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K Onozaki

Publications and source records attributed to K Onozaki.

At least 73 records · Page 4Linked to original sources
PubMed1993

Meeting report of the International Symposium of Molecular Cell Biology of Macrophages '92.

The International Symposium of Molecular Cell Biology of Macrophages '92 was held on October 15th and 16th in Kanazawa, Japan. Nineteen speakers including 4 speakers from Europe and the USA were invited. The total number of participants was limited to 100. This symposium was initiated last year with the intention of bringing together experts of macrophage investigation once a year to discuss progress in the field of molecular cell biology of macrophages.

Apoptosis↗
PubMed1993

Development of neoglycoproteins conjugated with natural oligosaccharides through carboxyl residues of proteins and its application to recombinant human interleukin 1.

In order to develop glycosylated cytokines, neoglycoproteins were synthesized utilizing naturally occurring oligosaccharides. High mannose type oligosaccharide-asparagine (Asn)s, containing Man8GN2-Asn, Man7GN2-Asn and Man6GN2-Asn, were obtained from quail ovalbumin and were coupled to bovine serum albumin (BSA) by carbodiimide-mediated coupling. Major reaction occurred between amino residues of oligosaccharide-Asns and carboxyl residues of BSA. Approximately one molecules of oligosaccharides-Asns were coupled to per molecule of BSA with 50% yield of glycosylation. Among the oligosaccharides, Man6GN2-Asn appeared to be conjugated predominantly. While this strategy was applied to recombinant human interleukin 1 alpha (IL-1 alpha), three molecules of oligosaccharide-Asns were introduced into per molecule of IL-1 with 10% yield of glycosylation.

Animals↗
PubMed1993

Differential production of interleukin 1 (IL-1), IL-6, tumor necrosis factor, and IL-1 receptor antagonist by human monocytes stimulated with Mycobacterium leprae and M. bovis BCG.

Human blood monocytes cultured in various serum conditions were stimulated with Mycobacterium leprae or M. bovis BCG and their cytokine-inducing abilities were compared. BCG, either live or killed, induced production of interleukin 1 (IL-1), IL-6, tumor necrosis factor (TNF), and IL-1 receptor antagonist (IL-1ra). Live BCG at a lower bacterial number was more potent than killed BCG in the induction of IL-6 and TNF. In contrast to BCG, killed M. leprae induced few cytokines except for IL-1ra. Similar results were obtained when monocytes were cultured in the presence of untreated or heat-inactivated fetal bovine serum (FBS). When FBS and human serum (HS) were compared and the effect of heat inactivation was investigated, monocytes in HS produced the most cytokines, then those in FBS, irrespective of heat inactivation, and those in heat-inactivated HS produced the least cytokines. There were no differences between live and killed M. leprae, and BCG were far more potent than M. leprae in all of our experimental conditions, indicating that the poor cytokine (IL-1, IL-6 and TNF)-inducing ability of M. leprae was not due to their viability. Cytokine production was partially in parallel with the phagocytosis of the mycobacteria. These results suggest that M. leprae favor their infection by evoking little host reaction through the induction of only low levels of immunostimulatory or proinflammatory cytokines but a substantial amount of immunosuppressive cytokine.

Animals↗
PubMed1993

Occurrence of heterogeneity of N-linked oligosaccharides attached to sycamore (Acer pseudoplatanus L.) laccase after excretion.

The N-linked oligosaccharide moieties of sycamore (Acer pseudoplatanus L.) laccase are known to be highly heterogeneous. We confirmed that this oligosaccharide heterogeneity was caused not only during the oligosaccharide biosynthesis in Golgi apparatus, but also after the excretion of laccase protein into a culture medium. The culture medium for the sycamore cells (Acer pseudoplatanus L.) contained beta-galactosidase, alpha-L-fucosidase, beta-N-acetylglucosaminidase, alpha-mannosidase and beta-xylosidase activities. We showed that the largest sugar chain in laccase, oligosaccharide F, [formula: see text] was degraded to [formula: see text] by a crude exoglycosidase mixture in the culture medium.

Acetylglucosaminidase↗
PubMed1992

Interleukin-1 up-regulates transcription of its own receptor in a human fibroblast cell line TIG-1: role of endogenous PGE2 and cAMP.

The regulation of interleukin-1 receptor (IL-1R) mRNA expression by IL-1 in a human lung fibroblast cell line (TIG-1) was investigated. After 2 h of stimulation with human recombinant IL-1 alpha or IL-1 beta, the levels of T cell/fibroblast-type IL-1R mRNA increased, and the elevation was sustained for at least 72 h. IL-1 also stimulated synthesis of prostaglandin E2 (PGE2) and secondary cAMP accumulation. Exogenously added PGE2 increased the levels of both IL-1R mRNA and intracellular cAMP. Forskolin, cholera toxin and 8-Bromo adenosine (8-Br-cAMP) all increased IL-1R mRNA levels. Indomethacin blocked IL-1 stimulation of IL-1R mRNA expression, PGE2 production and cAMP. 125I-labeled IL-1 alpha-binding studies showed that this cell line expresses 2.6 x 10(4) IL-1R per cell with a Kd of 5.1 x 10(-10) M. After treatment of the cells with IL-1, the level of IL-1R increased over that of control cells. PGE2 also increased IL-1R without alteration in its affinity. Cross-linking experiments indicate that this cell line expresses the 80-kDa receptor molecule before and after treatment with PGE2; the molecular mass corresponds to the T cell/fibroblast type I IL-1R. These results indicate that IL-1 does not directly stimulate expression of IL-1R mRNA or cell surface IL-1R, but only indirectly by stimulation of endogenous PGE2.

Cell Line↗
PubMed1992

Cyclic AMP mimics IL-1 action in augmenting the differentiation of a mouse myeloid leukemic cell line (M1).

We have shown previously that recombinant human interleukin 1(IL-1) and interleukin 6 (IL-6) inhibited the proliferation of a mouse myeloid leukemic cell line (M1), and that IL-6 induced differentiation of the cells into macrophage-like cells and that IL-1 augmented this differentiation. Using this model we investigated the action mechanisms of IL-1 and IL-6. IL-6, but not IL-1, stimulated prostaglandin E2 (PGE2) production. The differentiative effect of IL-6 however, was not suppressed by indomethacin, although PGE2 induction by IL-6 was completely inhibited. Exogenously added PGE2 neither augmented the differentiative effect of IL-6 nor induced differentiation in combination with IL-1. Therefore, stimulation of PGE2 production did not appear to be essential for differentiative effects of these cytokines. Dibutyryl cAMP, 8-Br-cAMP and two adenylate cyclase-activating reagents, cholera toxin (CT) and forskolin (FK), all exhibited the similar augmenting effects as IL-1. These reagents augmented M1 cell differentiation by IL-6, and they did not induce differentiation in combination with IL-1. cAMP derivatives, CT, FK, IL-1 and IL-6 all inhibited the proliferation of M1 cells. CT and FK increased the intracellular cAMP levels. However, neither IL-1 nor IL-6 increased the cAMP levels. In contrast to the cAMP derivatives and reagents that activate adenylate cyclase activity, phorbol 12-myristate 13-acetate (PMA) and calcium ionophore neither induced nor augmented the differentiation in combination with either IL-1 or IL-6. Intracellular Ca2+ concentration was not altered by IL-1 or IL-6 suggesting that Ca2+/Calmodulin kinase and protein kinase C activation are not involved in this signal transduction pathway. Therefore, the present study suggests that IL-1 exhibits an effect similar to that of cAMP without affecting intracellular cAMP level.

Adenylyl Cyclases↗
PubMed1992

[Monokine production by mouse peritoneal macrophages after phagocytosis of mycobacteria].

It is well known that monokines, IL-1 (Interleukin-1) and TNF (Tumor Necrosis Factor), are produced by macrophages after stimulated with various agents. These cytokines are involved in various aspects of the inflammatory process and immunological response in addition to their original activities to proliferate T lymphocytes and causing tumor necrosis, respectively. Recently, there have been reported that IL-1 and TNF also play an important role in mycobacterial infections such as granuloma formation. In the present study, IL-1 and TNF productions were observed by mouse peritoneal exudate and resident macrophages after incubation with heat-killed M. lepraemurium and M. avium in vitro. The production was enhanced by phagocytosis of these mycobacteria in a dose dependent manner, and the time course of the production was maximum within 24 hr after phagocytosis of these mycobacteria. It was also shown of morphological changes and enhanced glucose consumption in media by these macrophages. Above results suggest that phagocytosis of mycobacteria by macrophages leads to monokine production, which would not only causes well known immunological reactions but also makes characteristic phenomena to be observed in mycobacterial infections.

Animals↗
PubMed1991

Effect of dietary alpha-linolenate/linoleate balance on lipopolysaccharide-induced tumor necrosis factor production in mouse macrophages.

We examined the effect of dietary alpha-linolenate (18:3n-3)/linoleate (18:2n-6) balance on lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) production in mouse macrophages. Resident and casein-induced peritoneal macrophages from mice fed a high alpha-linolenate diet produced a higher amount of TNF than in the high linoleate diet group. However, TNF production was not affected by the dietary alpha-linolenate/linoleate balance when thioglycollate- and complete Freund's adjuvant-induced macrophages were stimulated with LPS. Serum TNF levels of mice intraperitoneally injected with LPS was also higher in the high alpha-linolenate group than in the high linoleate group. These diets affected the n-3/n-6 ratios of 20 and 22 carbon highly unsaturated fatty acids in macrophage lipids. Thus, the dietary enrichment with alpha-linolenate was found to enhance TNF production of macrophages isolated under limited conditions.

Animals↗
PubMed1991

[The kinetics of interleukin 1 and prostaglandin concentrations in human amniotic fluid].

In order to understand the role of Interleukin 1 (IL-1) in human amniotic fluid (AF), the amount of IL-1 in normal human AF at various gestational ages was measured using ELISA. Materials were divided into three groups based on gestational ages. Group 1, less than 22 weeks (n = 16), consisted of AF samples which were collected by amniocentesis. Group 2, greater than or equal to 36 weeks (n = 54), consisted of AF samples collected transvaginally at delivery. Group 3, greater than or equal to 36 weeks (n = 9), transabdominally collected AF samples from elective cesarean section without labor. IL-1 alpha was present in AF of early gestational age in group 1 and appeared to increase with gestational age in group 3. In contrast, IL-1 beta was not detectable in either group 1 or 3. However, the concentration of IL-1 in group 2 was extremely high (IL-1 alpha 201.0 +/- 299.3 pg/ml, IL-1 beta 1,024.1 +/- 1,321.9 pg/ml) when compared to the other groups. Moreover, the IL-1 alpha and IL-1 beta concentrations correlated with those of Prostaglandin E2 and F2 alpha in AF, measured by RIA. These findings suggest that IL-1 has an important role during pregnancy and during labor in particular.

Amniotic Fluid↗
PubMed1990

Antiproliferative effect of interleukin 1 (IL-1) on tumor cells: G0-G1 arrest of a human melanoma cell line by IL-1.

Interleukin 1 (IL-1) has been shown to have antiproliferative or cytocidal effects on several tumor cell lines and this effect is closely related to the induction of terminal differentiation of the target tumor cells. In this study we analyzed the antiproliferative effect of recombinant human IL-1 alpha on a human melanoma cell line A375 in relation to cell cycle. Nutrient-starved cells, most of which were in G0 + G1, were stimulated by culturing in fresh medium, causing them to enter S. IL-1 treatment induced a slight decrease in the first cell cycle progression from G0 + G1 to S. In addition IL-1 retarded progression of the cells through G2M and inhibited progression of the second cell cycle from G0 + G1 to S. Therefore we concluded that IL-1 exerts its antiproliferative effect by arresting the cells in G0 + G1.

Cell Cycle↗
PubMed1990

Isolation and long-term cultivation of human tonsil follicular dendritic cells.

Highly purified follicular dendritic cells (FDC) were isolated from human tonsils and cultivated for up to 150 days. The cell separation method employed produced pure aggregates (FDC-clusters) composed of FDC and germinal center lymphoid cells, useful for the analysis of the relationship between these two cell types and of the behavior of FDC in culture. During the first few days of culture, lymphoid cells located between FDC extensions survived better than those which were free or partly covered by FDC. After 6 days, the lymphoid population degenerated and only the FDC survived. The unique antigenic pattern of FDC (positive for HLA-DR. DRC-1, CD14b, CD21, CD23, CD35) disappeared within a few days of culture. Recombinant interferon-gamma exerted a positive effect either on retaining HLA-DR expression or on the reexpression of these antigens by FDC. HLA-ABC antigens were traced until the 10th day and desmosomal junctions until the 14th day. Subsequently, FDC presented peculiar features, including oval and rhomboid shapes, one to ten nuclei, fine amoeboid extensions, stress fibers and a radical dense zone in their cytoplasm. FDC possessed actin, tubulin and vimentin, but neither desmin nor cytokeratin. After 40 days of culture, FDC enlarged and were covered with abundant membrane extensions. Even when kept as long as 150 days in vitro. FDC did not proliferate in any of the culture conditions employed.

Actins↗
PubMed1990

Changes in interleukin 1 levels in human amniotic fluid with gestational ages and delivery.

In order to understand the role of interleukin 1 (IL-1) in pregnancy, the amount of IL-1 in normal human amniotic fluid (AF) from various gestational ages and delivery was measured using an ELISA. AF samples were divided into three groups of varying gestational ages. Group 1 of AF was collected by amniocentesis from gestational ages less than 24 weeks (n = 13). Group 2 was collected transvaginally during delivery following labor greater than or equal to 36 weeks (n = 36). Group 3 was transabdominally collected from elective cesarean section without labor greater than or equal to 36 weeks (n = 8). IL-1 alpha was present in AF of early gestational age, 19.2 +/- 21.7 pg/ml, in group 1, and appeared to increase with gestational age, 63.4 +/- 50.1 pg/ml, in group 3. In contrast, IL-1 beta was not detectable in either group 1 or 3. However, the concentrations of IL-1 in group 2 was extremely high (IL-1 alpha, 233.1 +/- 351.9 pg/ml; IL-1 beta, 1,093.5 +/- 1,369.7 pg/ml) compared to the other groups. Moreover, these concentrations tended to increase with the duration of labor. IL-1 alpha and IL-1 beta concentrations in AF were intimately related. These findings suggest that IL-1 has some roles during pregnancy and especially during labor.

Amniotic Fluid↗
PubMed1990

[Inflammatory reaction and laboratory tests: interleukin-1].

Recent progress on the study of IL 1 is summarized and depicted, particularly emphasizing the variety of IL 1 function, and the role of other cytokine inducers. While it has been established that IL 1 has a variety of biological functions in vitro and in vivo, some of these functions are not a direct action of IL 1, but may be ascribed to some other cytokines induced by IL 1, since IL 1 can induce IL 6 (as an inducer of acute phase protein), IL 8 (as a neutrophil chemotactic factor), or IL 1 itself. Other important functions of IL 1 in vivo including resistance to bacterial infection, radioresistance and anti-tumor activity are of great interest to determine whether its action is direct or indirect through the induction of other factors, although the importance of IL 1 yet remains. Finally, the bioassay and ELISA assay of IL 1 alpha and IL 1 beta were established. The IL 1 level in serum, amniotic fluids, and synovial fluids from rheumatoid arthritis have been determined and its biological significance has been discussed.

Enzyme-Linked Immunosorbent Assay↗
PubMed1990

Regulation of fibronectin synthesis by interleukin-1 and interleukin-6 in rat hepatocytes.

The authors have observed previously that recombinant human interleukin-1 (rhIL-1) administered into rats increased plasma fibronectin (Fn) level concomitant with the increase of Fn in the liver. Because IL-1 induces interleukin-6 (IL-6) in certain cell types, the IL-1 effect might be mediated by IL-6. To evaluate this possibility, the effect of recombinant human interleukin-6 (rhIL-6), rhIL-1 alpha, and rhIL-1 beta on Fn synthesis in cultured rat hepatocytes was studied. It was shown that rhIL-6 increased Fn synthesis in hepatocytes, in contrast, rhIL-1 alpha, rhIL-I beta and TNF did not have any effect on Fn synthesis. When we studied the interaction of IL-1 and IL-6, IL-1 did not exhibit any synergistic effect with IL-6. Conditioned medium (CM) from rhIL-1 stimulated peripheral blood monocytes (PBM) increased the Fn synthesis, and its activity was neutralized significantly by anti-rhIL-6 antibodies. The CM from rhIL-1-stimulated PBM was analyzed by enzyme linked immunosorbent assay and revealed the increase of IL-6. Furthermore, it was found that intraperitoneal administration of rhIL-1 induced IL-6 into blood. The administration of rhIL-6 into rats increased circulating Fn levels. These results strongly suggest that the in vivo effect of IL-1 on Fn synthesis is mediated by IL-6.

Animals↗
PubMed1989

Contribution of IL-6 to the antiproliferative effect of IL-1 and tumor necrosis factor on tumor cell lines.

The role of IL-6 in the antiproliferative effect of IL-1 for tumor cell lines was investigated using IL-1-sensitive cell lines. Human recombinant IL-1 alpha and IL-6 both inhibited the growth of an IL-1-sensitive cloned human melanoma cell line (A375-C6). However, IL-1 has greater maximum growth inhibitory activity than IL-6. Conditioned medium of the tumor cells that were treated with IL-1 contained IL-6 as determined by ELISA. Northern blot analysis revealed that IL-6 mRNA expression increased in IL-1-treated cells. In addition, antibody against human IL-6 neutralized about 50% of the antiproliferative effect of IL-1. The growth of an IL-1-resistant clone of A375 cells (A375-C5), which cannot be shown to express any detectable IL-1R, was inhibited by IL-6 to the same degree as A375-C6 cells. The A375-C5 cell line did not produce IL-6 or increase IL-6 mRNA after stimulation with IL-1. These results indicate that IL-6 mediates in part the antiproliferative effect of IL-1 on A375-C6 cells by acting as an autocrine antiproliferative factor. IL-1 also inhibited the growth of a malignant human mammary cell line (MDA-MB-415). IL-6 exhibited only slight growth inhibition in this cell line. Neither IL-6 production nor IL-6 mRNA expression was induced in this cell line by IL-1. Antibody against IL-6 did not neutralize the antiproliferative effect of IL-1. Therefore, for MDA-MB-415 cells IL-6 appeared not to be involved in the antiproliferative effect of IL-1. These results indicate that the antiproliferative effect of IL-1 involves at least two pathways, one IL-6 dependent and another IL-6 independent. The contribution of IL-6 to the antiproliferative effect of TNF was also examined. IL-6 appeared not to play a role in the antiproliferative effect of TNF in these cell lines.

Animals↗
PubMed1989

Synergistic regulatory effects of interleukin 6 and interleukin 1 on the growth and differentiation of human and mouse myeloid leukemic cell lines.

We analyzed the effect of recombinant human interleukin 6 (IL-6), in combination with human recombinant interleukin 1 alpha (IL-1 alpha), on the growth and differentiation of several human and mouse myeloid leukemic cell lines, specifically U937, HL-60, M1, and its subclone M1-3b-N, into macrophage-like cells. IL-6 and IL-1 inhibited the growth of U937, M1, and M1-3b-N in a dose-dependent manner. Treatment of these cells with both IL-6 and IL-1 resulted in either an additive or a synergistic growth inhibition. IL-6 alone induced moderate differentiation of U937 and M1-3b-N, but the combination of IL-6 and IL-1 synergistically augmented this differentiation. In M1, only the combination of IL-1 and IL-6 resulted in differentiation. These two cytokines, whether alone or in combination, did not influence the growth and differentiation of HL-60. Therefore IL-6 in conjunction with IL-1 can induce differentiation in several human and mouse myeloid leukemic cell lines, although this effect varies with cell type. IL-6 did not stimulate the expression of IL-1 mRNA or IL-1 activity in U937 cells. IL-1 also failed to stimulate IL-6 production. Furthermore, the differentiation of U937 cells induced by IL-6 was not neutralized by antibody against either IL-1 alpha or IL-1 beta. The minimal differentiative effect of IL-1 was not affected by anti-IL-6 antibody. Therefore IL-6 and IL-1 appear to provide distinct signals for differentiation.

Animals↗
PubMed1989

Cytokines produced in lymph follicles.

The events occurring inside lymph follicles during a germinal center reaction are poorly understood. Using B and T lymphoid cell populations prepared from human tonsillar lymph follicles, and enriched or not in macrophages or in follicular dendritic cells, we examined the production of cytokines by these cells in vitro. Interleukin 6 (IL-6) and tumor necrosis factor (TNF) were found in the supernatants of cultures stimulated with phytohemagglutinin or pokeweed mitogen. IL-1 beta was occasionally detected; its secretion apparently depends on the origin of the tonsils, the stimulation, and the cell populations. IFN-gamma and IL-2 were not produced in significant amounts by these lymph follicle cells. IL-4 was only found in very low concentrations in the supernatant of the different cell cultures. The cell populations containing follicular dendritic cells produced more IL-6 and TNF than the others, especially than those composed of only B and T cells.

Adenoids↗