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Shosaku Narumi

Publications and source records attributed to Shosaku Narumi.

15 recordsLinked to original sources
PubMed2006

Role of IP-10/CXCL10 in the progression of pancreatitis-like injury in mice after murine retroviral infection.

Exocrinopathy and pancreatitis-like injury were developed in C57BL/6 (B6) mice infected with LP-BM5 murine leukemia virus, which is known to induce murine acquired immunodeficiency syndrome (MAIDS). The role of chemokines, especially CXCL10/interferon (IFN)-gamma-inducible protein 10 (IP-10), a chemokine to attract CXCR3+ T helper 1-type CD4+ T cells, has not been investigated thoroughly in the pathogenesis of pancreatitis. B6 mice were inoculated intraperitoneally with LP-BM5 and then injected every week with either an antibody against IP-10 or a control antibody. Eight weeks after infection, we analyzed the effect of IP-10 neutralization. Anti-IP-10 antibody treatment did not change the generalized lymphadenopathy and hepatosplenomegaly of mice with MAIDS. The treatment significantly reduced the number of IP-10- and CXCR3-positive cells in the mesenteric lymph nodes (mLNs) but not the phenotypes and gross numbers of cells. In contrast, IP-10 neutralization reduced the number of mononuclear cells infiltrating into the pancreas. Anti-IP-10 antibody treatment did not change the numbers of IFN-gamma+ and IL10+ cells in the mLN but significantly reduced their numbers, especially IFN-gamma+ and IL-10+ CD4+ T cells and IFN-gamma+ Mac-1+ cells, in the pancreas. IP-10 neutralization ameliorated the pancreatic lesions of mice with MAIDS probably by blocking the cellular infiltration of CD4+ T cells and IFN-gamma+ Mac-1+ cells into the pancreas at least at 8 wk after infection, suggesting that IP-10 and these cells might play a key role in the development of chronic autoimmune pancreatitis.

Animals↗
PubMed2005

IFN-inducible protein-10 plays a pivotal role in maintaining slit-diaphragm function by regulating podocyte cell-cycle balance.

IFN-inducible protein-10 (IP-10/CXCL10) is a potent chemoattractant for activated T lymphocytes and was reported recently to have several additional biologic activities. In this study, the pathophysiologic role of IP-10 in the glomerular visceral epithelial cell (podocyte) was investigated. In cultured podocytes subjected to recombinant IP-10 treatment, the expression of slit-diaphragm (SD) components nephrin and podocin clearly was heightened. Rats that had puromycin aminonucleoside nephropathy and anti-nephrin antibody-induced nephropathy and were subjected to anti-IP-10 function-blocking antibody (anti-IP-10 mAb) treatment displayed a decrease in the protein level of SD components, as well as exacerbated proteinuria. For exploration of the mechanisms of this process, the interaction between IP-10 and the cell-cycle regulatory proteins was investigated. Cultured podocytes subjected to recombinant IP-10 treatment displayed an increase in the protein level of p27(Kip1), whereas the levels of cyclins E and A decreased. The expression of IP-10 and SD components was heightened by the treatment of siRNA of cyclin A, whereas these expressions were lowered by the treatment of siRNA of p27(Kip1). Proteinuric rats subjected to anti-IP-10 mAb treatment displayed a heightened expression of cyclin A from the early phase of the disease, which indicates that the anti-IP-10 mAb treatment exacerbates podocyte injury by disturbing the cell-cycle balance. These results raise the possibility that IP-10 could become a novel therapeutic target in nephrotic syndrome and several diseases with altered cell-cycle balance.

Animals↗
PubMed2005

CXCL10 DNA vaccination prevents spontaneous diabetes through enhanced beta cell proliferation in NOD mice.

CXCL10, a chemokine for Th1 cells, is involved in the pathogenesis of various Th1-dominant autoimmune diseases. Type 1 diabetes is considered to be a Th1-dominant autoimmune disease, and a suppressive effect of CXCL10 neutralization on diabetes development has been reported in a cyclophosphamide-induced accelerated diabetes model through induction of beta cell proliferation. However, intervention in a diabetes model might bring about opposite effects, depending on the timing, amount, or method of treatment. In the present study, we examined the effect of CXCL10 neutralization in a "spontaneous diabetes" model of NOD mice, using CXCL10 DNA vaccination (pCAGGS-CXCL10). pCAGGS-CXCL10 treatment in young NOD mice induced the production of anti-CXCL10 Ab in vivo and suppressed the incidence of spontaneous diabetes, although this treatment did not inhibit insulitis or alter the immunological response. pCAGGS-CXCL10 treatment enhanced the proliferation of pancreatic beta cells, resulting in an increase of beta cell mass in this spontaneous diabetes model as well. Therefore, CXCL10 neutralization is suggested to be useful for maintaining beta cell mass at any stage of autoimmune diabetes.

Animals↗
PubMed2005

Significance of serum CXCL10/IP-10 level in type 1 diabetes.

Although we have previously reported an elevated serum level of CXCL10/IP-10 (CXCL10), a Th1 chemokine, in type 1 diabetic patients, little is known about the origin of serum CXCL10 and its significance in type 1 diabetes. Therefore, we examined serum CXCL10 level in NOD mice in association with the expression level of CXCL10 in the pancreas, pancreatic lymph nodes (LN) and spleen. Serum CXCL10 level increased over time towards the onset of diabetes, and was significantly higher in the "diabetic" period (20 and 24 weeks of age and at onset of diabetes) than in the "pre-diabetic" period (4, 8 and 16 weeks of age). Moreover, serum CXCL10 level was associated with CXCL10 and CXCR3 mRNA level in pancreatic LN. Furthermore, it seemed that serum CXCL10 level increased just before (or at) the onset of overt diabetes. These results suggest that serum CXCL10 level may reflect accumulation of Th1 lymphocytes in pancreatic LN, and measurement of serum CXCL10 level may be useful to assess the pathophysiology of the disease course in type 1 diabetes.

Animals↗
PubMed2005

Plasmacytoid DCs help lymph node DCs to induce anti-HSV CTLs.

Antiviral cell-mediated immunity is initiated by the dendritic cell (DC) network in lymph nodes (LNs). Plasmacytoid DCs (pDCs) are known to migrate to inflamed LNs and produce interferon (IFN)-alpha, but their other roles in antiviral T cell immunity are unclear. We report that LN-recruited pDCs are activated to create local immune fields that generate antiviral cytotoxic T lymphocytes (CTLs) in association with LNDCs, in a model of cutaneous herpes simplex virus (HSV) infection. Although pDCs alone failed to induce CTLs, in vivo depletion of pDCs impaired CTL-mediated virus eradication. LNDCs from pDC-depleted mice showed impaired cluster formation with T cells and antigen presentation to prime CTLs. Transferring circulating pDC precursors from wild-type, but not CXCR3-deficient, mice to pDC-depleted mice restored CTL induction by impaired LNDCs. In vitro co-culture experiments revealed that pDCs provided help signals that recovered impaired LNDCs in a CD2- and CD40L-dependent manner. pDC-derived IFN-alpha further stimulated the recovered LNDCs to induce CTLs. Therefore, the help provided by pDCs for LNDCs in primary immune responses seems to be pivotal to optimally inducing anti-HSV CTLs.

Animals↗
PubMed2004

CXC chemokine ligand 10 neutralization suppresses the occurrence of diabetes in nonobese diabetic mice through enhanced beta cell proliferation without affecting insulitis.

We have shown that neutralization of IFN-inducible protein 10/CXCL10, a chemokine for Th1 cells, breaks Th1 retention in the draining lymph nodes, resulting in exacerbation in Th1-dominant autoimmune disease models induced by immunization with external Ags. However, there have been no studies on the role of CXCL10 neutralization in Th1-dominant disease models induced by constitutive intrinsic self Ags. So, we have examined the effect of CXCL10 neutralization using a type 1 diabetes model initiated by developmentally regulated presentation of beta cell Ags. CXCL10 neutralization suppressed the occurrence of diabetes after administration with cyclophosphamide in NOD mice, although CXCL10 neutralization did not significantly inhibit insulitis and gave no influence on the trafficking of effector T cells into the islets. Because both CXCL10 and CXCR3 were, unexpectedly, coexpressed on insulin-producing cells, CXCL10 was considered to affect mature and premature beta cells in an autocrine and/or paracrine fashion. In fact, CXCL10 neutralization enhanced proliferative response of beta cells and resultantly increased beta cell mass without inhibiting insulitis. Thus, CXCL10 neutralization can be a new therapeutic target for beta cell survival, not only during the early stage of type 1 diabetes, but also after islet transplantation.

Animals↗
PubMed2004

Evidence for recruitment of plasmacytoid dendritic cell precursors to inflamed lymph nodes through high endothelial venules.

Recruitment of dendritic cells (DCs) to lymph nodes (LNs) is pivotal to the establishment of immune response. Whereas DCs have been proven to undergo afferent lymphatic pathway to enter LNs from peripheral tissues, a question remains if DCs also migrate into LNs directly from the circulation. Here we demonstrate that plasmacytoid DC (pDC) precursors can transmigrate across high endothelial venules (HEVs) of inflamed LNs in mice. Bacterial infection induces a significant number of pDC and myeloid DC (mDC) precursors into the circulation. Both subsets express a common set of chemokine receptors except CXCR3, display parallel mobilization into the blood, but show distinct trafficking pathway to the LNs. In a short-term homing assay, whereas mDC precursors migrate to peripheral tissues and subsequently to draining LNs, pDC precursors directly enter the LNs in a CXCL9 and E-selectin dependent manner. Tumor necrosis factor-alpha controls not only DC precursor mobilization into the blood but also chemokine up-regulation on LN HEVs. A similar trafficking pathway is observed also in viral infection, and CXCR3(-/-) mice-derived pDC precursors show defective trans-HEV migration. This study clarifies the inflammation-dependent, chemokine-driven distinct property of DC precursor trafficking.

Animals↗
PubMed2003

T-cell function in anti-GAD65(+)diabetes with residual beta-cell function.

We have recently reported that in patients with anti-glutamic acid decarboxylase (GAD) 65(+)diabetes with residual beta-cell function, most with a 'high-titer' (>10U/ml) required insulin within 5 years, whereas most with a 'low-titer' (1.3-9.9U/ml) did not need insulin for over 15-20 years after the onset. We therefore examined T-cell function to evaluate the difference between the high-titer and low-titer groups. Interleukin (IL)-10 production upon polyclonal activation was significantly lower in the high-titer group than in the low-titer group. The serum level of interferon-inducible protein-10 (IP-10) was higher in the high-titer than the low-titer group. Although GAD65-reactive CD4(+)cells in the periphery were detected in both groups, a significant positive correlation between serum IP-10 level and the number of GAD65-reactive CD4(+)cells was observed only in the high-titer group. Therefore, it has been speculated that the co-existence of GAD65-reactive IFN-gamma-producing CD4(+)cells and a high serum IP-10 level may be important for rapid disease progression as seen in the high-titer group. Based upon these results, T-cell function is considered to be different between the high-titer and low-titer groups in anti-GAD65(+)diabetes with residual beta-cell function, supporting our previous findings regarding the clinical outcome of insulin-dependence in the two groups.

Adult↗
PubMed2003

IL-1-induced tumor necrosis factor-alpha elicits inflammatory cell infiltration in the skin by inducing IFN-gamma-inducible protein 10 in the elicitation phase of the contact hypersensitivity response.

Contact hypersensitivity (CHS) is a typical inflammatory response against contact allergens. Inflammatory cytokines, including IL-1 and tumor necrosis factor (TNF)-alpha, are implicated in the reaction, although the precise roles of each cytokine have not been completely elucidated. In this report, we dissected the functional roles of IL-1 and TNF-alpha during CHS. CHS induced by 2,4,6-trinitorochlorobenzene as well as oxazolone was suppressed in both IL-1alpha/beta(-/-) and TNF-alpha(-/-) mice. Hapten-specific T cell activation, as examined by T cell proliferation, OX40 expression and IL-17 production, was reduced in IL-1alpha/beta(-/-) mice, but not in TNF-alpha(-/-) mice, suggesting that IL-1 but not TNF-alpha is required for hapten-specific T cell priming in the sensitization phase. On the other hand, TNF-alpha, induced by IL-1, was necessary for the induction of local inflammation during the elicitation phase. We also found that the expression of IFN-gamma-inducible protein 10 (IP-10) was augmented at the inflammatory site. Although IP-10 mRNA expression was abrogated in TNF-alpha(-/-) mice, both CHS development and TNF-alpha mRNA expression occurred normally in IFN-gamma(-/-) mice, indicating that the induction of IP-10 during CHS was primarily controlled by TNF-alpha. Interestingly, CHS was suppressed by treatment with anti-IP-10 mAb, suggesting a critical role for IP-10 in CHS. Reduced CHS in TNF-alpha(-/-) mice was reversed by IP-10 injection during the elicitation phase. Thus, it was shown that the roles for IL-1 and TNF-alpha are different, although both cytokines are crucial for the development of CHS.

Animals↗
PubMed2003

IFN-inducible protein-10 has a differential role in podocyte during Thy 1.1 glomerulonephritis.

IFN-inducible protein-10 (IP-10/CXCL10) is a potent chemoattractant for activated T lymphocytes and was recently reported to have several additional biologic activities. In this study, the expression and the function in normal glomeruli and in Thy1.1 glomerulonephritis (GN) were investigated. The expression of IP-10 was detected in normal rat glomeruli mainly in the podocyte. The expression of IP-10 was also detected on the cultured podocyte. The IP-10 expression was elevated at the early phase of Thy1.1 GN. The double staining immunofluorescence study clearly demonstrated that the elevated expression of IP-10 was mostly detected in the podocyte and very partly in mesangial area. A receptor for IP-10, CXCR3, showed similar expression patterns to that of IP-10. Expressions of neither of IP-10 nor of CXCR3 were detected on the inflammatory cells. For elucidating the role of IP-10, the blocking study was carried out with monoclonal anti-IP-10 antibody. The monoclonal anti-IP-10 antibody treatment decreased the expression of IP-10 and podocyte-associated proteins such as nephrin and podocin that are reported to be essential for maintaining the podocyte function (IP-10, 53.0% to control; nephrin, 43.5%; podocin, 60.4%). The findings indicated that the anti-IP-10 treatment disturbed the podocyte function. The anti-IP-10 treatment given to the rats with Thy1.1 nephritis exacerbated proteinuria, mesangiolysis, and matrix expansion. Collectively, the findings indicated that IP-10 plays a role in maintaining the podocyte function. Also, the findings suggested that anti-IP-10 treatment exacerbated the glomerular alterations in Thy1.1 GN by disturbing the podocyte function.

Animals↗
PubMed2003

Two cases of "fulminant" type 1 diabetes suggesting involvement of autoimmunity.

Recently, a novel subtype of type 1 diabetes, so-called fulminant type 1 diabetes, has been proposed. One of the characteristics of this subtype is the absence of detectable "islet-associated" autoantibody, so it was originally proposed as being "nonautoimmune-mediated"; however, it has not yet been concluded whether autoimmunity is involved. We have previously shown that serum interferon-inducible protein-10 and glutamic acid decarboxylase-reactive CD4(+) interferon-gamma-producing cells in the peripheral blood are good markers for T cell-mediated autoimmunity in type 1 diabetes. Here, we report two cases of fulminant type 1 diabetes in which these markers were detected and in which the involvement of islet-associated autoimmunity is suggested.

Adult↗
PubMed2002

Pivotal role of dendritic cell-derived CXCL10 in the retention of T helper cell 1 lymphocytes in secondary lymph nodes.

Various immune diseases are considered to be regulated by the balance of T helper (Th)1 and Th2 subsets. Although Th lymphocytes are believed to be generated in draining lymph nodes (LNs), in vivo Th cell behaviors during Th1/Th2 polarization are largely unexplored. Using a murine granulomatous liver disease model induced by Propionibacterium acnes, we show that retention of Th1 cells in the LNs is controlled by a chemokine, CXCL10/interferon (IFN) inducible protein 10 produced by mature dendritic cells (DCs). Hepatic LN DCs preferentially produced CXCL10 to attract 5'-bromo-2'-deoxyuridine (BrdU)+CD4+ T cells and form clusters with IFN-gamma-producing CD4+ T cells by day 7 after antigen challenge. Blockade of CXCL10 dramatically altered the distribution of cluster-forming BrdU+CD4+ T cells. BrdU+CD4+ T cells in the hepatic LNs were selectively diminished while those in the circulation were significantly increased by treatment with anti-CXCL10 monoclonal antibody. This was accompanied by accelerated infiltration of memory T cells into the periphery of hepatic granuloma sites, most of them were in cell cycle and further produced higher amount of IFN-gamma leading to exacerbation of liver injury. Thus, mature DC-derived CXCL10 is pivotal to retain Th1 lymphocytes within T cell areas of draining LNs and optimize the Th1-mediated immune responses.

Animals↗
PubMed2002

Neutralization of IFN-inducible protein 10/CXCL10 exacerbates experimental autoimmune encephalomyelitis.

We examined the effect of a monoclonal antibody (mAb) against interferon (IFN)-inducible protein 10 (IP-10)/CXCL10 on the development of experimental autoimmune encephalomyelitis (EAE) in rats induced by injecting xenogeneic brain homogenates into footpads. Treatment with neutralizing mAb against CXCL10 exacerbated EAE with increased infiltrating CD4+ cells in the central nervous system. Furthermore, the exacerbation by the mAb treatment was accompanied by less enlarged draining popliteal lymph nodes (LN) in parallel with cell number compared with those of EAE rats treated with control mAb, whereas other lymphoid organs such as the spleen and thymus were not significantly different between rats treated with anti-CXCL10 and the control mAb. Induction of gene expression of CXCL9/Mig and CXCL10 and their receptor CXCR3 was confirmed in the draining LN in EAE rats. Induction of the third CXCR3 ligand, CXCL11/I-TAC was not seen in the draining LN, whereas all three CXCR3 ligands and CXCR3 itself were markedly detected in the spinal cords following the development of EAE. These findings suggest that CXCL10 produced in the LN plays a specific inhibitory role in the development of Th1-mediated diseases such as EAE by holding sensitized and activated Th1s expressing CXCR3 in the draining LN.

Animals↗
PubMed2002

Blockade of CXCL10 protects mice from acute colitis and enhances crypt cell survival.

Crypt cell renewal is essential for normal intestinal homeostasis as well as mucosal regeneration following injury. However, the factors regulating crypt cell growth in pathological conditions are not fully understood. We report here that the endogenously produced chemokine CXCL10 regulates crypt cell proliferation. CXCL10 was constitutively expressed by basal crypts in mouse colon, but the expression of CXCL10 as well as CXCR3 was enhanced in the epithelium in the proliferative zone after oral administration of dextran sulfate sodium. Neutralization of CXCL10 protected mice from epithelial ulceration by promoting crypt cell survival without evidence of altered immune cell infiltration. Furthermore, recombinant CXCL10 administration into mice inhibited intestinal epithelial cell proliferation. These findings suggest that CXCL10 regulates crypt cell growth to maintain intestinal homeostasis in an autocrine or paracrine fashion. Thus, CXCL10 can be a new therapeutic target for inflammatory bowel disease by controlling the dynamics of epithelial homeostasis.

Acute Disease↗