Biomedical subjects

Hideki Nakano

Publications and source records attributed to Hideki Nakano.

At least 19 recordsLinked to original sources

PubMed2006

Enhanced allergen-induced airway inflammation in paucity of lymph node T cell (plt) mutant mice.

BACKGROUND: Dendritic cells and lymphocytes play a central role in allergic asthma. Chemokines for these cells include the CCR7 agonists secondary lymphoid chemokine/CCL21 and EBV-induced lymphoid chemokine/CCL19, but their role in allergic asthma is poorly understood. OBJECTIVE: We sought to determine the effects of abrogation of lymphoid tissue expression of CCR7 agonists on allergic airway responses. METHODS: Paucity of lymphocyte T cell (plt) mutant mice, deficient in EBV-induced lymphoid chemokine/CCL19 and the lymphoid form of secondary lymphoid chemokine/CCL21, were evaluated in an established ovalbumin (OVA)-induced asthma model (plt-OVA group) and compared with similarly immunized +/+ BALB/c mice (+/+OVA group). RESULTS: APTI responses to methacholine increased similarly in OVA-challenged plt and +/+ mice. However, airway inflammation was strikingly enhanced in plt-OVA mutants over +/+OVA mice and included increased numbers of eosinophils, CD4 and B cells, neutrophils, and total leukocytes in bronchoalveolar lavage fluid and inflammatory cell cuffing around pulmonary arterioles. Enhanced airway inflammation was accompanied by an increase in lung T(H)2 activity, with increased levels of IL-4 and monocyte-derived chemoattractant/CCL22. CONCLUSIONS: Induction of allergic asthma in mutant mice with impaired CCR7 responses results in characteristics that resemble severe asthma in human subjects, including severe bronchial lymphocytosis, eosinophilia, and neutrophilia, but not in enhancement in airway hyperreactivity. CLINICAL IMPLICATIONS: Disruption of chemokines responsible for trafficking of antigen-processing cells and lymphocytes to the draining lymph nodes might lead to enhanced allergic airway responses.

Allergens↗

PubMed2006

Chemokines CCL19 and CCL21 promote activation-induced cell death of antigen-responding T cells.

Secondary lymphoid organs (SLOs) provide a niche for the initiation and regulation of T-cell responses, but the mechanisms have been poorly understood. We investigated the influence of chemokines CCL19 and CCL21 constitutively expressed in SLOs on activation-induced cell death (AICD) of CD4+ T cells. When paucity of lymph node T cells (plt) mutant mice lacking expression of CCL19/CCL21 were primed with OVA/CFA, both expansion of OVA-responding CD4+ T cells in the draining lymph nodes and an in vitro recall response were prolonged as compared with responses in wild-type (WT) mice. The apoptotic cell frequency among OVA-responding CD4+ T cells was similarly low in plt/plt and WT mice during the clonal expansion phase. However, during the clonal contraction phase, the frequency never increased in plt/plt mice, whereas in WT mice it continuously increased to a peak 18 days after immunization. The presence of CCL19/CCL21 during the in vitro stimulation of CD4+ T cells with anti-CD3 plus anti-CD28 significantly enhanced in vitro AICD induction of the restimulated T cells, partially through enhancing expression of Fas ligand. Our results suggest that CCL19/CCL21 produced by stromal cells and antigen-presenting cells regulate CD4+ T-cell immune responses in SLOs by promoting AICD.

Animals↗

PubMed2006

Lithium and dementia: a preliminary study.

Recent studies have shown that lithium may block the accumulation of amyloid-beta (Abeta) peptides and to inhibit the hyperphosphorylation of tau via the inhibition of GSK-3alpha in the brain of mice. The purpose of the present study is to examine whether lithium could potentially be effective for the prevention of Alzheimer's disease. We investigated the clinical records of 1,423 outpatients at a university psychiatric outpatient clinic and classified patients according to the following criteria: (a) absence of a diagnosis of dementia, (b) age 60 years or older, and (c) lithium had been prescribed and/or was currently prescribed. We compared these patients with randomly selected age and gender matched control group who had never been prescribed lithium. Despite no significant difference in MMSE scores between the lithium group, which consisted of patients receiving lithium treatment, and the control group, those who had previously received lithium and/or were currently prescribed lithium had significantly better MMSE scores than the control patients. The findings provide partial evidence to support the contention that lithium could offer hope as a preventive treatment for Alzheimer's disease. Further prospective studies with a large number of patients are warranted to investigate this potentially important effect.

Aged↗

PubMed2006

TLR4 signaling attenuates ongoing allergic inflammation.

The relationship between LPS exposure and allergic asthma is poorly understood. Epidemiologic studies in humans have found that exposure to LPS can protect, have no effect, or exacerbate allergic asthma. Similarly, LPS has had variable effects on allergic pulmonary inflammation in the mouse, depending on the model used. In the present study, we studied the effect of very low doses of LPS in models of both short-term and long-term allergen challenge. When challenged with allergen for short periods, wild-type and tlr4-deficient mice had similar responses. However, when challenged for periods of 1 wk or longer, tlr4-deficient mice developed dramatically increased airway eosinophils, serum IgE, and Th2 cytokines compared with similarly challenged, genetically matched C57BL/6 mice. The relative attenuation of allergic responses seen in C57BL/6 mice was dependent on bone marrow-derived cell-specific expression of tlr4, and was not associated with an increase in Th1 responses. The number of dendritic cells in lungs of challenged tlr4-deficient mice was significantly increased compared with those in challenged C57BL/6 mice. No differences were seen in the abilities of naive C57BL/6 and tlr4-deficient mice to develop allergen-specific tolerance after exposure to similar preparations of OVA, suggesting that tolerance and regulation of existing inflammation develop through different mechanisms. The attenuation of eosinophilic inflammation in C57BL/6 mice was abolished when these mice were challenged with OVA supplemented with additional LPS. Together, these findings show that low doses of endotoxin can have regulatory effects on allergic inflammation, particularly in the setting of ongoing allergen exposure.

Allergens↗

PubMed2006

Loss of dendritic cell migration and impaired resistance to Leishmania donovani infection in mice deficient in CCL19 and CCL21.

The encounter between APC and T cells is crucial for initiating immune responses to infectious microorganisms. In the spleen, interaction between dendritic cells (DC) and T cells occurs in the periarteriolar lymphoid sheath (PALS) into which DC and T cells migrate from the marginal zone (MZ) along chemokine gradients. However, the importance of DC migration from the MZ into the PALS for immune responses and host resistance to microbial infection has not yet been elucidated. In this study, we report that following Leishmania donovani infection of mice, the migration of splenic DC is regulated by the CCR7 ligands CCL19/CCL21. DC in plt/plt mutant mice that lack these chemokines are less activated and produce less IL-12, compared with those in wild-type mice. Similar findings are seen when mice are treated with pertussis toxin, which blocks chemokine signaling in vivo. plt/plt mice had increased susceptibility to L. donovani infection compared with wild-type mice, as determined by spleen and liver parasite burden. Analysis of splenic cytokine profiles at day 14 postinfection demonstrated that IFN-gamma and IL-4 mRNA accumulation was comparable in wild-type and plt/plt mice. In contrast, accumulation of mRNA for IL-10 was elevated in plt/plt mice. In addition, plt/plt mice mounted a delayed hepatic granulomatous response and fewer effector T cells migrated into the liver. Taken together, we conclude that DC migration from the MZ to the PALS is necessary for full activation of DC and the optimal induction of protective immunity against L. donovani.

Animals↗

PubMed2006

Global estimates of shark catches using trade records from commercial markets.

Despite growing concerns about overexploitation of sharks, lack of accurate, species-specific harvest data often hampers quantitative stock assessment. In such cases, trade studies can provide insights into exploitation unavailable from traditional monitoring. We applied Bayesian statistical methods to trade data in combination with genetic identification to estimate by species, the annual number of globally traded shark fins, the most commercially valuable product from a group of species often unrecorded in harvest statistics. Our results provide the first fishery-independent estimate of the scale of shark catches worldwide and indicate that shark biomass in the fin trade is three to four times higher than shark catch figures reported in the only global data base. Comparison of our estimates to approximated stock assessment reference points for one of the most commonly traded species, blue shark, suggests that current trade volumes in numbers of sharks are close to or possibly exceeding the maximum sustainable yield levels.

Animals↗

PubMed2006

[Risk factors for suicide: a questionnaire survey by psychiatrists in Fukuoka Prefecture].

In our previous study, we demonstrated a preliminary questionnaire survey to psychiatrists from university hospitals, psychiatric hospitals, psychiatric clinics, and departments of psychiatry in general hospitals in Fukuoka Prefecture. In that study, 324 psychiatric patients who committed suicide between January 1, 1998 and December 31, 2001 were ascertained. In the present study, we have recruited matched control patients from the same clinics/hospitals and further demonstrated a secondary questionnaire survey to the psychiatrists in order to reveal the various risk factors for suicide suggested by the literature. Associations between completed suicide and possible risk factors were examined in 192 completed suicide psychiatric patients and 356 non-suicidal psychiatric patients (controls). Significant association was found for history of admission to psychiatric hospitals, history of suicide attempts, history of substance abuse, cluster B personality disorders, and hopelessness in our sample. In male samples, history of suicide attempts, cluster B personality disorders, recent loss, and hopelessness were significantly associated with suicide. In females, history of admission to psychiatric hospitals, history of suicide attempts, and hopelessness were significant.

Female↗

PubMed2005

Immunization with dendritic cells retrovirally transduced with mycobacterial antigen 85A gene elicits the specific cellular immunity including cytotoxic T-lymphocyte activity specific to an epitope on antigen 85A.

In the present study, we evaluated antigen 85A (Ag85A) gene-transduced dendritic cells (DCs) vaccine against Mycobacterium tuberculosis. Murine bone marrow-derived DCs were retrovirally transduced with mycobacterial Ag85A gene and injected to BALB/c mice intravenously. The DC vaccine was capable of inducing purified protein derivative (PPD)- and the antigen-specific spleen cell proliferation and IFN-gamma production from both CD4+ and CD8+ T cells in spleens of the immune mice. In addition, the DC vaccination induced cytotoxic T-lymphocytes (CTL) and IFN-gamma-producing cells specific for a 9-mer CTL epitope on Ag85A molecule. This eliciting cellular immunity led to protection against wasting disease due to M. tuberculosis infection and induction of moderate bacterial clearance.

Animals↗

PubMed2005

Role of CXC chemokine ligand 13, CC chemokine ligand (CCL) 19, and CCL21 in the organization and function of nasal-associated lymphoid tissue.

Nasal-associated lymphoid tissue (NALT) orchestrates immune responses to Ags in the upper respiratory tract. Unlike other lymphoid organs, NALT develops independently of lymphotoxin-alpha (LTalpha). However, the structure and function of NALT are impaired in Ltalpha(-/-) mice, suggesting a link between LTalpha and chemokine expression. In this study we show that the expression of CXCL13, CCL19, CCL21, and CCL20 is impaired in the NALT of Ltalpha(-/-) mice. We also show that the NALT of Cxcl13(-/-) and plt/plt mice exhibits some, but not all, of the structural and functional defects observed in the NALT of Ltalpha(-/-) mice. Like the NALT of Ltalpha(-/-) mice, the NALT in Cxcl13(-/-) mice lacks follicular dendritic cells, BP3(+) stromal cells, and ERTR7(+) lymphoreticular cells. However, unlike the NALT of Ltalpha(-/-) mice, the NALT of Cxcl13(-/-) mice has peripheral node addressin(+) high endothelial venules (HEVs). In contrast, the NALT of plt/plt mice is nearly normal, with follicular dendritic cells, BP3(+) stromal cells, ERTR7(+) lymphoreticular cells, and peripheral node addressin(+) HEVs. Functionally, germinal center formation and switching to IgA are defective in the NALT of Ltalpha(-/-) and Cxcl13(-/-) mice. In contrast, CD8 T cell responses to influenza are impaired in Ltalpha(-/-) mice and plt/plt mice. Finally, the B and T cell defects in the NALT of Ltalpha(-/-) mice lead to delayed clearance of influenza from the nasal mucosa. Thus, the B and T cell defects in the NALT of Ltalpha(-/-) mice can be attributed to the impaired expression of CXCL13 and CCL19/CCL21, respectively, whereas impaired HEV development is directly due to the loss of LTalpha.

Animals↗

PubMed2005

CCL19 and CCL21 induce a potent proinflammatory differentiation program in licensed dendritic cells.

Dendritic cells (DCs) are key instigators of adaptive immune responses. Using an alphaviral expression cloning technology, we have identified the chemokine CCL19 as a potent inducer of T cell proliferation in a DC-T cell coculture system. Subsequent studies showed that CCL19 enhanced T cell proliferation by inducing maturation of DCs, resulting in upregulation of costimulatory molecules and the production of proinflammatory cytokines. Moreover, CCL19 programmed DCs for the induction of T helper type (Th) 1 rather than Th2 responses. Importantly, only activated DCs that migrated from the periphery to draining lymph nodes, but not resting steady-state DCs residing within lymph nodes, expressed high levels of CCR7 in vivo and responded to CCL19 with the production of proinflammatory cytokines. Migrating DCs isolated from mice genetically deficient in CCL19 and CCL21 (plt/plt) presented an only partially mature phenotype, highlighting the importance of these chemokines for full DC maturation in vivo. Our findings indicate that CCL19 and CCL21 are potent natural adjuvants for terminal activation of DCs and suggest that chemokines not only orchestrate DC migration but also regulate their immunogenic potential for the induction of T cell responses.

Animals↗

PubMed2005

CXCL9 antagonism further extends prolonged cardiac allograft survival in CCL19/CCL21-deficient mice.

CCL19/MIP-3beta and CCL21/SLC are essential for chemotactic recruitment of mature dendritic cells (DC) to T-cell areas of secondary lymphoid tissue. Paucity of lymph node T-cells (plt/plt) mice lack CCL21-serine (ser) and CCL19 expression. We tested plt/plt and wild type (wt) BALB/c (H2d) mice as recipients of heart or skin allografts from C57BL/10J (H2b) donors. Donor DC trafficking to secondary lymphoid tissue was markedly reduced in plt heart but not skin allograft recipients. Heart, but not skin grafts survived significantly longer in plt recipients. Accordingly, T cells from plt heart transplant recipients demonstrated poor anti-donor responses in ex vivo MLR, compared to wt heart or wt and plt skin recipients. Moreover, donor-reactive T cells from plt heart recipients exhibited Th2-skewing in comparison to T cells from wt heart or skin graft recipients. Anti-CXCL9/Mig was administered for 2 weeks post-transplant to determine whether impairment of activated T-cell migration could further prolong cardiac allograft survival in plt recipients. CXCL9-antagonism extended graft survival significantly only in plt mice, likely due, in part, to retention of alloactivated T cells in secondary lymphoid tissue/reduction of graft-infiltrating T cells. Thus, targeting DC and activated T-cell migration concomitantly has additive effects in prolonging heart graft survival with potential for therapeutic application.

Animals↗

PubMed2005

[Analysis of CD1 molecules in the process of granuloma formation with sarcoidosis].

There have been many reports studying the presentation for lipid antigen by CD1 molecules on dendritic cells (DC), mainly in the infection of acid-fast bacilli. But little is known about the expression of CD1 molecules in sarcoidosis. In this study, we analyzed the expression of CD1 molecules by immunohistochemical stain with monoclonal anti-CD1a, CD1b and CD1c antibody for the specimens of nine sarcoidosis patients (sarcoidosis group) and seven control cases (control group). Aggregation of CD1 positive cells was present adjacent to granulomas in five cases of the sarcoidosis group, but was absent in all cases of the control group. There were no differences in the results of laboratory findings or disease activity between CD1-positive and negative cases in the sarcoidosis group. These data suggest that the presentation of lipid antigens mediated by CD1 molecules on DC is involved in granuloma formation in sarcoidosis.

Adult↗

PubMed2005

[An adult case of asymptomatic congenital tracheal stenosis].

A 42-year-old woman was admitted with abnormal chest radiographs. Though interstitial pneumonia associated with dermatomyositis was diagnosed, her chest radiograph also revealed a narrowed trachea about 6 mm in diameter. Bronchoscopy showed that her trachea lacked a membranous posterior segment and O-shaped complete tracheal rings were present throughout the trachea, indicating congenital tracheal stenosis. Congenital tracheal stenosis is a rare disorder and is usually recognized in the first few weeks of life, but the patient had no history of dyspnea or recurrent pneumonia. This case suggests that among healthy people there are a very few who have asymptomatic congenital tracheal stenosis.

Adult↗

PubMed2004

Localization of marginal zone macrophages is regulated by C-C chemokine ligands 21/19.

The marginal zone (MZ) of the spleen is an important site for the capture of blood-borne pathogens and a gateway for lymphocytes entering the white pulp. We have recently reported that Leishmania donovani infection results in a remarkably selective loss of MZ macrophages (MZM) from the MZ. To understand the basis of this observation, we have investigated how MZM maintain their anatomical distribution in the steady state in uninfected mice. We now report that plt/plt mice, which lack functional CCL19 and CCL21, have significantly reduced numbers of MZM compared with normal C57BL/6 (B6) mice. Similarly, in B6.CD45.1-->plt/plt chimeras, donor-derived MZM were rare compared with the number observed in reciprocal plt/plt-->B6.CD45.1 chimeras. Moreover, we show that administration of pertussis toxin, an inhibitor of chemokine receptor signaling, to B6 mice results in exit of MZM from the MZ, that MZM can migrate in response to CCL19 and CCL21 in vitro, and that MZM colocalize with CD31+CCL21+ endothelial cells. Collectively, these data indicate that CCL21 and, to a lesser extent, CCL19 play significant roles in the distinctive localization of MZM within the splenic MZ. Deficiency of CCL19 and CCL21, as also previously observed in mice infected with L. donovani, may thus account for the selective loss of MZM seen during this infection.

Animals↗

PubMed2004

The role of CCL21 in recruitment of T-precursor cells to fetal thymi.

During embryonic development, T-lymphoid precursor cells colonize the thymus. Chemoattraction by the fetal thymus is thought to mediate T-precursor cell colonization. However, the molecules that attract T-precursor cells to the thymus remain unclear. By devising time-lapse visualization in culture, the present results show that alymphoid fetal thymus lobes attract T-precursor cells from fetal liver or fetal blood. CD4(-)CD8(-)CD25(-)CD44+ fetal thymocytes retained the activity to specifically re-enter the thymus. The attraction was predominantly due to I-A-expressing thymic epithelial cells and was mediated by pertussis toxin-sensitive G-protein signals. Among the chemokines produced by the fetal thymus, CCL21, CCL25, and CXCL12 could attract CD4(-)CD8(-)CD25(-)CD44+ fetal thymocytes. However, fetal thymus colonization was markedly diminished by neutralizing antibodies specific for CCL21 and CCL25, but not affected by anti-CXCL12 antibody. Fetal thymus colonization was partially defective in CCL21-deficient plt/plt mice and was further diminished by anti-CCL25 antibody. These results indicate that CCL21 is involved in the recruitment of T-cell precursors to the fetal thymus and suggest that the combination of CCL21 and CCL25 plays a major role in fetal thymus colonization.

Animals↗

PubMed2004

CCR7 signals are essential for cortex-medulla migration of developing thymocytes.

Upon TCR-mediated positive selection, developing thymocytes relocate within the thymus from the cortex to the medulla for further differentiation and selection. However, it is unknown how this cortex-medulla migration of thymocytes is controlled and how it controls T cell development. Here we show that in mice deficient for CCR7 or its ligands mature single-positive thymocytes are arrested in the cortex and do not accumulate in the medulla. These mutant mice are defective in forming the medullary region of the thymus. Thymic export of T cells in these mice is compromised during the neonatal period but not in adulthood. Thymocytes in these mice show no defects in maturation, survival, and negative selection to ubiquitous antigens. TCR engagement of immature cortical thymocytes elevates the cell surface expression of CCR7. These results indicate that CCR7 signals are essential for the migration of positively selected thymocytes from the cortex to the medulla. CCR7-dependent cortex-medulla migration of thymocytes plays a crucial role in medulla formation and neonatal T cell export but is not essential for maturation, survival, negative selection, and adult export of thymocytes.

Animals↗

PubMed2004

Symptomatological and cognitive predictors of insight in chronic schizophrenia.

Studies of schizophrenia show lack of agreement about the relationship of symptomatological and cognitive factors to insight. In this study, positive and negative symptomatology and cognitive function were assessed by the Positive and Negative Syndrome Scale (PANSS), the Wisconsin Card Sorting Test (WCST), and the Wechsler Adult Intelligence Scale Revised (WAIS-R) in male chronic schizophrenic patients in relation to level of insight measured with the Japanese version of the Schedule for the Assessment of Insight (SAI-J). Negative symptoms were significantly and negatively associated with overall insight, particularly with treatment compliance and recognition of mental illness. The present findings suggest that aspects of insight such as treatment compliance and recognition of mental illness are negatively associated with negative symptoms.

Adult↗

PubMed2004

Predicting denial function of schizophrenic patients by the picture completion subtest of WAIS-R.

In the previous study, picture completion (PC) test scores of Wechsler Adult Intelligence Scale Revised (WAIS-R) were negatively associated with recognition of mental illness measured by Schedule for the Assessment of Insight (SAI). Therefore, it can be hypothesized that function measured by the PC test is positively associated with denial function. To investigate this hypothesis, we investigated the relationship between two picture tests (picture completion and picture arrangement) of the WAIS-R and denial function tests (lie scale, frequency scale and correction scale) of the Minnesota Multiphasic Personality Inventory (MMPI) in 26 schizophrenic patients. As a result, the lie scale score and the correction scale score were positively and significantly associated with picture completion whereas no scale score was significantly associated with picture arrangement. The present findings suggest that the positive association between function measured by the PC test and denial function measured by lie and correction scale scores. Further studies are warranted to investigate the usefulness of the PC test for the measurement of denial function in schizophrenia.

Adult↗