Biomedical subjects

H Takimoto

Publications and source records attributed to H Takimoto.

At least 73 records · Page 4Linked to original sources

PubMed1992

A new subpopulation of intestinal intraepithelial lymphocytes expressing high level of T cell receptor gamma delta.

The murine intestinal epithelium contains T cell receptor (TcR) gamma delta-bearing T cells in high frequency. In the present report, we showed that TcR gamma delta-bearing intestinal intraepithelial lymphocytes (IEL) from C3H/He (H-2k) mice can be divided into two subpopulations based on TcR expression level; a subpopulation with a remarkably high level of TcR expression and a subpopulation with a moderate level of TcR expression, designated as TcR gamma delta hi IEL and TcR gamma delta mod IEL, respectively. In flow cytometric analysis, the TcR gamma delta hi IEL expressed a high level of TcR (mean fluorescence channel 518) when compared with the TcR level of TcR gamma delta+ T cells in other lymphoid organs (mean fluorescence channel 88). The TcR gamma delta hi IEL were detected in IEL from mice of H-2k and H-2k/b haplotypes but not in H-2b and H-2d haplotypes. V delta 4, which was reported to be frequently expressed in IEL of H-2k mice, was preferentially expressed by TcR gamma delta hi IEL. These results suggested that the existence of the TcR gamma delta hi population is related to the high frequency of V delta 4 in H-2k mice.

Animals↗

PubMed1992

Protective effect of ren-shen-yang-rong-tang (Ninjin-youei-to) in mice with drug-induced leukopenia against Pseudomonas aeruginosa infection.

When 200 mg/kg of cyclophosphamide (CY) or 5-fluorouracil (5-FU) were given subcutaneously to mice, severe reduction of leukocyte numbers in the peripheral blood was observed on day 4 and from day 4 to day 8 after the treatment, respectively. Daily administration of ren-shen-yang-rong-tang (Japanese name: Ninjin-youei-to, NYT), (1 g/kg/day) and recombinant human granulocyte-colony stimulating factor (rhuG-CSF, 2 micrograms/mouse/day) either from day 0 to day 4 after treatment with CY or from day 0 to day 8 after treatment with 5-FU accelerated the recovery of peripheral leukocytes. Administration of NYT and rhuG-CSF inhibited decreases in the number of colony forming units in the spleen (CFU-S) in drug-treated mice. In mice infected intraperitoneally with a virulent strain of Pseudomonas aeruginosa 4 days and 8 days after treatment with CY and 5-FU, respectively, lethal doses were much lower (approximately 1/1000) than that in normal mice. Administration of NYT and rhuG-CSF to drug-treated mice inhibited the enhanced bacterial growth in the peritoneal cavity. Administration of NYT or rhuG-CSF to drug-treated mice enhanced the recovery of accumulation of leukocytes into the infected peritoneal cavity from their depressed state. Administration of NYT was more effective for improving the host resistance of 5-FU-treated mice than for improving that of CY-treated mice in contrast to rhuG-CSF which exhibited stronger effect in CY-treated mice than in 5-FU treated mice.

Animals↗

PubMed1992

Effect of a traditional Chinese medicine, bu-zhong-yi-qi-tang (Japanese name: Hochu-ekki-to) on the protection against Listeria monocytogenes infection in mice.

Effects of Bu-Zhong-Yi-Qi-Tang (Japanese name: Hochu-ekki-to) on the resistance against Listeria monocytogenes were observed in ICR mice orally administered this medicine daily for 10 days. Survival rates were increased by the pretreatment in mice inoculated i.v. with bacteria 1 day after the last administration and in mice inoculated i.p. 4 days after the last administration. After an i.v. inoculation of L. monocytogenes, the numbers of bacteria in the spleen and liver increased gradually to kill mice by day 5 in untreated group but the bacterial numbers increased slightly by day 3 and decreased from day 3 to day 8 in Hochu-ekki-to pretreated group. After an i.p. inoculation, the number of bacteria in the peritoneal cavity decreased very rapidly within 6h in Hochu-ekki-to treated group compared to that in untreated group. After the administration, number of polymorphonuclear cells increased in the peripheral blood, peritoneal cavity and spleen. In treated mice, macrophages increased in number in the peritoneal cavity and the spleen but decreased in the peripheral blood. Peritoneal macrophages from treated mice showed an enhanced activity to kill L. monocytogenes in vitro within 60 min after ingestion of bacteria. Hochu-ekki-to may augment the host defense against L. monocytogenes through the activation of macrophage series during an early phase of infection.

Administration, Oral↗

PubMed1991

Self-reactive T cells are activated by the 65-kDa mycobacterial heat-shock protein in neonatally thymectomized mice.

To elucidate the mechanism of autoimmune disease in neonatally thymectomized (NTX) mice, we have investigated the responsiveness of the self-reactive T cells which have not undergone clonal deletion in such animals. Consistent with a recent report (Yuuki et al., Eur. J. Immunol. 1990. 20: 1475), T cells bearing V beta 11-gene products capable of recognizing I-E-encoded molecules were readily detected in the mature T cell pool of NTX BALB/c (I-Ed, Mls-2a) mice. The V beta 11-bearing T cells in NTX mice expressed interleukin 2 receptors and responded normally to signals delivered through the T cell receptor. Notably, these T cells in NTX mice proliferated significantly after culture with the 65-kDa mycobacterial heat-shock protein, whose amino acid sequence is highly homologous to that in eukaryotes. These results suggest that self-reactive T cells in NTX mice may be activated by heat-shock proteins derived from various pathogens and/or stressed autologous cells, resulting in the development of autoimmune diseases in such animals.

Animals↗

PubMed1991

Effect of methyl esterification of isoglutamine residue in 6-O-acylated muramyl dipeptides on expression of immunopharmacological activities.

The effect of methyl esterification of the isoglutamine residue in 6-O-acylated muramyl dipeptide (MDP) on some biological activities was investigated. Methyl esterification influenced more or less the expression of all activities tested. The adjuvant and colony stimulating factor (CSF)-inducing activities of 6-O-acylated MDP analogs carrying a 3-hexadecanoyloxytetradecanoyl [C14-O-(C16)] group were stronger than those of the corresponding analogs carrying a 2-tetradecylhexadecanoyl (B30) group. Macrophage activation, i.e. induction of tumor necrosis factor (TNF) and promotion of phagocytosis, by 6-O-C14-O-(C16)-MDP methyl esters was weaker.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1991

Failure of T cell receptor V beta negative selection in murine intestinal intra-epithelial lymphocytes.

The intestinal intra-epithelial lymphocytes (IEL) are divided into several subsets on the basis of expression of T cell receptor (TCR) alpha beta and gamma delta, intensity of Thy-1 expression and expression of Lyt-3 chain. To investigate the differentiation pathway of the IEL, we examined the repertoire of V beta segments of T cells in the IEL in BALB/c (H-2d, MIs-1b2a) or AKR/J (H-2k, MIs-1a2b) mice. Among freshly isolated IEL, an appreciable number of T cells bearing V beta 3 or V beta 11, which recognize MIs-2a- or MHC IE-encoded molecules respectively, were detected in BALB/c mice. Similarly, in AKR/J mice, IEL contained appreciable levels of V beta 6-bearing T cells. V beta 3- or V beta 11-bearing T cells in the IEL in BALB/c mice increased to a significant level when incubated with staphylococcal enterotoxin A which specifically stimulates V beta 3- and V beta 11-bearing T cells. Most of IEL without clonal deletion expressed Lyt-2 but not Lyt-3 antigens. Such T cells were hardly detected in other organs, including liver. Our results indicate that TCR alpha beta-bearing intestinal IEL that have not undergone negative selection may have differentiated outside the thymus, presumably at a local site of the intestine and can respond normally to the signal via their TCR.

Animals↗

PubMed1991

Structural and biological comparison of lipopolysaccharides (LPS) from Bordetella species.

Lipopolysaccharides (LPS) isolated from Bordetella pertussis (Bp), B. parapertussis (Bpp), and B. bronchiseptica (Bbs) were analysed for their chemical composition, molecular heterogeneity, and immunological and biological properties. All LPS contained heptose, KDO, GlcN, uronic acid, phosphate, and fatty acids. The fatty acids C14:0, C16:0 and 3-OHC14:0 were common to all LPS preparations. By SDS-PAGE, Bp-LPS had two bands of low molecular mass, and Bpp- and Bbs-LPS showed a low molecular mass band together with ladder bands of high molecular mass. Immunological assays demonstrated that Bp-LPS reacted with antisera prepared from Bp and Bpp; Bpp-LPS reacted with antisera against Bpp and Bbs, and Bbs-LPS reacted with antisera against any of the three species. Bp-LPS showed biological activities comparable to those of E. coli LPS in terms of lethal toxicity, pyrogenicity, mitogenicity, macrophage activation, and induction of tumor necrosis factor. All activities of Bpp-LPS, except mitogenicity, were lower than those of E. coli LPS. Biological activities stronger or comparable to those of E. coli LPS were observed for Bbs-LPS.

Animals↗

PubMed1991

The stage of negative selection in tolerance induction in neonatal mice.

In flow microfluorometry analysis of thymus and lymph node cells of C57BL/6(I-E-,Mlsb) mice rendered neonatally tolerant to (C57BL/6 x AKR/J)F1 (I-E+,Mlsb/a) lymphoid cells, both CD4+ and CD8+ cells showed a striking reduction in the number of V beta 6+ cells capable of recognizing Mlsa in the context of major histocompatibility complex (MHC) class II molecules, indicating that clonal deletion of V beta 6+ cells by Mlsa antigen occurs just at a stage of immature V beta 6lowCD4+CD8+ thymocytes. On the other hand, the number of V beta 11+ cells capable of recognizing I-E was markedly reduced in CD4+ cells, but CD8+ cells showed only partial (20%) reduction of such a population. The clonal deletion of V beta 11+ cells by I-E may begin at the transitional stage from V beta 11lowCD4+CD8+ to V beta 11highCD4+CD8- single-position cells, and V beta 11lowCD4+CD8+ cells differentiating to V beta 11highCD4-CD8+ cells seem to be resistant to clonal deletion. V beta 11+ T cells are also stimulated by staphylococcal enterotoxin A (SEA) irrespective of expression of CD4 or CD8. Nearly all of both V beta 11+CD4+ and V beta 11+CD8+ lymph node T cells were deleted by the injection of SEA every other day from birth. In their thymi, both V beta 11+CD4+CD8- and V beta 11+CD4-CD8+ single-positive thymocytes were deleted, and the proportion of V beta 11low thymocytes was lower than that of normal mice. The clonal deletion of V beta 11+ T cells by SEA injection occurs at a stage of immature V beta 11lowCD4+CD8+ double-positive thymocytes, resulting in deletion of both V beta 11+CD4+ and V beta 11+CD8+ T cells.

Animals↗

PubMed1990

Stimulation of all T cells bearing V beta 1, V beta 3, V beta 11 and V beta 12 by staphylococcal enterotoxin A.

To determine the molecular mechanisms of T cell stimulation by staphylococcal enterotoxin A (SEA), we examined the expression of T cell receptor (TcR) V beta on the T cells from four strains of mice stimulated in vitro with SEA, using flow cytometric analysis for the number of T cells bearing V beta 3, V beta 6, V beta 8, V beta 11 and RNA blotting analysis for the amount of transcripts of V beta 1, V beta 5 and V beta 12. The number of T cell blasts bearing V beta 1, V beta 3, V beta 1 or V beta 12 were increased in the T cell blasts proliferating in vitro in response to SEA in C57BL/6 mice. In AKR/J mice, which contain few V beta 11- or V beta 12-bearing T cells due to a tolerance to the self-MHC class II IE-antigens, T cells bearing V beta 1 or V beta 3 responded to SEA. SEA enriched only V beta 1-bearing T cells in BALB/c mice carrying Mls-2a which lack Mls-1a-reactive V beta 3-bearing T cells as well as V beta 11- and V beta 12-bearing T cells. In spite of the presence of V beta 1-bearing T cells, C3H/He T cells exhibited a very low responsiveness to SEA. T cell repertoires skewed by clonal deletion of self-reactive T cells may in part account for the different sensitivity to SEA among the different strains. A tolerance to SEA can be established in C57BL/6 mice which have been primed i.v. with SEA and treated i.p. with 200 mg/kg of cyclophosphamide 2 days later. All mature T cells bearing V beta 3 or V beta 11 were virtually abolished in the periphery of tolerant mice. These results suggest that most T cells reactive to SEA bear V beta 1, V beta 3, V beta 11 or V beta 12 and that clonal deletion of mature T cells reactive to SEA may account for the cellular mechanisms for cyclophosphamide-induced tolerance to SEA.

Animals↗

PubMed1990

Clonal anergy in self-reactive alpha/beta T cells is abrogated by heat-shock protein-reactive gamma/delta T cells in aged athymic nude mice.

Although T cells proliferate and differentiate primarily in the thymus, athymic nude mice contain an appreciable level of T cell receptor alpha/beta and gamma/delta T cells, suggesting the existence of the extrathymic pathway in the development of both T cells. Recent studies with nude mice indicate that clonal deletion of self-reactive T cells does not occur extrathymically. In the present study, we have investigated the responsiveness of self-reactive T cells differentiating along an extrathymic pathway in aged BALB/c (H-2d, Mls-1b2a, I-E+, 7-8 month old) nude mice. Consistent with recent reports, T cells bearing V beta 3 or V beta 11, which are important for recognizing proteins encoded by the Mls-2a or the I-E allele, respectively, are readily detected in age nude mice. The V beta 3- or V beta 11-bearing T cells, however, do not proliferate in response to staphylococcal enterotoxin A which specifically stimulates V beta 3- or V beta 11-bearing T cells. When exogenous recombinant interleukin 2 was added to the culture, the V beta 3-bearing T cells in aged nude mice significantly proliferated in response to staphylococcal enterotoxin A. Aged nude mice also contained a substantial level of gamma/delta T cells which account for 15.6% of all Thy-1.2+ cells. The gamma/delta T cells proliferated and produced a significant level of interleukin 2 in response to the 65-kDa mycobacterial heat-shock protein, which is highly homologous to its eukaryotic counterpart. These results suggest that unresponsiveness of self-reactive T cells may be reversed by T cells responding to stress proteins expressed by the invading microbes and/or the stressed autologous cells.

Aging↗

PubMed1990

Biological properties of lipopolysaccharides isolated from Bordetella.

Biological activity of lipopolysaccharides (LPSs) separated from Bordetella, i.e., B. pertussis (Bp), B. parapertussis (Bpp) and B. bronchiseptica (Bbs), was determined and compared with that of an Escherichia coli LPS as a control. Two Bp-LPS preparations showed marked biological activities comparable to those of E. coli LPS in terms of lethal toxicity in galactosamine-sensitized mice, pyrogenicity in rabbits, mitogenicity in C3H/He spleen cell cultures, macrophage activation and tumor necrosis factor-inducing activity. All the activities except mitogenicity of two Bpp-LPS preparations were lower than or comparable to those of E. coli LPS. Activities stronger than or comparable to those of E. coli LPS were observed in two Bbs-LPS preparations. Among six LPS preparations from Bordetella tested, a Bbs-LPS from L3 strain exhibited the most intensive activities.

Animals↗

PubMed1990

Protective effect of saikosaponin A, saikosaponin D and saikogenin D against Pseudomonas aeruginosa infection in mice.

Effects of saikosaponins and their genins on nonspecific resistance against Pseudomonas aeruginosa and Listeria monocytogenes infections were investigated. When mice were administered intraperitoneally (i.p.) saikosaponins one day before i.p. infection with P. aeruginosa, saikosaponins a and d induced a marked enhancement of nonspecific resistance at a dose of 10 micrograms/mouse. Also, saikogenin D, a secondary metabolite of saikosaponin d, showed an enhancing effect. The most effective condition for enhancing the nonspecific resistance was i.p. administration of saikosaponin d one day before i.p. or intravenous (i.v.) infection with P. aeruginosa, when mice were treated i.p., i.v., or subcutaneously with saikosaponin d 1, 4 or 7 days previously. Effect of saikosaponin d was weaker than that of formalin-killed bacilli of Propionibacterium acnes and lipopolysaccharide. On the other hand, effect of saikosaponin d on enhancement of nonspecific resistance against L. monocytogenes was not seen. Effector cells participating in the enhanced protection induced by saikosaponin d may be macrophages, since macrophages were a major component in peritoneal cells obtained from mice administered i.p. saikosaponin d 1 day earlier and intracellular bactericidal activity of peritoneal macrophages against P. aeruginosa increased.

Animals↗

PubMed1990

Biological properties of lipopolysaccharides from Bordetella species.

Biological activities of lipopolysaccharides (LPS) extracted from Bordetella pertussis, B. parapertussis and B. bronchiseptica were compared with those of Escherichia coli LPS. The LPS preparations from B. pertussis showed biological activities comparable to those of E. coli LPS in terms of lethal toxicity in galactosamine-sensitized mice, pyrogenicity in rabbits, mitogenicity in C3H/He spleen cell cultures, macrophage activation, and induction of tumour necrosis factor. All the activities of LPS preparations from B. parapertussis, except mitogenicity, were lower than those of E. coli LPS. LPS from B. parapertussis gave the greatest mitogenic action of all those tested. Biological activities stronger than or comparable to those of E. coli LPS were observed for LPS from B. bronchiseptica.

Animals↗

PubMed1989

Activation of murine peritoneal macrophages by saikosaponin a, saikosaponin d and saikogenin d.

Macrophage activation by saikosaponins and saikogenins was investigated and compared with that by other saponins and macrophage stimulants. Saikosaponins a and d induced a marked cell accumulation in the peritoneal cavity when administered intraperitoneally. Among saikosaponins and saikogenins tested, saikosaponin d significantly activated peritoneal macrophages in terms of enhancement of phagocytic activity, increased level of cellular lysosomal enzyme (acid phosphatase), induction of cytostatic activity and expression of Ia antigen on the cell surface. The activities of saikosaponin d were much stronger than those of typical saponins ginsenoside Rg1 and glycyrrhizin and almost comparable with or somewhat weaker than those of lipopolysaccharide, a streptococcal preparation OK-432 and formalin-killed Propionibacterium acnes, indicating that saikosaponin d is a potent macrophage activator.

Animals↗

PubMed1989

Immunostimulatory activity of 1-O-acylated muramyl dipeptides, with or without a 6-O-phosphoryl group, in aqueous form.

Immunostimulatory effects of 1-O-acylated derivatives of N-acetyl-muramyl-L-alanyl-D-isoglutamine (MDP) methyl ester, with or without the 6-O-phosphoryl group, on augmentation of IgG antibody response against influenza hemagglutinin (HA) vaccine, in vivo macrophage activation and enhancement of non-specific host resistance against Pseudomonas aeruginosa infection were investigated. The activities were tested intraperitoneally (i.p.) in mice administered test samples solubilized or suspended in saline. The introduction of longer chain acyl groups into MDP methyl esters significantly induced enhancement of the IgG antibody response. Among them, the adjuvant activity of 1-O-linked 2-tetradecylhexadecanoyl (B30)-MDP methyl ester was comparable to that of 6-O-B30-MDP used as a positive control. Phosphorylation at the C6 position of the acylated MDP analogs did not induce a significant increment in the activity. With respect to phagocytic, cellular acid phosphatase and cytostasis-inducing activities, i.p. administration of acylated MDP analogs caused significant increment and activation of peritoneal macrophages. The cytostasis-inducing activity of 1-O-octadecanoyl- or 1-O-B30-MDP methyl ester with or without a phosphoryl group was more intensive than that of 6-O-B30-MDP. Acylated MDP analogs enhanced non-specific resistance against P. aeruginosa infection when the analogs were administered i.p. on the day before the infection. The enhancement was closely related to the accumulation of polymorphonuclear cells in the peritoneal cavity. The manifestation of these immunostimulatory activities by 1-O-acylated MDP analogs depended closely on the increasing carbon chain length of fatty acid substituents when administered in aqueous form.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1989

Enhancement of immunoglobulin G responses in mice against hepatitis B virus surface antigen, influenza virus hemagglutinin vaccine, and tetanus toxoid by 6-O-acylated muramyl dipeptides.

The adjuvant activity of chemically synthesized 6-O-acylated muramyl dipeptides (MDP) was tested in aqueous form. The activity was assessed by determining immunoglobulin G (IgG) titers in sera of mice immunized with hepatitis B virus surface antigen, influenza virus hemagglutinin (HA) vaccine, or tetanus toxoid with an enzyme-linked immunosorbent assay. Administration of 6-O-acyl-MDP analogs with antigens induced marked enhancement of primary and secondary IgG antibody responses and maintained high antibody levels for at least 7 weeks. Among the analogs tested, an MDP methyl ester carrying a 6-O-3-hexadecanoyl-oxytetradecanoyl group (compound 309) exhibited the most intensive adjuvant activity. Its activity was stronger than that of 6-O-2-tetradecylhexadecanoyl (B3O)-MDP used as a positive control. However, accumulation of peritoneal cells and activation of peritoneal macrophages by compound 309 was weaker than that by 6-O-B30-MDP, suggesting that 309 as an immunoadjuvant is more suitable for vaccination in terms of its stronger enhancement of antibody formation and lower induction of inflammatory response than 6-O-B30-MDP.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1989

Immunopharmacological activities of 2-keto-3-deoxyoctonic acid-(alpha 2----6)-linked 4-O-phosphono-D-glucosamine derivatives carrying N- and 3-O-acyl substituents.

The immunopharmacological activities of 2-keto-3-deoxyoctonic acid (KDO)-(alpha 2----6)-linked lipid A-subunit analogs, 4-O-phosphono-D-glucosamine derivatives carrying N- and 3-O-acyl substituents, were compared with those of the corresponding analogs without KDO, GLA-27, GLA-47, and GLA-60. Among the analogs tested, GLA-60, a 4-O-phosphono-D-glucosamine carrying N-3-hydroxytetradecanoyl and 3-O-3-tetradecanoyloxytetradecanoyl groups, exhibited the most intensive activities in terms of mitogenicity, adjuvanticity, and mediator (tumor necrosis factor and colony-stimulating factor) induction. Binding (alpha 2----6) of KDO to GLA-60 failed to enhance the activities. Similarly, the activities of GLA-27 and GLA-47 were also decreased by introduction of KDO to the O-6 of the analogs. This indicates that the strengths of the activities of the subunit analogs depend on the kinds of N- and 3-O-linked acyl substituents and not on the presence of the KDO linked to the O-6.

Adjuvants, Immunologic↗

PubMed1989

[Adoptive immunotherapy in patients with medulloblastoma by LAK cells].

Medulloblastoma is one of the most popular malignant brain tumors in children. It accounts for about 15% of all pediatric brain tumors. Radiochemotherapy has prolonged the 5-year survival rate up to 60-85% for patients with medulloblastoma. But the conventional therapy is not so effective to recurrent cases, especially with meningeal dissemination, and generally fatal. There remains a big problem of the neurotoxicity to infants in a growth process under the whole-neuraxis irradiation and chemotherapy. Aiming to relieve the radiation and antitumor drugs, adoptive immunotherapy is greatly expectant. We have had clinical trials of adoptive immunotherapy for 8 patients with medulloblastoma by lymphokine-activated killer (LAK) cells. They were from 2-9 years in age and had cerebrospinal fluid (CSF) dissemination of the tumors. All patients underwent the whole-neuraxis irradiation and chemotherapy. After they had CSF dissemination, they were submitted to an adoptive transfer of allogeneic LAK cells. LAK cells were induced from peripheral blood lymphocytes (PBL) of their relatives with human recombinant interleukin-2. 3-15 x 10(9) LAK cells were transferred intrathecally in 2-3 months. In 3 of 8 patients, neurological signs were improved and malignant cells had never been detected on CSF cytology after the adoptive immunotherapy. One among these 3 patients showed complete response in 20 months. Thus, this is an attractive treatment for patients with medulloblastoma, especially with CSF dissemination, which cannot be cured by current therapeutic intervention.

Brain Neoplasms↗