Biomedical subjects

I Iwamoto

Publications and source records attributed to I Iwamoto.

At least 91 records · Page 5Linked to original sources

PubMed1996

Common T cell receptor clonotype in lacrimal glands and labial salivary glands from patients with Sjögren's syndrome.

Sjogren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration into lacrimal and salivary glands leading to symptomatic dry eyes and mouth. Immunohistological studies have clarified that the majority of infiltrating lymphocytes around the lacrimal glands and labial salivary glands are CD4 positive alphabeta T cells. To analyze the pathogenesis of T cells infiltrating into lacrimal and labial salivary glands, we examined T cell clonotype of these cells in both glands from four SS patients using PCR-single-strand conformation polymorphism (SSCP) and a sequencing method. SSCP analysis showed that some infiltrating T cells in both glands expand clonally, suggesting that the cells proliferate by antigen-driven stimulation. Intriguingly, six to sixteen identical T cell receptor (TCR) Vbeta genes were commonly found in lacrimal glands and labial salivary glands from individual patients. This indicates that some T cells infiltrating into both glands recognize the shared epitopes on autoantigens. Moreover, highly conserved amino acid sequence motifs were found in the TCR CDR3 region bearing the same TCR Vbeta family gene from four SS patients, supporting the notion that the shared epitopes on antigens are limited. In conclusion, these findings suggest that some autoreactive T cells infiltrating into the lips and eyes recognized restricted epitopes of a common autoantigen in patients with SS.

Amino Acid Sequence↗

PubMed1996

Mechanistic analysis of high antitumor effect of intradermal administration of lipopolysaccharide from Pantoea Agglomerans.

Lipopolysaccharide from Pantoea Agglomerans (LPSp) has a remarkably high antitumor activity even against poorly immunogeneic tumors when given by intradermal injection combined with cyclophosphamide (CY). We have extended this study to gain an insight into the mechanism of this antitumor effect, and especially into the induction of cell mediated immunity. In immunohistological studies, extensive necrosis and marked infiltration of the inflammatory cells at the tumor were observed after intradermal injection of LPSp combined with CY, but not after CY alone or after no treatment. The cells around the tumors were mostly neutrophils and macro phages (Mac 1+); T cells (CD4+, CD8+) were also present. The serum levels of cytokines, induced after intradermal injection of LPSp, were determined and compared with intravenous administration of LPSp or recombinant TNF-SAM2. TNF-alpha, IL-1, IL-6 and GM-CSF were measured by ELISA as a marker of cytokine induction. The peak level of TNF-alpha induced by intradermal injection of LPSp was about 5000 pg ml-1, which was considered relatively small since this level was observed even in clinical trial. There seems to be a longer period of release of TNF-alpha after an intradermal injection than after an intravenous injection. This may produce the remarkably high antitumor effect of the intradermal injection. The antitumor effect of intradermal administration combined with CY was evaluated in nude mice to clarify the role of T cells in high antitumor activity. In this experiment, antitumor activity was found to be much less in BALB/c nu/nu mice without regression, while complete regression was frequently observed in syngeneic mice, showing the crucial role of T cells in this treatment. These observations suggest that intradermal administration of LPSp in combination with CY continuously releases and induces not only extensive necrosis of the tumor but also cell mediated antitumor immunity, which may be indispensable for complete regression of the tumor. Clinical application of this treatment for advanced cancer patients is in progress.

Animals↗

PubMed1996

T-cell receptor repertoire of infiltrating T cells in lachrymal glands, salivary glands and kidneys from alymphoplasia (aly) mutant mice: a new model for Sjögren's syndrome.

Alymphoplasia (aly) mice are thought to provide a new model for systemic Sjögren's syndrome (SS), since they reveal remarkable infiltration of mononuclear cells into salivary glands, lachrymal glands and kidneys, and show histological findings similar to those in patients with SS. Cell transfer experiments demonstrate that T cells induce the infiltration of mononuclear cells into several tissues in aly mice. To analyse the pathogenesis of cell infiltration in various tissues, we examined T-cell receptor (TCR) V beta usage of T cells in salivary glands, lachrymal glands and kidneys from aly mice, using family-polymerase chain reaction (PCR) and PCR-single-strand conformation polymorphism (SSCP) methods. The results of SSCP demonstrated that the infiltrating T cells in the three organs expanded clonally, suggesting that they proliferate by antigen-driven stimulation. Some TCR V beta genes (V beta 1, 3, 6, 11, 12, 16) were commonly used in salivary glands, lachrymal glands and kidneys, while the V beta 7 gene was specifically expressed in kidneys. SSCP also showed that there were a few shared T-cell clones (V beta 3- and V beta 6-positive cells) among the three tissues. Indeed, sequence analysis of accumulated T cells showed that a conserved amino acid (leucine) at position 98 in the TCR V beta complementary determining region (CDR) 3 was detected in all organs at high frequency (41-57%) and the amino acid sequence motif (LG) was specifically conserved at a frequency of 32% in the three organs. In conclusion, T cells that infiltrate into lachrymal glands, salivary glands and kidneys of aly mutant mice might recognize shared common epitopes in all three organs and a kidney-specific antigen.

Animals↗

PubMed1996

Interleukin-12 prevents antigen-induced eosinophil recruitment into mouse airways.

Interleukin-12 (IL-12) is a key cytokine that promotes Th1-type cell-mediated immunity and inhibits Th2-type responses. We have previously shown that antigen-induced eosinophil recruitment into the airways of sensitized mice is mediated by Th2-type CD4+ T cells that produce IL-5. Therefore, to determine whether IL-12 regulates antigen-induced eosinophil recruitment into the airways, we studied the effect of recombinant murine IL-12 on antigen-induced eosinophil infiltration into the tracheas of sensitized mice, and also the effect of IL-12 on IL-5 and interferon-gamma (IFN-gamma) levels in bronchoalveolar lavage fluid (BALF) from the mice. The intraperitoneal administration of recombinant IL-12 (rIL-12) inhibited antigen-induced eosinophil infiltration into the mouse trachea in a dose-dependent manner. The administration of rIL-12 suppressed IL-5 levels but enhanced IFN-gamma levels in the BALF of the mice after antigen inhalation. The administration of rIL-12 also decreased in vitro antigen-induced IL-4 and IL-5 production, but not IFN-gamma production, in spleen cells of the mice. Furthermore, pretreatment with anti-IFN-gamma monoclonal antibody prevented the IL-12 inhibition of antigen-induced eosinophil infiltration into the tracheas of the mice. These results indicate that IL-12 downregulates antigen-induced eosinophil recruitment into the airways by inhibiting IL-5 production in sensitized animals.

Animals↗

PubMed1996

[Lupus anticoagulants in patients with systemic lupus erythematosus].

Lupus anticoagulants (LA) and anticardiolipin antibodies (aCL) are known as thrombosis-related antiphospholipid antibodies. LA is not as well characterized as aCL, and the relation between LA and aCL is not clarified. Since standardized method for the detection of LA has not been established, we measured LA activities in outpatients with SLE by using two different methods (KCT and dRVVT), and analyzed the characteristics of LA in SLE. LA was detected in 29.8% of all samples (14.3% in both methods, 15.5% in one method). IgG-aCL and IgM-aCL was detected in 38% and 20%, respectively, of all LA positive samples. Though a good correlation was observed between LA activities and IgG-aCL levels, a considerable number of LA positive samples were negative for aCL. This indicated the presence of factors with LA activity other than aCL. On the contrary there was also a high percentage of LA negative samples with positive aCL (42.4% in IgG-aCL, 47.4% in IgM-aCL), suggesting the presence of aCL with poor or low LA activity. These findings showed the heterogeneity of antiphospholipid antibodies both in LA and in aCL. The platelet function tests showed increased platelet adhesiveness and normal platelet aggregation in LA positive patients with SLE even in the inactive phase. The serum levels of factors such as protein C, protein S, antithrombin III and thrombomodulin were within normal range. Clinical features such as hemolytic anemia, thrombosis and abortion were more frequently observed in LA positive population than in LA negative population. The clinical features tend to be different between patients with dRVVT-LA and those with KCT-LA, though not significant. Because of the heterogeneity in LA, a combination of more than two different methods including dRVVT was recommended for the detection and the evaluation of LA.

Adult↗

PubMed1996

[Mechanism and regulation of IgE production in allergy].

IgE plays an important role in allergic inflammation. IgE production is regulated by CD4 T cells, in which two functional subsets, Th1 and Th2 cells, exist on the basis of cytokine profiles. Th1 cells produce IL-2 and IFN-gamma that mediate cell-mediated immunity, and Th2 cells produce IL-4, IL-5, IL-6, and IL-10 that mediate humoral immunity. In addition, Th1 and Th2 cells regulate each other. B cell differentiation into IgE producing cells requires two signals, provided by Th2 cells, those through CD40 and IL-4. Humoral immune response, producing IgE, is terminated through the deletion of activated B cells by Th1 cells expressing FasL. Therefore, a balance between Th1 and Th2 cells is critical in the regulation of allergic inflammation. Finally, two possible strategies for allergic diseases are discussed, one is an induction of antigen-specific T cell tolerance and the other is immune deviation to Th1 cells.

Animals↗

PubMed1995

Limited TCR repertoire of infiltrating T cells in the kidneys of Sjögren's syndrome patients with interstitial nephritis.

To analyze the mechanism of interstitial nephritis in patients with Sjörgren's syndrome (SS), we examined the TCR repertoire of infiltration T cells in kidney, labial salivary glands, and PBLs using a PCR. The repertoire of the TCR V beta gene on infiltrating T cells from the kidneys of SS patients was more restricted than those on infiltrating T cells in labial salivary glands and PBL. The TCR V beta 2 gene was expressed predominantly in six of seven (86%) SS patients. Junctional sequences of cDNAs encoding the V beta 2 gene on infiltrating T cells in the kidneys of five SS patients showed that some of the cells expanded clonally, indicating Ag-driven stimulation rather than superantigen-induced proliferation. The same V beta 2 clones in the kidney were not detected in labial salivary glands of the same SS patients; the conserved amino acid (arginine at position 96) in the CDR3 region of the V beta 2 gene was found at a frequency of 48.0% in the kidney, whereas it was detected in only 15.4% of the clones in lips. In conclusion, these findings suggest the possibility that T cells that infiltrate the kidneys of SS patients with interstitial nephritis might recognize different autoantigens than those that infiltrate labial salivary glands.

Amino Acid Sequence↗

PubMed1995

Selective reduction of T cells bearing invariant V alpha 24J alpha Q antigen receptor in patients with systemic sclerosis.

A novel subset of T cells characterized by the expression of an invariant T cell antigen receptor (TCR) encoded by V alpha 24J alpha Q gene segments was investigated in patients with systemic sclerosis (SSc). Polymerase chain reaction analysis demonstrated that the V alpha 24 TCR repertoire was selectively used in CD4-CD8- double-negative T cells both in patients and in healthy individuals, while almost all families of TCR V alpha were expressed in single-positive T cell fractions. The V alpha 24+ double-negative T cells were increased by approximately fivefold in patients. However, sequence analysis clearly showed significant differences in the V alpha 24 TCR repertoire dominating in patients and healthy donors. In healthy individuals, the invariant V alpha 24J alpha Q was expanded and comprised 20-50% of the total TCR-alpha, while their selective reduction was observed in SSc patients who also showed expansion of invariant V alpha 24 TCR other than V alpha 24J alpha Q. Analogous to murine invariant V alpha 14J alpha 281 TCR, these results suggest that T cells with invariant V alpha 24J alpha Q TCR would function as regulatory T cells, whereas T cells bearing other invariant V alpha 24 TCR in SSc patients could be autoaggressive T cells in nature.

Asian People↗

PubMed1995

Investigation of EB virus and cytomegalovirus in rapidly progressive interstitial pneumonitis in polymyositis/dermatomyositis by in situ hybridization and polymerase chain reaction.

In polymyositis/dermatomyositis (PM/DM), a rapidly progressive interstitial pneumonitis (RPIP) which is a fatal complication of unknown etiology has received increasing attention. We have encountered 9 RPIP cases among 150 PM/DM cases in the past 10 years. To investigate the pathogenic role of viruses in RPIP, we examined lung specimens from patients with RPIP in PM/DM for the presence of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) using polymerase chain reaction (PCR) and in situ hybridization (ISH). We analyzed 21 specimens from RPIP in PM/DM (n = 9), collagen diseases (n = 6; 4 had interstitial lung disease), and controls (n = 6). EBV was frequently detected in RPIP (7/9 by PCR 3/9 by ISH), but was also detected in other collagen diseases of the lungs. In lung specimens from both patients with RPIP in PM/DM and those with collagen diseases, EBV was significantly detected (13/15 by PCR, 5/15 by ISH, P < 0.005) compared to controls (1/6 by PCR, 0/6 by ISH). CMV was detected by ISH in 2 RPIP patients but in none of he others, though by PCR CMV was detected equally in the three groups studied. These findings indicate that a direct involvement of EBV or CMV in RPIP of PM/DM is unlikely, although it is possible that an immune response to latent viruses or viral products in PM/DM may have a role in the pathogenesis of the RPIP.

Adult↗

PubMed1995

Esophagoaortic fistula caused by esophageal tuberculosis: report of a case.

We report herein the case of a 73-year-old woman who was urgently admitted to hospital with severe hematemesis. An emergency endoscopy revealed a protruding lesion 36 cm from the incisors; however, respiratory insufficiency precluded surgery and despite aggressive medical treatment, the patient's respiratory status continued to deteriorate, leading to death on the 36th hospital day. An autopsy revealed the source of the hemorrhage to be a fistula connecting the esophagus and the descending aorta. Histopathologic studies showed that this fistula was caused by esophageal tuberculosis.

Aged↗

PubMed1995

Induction of Th2 cell tolerance to a soluble antigen by blockade of the LFA-1-dependent pathway prevents allergic inflammation.

In this article, we show that induction of Th2 cell tolerance prevents antigen-induced eosinophil recruitment into the tissue and IgE antibody production, and that ICAM-1/LFA-1 interaction is involved as a costimulatory signal in inducing T cell tolerance to a soluble antigen. In vivo pretreatment with anti-ICAM-1 monoclonal antibody (mAb), anti-LFA-1 mAb, and a soluble antigen inhibited antigen-induced eosinophil recruitment into the airways and IgE antibody production in mice in an antigen-specific manner. In vitro antigen-induced IL-2, IL-4 and IL-5 production were decreased in spleen cells of the mice pretreated with the two mAbs and the antigen, indicating the induction of both Th1 and Th2 cell tolerance in vivo. These results suggest that the induction of antigen-specific Th2 cell tolerance by allergen immunotherapy with blockade of the ICAM-/LFA-1 interaction would be a rational therapeutic approach to allergic inflammation such as asthma.

Animals↗

PubMed1995

Intrapleural perfusion hyperthermo-chemotherapy for malignant pleural dissemination and effusion.

Taking advantage of the antitumor effect of hyperthermia, we administered intrapleural perfusion hyperthermo-chemotherapy for the treatment of malignant pleural seeding or pleural effusion. This consists of irrigating the pleural space for 2 hours with 43 degrees C saline solution containing cis-platinum using specially devised extracorporeal circuits. From January 1988 through December 1993, we performed this technique in 12 patients with malignant disseminated lesions stemming from lung cancer who also underwent surgical resection of the primary lesions and in 7 patients with malignant pleural effusions who did not undergo thoracotomy or surgical resection. There were no serious clinical complications associated with this procedure. The pharmacokinetics showed that a high concentration of cis-platinum (more than 17.6 micrograms/mL in the free form) was retained in the pleural cavity during perfusion. After this therapy, the cancer cells showed marked degeneration with fibrosis in the pleural wall. The pleural effusion was well controlled in 100% of the patients. The median survival time in the 12 patients with pleural disseminated lesions who were treated with intrapleural perfusion hyperthermo-chemotherapy was 20 months. On the other hand, the median survival time in 7 patients with similar lesions who did not receive IPHC was only 6 months. Intrapleural perfusion hyperthermo-chemotherapy seems to have considerable value as an adjuvant therapy for patients with pleural dissemination who have had their primary lesions removed.

Adult↗

PubMed1995

Substance P induces the expression of intercellular adhesion molecule-1 on vascular endothelial cells and enhances neutrophil transendothelial migration.

To determine whether substance P induces the expression of adhesion molecules ICAM-1 and VCAM-1 on vascular endothelial cells, we examined the effect of substance P, its carboxyl- and amino-terminal peptides, and neurokinin A on the expression of ICAM-1 and VCAM-1 on cultured human umbilical vein endothelial cells (HUVEC). Substance P and the carboxyl-terminal peptide SP(6-11), but not the amino-terminal peptide SP(1-9) or neurokinin A, increased ICAM-1 expression on HUVEC. In contrast, substance P did not significantly induce VCAM-1 expression on HUVEC. Furthermore, stimulation of HUVEC with substance P increased neutrophil transendothelial migration through an ICAM-1-dependent mechanism, as indicated by the inhibitory effect of anti-ICAM-1 antibody. These results indicate that substance P induces ICAM-1 expression on vascular endothelial cells and thereby enhances neutrophil transendothelial migration.

Antibodies, Monoclonal↗

PubMed1995

Effect of IL-4 and interferon-gamma (IFN-gamma) on IL-3- and IL-5-induced eosinophil differentiation from human cord blood mononuclear cells.

IL-4 and IFN-gamma positively and negatively regulate allergic inflammation. To determine the regulatory mechanisms of eosinopoiesis by cytokines, we examined the effect of recombinant IL-4 and IFN-gamma and of anti-IL-4 and anti-IFN-gamma antibodies on IL-3- and IL-5-induced eosinophil differentiation from human umbilical cord blood mononuclear cells. rhIL-4 (10-300 U/ml) inhibited IL-3- and IL-5-induced eosinophil differentiation from cord blood mononuclear cells on day 28 of culture by 62-81% in a concentration-dependent manner. rhIFN-gamma (5-500 U/ml) also inhibited IL-3- and IL-5-induced eosinophil differentiation by 80-99% in a concentration-dependent manner. The inhibitory effect of rhIL-4 and rhIFN-gamma was observed only when rhIL-4 or rhIFN-gamma were present in the culture from day 0 to day 14, but not from day 15 to day 28. Addition of anti-IL-4 antibody to the culture enhanced IL-3- and IL-5-induced eosinophil differentiation on day 28 of culture by 30%, whereas anti-IL-2 MoAb and anti-IFN-gamma MoAb had no significant effect. These results indicate that IL-4 and IFN-gamma have inhibitory effects on IL-3- and IL-5-induced eosinophil differentiation from its progenitor cells.

Antibodies↗

PubMed1995

Role of vascular cell adhesion molecule-1 and platelet-activating factor in selective eosinophil migration across vascular endothelial cells.

To determine the role of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in mediating selective eosinophil migration across vascular endothelial cells, we examined the effect of anti-ICAM-1 monoclonal antibody (mAb) and anti-VCAM-1 mAb on transendothelial migration of human eosinophils and neutrophils across IL-1- and IL-1-stimulated cultured vascular endothelial cells. We also studied the effect of a selective antagonist for platelet-activating factor (PAF) on the transendothelial migration of eosinophils and neutrophils. Transendothelial migration of eosinophils was increased by stimulation of the endothelial cells with IL-1 and IL-4, the latter of which has been shown to selectively induce VCAM-1 expression on the endothelial cells. On the other hand, neutrophil transendothelial migration was increased only by IL-1. Eosinophil migration across IL-4-stimulated endothelial cells was decreased by anti-ICAM-1 mAb and anti-VCAM-1 mAb. A selective PAF antagonist E6123 also decreased eosinophil migration across IL-4-stimulated endothelial cells. Eosinophil migration across IL-1-stimulated endothelial cells was also decreased by anti-ICAM-1 mAb and anti-VCAM-1 mAb in the presence of PAF antagonist. In contrast, neutrophil migration across IL-1-stimulated endothelial cells was decreased by anti-ICAM-1 mAb but not anti-VCAM-1 mAb. PAF antagonist alone or together with anti-VCAM-1 had no significant effect on IL-1-induced neutrophil transendothelial migration. These results indicate that VCAM-1 and PAF play an important role in mediating selective eosinophil migration across vascular endothelial cells.

Antibodies, Monoclonal↗

PubMed1995

Effect of a selective thromboxane A2 receptor antagonist BAY u3405 on antigen-, leukotriene C4- and leukotriene D4-induced bronchoconstriction in guinea pigs.

We studied the effect of a selective thromboxane (TX) A2 receptor antagonist BAY u3405 on prostanoid-, leukotriene (LT) C4, LTD4- and antigen-induced bronchoconstriction in nonanesthetized guinea pigs in vivo. Oral administration of BAY u3405 inhibited bronchoconstriction induced by inhaled TXA2 mimetic U46619, prostaglandin (PG) D2 and PGF2 alpha. BAY u3405 also decreased the bronchoconstriction induced by inhaled LTC4 and LTD4. Intraperitoneal administration of TXA2 synthetase inhibitor OKY-046 did not affect PGD2- and PGF2 alpha-induced bronchoconstriction, but attenuated LTC4- and LTD4-induced bronchoconstriction. BAY u3405 and OKY-046 decreased antigen-induced bronchoconstriction in actively sensitized guinea pigs. These results indicate that BAY u3405 not only inhibits TXA2-, PGD2- and PGF2 alpha-induced bronchoconstriction that is mediated through a TXA2 receptor but also decreases LTC4. LTD4- and antigen-induced bronchoconstriction which is mediated in part through TXA2 synthesis. These results suggest that BAY u3405 might be useful in controlling prostanoid-induced bronchoconstriction in asthma.

Animals↗

PubMed1995

[Effects of fluconazole on onychomycosis in the patients with collagen diseases].

Thirty-four patients with collagen diseases suffering from onychomycosis were treated with fluconazole and showed remarkable improvement. Thirty-one patients showed improvement while only four patients showed adverse reactions. More than half of the cases with onychomycosis in their fingers showed improvement within four weeks and complete recovery within 20 weeks after the administration of fluconazole. Patients with collagen diseases are liable to have onychomycosis as an opportunistic infection which is recalcitrant and resistant disease from the previous therapy. In this trial it became obvious that fluconazole was not only effective on onychomycosis but also a safe drug for the patients with collagen diseases.

Adult↗

PubMed1995

Identification of Ro(SSA) 52 kDa reactive T cells in labial salivary glands from patients with Sjögren's syndrome.

OBJECTIVE: To identify the self-antigens recognized by autoreactive T cells in labial salivary glands from patients with Sjõgren's syndrome (SS). METHODS: T cells lines were established from infiltrating T cells in the labial salivary glands from 6 patients with SS, using interleukin 2 and phytohemagglutinin. Bulk cultured T cells and T cell lines were examined for the proliferative response to recombinant Ro(SSA) 52 kDa and SSB proteins. The usage of T cell receptor (TCR) V beta and V alpha genes from Ro(SSA) 52kDa reactive T cells was analyzed by family polymerase chain reaction. The sequences of complementary determining region 3 of TCR V beta genes were also examined. RESULTS: Three of 6 bulk cultured T cells and 4 of 16 T cell lines showed a significant proliferative response to Ro(SSA) 52 kDa protein. All T cell lines represented CD4+ alpha beta T cells by flow cytometry analysis. All 4 RO(SSA) 52 kDa reactive T cell lines utilized the V beta 2 gene and 3 lines used the V beta 13 gene, suggesting preferential usage of the V beta 2 and the V beta 13 genes in Ro(SSA) 52 kDa reactive T cells. Junctional sequences of TCR V beta genes from Ro(SSA) 52 kDa reactive T cell lines showed the conserved amino acid sequences in CDR3 region. CONCLUSION: These findings support the notion that Ro(SSA) 52 kDa is a possible autoantigen recognized by autoreactive T cells and that limited epitope is present on the Ro(SSA) 52 kDa antigen.

Amino Acid Sequence↗