Biomedical subjects

H Nariuchi

Publications and source records attributed to H Nariuchi.

At least 73 records · Page 4Linked to original sources

PubMed1994

Second signal activity of IL-12 on the proliferation and IL-2R expression of T helper cell-1 clone.

In these experiments, effects of IL-12 on the proliferation and IL-2R expression of Th1 and Th2 clones were studied. Although neither Th1 nor Th2 clones proliferated on an Ag stimulation with B cell APC, Th1 clones but not Th2 clones, exhibited IL-2-dependent proliferation in the presence of IL-12 in response to the Ag stimulation. The IL-2R alpha-chain was also shown to be induced on Th1 clones when they were stimulated with B cell APC in the presence of IL-12. Effects of IL-12 on these T cell functions were indicated to be exerted in concert with IL-2, although IL-12 did not enhance IL-2 production of Th1 clones. Cytokines produced by Th1 clones such as IFN-gamma and TNF-alpha were indicated not to be involved in induction of the IL-2R alpha-chain expression or proliferation. IL-12 also induced proliferation and IL-2R alpha-chain expression of Th1 clone stimulated with anti-CD3 in the absence of APC, indicating that IL-12 exerted the effect on Th1 cells directly and other costimulator signal from APC is not required for the function of IL-12. In contrast to IL-12, IL-1 induced proliferation and IL-2R alpha-chain expression of Th2 clones stimulated with Ag on B cell APC. The failure of IL-12 in the induction of IL-2R alpha-chain expression on Th2 clone seemed not to be caused by the IL-4 produced by the clone. These results suggest that IL-12 plays an important role in IL-2R alpha-chain expression and proliferation of Th1 clones, but not Th2 clones, as a second signal.

Animals↗

PubMed1994

Mechanisms of T cell contact-dependent B cell activation.

It has been reported that activated Th cells express CD40 ligand, and the interaction of the CD40 ligand and CD40 on B cells results in B cell cycle entry. In this report, mechanisms of B cell activation induced by CD40-CD40 ligand interaction were studied by using an activated Th cell membrane as a source of CD40 ligand. The rise in cAMP concentration and tyrosine phosphorylation of a 69-kDa protein were induced in B cells stimulated with the activated Th cell membrane, and both of them were suppressed by the inclusion of soluble CD40 in cultures. The membrane stimulation did not elicit either inositol phosphates metabolism nor elevation of intracellular Ca2+ concentration. Protein kinase C depletion did not affect the proliferation, rise in cAMP level, or the 69-kDa protein tyrosine phosphorylation. Addition of anti-CD45 to the culture resulted in suppression of the B cell proliferation as well as the 69-kDa protein tyrosine phosphorylation. Furthermore, a protein kinase A inhibitor, H-89, suppressed the B cell proliferation induced by the membrane. These results indicate that both protein tyrosine kinase and protein kinase A were involved in the signal transduction pathway for the B cell proliferation evoked by the CD40-CD40 ligand interaction in Th cell contact-dependent B cell proliferation.

Animals↗

PubMed1994

A V beta 8.2-specific superantigen from exogenous mouse mammary tumor virus carried by FM mice.

A number of endogenous mouse mammary tumor virus (MMTV) proviruses encode superantigen that have the ability to stimulate T cells with a certain T cell receptor (TCR) beta-chain variable region (V beta) and to mediate the V beta-specific clonal deletion. The tumorigenic milk-borne MMTV carried by C3H and GR mice also have superantigenic properties in vivo. In the present study we identified and characterized a novel V beta 8.2-specific superantigen of exogenous MMTV carried by FM mice. The open reading frame (ORF) in the 3' long terminal repeat of the MMTV was cloned by polymerase chain reaction with primers corresponding to conserved regions spanning the ORF coding region. Sequence analysis of the ORF revealed that there is no sequence identical to those in other known MMTV in the carboxy terminus implicated in TCR V beta recognition. Subcutaneous injection of the virus into adult BALB/c mice induced an approximately three- to fourfold enlargement of draining lymph nodes and a substantial increase of V beta 8.2+ CD4+ T cells in the lymph nodes within 6 days. The exposure of newborn BALB/c mice to the virus by foster nursing resulted in a marked deletion of V beta 8.2+ cells both in CD4+ and CD8+ T cells. Thus, a novel milk-borne MMTV in FM mice expresses strong superantigenic properties capable of stimulating V beta 8.2+ T cells. V beta 8.2+ T cells have been demonstrated to be frequently involved in recognition of conventional antigens and responsible for autoimmune diseases such as experimental allergic encephalomyelitis. Therefore, the MMTV (FM) may provide a new mouse model system for inducing immunodeficiency or autoimmune disease by retroviral infection.

Amino Acid Sequence↗

PubMed1994

Different requirements of CD3 cross-linkage for the activation of memory and naive CD8+ T cells.

In the present experiments, the requirement of CD3 cross-linkage was studied in terms of activation of naive and Ag-primed CD8+ T cells in a murine system. The results showed that Ag-primed CD8+ T cells and both monoclonal and polyclonal T cell lines produced IL-2 by Fab anti-CD3 stimulation without cross-linkage in the absence of accessory cells. In contrast, naive T cells did not produce IL-2 in response to Fab anti-CD3 without participation of accessory cells; however, they produced IL-2 in the presence of accessory cells. These results indicate that the cross-linkage of CD3 molecules is not necessarily required for both naive and memory CD8+ T cells, but naive T cells, not memory T cells, require some interaction with accessory cells for IL-2 production in response to soluble monovalent anti-CD3.

Animals↗

PubMed1994

A targeting model of boron neutron-capture therapy to hepatoma cells in vivo with a boronated anti-(alpha-fetoprotein) monoclonal antibody.

We described previously that 10B atoms delivered by monoclonal antibody (mAb) exerted a cytotoxic effect on AH66 cells in a dose-dependent manner upon thermal neutron irradiation in vitro. In the present study, the delivering capacity of boronated anti-(alpha-fetoprotein) (AFP) mAb to carry 10B atoms to AFP-producing tumor xenografts in nude mice was determined. Boronated mAb was prepared by conjugating 50 mM 10B compound to an anti-AFP mAb (2 mg/ml) using N-succinimidyl-3-) (2-pyridyldithio) propionate. The number of 10B atoms conjugated directly to the mAb was estimated to be 459/antibody by prompt gamma-ray spectrometry. Boron concentrations in tumor tissue obtained 12, 24, 72, and 120 h after injection of 3.0 mg 10B-conjugated anti-AFP mAb were 11.10 +/- 3.12 (SD, n = 6). 29.30 +/- 5.11, 33.02 +/- 11.8, and 12.91 +/- 5.62 ppm respectively. For control 10B-conjugated anti-dinitrophenol (DNP) mAb, the values were 9.59 +/- 0.99, 10.37 +/- 2.86, 10.00 +/- 2.95, and 8.83 +/- 4.71 ppm respectively. The concentrations in blood were less than 0.40 +/- 0.10 ppm with anti-AFP mAb and less than 0.51 +/- 0.15 ppm with anti-DNP mAb at each sampling time (12, 24, 72, and 120 h). The number of 10B atoms delivered to the tumor cells was calculated to be 0.62 x 10(9), 1.63 x 10(9), 1.84 x 10(9) and 0.72 x 10(9) at each sampling time after injection of 10B-anti-AFP mAb. The amount of 10B atoms necessary for effective boron neutron-capture therapy was estimated to be 10(9)/tumor cell. We were able to carry 1.84 x 10(9) 10B atoms to AH66 tumor cells by using 10B-anti-AFP mAb. The accumulation reached its peak 72 h after injection. These data indicated that the 10B-conjugated antitumor mAb could deliver a sufficient amount of 10B atoms to the tumor cells to induce cytotoxic effects 72 h after injection upon thermal neutron irradiation.

Animals↗

PubMed1994

Enhancement of B cell function as antigen-presenting cell during interplay with Th cells.

We have previously reported that C57BL/6 mouse B cells present Ag to an I-Ab-restricted and OVA-specific T cell clone, 34-7F, to secrete IL-2 but not to proliferate, whereas spleen adherent cells as APC induce a proliferative response of 34-7F cells to OVA. In this T cell response, it was examined whether B cells were stimulated during presenting Ag and acquired the ability as APC to induce proliferative Ag-response of 34-7F cells. For this aim, B cells prepared from unstimulated mouse spleen cells were cultured with 34-7F cells in the presence of OVA and then compared with unstimulated B cells for APC function in the OVA-response of 34-7F cells. Unstimulated B cells proliferated when cultured for 2 days with irradiated 34-7F cells and OVA, and the proliferation was inhibited by an anti-I-Ab mAb. B cells which had been stimulated for 2 days with 34-7F cells and OVA induced an increase in phosphatidyl inositol metabolism in 34-7F cells in the presence of Ag, whereas unstimulated B cells failed to do so. The increase was dependent on the dose of OVA and on the number of the stimulated B cells. Ag presentation by the stimulated B cells (but not by unstimulated ones), also induced IL-2R expression on 34-7F cells, which resulted in IL-2-dependent proliferation. The IL-2R expression does not depend on the possible increase in IL-2 production by the T cells, inasmuch as the activated B cells induced lower expression of IL-2 mRNA or lower secretion of IL-2 by 34-7F cells than that induced by unstimulated B cells. These results suggest that B cells receive signal(s) from 34-7F cells to enhance APC function during Ag-presentation to the T cells which do not proliferate in the response to Ag on unstimulated B cells, and that the stimulated B cells induce the proliferative response of 34-7F cells to OVA.

Animals↗

PubMed1994

Mechanisms of hearing disturbance in an autoimmune model mouse NZB/kl.

A subline of the NZB mouse, NZB/kl, was found to develop severe hearing disturbances at high frequency sound at the age of 4 to 6 months. Deposition of IgG was observed on the capillary wall of the stria vascularis of the mice, but the concentration of circulating immune complex did not seem to be correlated to the deposition. Electron microscopic examination revealed that the capillaries had a thick basement membrane, and in severe cases the membrane contained foamy structures of various size. In some cases the base membrane was so thick that the capillary lumen was narrowed, and the intermediate cells seemed to be damaged. No pathological findings were found in other inner ear tissues. These results suggest that the changes in the stria vascularis were possibly caused by an autoimmune mechanism which resulted in hearing disturbance.

Animals↗

PubMed1994

[Cultivation and activation of Th1 and Th2 clones].

Murine T helper clones are classified into two subpopulations, Th1 and Th2, according to the cytokines they produce. Immune function is considered to depend which subpopulation is activated by an antigen stimulation. These subpopulations are different from each other in humoral second signal molecules required for their proliferation produced by antigen-presenting cells. Th1 requires IL-12, and Th2 IL-1, indicating that antigen-presenting cells regulate subpopulation responding to some stimulation. These subpopulations are also different in their activation signal transduction pathway mediated by TCR stimulation, suggesting a possibility of a selective activation of these subpopulations.

Animals↗

PubMed1993

Difference in signal transduction pathway for IL-2 and IL-4 production in T helper 1 and T helper 2 cell clones in response to anti-CD3.

To elucidate Th2 cell clone activation mechanism through TCR-CD3 complex, we examined the reactivity of Th2 cell clones to soluble anti-CD3 in the absence of accessory cells or costimulator. The soluble anti-CD3 stimulated IL-4 production of Th2 cell clones as efficiently as specific Ag. IL-4 production of Th2 cell clones was consistent with the elevation of intracellular free Ca2+ concentration ([Ca2+]i). The elevation was slow and sustained but occurred consistently after the anti-CD3 stimulation in all Th2 cell clones tested. The [Ca2+]i elevation appeared to depend on Ca2+ influx because it could not be observed in Ca(2+)-free medium. Several chemicals such as cholera toxin, neomycin, and herbimycin A, which have been shown to block phosphatidylinositol-4,5-bisphosphate (PIP2) breakdown pathway or protein tyrosine kinase activation, exerted no effect on the IL-4 production. In accordance with these findings, neither PIP2 breakdown nor protein tyrosine phosphorylation was observed in Th2 cell clones stimulated with anti-CD3. The inclusion of anti-CD4 in culture and the depletion of protein kinase C (PKC) did not affect IL-4 production of Th2 cell clones either. These findings support a hypothesis that Th2 cell clones use a signaling pathway for IL-4 production that is independent of protein tyrosine kinase, PIP2 breakdown or PKC, and that the [Ca2+]i elevation is the only pathway common to an IL-2 production of Th1 cell subset.

Animals↗

PubMed1993

Differential requirement for humoral factors for IL-2R expression of murine T cell subsets, Th1, Th2, and CD8Th clones.

Three types of alloreactive T helper (Th) cell clones, Th1, Th2, and CD8Th, were examined for the requirement of costimulatory factors for IL-2 receptor (IL-2R) expression and proliferation. When stimulated with allogeneic spleen adherent cells, these Th cell clones all expressed IL-2R strongly, whereas they expressed the receptor only weakly when subjected to allogeneic B cell stimulation. The addition of partially purified IL-2RIF to Th1, Th2, or CD8Th cell clones stimulated with B cell antigen-presenting cells increased the IL-2R expression of Th1 and CD8Th cell clones but not of the Th2 cell clone. Conversely, IL-1 up-regulated IL-2R expression of Th2 cell clones stimulated with B cell APC but not of Th1 and CD8Th cell clones. Neither IL-2RIF nor IL-1 induced IL-2R expression of unstimulated Th cell clones. IL-2R expressed in the presence of these costimulators contributed to IL-2-dependent proliferation of these cells. Thus, the expression of IL-2R was indicated to be regulated differently in three types of Th cell subsets through different cytokines.

Animals↗

PubMed1992

T cell activation through TCR/-CD3 complex. IL-2 production of T cell clones stimulated with anti-CD3 without cross-linkage.

To elucidate the Th cell activation mechanism through the TCR/CD3 complex, we examined the reactivity of T cell clones to soluble monovalent and divalent anti-CD3 without accessory cells or costimulatory factor. All T cell clones tested produced IL-2 in response to monovalent anti-CD3, although reactivity to divalent anti-CD3 was variable depending upon clones. IL-2 production of T cell clones induced by monovalent anti-CD3 was suppressed by cross-linking of the antibody with anti-hamster IgG. IL-2 mRNA expression and the increment of intracellular Ca2+ concentration were consistent with the IL-2 production. When T cell clones were stimulated with monovalent anti-CD3, they increased in size, although divalent anti-CD3 stimulation did not affect their size irrespective of their IL-2 production. These results indicate that monovalent anti-CD3 is more efficient than divalent anti-CD3 in induction of IL-2 production and that the cross-linkage of the TCR/CD3 complex is not necessarily required for the T cell clone activation.

Animals↗

PubMed1992

Tyrosine protein kinase is involved in anti-IgM-mediated signaling in BAL17 B lymphoma cells.

BAL17 B lymphoma cells, representing mature B lymphocytes, were used to analyze the role of tyrosine kinase in B cell activation. Anti-IgM-induced tyrosine phosphorylation was inhibited by preincubation of cells with tyrosine kinase inhibitor herbimycin A. Enzymatic activity of lyn protein was also inhibited by this drug, accompanied by down-regulation of p53lyn and p56lyn. However, a protein kinase C-mediated event was intact in the herbimycin A-pretreated cells, suggesting that the inhibitor acts selectively on tyrosine kinase. Anti-IgM failed to stimulate herbimycin A-pretreated cells to induce increases in inositol phospholipid metabolism or increased [Ca2+]i, whereas aluminum fluoride-induced metabolism was not altered. Moreover, membrane IgM density as revealed by flow cytometry was not changed by herbimycin A. These results indicate that tyrosine kinase(s) participates in the coupling of an Ag receptor cross-linkage to phospholipase C activation through a phosphorylation event in B lymphoma cells.

Animals↗

PubMed1992

Induction of IL-2 receptor expression and proliferation of T cell clones by a novel cytokine(s).

We found a unique T cell IL-2 receptor (IL-2R)3-inducing activity in the supernatant (SN) of the TH1 clone stimulated with antigen on spleen cells as antigen-presenting cells (APC). We have tentatively named this activity the IL-2R-inducing factor (IL-2RIF) and have characterized the activity. The SN induced IL-2R and proliferation of TH1 clones stimulated with B cell APC, which could not induce IL-2R in the absence of the SN. Other known cytokines were examined for a IL-2RIF activity; however, none of cytokines examined exerted a similar activity. Moreover, the neutralizing antibodies against the known cytokines tested did not block the IL-2RIF activity in the SN. When TH1 clones were stimulated with immobilized anti-CD3 or with fixed B cell APC in the presence of partially purified IL-2RIF, these clones expressed IL-2R and showed IL-2-dependent proliferation, whereas they induced neither IL-2R expression nor proliferation in the absence of IL-2RIF activity. These observations suggest that IL-2RIF activity is mediated by a novel cytokine(s) and the cytokine plays an important role as a second signal in the activation of the TH1 clone.

Animals↗

PubMed1992

Mechanism of augmentation of endotoxin fever by beta interferon in rabbits: possible participation of tumor necrosis factor (cachectin).

We analyzed the mechanism of the augmentation of endotoxin fever by human beta interferon (IFN) cross-reacting to rabbit cells in rabbits by using a purified rabbit tumor necrosis factor (RaTNF) and a monoclonal anti-RaTNF. The late peak of fever evoked by the injection with both endotoxin and HuIFN was suppressed when the animals were injected previously with anti-RaTNF. IFN also augmented the pyrogenicity of RaTNF in a synergistic manner in rabbits. The blood collected 2 h after the injection of RaTNF plus IFN contained a significant endogenous TNF activity, and the serum was shown to be pyrogenic. The endogenous pyrogen activity in the 2-h blood was heat stable (70 degrees C, 30 min) and was reduced by the in vitro treatment with anti-RaTNF. These results suggest that IFN augments the febrile response of rabbits to endotoxin by stimulating endogenous TNF-mediated TNF production to induce the late peak of fever.

Animals↗

PubMed1992

Enhancement by concanavalin A of the suppressive effect of prodigiosin 25-C on proliferation of murine splenocytes.

Proliferation of concanavalin A (Con A)-activated nylon-wool purified murine splenic T cells was increasingly suppressed by prodigiosin 25-C as higher concentrations of Con A were used for the activation. Enhancement of suppressive effect of prodigiosin 25-C was not observed when T cells were stimulated with phytohemagglutinin (PHA), anti-CD3 antibody, or allogeneic splenic adherent cells. The suppressive effect of prodigiosin 25-C was enhanced by the addition of Con A in various T cell subpopulations as well as in LPS-activated splenic B cells. Lectins that recognize mannose residue of biantennary-complex-type sugar chains significantly enhanced the suppressive effect of prodigiosin 25-C, whereas a lectin that binds to N-acetylglucosamine did not. These results suggest that binding of lectins to the mannose residue of biantennary-complex-type sugar chains on cell surface of both T and B lymphocytes plays a central role on the enhancement of the suppressive effect of prodigiosin 25-C.

Animals↗

PubMed1992

The role of T cells in pathogenesis and protective immunity to murine malaria.

T-cell-mediated immunity to a virulent strain of Plasmodium berghei NK65 (Pb NK65) and to an attenuated derivative (Pb XAT) of the strain were examined in CBA mice by the administration of monoclonal antibodies against T-cell subsets or interferon-gamma (IFN-gamma). The injection of anti-CD8+ or anti-IFN-gamma delayed the mortality of mice infected with Pb NK65, although it did not affect the parasitaemia. In the late stage of PB NK65 infection, T cells, especially CD8+ T cells, were increased in number in the liver at the expense of splenic CD8+ T cells. These CD8+ T cells released IFN-gamma in culture without antigen stimulation and were thought to induce tumour necrosis factor-alpha (TNF-alpha) production by the cells in the liver. In mice infected with Pb XAT, or mice primed with Pb XAT and then challenged with Pb NK65, CD4+ T cells had a crucial role in preventing parasite growth and in protective immunity. IFN-gamma was again the key molecule in protective immunity. These results suggest that T cells stimulated with malaria antigen play important roles both in protective immunity and pathogenesis depending upon their subsets; CD8+ T cells in pathogenesis, and CD4+ T cells in protective immunity. These apparently contradictory responses may be mediated by the same cytokine, IFN-gamma.

Animals↗

PubMed1991

Inhibition by brefeldin A of the specific B cell antigen presentation to MHC class II-restricted T cells.

We have shown previously that specific Ag presentation is prevented by the inhibition of protein synthesis but nonspecific presentation is not. In the present paper, Ag presentation by Ag-specific B cells was examined for sensitivity to brefeldin A (BFA), which blocks protein export from the endoplasmic reticulum. A20-HL B lymphoma expressing surface receptors specific for TNP was used as a B cell, and TNP-OVA was used as a specific Ag. The presence of BFA during pulsing of A20-HL cells with TNP-OVA inhibited the ability of the pulsed cells to stimulate 42-6A T cell clone, specific for OVA323-339 and Iad. The inhibition was not due to nonspecific toxicity of BFA, because the presence of BFA during pulsing of A20-HL cells with OVA323-339 did not affect their APC function. Ag binding to the receptor on A20-HL cells and internalization by the cells were observed in the presence of BFA. Thus, BFA might inhibit intracellular processing of specific Ag or intracellular complex formation of antigenic peptide from specific Ag with MHC class II molecules. Nonspecific Ag presentation by A20-HL cells, however, was resistant to BFA. A20-HL cells pulsed with OVA in the presence of BFA, even after fixation, could stimulate 42-6A cells to produce IL-2, although the IL-2 production was lower than that induced by A20-HL cells pulsed in the absence of BFA. These results suggest that the processing pathways for specific Ag and nonspecific Ag are different from each other, at least partly, in A20-HL cells.

Animals↗

PubMed1991

Role of bone marrow cells in autoantibody production and lymphoproliferation in the novel mutant strain of mice, CBA/KlJms-lprcg/lprcg.

The novel mutant gene, lprcg, is allelic with lpr, but complements the gld gene in induction of lymphoproliferation. Mice with this autosomal recessive mutation, CBA/KlJms-lprcg/lprcg (CBA-lprcg), served in this study to analyze the abnormalities of bone marrow (BM) stem cells responsible for autoantibody production and lymphoproliferation by BM transfer experiments. Transferred CBA-lprcg BM cells might have differentiated into so-called double-negative, anomalous lymphoid cells and caused production of autoantibodies such as anti-DNA antibodies in the environment of normal CBA/KlJms-(+)/+ (CBA-(+)) mice. Macroscopic graft-vs.-host-like disease as reported in lpr----non-lpr BM transfer was not observed in these recipients. In this BM chimera, however, lymphoproliferation did not ensue and the host's lymph nodes became atrophic. The lymphoproliferation required the coexistence of lprcg BM cells and lprcg lymph nodes in CBA-(+) mice. The results indicate that the functions of the lprcg gene are expressed at both BM and lymph node levels. Thus, this mutant strain of mice should provide an excellent model for analyzing aberrant lymphocyte differentiation from the BM cells leading to autoimmunity and lymphoproliferative disorder.

Animals↗