DCs are highly attractive therapeutic targets and may hold the potential to control detrimental immune responses. TIM-4, expressed on APCs, has complex functions in vivo, acting both as a costimulatory molecule and a phosphatidylserine receptor. The effect of TIM-4 costimulation on T cell activation remains unclear. In this study, we demonstrate that Ab blockade of DC-expressed TIM-4 leads to increased induction of induced regulatory T cells (iTregs) from naive CD4(+) T cells, both in vitro and in vivo. iTreg induction occurs through suppression of IL-4/STAT6/Gata3-induced Th2 differentiation. In addition, blockade of TIM-4 on previously activated DCs still leads to increased iTreg induction. iTregs induced under TIM-4 blockade have equivalent potency to control and, upon adoptive transfer, significantly prolong skin allograft survival in vivo. In RAG(-/-) recipients of skin allografts adoptively transferred with CD4(+) T cells, we show that TIM-4 blockade in vivo is associated with a 3-fold prolongation in allograft survival. Furthermore, in this mouse model of skin transplantation, increased induction of allospecific iTregs and a reduction in T effector responses were observed, with decreased Th1 and Th2 responses. This enhanced allograft survival and protolerogenic skewing of the alloresponse is critically dependent on conversion of naive CD4(+) to Tregs in vivo. Collectively, these studies identify blockade of DC-expressed TIM-4 as a novel strategy that holds the capacity to induce regulatory immunity in vivo.
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http://dx.doi.org/10.4049/jimmunol.1300992DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3804420PMC
October 2013

Monocyte-derived dendritic cells perform hemophagocytosis to fine-tune excessive immune responses.

Immunity 2013 Sep 12;39(3):584-98. Epub 2013 Sep 12.

Department of Hematology, Nephrology and Rheumatology, Akita University Graduate School of Medicine, Akita 010-8543, Japan.

Because immune responses simultaneously defend and injure the host, the immune system must be finely regulated to ensure the host's survival. Here, we have shown that when injected with high Toll-like receptor ligand doses or infected with lymphocytic choriomeningitis virus (LCMV) clone 13, which has a high viral turnover, inflammatory monocyte-derived dendritic cells (Mo-DCs) engulfed apoptotic erythroid cells. In this process, called hemophagocytosis, phosphatidylserine (PS) served as an "eat-me" signal. Type I interferons were necessary for both PS exposure on erythroid cells and the expression of PS receptors in the Mo-DCs. Importantly, hemophagocytosis was required for interleukin-10 (IL-10) production from Mo-DCs. Blocking hemophagocytosis or Mo-DC-derived IL-10 significantly increased cytotoxic T cell lymphocyte activity, tissue damage, and mortality in virus-infected hosts, suggesting that hemophagocytosis moderates immune responses to ensure the host's survival in vivo. This sheds light on the physiological relevance of hemophagocytosis in severe inflammatory and infectious diseases.
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http://dx.doi.org/10.1016/j.immuni.2013.06.019DOI Listing
September 2013

T-cell immunoglobulin and mucin domain 3 acts as a negative regulator of atherosclerosis.

Arterioscler Thromb Vasc Biol 2013 Nov 29;33(11):2558-65. Epub 2013 Aug 29.

From the Division of Biopharmaceutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.C.F., I.A.R., L.W., V.F., M.N.D.t.B., S.C.A.d.J., P.J.v.S., I.B., J.K., G.H.M.v.P.); Experimental Cardiology Laboratory, University Medical Center Utrecht, Utrecht, The Netherlands (S.C.A.d.J.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y., H.A.).

Objective: Atherosclerosis is a chronic autoimmune-like disease in which lipids and fibrous elements accumulate in the arterial blood vessels. T cells are present within atherosclerotic plaques, and their activation is partially dependent on costimulatory signals, which can either provide positive or negative signals that promote T-cell activation or limit T-cell responses, respectively. T-cell immunoglobulin and mucin domain 3 (Tim-3) is a coinhibitory type 1 transmembrane protein that affects the function of several immune cells involved in atherosclerosis, such as monocytes, macrophages, effector T cells, and regulatory T cells. In the present study, we determined the role of Tim-3 in the development of atherosclerosis.

Approach And Results: Western-type diet-fed low-density lipoprotein receptor-deficient (LDLr(-/-)) mice were treated with an anti-Tim-3 antibody for 3 and 8 weeks. Anti-Tim-3 administration increased fatty streak formation with 66% and increased atherosclerotic plaque formation after 8 weeks with 35% in the aortic root and with 50% in the aortic arch. Furthermore, blockade of Tim-3 signaling increased percentages of circulating monocytes with 33% and lesional macrophages with 20%. In addition, anti-Tim-3 administration increased CD4(+) T cells with 17%, enhanced their activation status, and reduced percentages of regulatory T cells with 18% and regulatory B cells with 37%.

Conclusions: It is known that Tim-3 acts as a negative regulator of both innate and adaptive immune responses, and in the present study, we show that anti-Tim-3 treatment augments lesion development, accompanied by an increase in the number of monocytes/macrophages and CD4(+) T cells and by decreased regulatory T cells and regulatory B cells.
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http://dx.doi.org/10.1161/ATVBAHA.113.301879DOI Listing
November 2013

Galectin-9-mediated protection from allo-specific T cells as a mechanism of immune privilege of corneal allografts.

PLoS One 2013 7;8(5):e63620. Epub 2013 May 7.

Department of Ophthalmology, Nippon Medical School, Tokyo, Japan.

The eye is an immune-privileged organ, and corneal transplantation is therefore one of the most successful organ transplantation. The immunosuppressive intraocular microenvironment is known as one of the mechanisms underlying immune privilege in the eye. T-cell immunoglobulin and mucin domain (Tim)-3 is a regulatory molecule for T-cell function, and galectin (Gal)-9 is a Tim-3 ligand. We investigated the role of this pathway in establishing the immune-privileged status of corneal allografts in mice. Gal-9 is constitutively expressed on the corneal epithelium, endothelium and iris-ciliary body in normal mouse eyes and eyes bearing surviving allografts, and Tim-3 was expressed on CD8 T cells infiltrating the allografts. Allograft survival in recipients treated with anti-Tim-3 monoclonal antibody (mAb) or anti-Gal-9 mAb was significantly shorter than that in control recipients. In vitro, destruction of corneal endothelial cells by allo-reactive T cells was enhanced when the cornea was pretreated with anti-Gal-9 mAb. Blockade of Tim-3 or Gal-9 did not abolish anterior chamber-associated immune deviation. We propose that constitutive expression of Gal-9 plays an immunosuppressive role in corneal allografts. Gal-9 expressed on corneal endothelial cells protects them from destruction by allo-reactive T cells within the cornea.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0063620PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646846PMC
December 2013

TIM-3 regulates innate immune cells to induce fetomaternal tolerance.

J Immunol 2013 Jan 23;190(1):88-96. Epub 2012 Nov 23.

Transplantation Research Center, Brigham and Women's Hospital and Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.

TIM-3 is constitutively expressed on subsets of macrophages and dendritic cells. Its expression on other cells of the innate immune system and its role in fetomaternal tolerance has not yet been explored. In this study, we investigate the role of TIM-3-expressing innate immune cells in the regulation of tolerance at the fetomaternal interface (FMI) using an allogeneic mouse model of pregnancy. Blockade of TIM-3 results in accumulation of inflammatory granulocytes and macrophages at the uteroplacental interface and upregulation of proinflammatory cytokines. Furthermore, TIM-3 blockade inhibits the phagocytic potential of uterine macrophages resulting in a build up of apoptotic bodies at the uteroplacental interface that elicits a local immune response. In response to inflammatory cytokines, Ly-6C(hi)G(neg) monocytic myeloid-derived suppressor cells expressing inducible NO synthase and arginase 1 are induced. However, these suppressive cells fail to downregulate the inflammatory cascade induced by inflammatory granulocytes (Ly-6C(int)G(hi)) and apoptotic cells; the increased production of IFN-γ and TNF-α by inflammatory granulocytes leads to abrogation of tolerance at the FMI and fetal rejection. These data highlight the interplay between cells of the innate immune system at the FMI and their influence on successful pregnancy in mice.
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http://dx.doi.org/10.4049/jimmunol.1202176DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3529820PMC
January 2013

Combined blockade of TIM-3 and TIM-4 augments cancer vaccine efficacy against established melanomas.

Cancer Immunol Immunother 2013 Apr 10;62(4):629-37. Epub 2012 Nov 10.

Research Center for Infection-Associated Cancer, Institute for Genetic Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, Hokkaido, 060-0815, Japan.

Cancer vaccines have been developed to instruct the endogenous immune responses to autologous tumors and to generate durable clinical responses. However, the therapeutic benefits of cancer vaccines remain insufficient due to the multiple immunosuppressive signals delivered by tumors. Thus, to improve the clinical efficacy of cancer immunotherapy, it is important to develop new modalities to overcome immunosuppressive tumor microenvironments and elicit effective antitumor immune responses. In this study, we show that novel monoclonal antibodies (mAbs) specifically targeting either T cell immunoglobulin mucin protein-3 (TIM-3) or T cell immunoglobulin mucin protein-4 (TIM-4) enhance the therapeutic effects of vaccination against established B16 murine melanomas. This is true for vaccination with irradiated B16 melanoma cells engineered to express the flt3 ligand gene (FVAX). More importantly, combining anti-TIM-3 and anti-TIM-4 mAbs markedly increased vaccine-induced antitumor responses against established B16 melanoma. TIM-3 blockade mainly stimulated antitumor effector activities via natural killer cell-dependent mechanisms, while CD8(+) T cells served as the main effectors induced by anti-TIM-4 mAb. Our findings reveal that therapeutic manipulation of TIM-3 and TIM-4 may provide a novel strategy for improving the clinical efficacy of cancer immunotherapy.
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http://dx.doi.org/10.1007/s00262-012-1371-9DOI Listing
April 2013

Tumor-infiltrating DCs suppress nucleic acid-mediated innate immune responses through interactions between the receptor TIM-3 and the alarmin HMGB1.

Nat Immunol 2012 Sep 29;13(9):832-42. Epub 2012 Jul 29.

Research Center for Infection-Associated Cancer, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.

The mechanisms by which tumor microenvironments modulate nucleic acid-mediated innate immunity remain unknown. Here we identify the receptor TIM-3 as key in circumventing the stimulatory effects of nucleic acids in tumor immunity. Tumor-associated dendritic cells (DCs) in mouse tumors and patients with cancer had high expression of TIM-3. DC-derived TIM-3 suppressed innate immune responses through the recognition of nucleic acids by Toll-like receptors and cytosolic sensors via a galectin-9-independent mechanism. In contrast, TIM-3 interacted with the alarmin HMGB1 to interfere with the recruitment of nucleic acids into DC endosomes and attenuated the therapeutic efficacy of DNA vaccination and chemotherapy by diminishing the immunogenicity of nucleic acids released from dying tumor cells. Our findings define a mechanism whereby tumor microenvironments suppress antitumor immunity mediated by nucleic acids.
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http://dx.doi.org/10.1038/ni.2376DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622453PMC
September 2012

Blockade of CD70-CD27 interaction inhibits induction of allergic lung inflammation in mice.

Am J Respir Cell Mol Biol 2012 Sep 12;47(3):298-305. Epub 2012 Apr 12.

Department of Immunology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421, Japan.

The interaction between the TNF receptor family member CD27 and its ligand CD70 provides a costimulatory signal for T-cell activation. In this study, we investigated the effects of neutralizing anti-CD70 monoclonal antibody (mAb) in a murine model of allergic lung inflammation to determine whether CD27 contributes to the development of pathogenic Th2 cells and pulmonary inflammation. BALB/c mice were immunized by an injection of ovalbumin (OVA) with alum adjuvant and challenged with aerosolized OVA in PBS. Some groups of mice were treated with anti-CD70 mAb or control rat IgG during the induction or effector phase. The administration of anti-CD70 mAb during the induction phase, but not the effector phase, reduced eosinophil infiltration in lung tissue compared with control IgG-treated mice. Treatment with anti-CD70 mAb also resulted in the decreased production of Th2 cytokines (IL-4, IL-5, and IL-13) in the bronchoalveolar lavage fluid and draining lymph node cell cultures. We further revealed that antigen-specific CD4 T cells were separated into CD27(+) and CD27(-) populations in the lymph nodes of OVA-immunized DO11.10/Rag-2(-/-) mice. The CD27(+) CD4 T cells produced a high concentration of IFN-γ, representing Th1 cells. In contrast, CD27(-) CD4 T cells produced high concentrations of IL-4, IL-5, and IL-13, representing Th2 cells. Moreover, the population of CD27(-) Th2 cells was significantly reduced by the anti-CD70 mAb treatment. These results indicate an important role for CD27 in the development of pathogenic Th2 cells in a murine model of allergic lung inflammation.
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http://dx.doi.org/10.1165/rcmb.2011-0354OCDOI Listing
September 2012

Expression pattern changes and function of RANKL during mouse lymph node microarchitecture development.

Int Immunol 2012 Jun 21;24(6):369-78. Epub 2012 Feb 21.

Department of Supramolecular Biology, International Graduated School of Arts and Science Yokohama city university, Yokohama, Kanagawa 230-0045, Japan.

Receptor activator of nuclear factor kappa-B ligand (RANKL) expression was examined during the development of mouse fetal peripheral lymphoid organs. A shift in the expression pattern was detected during the transition from lymphoid tissue inducer (LTi) cells to lymphoid tissue organizer (LTo) cells in the lymph node (LN) anlagen but not in the Peyer's patch anlagen. In order to understand the functional impact of these changes in the fetal expression of RANKL, the RANKL function was blocked by a blocking antibody. Excess anti-RANKL antibody was administered to pregnant mice between 13.5 and 16.5 dpc and was found to completely block LN anlagen development, suggesting that RANKL function during this period is critical for LN development. In addition, small amounts of anti-RANKL antibodies were injected directly into the amniotic space at 13.5 dpc, resulting in perturbed B-cell follicle formation and high endothelial venule differentiation after birth. These results suggest that RANKL expression on LTi cells during the early phase of LN development is critical for the development LN microarchitecture.
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http://dx.doi.org/10.1093/intimm/dxs002DOI Listing
June 2012

Antibodies against B7-DC with differential binding properties exert opposite effects.

Hybridoma (Larchmt) 2012 Feb;31(1):40-7

Department of Molecular Immunology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.

Programmed cell death 1 (PD-1) is an immunoregulatory receptor on T cells that binds two ligands, B7-H1 and B7-DC. Although accumulating reports suggest a critical role for the B7-H1:PD-1 pathway in peripheral tolerance, the actual involvement of B7-DC has not been well confirmed. Here, we established a new MAb against mouse B7-DC (MIH37) and compared its functional properties with a previously established anti-B7-DC MAb (TY25). Binding analyses using flow cytometry demonstrated that MIH37 showed an approximately four-fold higher binding affinity to B7-DC and stronger inhibitory effects on B7-DC:PD-1 binding. In contrast to the effects of TY25, treatment with MIH37 at both sensitization and challenge inhibited hapten-induced contact hypersensitivity reactions. Furthermore, the addition of MIH37 inhibited OVA-specific T cell responses in vitro. The inhibitory effects of MIH37 were counteracted by co-blockade with PD-1 and absent in PD-1-deficient mice, suggesting PD-1-dependent action of MIH37. Our present results suggest that greater complexities of PD-1-mediated functions are induced via ligand binding for controlling immunity and tolerance.
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http://dx.doi.org/10.1089/hyb.2011.0087DOI Listing
February 2012

Endogenous Tim-1 (Kim-1) promotes T-cell responses and cell-mediated injury in experimental crescentic glomerulonephritis.

Kidney Int 2012 May 28;81(9):844-55. Epub 2011 Dec 28.

Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria, Australia.

The T-cell immunoglobulin mucin 1 (Tim-1) modulates CD4(+) T-cell responses and is also expressed by damaged proximal tubules in the kidney where it is known as kidney injury molecule-1 (Kim-1). We sought to define the role of endogenous Tim-1 in experimental T-cell-mediated glomerulonephritis induced by sheep anti-mouse glomerular basement membrane globulin acting as a planted foreign antigen. Tim-1 is expressed by infiltrating activated CD4(+) cells in this model, and we studied the effects of an inhibitory anti-Tim-1 antibody (RMT1-10) on immune responses and glomerular disease. Crescentic glomerulonephritis, proliferative injury, and leukocyte accumulation were attenuated following treatment with anti-Tim-1 antibodies, but interstitial foxp3(+) cell accumulation and interleukin-10 mRNA were increased. T-cell proliferation and apoptosis decreased in the immune system along with a selective reduction in Th1 and Th17 cellular responses both in the immune system and within the kidney. The urinary excretion and renal expression of Kim-1 was reduced by anti-Tim-1 antibodies reflecting diminished interstitial injury. The effects of anti-Tim-1 antibodies were not apparent in the early phase of renal injury, when the immune response to sheep globulin was developing. Thus, endogenous Tim-1 promotes Th1 and Th17 nephritogenic immune responses and its neutralization reduces renal injury while limiting inflammation in cell-mediated glomerulonephritis.
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http://dx.doi.org/10.1038/ki.2011.424DOI Listing
May 2012

Galectin-9 and T cell immunoglobulin mucin-3 pathway is a therapeutic target for type 1 diabetes.

Endocrinology 2012 Feb 20;153(2):612-20. Epub 2011 Dec 20.

Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.

Galectin-9 (Gal-9), a ligand for T cell Ig mucin-3 (Tim-3), induces apoptosis in cluster of differentiation 4 (CD4)(+) Tim-3(+) T helper 1 (T(H)1) cells via the Gal-9-Tim-3 pathway and negatively regulates T(H)1 immunity. In turn, Gal-9 activates dendritic cells (DC) to produce TNF-α, which promotes the T(H)1 response. We investigated the efficacy of Gal-9 against T(H)1-mediated autoimmune diabetes in NOD mice and compared with anti-Tim-3 monoclonal antibody (RMT3-23), which inhibited the binding between Tim-3-Ig and Gal-9 in a solid-phase binding assay. mRNA expression of Gal-9 was prominently induced by the treatment of interferon-γ in MIN6 cells, and Gal-9 was also expressed in the pancreatic β-cells in NOD mice, suggesting Gal-9 may be released from pancreatic β-cells to terminate T(H)1-mediated inflammation. Long-term injection of Gal-9 exhibits preventive efficacy for development of diabetes in NOD mice, but RMT3-23 demonstrated further prominent therapeutic potential compared with Gal-9. Gal-9 induced apoptosis of CD4(+)Tim-3(+) T(H)1 cells at the concentration of 0.2 μM, whereas RMT3-23 failed to enhance the apoptosis of CD4(+)Tim-3(+) T(H)1 cells. In contrast, Gal-9 induced TNF-α production in cultured DC in a dose-dependent manner; however, RMT3-23 inhibited Gal-9-induced TNF-α production in a dose-dependent manner. Although Gal-9 exhibited certain therapeutic potential against autoimmune diabetes by enhancing apoptosis of CD4(+)Tim-3(+) T(H)1 cells, RMT3-23 exhibited prominent therapeutic efficacy by suppressing the TNF-α production and activation of DC. Taken together, the inhibition of the Gal-9-Tim-3 pathway on DC, upstream of T(H)1 response, may be a new target for the treatment of type 1 diabetes.
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http://dx.doi.org/10.1210/en.2011-1579DOI Listing
February 2012

Tim-1 promotes cisplatin nephrotoxicity.

Am J Physiol Renal Physiol 2011 Nov 10;301(5):F1098-104. Epub 2011 Aug 10.

Centre for Inflammatory Diseases, Department of Medicine, Monash University, Clayton, Victoria, Australia.

Nephrotoxicity is a frequent complication of cisplatin-based chemotherapy, in which T cells are known to promote acute kidney injury. In this study, we examined the role of T cell immunoglobulin mucin 1 (Tim-1) in cisplatin-induced acute kidney injury using an inhibitory anti-Tim-1 antibody. Tim-1 acts to modulate T cell responses, but it is also expressed by damaged proximal tubules in the kidney, where it is known as kidney injury molecule-1 (Kim-1). Anti-Tim-1 antibodies attenuated cisplatin nephrotocity, with less histologic damage, improved renal function, and fewer leukocytes infiltrating the kidney compared with control antibody-treated mice. Renal NF-κB activation and apoptosis were reduced, and proinflammatory renal cytokine and chemokine mRNA expression was decreased. Renal Kim-1 expression was reduced, consistent with the diminished kidney injury after anti-Tim-1 antibody treatment. Furthermore, anti-Tim-1 antibodies reduced early systemic CD4+ and CD8+ T cell activation, apoptosis, and cytokine production. To determine whether the protective actions of anti-Tim-1 antibodies were due to effects on renal tubular cells, cisplatin nephrotoxicity was studied in Rag1(-/-) mice. Anti-Tim-1 antibodies did not affect renal dysfunction or histologic damage in Rag1(-/-) mice, showing that the benefits of inhibiting Tim-1 come from T cell effects. As Tim-1 plays an important role in promoting cisplatin nephrotoxicity, inhibiting Tim-1 may be a therapeutic strategy to prevent cisplatin-induced acute kidney injury.
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http://dx.doi.org/10.1152/ajprenal.00193.2011DOI Listing
November 2011

Regulatory B cells are identified by expression of TIM-1 and can be induced through TIM-1 ligation to promote tolerance in mice.

J Clin Invest 2011 Sep 8;121(9):3645-56. Epub 2011 Aug 8.

Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.

T cell Ig domain and mucin domain protein 1 (TIM-1) is a costimulatory molecule that regulates immune responses by modulating CD4+ T cell effector differentiation. However, the function of TIM-1 on other immune cell populations is unknown. Here, we show that in vivo in mice, TIM-1 is predominantly expressed on B rather than T cells. Importantly, TIM-1 was expressed by a large majority of IL-10-expressing regulatory B cells in all major B cell subpopulations, including transitional, marginal zone, and follicular B cells, as well as the B cell population characterized as CD1d(hi)CD5+. A low-affinity TIM-1-specific antibody that normally promotes tolerance in mice, actually accelerated (T cell-mediated) immune responsiveness in the absence of B cells. TIM-1+ B cells were highly enriched for IL-4 and IL-10 expression, promoted Th2 responses, and could directly transfer allograft tolerance. Both cytokine expression and number of TIM-1+ regulatory B cells (Bregs) were induced by TIM-1-specific antibody, and this was dependent on IL-4 signaling. Thus, TIM-1 is an inclusive marker for IL-10+ Bregs that can be induced by TIM-1 ligation. These findings suggest that TIM-1 may be a novel therapeutic target for modulating the immune response and provide insight into the signals involved in the generation and induction of Bregs.
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http://dx.doi.org/10.1172/JCI46274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3163958PMC
September 2011