Hideo Yagita | Juntendo University School of Medicine (original) (raw)

Papers by Hideo Yagita

The Journal of Immunology, 2012

Fully functional CD8 + T cell memory is highly dependent upon CD4 + T cell support. CD4 + T cells... more Fully functional CD8 + T cell memory is highly dependent upon CD4 + T cell support. CD4 + T cells play a critical role in inducing the expression of CD70, the ligand for CD27, on dendritic cells. In this study, we demonstrate that CD27 stimulation during primary CD8 + T cell responses regulates the ability to mount secondary CD8 + T cell responses. CD27 stimulation during vaccinia and dendritic cell immunization controls the expression of the IL-7R (CD127), which has been shown to be necessary for memory CD8 + T cell survival. Furthermore, CD27 stimulation during primary CD8 + T cell responses to vaccinia virus restrained the late expression on memory precursor cells of cytokine receptors that support terminal differentiation. The formation of CD8 + T cell memory precursors and secondary CD8 + T cell responses was restored in the absence of CD27 costimulation when endogenous IL-12 was not available. Similarly, the lesion in CD8 + T cell memory that occurs in the absence of CD4 + T cells did not occur in mice lacking IL-12. These data indicate that CD4 + T cell help and, by extension, CD27 stimulation support CD8 + T cell memory by modulating the expression of cytokine receptors that influence the differentiation and survival of memory CD8 + T cells.

Blood, 2009

Phagocytes such as macrophages and dendritic cells (DCs) engulf apoptotic cells to maintain perip... more Phagocytes such as macrophages and dendritic cells (DCs) engulf apoptotic cells to maintain peripheral immune tolerance. However, the mechanism for the recognition of dying cells by phagocytes is not fully understood. Here, we demonstrate that T-cell immunoglobulin mucin-3 (Tim-3) recognizes apoptotic cells through the FG loop in the IgV domain, and is crucial for clearance of apoptotic cells by phagocytes. Whereas Tim-4 is highly expressed on peritoneal resident macrophages, Tim-3 is expressed on peritoneal exudate macrophages, monocytes, and splenic DCs, indicating distinct Tim-mediated phagocytic pathways used by different phagocytes. Furthermore, phagocytosis of apoptotic cells by CD8(+) DCs is inhibited by anti-Tim-3 mAb, resulting in a reduced cross-presentation of dying cell-associated antigens in vitro and in vivo. Administration of anti-Tim-3 as well as anti-Tim-4 mAb induces autoantibody production. These results indicate a crucial role for Tim-3 in phagocytosis of apoptotic cells and cross-presentation, which may be linked to peripheral tolerance.

Immunology, 2000

NRS1 is a murine squamous cell carcinoma that constitutively expresses the co-stimulatory molecul... more NRS1 is a murine squamous cell carcinoma that constitutively expresses the co-stimulatory molecule CD80 at a high level yet grows as a tumour in syngeneic C3H mice. We examined the effect of gene transfer of the 4-1BB ligand (4-1BBL) into NRS1 cells. Introduction of the 4-1BBL gene ef®ciently elicited anti-tumour immune responses in syngeneic mice which acquired speci®c immunity against wild-type tumour. T-cell depletion studies showed that CD8 + , but not CD4 + T cells were essential for tumour eradication. Our results suggest that the transduced 4-1BBL is more effective than the spontaneously expressed CD80 for generation of primary anti-tumour CD8 + T-cell responses. In addition to CD80 and CD86, the host-derived 4-1BBL is also involved in the secondary anti-tumour responses. This study indicates the complicated contribution of 4-1BBL, CD80 and CD86 on tumour and host cells in anti-tumour immune responses and a possible therapeutic application of 4-1BBL for human tumour vaccination and gene therapy.

Oncogene, 2007

Deregulated cell death pathways may lead to the development of cancer, and induction of tumor cel... more Deregulated cell death pathways may lead to the development of cancer, and induction of tumor cell apoptosis is the basis of many cancer therapies. Knowledge accumulated concerning the molecular mechanisms of apoptotic cell death has aided the development of new therapeutic strategies to treat cancer. Signals through death receptors of the tumor necrosis factor (TNF) superfamily have been well elucidated,

Journal of Allergy and Clinical Immunology, 1994

Mast cells express fibronectin-receptor integrins on the cell surface, which are involved in cell... more Mast cells express fibronectin-receptor integrins on the cell surface, which are involved in cellular activation. In this study rat and mouse mast cells adhered to fibronectin through: very late antigen 4, 5 (ill integrin) and vitronectin receptor (~3 integrin), and engagement of these receptors promoted cellular degranulation induced by cross-linking of the high-affinity IgE receptor. Blocking of these adhesion molecules by monoclonal antibodies remarkably reduced passive cutaneous anaphylaxis reaction in vivo. On fibronectin, cytokine release from mast cells on IgE receptor aggregation was also enhanced, but not the expression of cytokine genes, with the exception of interleukin-3.

Journal of Clinical Investigation, 1993

Gastroenterology, 1997

BACKGROUND & AIMS: Fas has been implicated in liver damage. The aim of this study was to investig... more BACKGROUND & AIMS: Fas has been implicated in liver damage. The aim of this study was to investigate the role of its ligand to induce hepatocyte death and liver damage in T cell-dependent hepatitis.METHODS: Fas ligand-mediated lysis of primary hepatocytes from C57BL/6 wild-type, Fas ligand-deficient gld, and Fas-deficient lpr mice and concanavalin A-induced hepatitis in these mice were assessed.RESULTS: Freshly

Journal of Experimental Medicine, 2000

Because tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) preferentially induces ap... more Because tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) preferentially induces apoptosis in tumor cells and plays a critical role in tumor surveillance, its receptor is an attractive target for antibody-mediated tumor therapy. Here we report that a monoclonal antibody (mAb) against the mouse TRAIL receptor, DR5, exhibited potent antitumor effects against TRAIL-sensitive tumor cells in vivo by recruiting Fc receptor-expressing innate immune cells, with no apparent systemic toxicity. Administration of the agonistic anti-DR5 mAb also significantly inhibited experimental and spontaneous tumor metastases. Notably, the anti-DR5 mAbmediated tumor rejection by innate immune cells efficiently evoked tumor-specific T cell immunity that could also eradicate TRAIL-resistant variants. These results suggested that the antibody-based therapy targeting DR5 is an efficient strategy not only to eliminate TRAILsensitive tumor cells, but also to induce tumor-specific T cell memory that affords a long-term protection from tumor recurrence.

Immunology, 2010

The pore-forming protein perforin is synthesized as an inactive precursor in natural killer (NK) ... more The pore-forming protein perforin is synthesized as an inactive precursor in natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), and becomes active when a short C-terminal peptide is cleaved within acidic lysosome-like cytotoxic granules. Although it was shown more than a decade ago that this cleavage is pH dependent and can be inhibited by the generic cysteine cathepsin inhibitor E-64d, no protease capable of processing the perforin C terminus has been identified. Neither is it known whether a single protease is responsible or the processing has inbuilt redundancy. Here, we show that incubation of human NK cells and primary antigen-restricted mouse CTLs with the cathepsin L (CatL) inhibitor L1 resulted in a marked inhibition of perforin-dependent target cell death and reduced perforin processing. In vitro, CatL preferentially cleaved a site on full-length recombinant perforin close to its C terminus. The NK cells of mice deficient in CatL showed a reduction but not a complete absence of processed perforin, indicating that cysteine proteases other than CatL are also able to process perforin. We conclude that granulebound cathepsins are essential for processing perforin to its active form, and that CatL is an important, but not exclusive, participant in this process.

European Journal of Immunology, 2005

Naturally arising CD4 + CD25 + regulatory T (T R ) cells are engaged in the maintenance of self t... more Naturally arising CD4 + CD25 + regulatory T (T R ) cells are engaged in the maintenance of self tolerance and prevention of autoimmune diseases. However, accumulating evidence suggests that a fraction of peripheral CD4 + CD25 -T cells also possesses regulatory activity. Programmed death-1 (PD-1) is a new member of the CD28/CTLA-4 family, which has been implicated in the maintenance of peripheral self tolerance. Here, we identified a subpopulation of CD4 + CD25 -PD-1 + T cells in the spleen of naive mice that constitutively expressed CTLA-4 and FoxP3 and was hypoproliferative in response to anti-CD3 antibody stimulation in vitro. However, the CD4 + CD25 -PD-1 + T cells uniquely produced large amounts of IL-4 and IL-10 in response to anti-CD3 and anti-CD28 mAb stimulation, unlike the CD4 + CD25 + T R cells. The CD4 + CD25 -PD-1 + T cells exhibited a suppressor activity against the proliferation of anti-CD3 antibody-stimulated CD4 + CD25 -PD-1 -T cells in vitro, which was partially abrogated by anti-CTLA-4 mAb, but not by anti-IL-10 or anti-PD-1 mAb. Remarkably, the CD4 + CD25 -PD-1 + T cells inhibited the development of colitis induced by adoptive transfer of CD4 + CD45RB high T cells into C.B17-scid/scid mice, albeit to a lesser extent than CD4 + CD25 + T R cells, in a CTLA-4-dependent manner. These results indicate that the CD4 + CD25 -PD-1 + T cells contain substantial amounts of T R cells that are involved in the maintenance of peripheral tolerance.

Infection and Immunity, 2003

Innate immunity as a first defense is indispensable for host survival against infectious agents. ... more Innate immunity as a first defense is indispensable for host survival against infectious agents. We examined the roles of natural killer (NK) T cells in defense against Trypanosoma cruzi infection. The T. cruzi parasitemia and survival of CD1d-deficient mice exhibited no differences compared to wild-type littermates. NK T-cell activation induced by administering -galactosylceramide (-GalCer) to T. cruzi-infected mice significantly changed

PloS one, 2015

NK cells are the most abundant lymphocyte population in the feto-maternal interface during gestat... more 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.

Journal of immunology (Baltimore, Md. : 1950), Jan 27, 2015

Th2-type cytokines and TNF-α secreted by activated mast cells upon cross-linking of FcεRI contrib... more Th2-type cytokines and TNF-α secreted by activated mast cells upon cross-linking of FcεRI contribute to the development and maintenance of Th2 immunity to parasites and allergens. We have previously shown that cytokine secretion by mouse mast cells is enhanced by signaling through Notch receptors. In this study, we investigated the molecular mechanisms by which Notch signaling enhances mast cell cytokine production induced by FcεRI cross-linking. FcεRI-mediated production of cytokines, particularly IL-4, was significantly enhanced in mouse bone marrow-derived mast cells by priming with Notch ligands. Western blot analysis showed that Notch signaling augmented and prolonged FcεRI-mediated phosphorylation of MAPKs, mainly JNK and p38 MAPK, through suppression of the expression of SHIP-1, a master negative regulator of FcεRI signaling, resulting in the enhanced production of multiple cytokines. The enhancing effect of Notch ligand priming on multiple cytokine production was abolished b...

PloS one, 2015

Adoptive cellular immunotherapy using in vitro expanded CD8+ T cells shows promise for tumour imm... more Adoptive cellular immunotherapy using in vitro expanded CD8+ T cells shows promise for tumour immunotherapy but is limited by eventual loss of function of the transferred T cells through factors that likely include inactivation by tolerogenic dendritic cells (DC). The co-inhibitory receptor programmed death-1 (PD-1), in addition to controlling T-cell responsiveness at effector sites in malignancies and chronic viral diseases is an important modulator of dendritic cell-induced tolerance in naive T cell populations. The most potent therapeutic capacity amongst CD8+ T cells appears to lie within Tcm or Tcm-like cells but memory T cells express elevated levels of PD-1. Based on established trafficking patterns for Tcm it is likely Tcm-like cells interact with lymphoid-tissue DC that present tumour-derived antigens and may be inherently tolerogenic to develop therapeutic effector function. As little is understood of the effect of PD-1/PD-L1 blockade on Tcm-like CD8+ T cells, particularly...

Nature communications, 2015

To cause food-borne botulism, botulinum neurotoxin (BoNT) in the gastrointestinal lumen must trav... more To cause food-borne botulism, botulinum neurotoxin (BoNT) in the gastrointestinal lumen must traverse the intestinal epithelial barrier. However, the mechanism by which BoNT crosses the intestinal epithelial barrier remains unclear. BoNTs are produced along with one or more non-toxic components, with which they form progenitor toxin complexes (PTCs). Here we show that serotype A1 L-PTC, which has high oral toxicity and makes the predominant contribution to causing illness, breaches the intestinal epithelial barrier from microfold (M) cells via an interaction between haemagglutinin (HA), one of the non-toxic components, and glycoprotein 2 (GP2). HA strongly binds to GP2 expressed on M cells, which do not have thick mucus layers. Susceptibility to orally administered L-PTC is dramatically reduced in M-cell-depleted mice and GP2-deficient (Gp2(-/-)) mice. Our finding provides the basis for the development of novel antitoxin therapeutics and delivery systems for oral biologics.

Journal of immunology (Baltimore, Md. : 1950), 2014

Cytotoxic lymphocytes destroy pathogen-infected and transformed cells through the cytotoxic granu... more Cytotoxic lymphocytes destroy pathogen-infected and transformed cells through the cytotoxic granule exocytosis death pathway, which is dependent on the delivery of proapoptotic granzymes into the target cell cytosol by the pore-forming protein, perforin. Despite the importance of mouse models in understanding the role of cytotoxic lymphocytes in immune-mediated disease and their role in cancer immune surveillance, no reliable intracellular detection method exists for mouse perforin. Consequently, rapid, flow-based assessment of cytotoxic potential has been problematic, and complex assays of function are generally required. In this study, we have developed a novel method for detecting perforin in primary mouse cytotoxic T lymphocytes by immunofluorescence and flow cytometry. We used this new technique to validate perforin colocalization with granzyme B in cytotoxic granules polarized to the immunological synapse, and to assess the expression of perforin in cytotoxic T lymphocytes at ...

Journal of the American Society of Nephrology : JASN, 2015

Monocytes and kidney-resident macrophages are considered to be involved in the pathogenesis of re... more Monocytes and kidney-resident macrophages are considered to be involved in the pathogenesis of renal ischemia-reperfusion injury (IRI). Several subsets of monocytes and macrophages are localized in the injured tissue, but the pathologic roles of these cells are not fully understood. Here, we show that CD169(+) monocytes and macrophages have a critical role in preventing excessive inflammation in IRI by downregulating intercellular adhesion molecule-1 (ICAM-1) expression on vascular endothelial cells. Mice depleted of CD169(+) cells showed enhanced endothelial ICAM-1 expression and developed irreversible renal damage associated with infiltration of a large number of neutrophils. The perivascular localization of CD169(+) monocytes and macrophages indicated direct interaction with blood vessels, and coculture experiments showed that the direct interaction of CD169(+) cell-depleted peripheral blood leukocytes augments the expression levels of ICAM-1 on endothelial cells. Notably, the tr...

PloS one, 2014

Notch family members were first identified as cell adhesion molecules by cell aggregation assays ... more Notch family members were first identified as cell adhesion molecules by cell aggregation assays in Drosophila studies. However, they are generally recognized as signaling molecules, and it was unclear if their adhesion function was restricted to Drosophila. We previously demonstrated that a mouse Notch ligand, Delta-like 1 (Dll1) functioned as a cell adhesion molecule. We here investigated whether this adhesion function was conserved in the diversified mammalian Notch ligands consisted of two families, Delta-like (Dll1, Dll3 and Dll4) and Jagged (Jag1 and Jag2). The forced expression of mouse Dll1, Dll4, Jag1, and Jag2, but not Dll3, on stromal cells induced the rapid and enhanced adhesion of cultured mast cells (MCs). This was attributed to the binding of Notch1 and Notch2 on MCs to each Notch ligand on the stromal cells themselves, and not the activation of Notch signaling. Notch receptor-ligand binding strongly supported the tethering of MCs to stromal cells, the first step of c...

PloS one, 2014

Commensal bacteria in gastrointestinal tracts are reported to function as an environmental factor... more Commensal bacteria in gastrointestinal tracts are reported to function as an environmental factor to regulate intestinal inflammation and immune responses. However, it remains largely unknown whether such bacterial function exerts any effect on other immune organs distant from the intestine. In this study, the influence of commensal bacteria in the thymus, where T cell lineages develop into mature type to form proper repertoires, was investigated using germ-free (GF) mice and Nod1-deficient mice lacking an intracellular recognition receptor for certain bacterial components, in which a commensal bacterial effect is predicted to be less. In both mice, there was no significant difference in the numbers and subset ratios of thymocytes. Interestingly, however, autoimmune regulator (Aire) expression in thymic epithelial cells (TECs), main components of the thymic microenvironment, was decreased in comparison to specific pathogen-free (SPF) mice and Nod1 wild-type (WT) mice, respectively. ...

The Journal of Immunology, 2012

Fully functional CD8 + T cell memory is highly dependent upon CD4 + T cell support. CD4 + T cells... more Fully functional CD8 + T cell memory is highly dependent upon CD4 + T cell support. CD4 + T cells play a critical role in inducing the expression of CD70, the ligand for CD27, on dendritic cells. In this study, we demonstrate that CD27 stimulation during primary CD8 + T cell responses regulates the ability to mount secondary CD8 + T cell responses. CD27 stimulation during vaccinia and dendritic cell immunization controls the expression of the IL-7R (CD127), which has been shown to be necessary for memory CD8 + T cell survival. Furthermore, CD27 stimulation during primary CD8 + T cell responses to vaccinia virus restrained the late expression on memory precursor cells of cytokine receptors that support terminal differentiation. The formation of CD8 + T cell memory precursors and secondary CD8 + T cell responses was restored in the absence of CD27 costimulation when endogenous IL-12 was not available. Similarly, the lesion in CD8 + T cell memory that occurs in the absence of CD4 + T cells did not occur in mice lacking IL-12. These data indicate that CD4 + T cell help and, by extension, CD27 stimulation support CD8 + T cell memory by modulating the expression of cytokine receptors that influence the differentiation and survival of memory CD8 + T cells.

Blood, 2009

Phagocytes such as macrophages and dendritic cells (DCs) engulf apoptotic cells to maintain perip... more Phagocytes such as macrophages and dendritic cells (DCs) engulf apoptotic cells to maintain peripheral immune tolerance. However, the mechanism for the recognition of dying cells by phagocytes is not fully understood. Here, we demonstrate that T-cell immunoglobulin mucin-3 (Tim-3) recognizes apoptotic cells through the FG loop in the IgV domain, and is crucial for clearance of apoptotic cells by phagocytes. Whereas Tim-4 is highly expressed on peritoneal resident macrophages, Tim-3 is expressed on peritoneal exudate macrophages, monocytes, and splenic DCs, indicating distinct Tim-mediated phagocytic pathways used by different phagocytes. Furthermore, phagocytosis of apoptotic cells by CD8(+) DCs is inhibited by anti-Tim-3 mAb, resulting in a reduced cross-presentation of dying cell-associated antigens in vitro and in vivo. Administration of anti-Tim-3 as well as anti-Tim-4 mAb induces autoantibody production. These results indicate a crucial role for Tim-3 in phagocytosis of apoptotic cells and cross-presentation, which may be linked to peripheral tolerance.

Immunology, 2000

NRS1 is a murine squamous cell carcinoma that constitutively expresses the co-stimulatory molecul... more NRS1 is a murine squamous cell carcinoma that constitutively expresses the co-stimulatory molecule CD80 at a high level yet grows as a tumour in syngeneic C3H mice. We examined the effect of gene transfer of the 4-1BB ligand (4-1BBL) into NRS1 cells. Introduction of the 4-1BBL gene ef®ciently elicited anti-tumour immune responses in syngeneic mice which acquired speci®c immunity against wild-type tumour. T-cell depletion studies showed that CD8 + , but not CD4 + T cells were essential for tumour eradication. Our results suggest that the transduced 4-1BBL is more effective than the spontaneously expressed CD80 for generation of primary anti-tumour CD8 + T-cell responses. In addition to CD80 and CD86, the host-derived 4-1BBL is also involved in the secondary anti-tumour responses. This study indicates the complicated contribution of 4-1BBL, CD80 and CD86 on tumour and host cells in anti-tumour immune responses and a possible therapeutic application of 4-1BBL for human tumour vaccination and gene therapy.

Oncogene, 2007

Deregulated cell death pathways may lead to the development of cancer, and induction of tumor cel... more Deregulated cell death pathways may lead to the development of cancer, and induction of tumor cell apoptosis is the basis of many cancer therapies. Knowledge accumulated concerning the molecular mechanisms of apoptotic cell death has aided the development of new therapeutic strategies to treat cancer. Signals through death receptors of the tumor necrosis factor (TNF) superfamily have been well elucidated,

Journal of Allergy and Clinical Immunology, 1994

Mast cells express fibronectin-receptor integrins on the cell surface, which are involved in cell... more Mast cells express fibronectin-receptor integrins on the cell surface, which are involved in cellular activation. In this study rat and mouse mast cells adhered to fibronectin through: very late antigen 4, 5 (ill integrin) and vitronectin receptor (~3 integrin), and engagement of these receptors promoted cellular degranulation induced by cross-linking of the high-affinity IgE receptor. Blocking of these adhesion molecules by monoclonal antibodies remarkably reduced passive cutaneous anaphylaxis reaction in vivo. On fibronectin, cytokine release from mast cells on IgE receptor aggregation was also enhanced, but not the expression of cytokine genes, with the exception of interleukin-3.

Journal of Clinical Investigation, 1993

Gastroenterology, 1997

BACKGROUND & AIMS: Fas has been implicated in liver damage. The aim of this study was to investig... more BACKGROUND & AIMS: Fas has been implicated in liver damage. The aim of this study was to investigate the role of its ligand to induce hepatocyte death and liver damage in T cell-dependent hepatitis.METHODS: Fas ligand-mediated lysis of primary hepatocytes from C57BL/6 wild-type, Fas ligand-deficient gld, and Fas-deficient lpr mice and concanavalin A-induced hepatitis in these mice were assessed.RESULTS: Freshly

Journal of Experimental Medicine, 2000

Because tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) preferentially induces ap... more Because tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) preferentially induces apoptosis in tumor cells and plays a critical role in tumor surveillance, its receptor is an attractive target for antibody-mediated tumor therapy. Here we report that a monoclonal antibody (mAb) against the mouse TRAIL receptor, DR5, exhibited potent antitumor effects against TRAIL-sensitive tumor cells in vivo by recruiting Fc receptor-expressing innate immune cells, with no apparent systemic toxicity. Administration of the agonistic anti-DR5 mAb also significantly inhibited experimental and spontaneous tumor metastases. Notably, the anti-DR5 mAbmediated tumor rejection by innate immune cells efficiently evoked tumor-specific T cell immunity that could also eradicate TRAIL-resistant variants. These results suggested that the antibody-based therapy targeting DR5 is an efficient strategy not only to eliminate TRAILsensitive tumor cells, but also to induce tumor-specific T cell memory that affords a long-term protection from tumor recurrence.

Immunology, 2010

The pore-forming protein perforin is synthesized as an inactive precursor in natural killer (NK) ... more The pore-forming protein perforin is synthesized as an inactive precursor in natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), and becomes active when a short C-terminal peptide is cleaved within acidic lysosome-like cytotoxic granules. Although it was shown more than a decade ago that this cleavage is pH dependent and can be inhibited by the generic cysteine cathepsin inhibitor E-64d, no protease capable of processing the perforin C terminus has been identified. Neither is it known whether a single protease is responsible or the processing has inbuilt redundancy. Here, we show that incubation of human NK cells and primary antigen-restricted mouse CTLs with the cathepsin L (CatL) inhibitor L1 resulted in a marked inhibition of perforin-dependent target cell death and reduced perforin processing. In vitro, CatL preferentially cleaved a site on full-length recombinant perforin close to its C terminus. The NK cells of mice deficient in CatL showed a reduction but not a complete absence of processed perforin, indicating that cysteine proteases other than CatL are also able to process perforin. We conclude that granulebound cathepsins are essential for processing perforin to its active form, and that CatL is an important, but not exclusive, participant in this process.

European Journal of Immunology, 2005

Naturally arising CD4 + CD25 + regulatory T (T R ) cells are engaged in the maintenance of self t... more Naturally arising CD4 + CD25 + regulatory T (T R ) cells are engaged in the maintenance of self tolerance and prevention of autoimmune diseases. However, accumulating evidence suggests that a fraction of peripheral CD4 + CD25 -T cells also possesses regulatory activity. Programmed death-1 (PD-1) is a new member of the CD28/CTLA-4 family, which has been implicated in the maintenance of peripheral self tolerance. Here, we identified a subpopulation of CD4 + CD25 -PD-1 + T cells in the spleen of naive mice that constitutively expressed CTLA-4 and FoxP3 and was hypoproliferative in response to anti-CD3 antibody stimulation in vitro. However, the CD4 + CD25 -PD-1 + T cells uniquely produced large amounts of IL-4 and IL-10 in response to anti-CD3 and anti-CD28 mAb stimulation, unlike the CD4 + CD25 + T R cells. The CD4 + CD25 -PD-1 + T cells exhibited a suppressor activity against the proliferation of anti-CD3 antibody-stimulated CD4 + CD25 -PD-1 -T cells in vitro, which was partially abrogated by anti-CTLA-4 mAb, but not by anti-IL-10 or anti-PD-1 mAb. Remarkably, the CD4 + CD25 -PD-1 + T cells inhibited the development of colitis induced by adoptive transfer of CD4 + CD45RB high T cells into C.B17-scid/scid mice, albeit to a lesser extent than CD4 + CD25 + T R cells, in a CTLA-4-dependent manner. These results indicate that the CD4 + CD25 -PD-1 + T cells contain substantial amounts of T R cells that are involved in the maintenance of peripheral tolerance.

Infection and Immunity, 2003

Innate immunity as a first defense is indispensable for host survival against infectious agents. ... more Innate immunity as a first defense is indispensable for host survival against infectious agents. We examined the roles of natural killer (NK) T cells in defense against Trypanosoma cruzi infection. The T. cruzi parasitemia and survival of CD1d-deficient mice exhibited no differences compared to wild-type littermates. NK T-cell activation induced by administering -galactosylceramide (-GalCer) to T. cruzi-infected mice significantly changed

PloS one, 2015

NK cells are the most abundant lymphocyte population in the feto-maternal interface during gestat... more 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.

Journal of immunology (Baltimore, Md. : 1950), Jan 27, 2015

Th2-type cytokines and TNF-α secreted by activated mast cells upon cross-linking of FcεRI contrib... more Th2-type cytokines and TNF-α secreted by activated mast cells upon cross-linking of FcεRI contribute to the development and maintenance of Th2 immunity to parasites and allergens. We have previously shown that cytokine secretion by mouse mast cells is enhanced by signaling through Notch receptors. In this study, we investigated the molecular mechanisms by which Notch signaling enhances mast cell cytokine production induced by FcεRI cross-linking. FcεRI-mediated production of cytokines, particularly IL-4, was significantly enhanced in mouse bone marrow-derived mast cells by priming with Notch ligands. Western blot analysis showed that Notch signaling augmented and prolonged FcεRI-mediated phosphorylation of MAPKs, mainly JNK and p38 MAPK, through suppression of the expression of SHIP-1, a master negative regulator of FcεRI signaling, resulting in the enhanced production of multiple cytokines. The enhancing effect of Notch ligand priming on multiple cytokine production was abolished b...

PloS one, 2015

Adoptive cellular immunotherapy using in vitro expanded CD8+ T cells shows promise for tumour imm... more Adoptive cellular immunotherapy using in vitro expanded CD8+ T cells shows promise for tumour immunotherapy but is limited by eventual loss of function of the transferred T cells through factors that likely include inactivation by tolerogenic dendritic cells (DC). The co-inhibitory receptor programmed death-1 (PD-1), in addition to controlling T-cell responsiveness at effector sites in malignancies and chronic viral diseases is an important modulator of dendritic cell-induced tolerance in naive T cell populations. The most potent therapeutic capacity amongst CD8+ T cells appears to lie within Tcm or Tcm-like cells but memory T cells express elevated levels of PD-1. Based on established trafficking patterns for Tcm it is likely Tcm-like cells interact with lymphoid-tissue DC that present tumour-derived antigens and may be inherently tolerogenic to develop therapeutic effector function. As little is understood of the effect of PD-1/PD-L1 blockade on Tcm-like CD8+ T cells, particularly...

Nature communications, 2015

To cause food-borne botulism, botulinum neurotoxin (BoNT) in the gastrointestinal lumen must trav... more To cause food-borne botulism, botulinum neurotoxin (BoNT) in the gastrointestinal lumen must traverse the intestinal epithelial barrier. However, the mechanism by which BoNT crosses the intestinal epithelial barrier remains unclear. BoNTs are produced along with one or more non-toxic components, with which they form progenitor toxin complexes (PTCs). Here we show that serotype A1 L-PTC, which has high oral toxicity and makes the predominant contribution to causing illness, breaches the intestinal epithelial barrier from microfold (M) cells via an interaction between haemagglutinin (HA), one of the non-toxic components, and glycoprotein 2 (GP2). HA strongly binds to GP2 expressed on M cells, which do not have thick mucus layers. Susceptibility to orally administered L-PTC is dramatically reduced in M-cell-depleted mice and GP2-deficient (Gp2(-/-)) mice. Our finding provides the basis for the development of novel antitoxin therapeutics and delivery systems for oral biologics.

Journal of immunology (Baltimore, Md. : 1950), 2014

Cytotoxic lymphocytes destroy pathogen-infected and transformed cells through the cytotoxic granu... more Cytotoxic lymphocytes destroy pathogen-infected and transformed cells through the cytotoxic granule exocytosis death pathway, which is dependent on the delivery of proapoptotic granzymes into the target cell cytosol by the pore-forming protein, perforin. Despite the importance of mouse models in understanding the role of cytotoxic lymphocytes in immune-mediated disease and their role in cancer immune surveillance, no reliable intracellular detection method exists for mouse perforin. Consequently, rapid, flow-based assessment of cytotoxic potential has been problematic, and complex assays of function are generally required. In this study, we have developed a novel method for detecting perforin in primary mouse cytotoxic T lymphocytes by immunofluorescence and flow cytometry. We used this new technique to validate perforin colocalization with granzyme B in cytotoxic granules polarized to the immunological synapse, and to assess the expression of perforin in cytotoxic T lymphocytes at ...

Journal of the American Society of Nephrology : JASN, 2015

Monocytes and kidney-resident macrophages are considered to be involved in the pathogenesis of re... more Monocytes and kidney-resident macrophages are considered to be involved in the pathogenesis of renal ischemia-reperfusion injury (IRI). Several subsets of monocytes and macrophages are localized in the injured tissue, but the pathologic roles of these cells are not fully understood. Here, we show that CD169(+) monocytes and macrophages have a critical role in preventing excessive inflammation in IRI by downregulating intercellular adhesion molecule-1 (ICAM-1) expression on vascular endothelial cells. Mice depleted of CD169(+) cells showed enhanced endothelial ICAM-1 expression and developed irreversible renal damage associated with infiltration of a large number of neutrophils. The perivascular localization of CD169(+) monocytes and macrophages indicated direct interaction with blood vessels, and coculture experiments showed that the direct interaction of CD169(+) cell-depleted peripheral blood leukocytes augments the expression levels of ICAM-1 on endothelial cells. Notably, the tr...

PloS one, 2014

Notch family members were first identified as cell adhesion molecules by cell aggregation assays ... more Notch family members were first identified as cell adhesion molecules by cell aggregation assays in Drosophila studies. However, they are generally recognized as signaling molecules, and it was unclear if their adhesion function was restricted to Drosophila. We previously demonstrated that a mouse Notch ligand, Delta-like 1 (Dll1) functioned as a cell adhesion molecule. We here investigated whether this adhesion function was conserved in the diversified mammalian Notch ligands consisted of two families, Delta-like (Dll1, Dll3 and Dll4) and Jagged (Jag1 and Jag2). The forced expression of mouse Dll1, Dll4, Jag1, and Jag2, but not Dll3, on stromal cells induced the rapid and enhanced adhesion of cultured mast cells (MCs). This was attributed to the binding of Notch1 and Notch2 on MCs to each Notch ligand on the stromal cells themselves, and not the activation of Notch signaling. Notch receptor-ligand binding strongly supported the tethering of MCs to stromal cells, the first step of c...

PloS one, 2014

Commensal bacteria in gastrointestinal tracts are reported to function as an environmental factor... more Commensal bacteria in gastrointestinal tracts are reported to function as an environmental factor to regulate intestinal inflammation and immune responses. However, it remains largely unknown whether such bacterial function exerts any effect on other immune organs distant from the intestine. In this study, the influence of commensal bacteria in the thymus, where T cell lineages develop into mature type to form proper repertoires, was investigated using germ-free (GF) mice and Nod1-deficient mice lacking an intracellular recognition receptor for certain bacterial components, in which a commensal bacterial effect is predicted to be less. In both mice, there was no significant difference in the numbers and subset ratios of thymocytes. Interestingly, however, autoimmune regulator (Aire) expression in thymic epithelial cells (TECs), main components of the thymic microenvironment, was decreased in comparison to specific pathogen-free (SPF) mice and Nod1 wild-type (WT) mice, respectively. ...