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Biomedical subjects

H Nariuchi

Publications and source records attributed to H Nariuchi.

At least 91 records · Page 5Linked to original sources

IL-2 production by B cells stimulated with a specific antigen.

The ability of a specific antigen (Ag) to stimulate B cells to produce IL-2 was examined with a murine B lymphoma line, A20-HL, which expressed surface IgM specific for trinitrophenyl (TNP). The culture supernatant of A20-HL cells stimulated with TNP3.9-ovalbumin (-OVA) or anti-IgM goat IgG contained an activity which supported the proliferation of an IL-2-dependent T cell line, CTLL-2. Neither TNP3.9-OVA nor anti-IgM antibody stimulated the parent line, A20.2J, which did not bear TNP-specific sIg, whereas anti-mouse Ig rabbit IgG F(ab)2 did stimulate both A20-HL cells and A20.2J cells. The active material in the culture supernatant was identified as IL-2 based on the experiments in which the activity was inhibited by anti-IL-2 mAb, and IL-2 mRNA was expressed in A20-HL cells stimulated with TNP3.9-OVA or anti-IgM antibody. These results support the conclusion that a specific Ag can stimulate A20-HL cells to produce IL-2. For IL-2 production, TNP receptors on A20-HL cells have to be appropriately cross-linked, inasmuch as either TNP3.9-OVA or TNP6.7-OVA was much more effective than TNP1.2-OVA and TNP22.9-OVA in the induction of IL-2 production by A20-HL cells.

Antigens↗

Application of boronated anti-CEA immunoliposome to tumour cell growth inhibition in in vitro boron neutron capture therapy model.

An immunoliposome containing a 10B-compound has been examined as a selective drug delivery system in boron neutron-capture therapy. Liposomes, conjugated with monoclonal antibodies specific for carcinoembryonic antigen (CEA) were shown to bind selectively to cells bearing CEA on their surface. The immunoliposomes attached to tumour cells suppressed growth in vitro upon thermal neutron irradiation and suppression was dependent upon the concentration of the 10B-compound in the liposomes and on the density of antibody conjugated to the liposomes. The results suggest that immunoliposomes containing the 10B-compound could act as a selective and efficient carrier of 10B atoms to target tumour cells in boron neutron-capture therapy.

Antibodies, Monoclonal↗

Induction of suppurative arthritis in rabbits by Haemophilus endotoxin, tumor necrosis factor-alpha, and interleukin-1 beta.

Because Haemophilus influenzae type b (Hib) is the principal cause of suppurative arthritis in young children and its lipooligosaccharide (LOS) is thought to be the main virulence factor, Hib endotoxin was evaluated for its ability to induce synovial inflammation in rabbits. Also, the role of the cytokines tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta (IL-1 beta) in mediating the synovial inflammatory process was studied. Intraarticular inoculation of 2 pg to 20 ng of Hib LOS produced a dose-dependent increase in concentrations of leukocytes and protein in synovial lavage fluid that was significantly modulated by concomitant administration of rabbit TNF alpha- and rabbit IL-1 beta-specific antibodies. Inoculation of joints with either 10(4) IU of rabbit TNF alpha or 10 ng recombinant rabbit IL-beta induced synovial inflammatory changes similar to those observed after LOS intraarticular challenge. These data provide evidence for the role of Hib LOS in inducing suppurative arthritis and for the critical participation of TNF alpha and IL-1 beta in the initial events of the synovial inflammatory response.

Animals↗

Differential sensitivity of specific and nonspecific antigen-presentation by B cells to a protein synthesis inhibitor.

Specific and nonspecific Ag-presentation by B cells was examined for the sensitivity to the treatment with emetin, an irreversible protein synthesis inhibitor. For this aim, A20-HL B lymphoma cells expressing surface IgM receptors specific for TNP were used as APC. OVA and TNP-OVA were used as nonspecific and specific Ag, respectively. The treatment with emetin greatly impaired the ability of A20-HL cells to present specific Ag, but not nonspecific Ag, to 42-6A cloned T cells specific for OVA. The ability of the emetin-treated A20-HL cells to present nonspecific Ag indicates that the treated cells are able to process nonspecific Ag and to present processed Ag. Ag binding and the internalization by A20-HL cells through surface receptors were not affected by the emetin treatment. A20-HL cells took up specific Ag for stimulation of 42-6A cells in the presence of cycloheximide, a reversible protein synthesis inhibitor. These results suggest that the action of emetin is localized to the intracellular processing of specific Ag, not of nonspecific Ag. Thus, the processing pathway for specific Ag seems to be different from that for nonspecific Ag.

Animals↗

Tumor necrosis factor alpha/cachectin and interleukin 1 beta initiate meningeal inflammation.

Although previous studies using human cytokines in rabbits and rats have provided evidence of the participation of tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) in the meningeal inflammatory cascade, the results obtained by several groups of investigators have been discordant or, at times, contradictory. In the present study, homologous cytokines were applied to the rabbit meningitis model. Intracisternal administration of 10(2)-10(5) IU of purified rabbit TNF-alpha (RaTNF-alpha) produced significant cerebrospinal fluid (CSF) inflammation. A similar response was observed after intracisternal inoculation of 5-200 ng of rabbit recombinant IL-1 beta (rrIL-1 beta). Preincubation of these two mediators with their specific antibodies resulted in an almost complete suppression of the CSF inflammatory response. In animals with Haemophilus influenzae type b lipooligosaccharide-induced meningitis, intracisternal administration of anti-rrIL-1 beta, anti-RaTNF-alpha, or both resulted in a significant modulation of meningeal inflammation. Simultaneous administration of 10(3) IU of RaTNF-alpha and 5 ng of rrIL-1 beta resulted in a synergistic inflammatory response manifested by a more rapid and significantly increased influx of white blood cells into the CSF compared with results after each cytokine given alone. These data provide evidence for a seminal role of TNF-alpha and IL-1 beta in the initial events of meningeal inflammation.

Animals↗

Regulatory role of CD4/L3T4 molecules in IL-2 production by affecting intracellular Ca2+ concentration of T cell clone stimulated with soluble anti-CD3.

To elucidate the role of CD4 molecule in T cell activation, the effect of anti-CD4 on T cell IL-2 production was examined by using an alloreactive Th clone. The alloreactive T cell used in the present experiments produced IL-2 in response to soluble anti-CD3 epsilon-chain (anti-CD3) without accessory cell or insoluble antibody carrier. The IL-2 production was suppressed by the addition of anti-CD4 in cultures. An intracellular free Ca2+ concentration ([Ca2+]i) of the T cell clone was elevated by anti-CD3 stimulation, but the elevation was suppressed in the presence of anti-CD4. When the clone was stimulated in Ca2(+)-free medium, the elevation of [Ca2+]i was not observed. When Ca2+ influx was induced by calcium ionophore A23187 or ionomycin, the clone produced IL-2 in response to anti-CD3 in the presence of anti-CD4. When polyclonal T cell line or several other alloreactive T cell clones were examined for their anti-CD3 response, essentially the same results as mentioned above were obtained. Taken together, these results suggest that the slow and sustained elevation of [Ca2+]i is an essential signal for IL-2 production of T cells, and that anti-CD4 suppresses the IL-2 production by interfering the [Ca2+]i elevation. The significance of CD4 molecules in murine T cell activation was discussed.

Animals↗

Actions of TNF and IFN-gamma on angiogenesis in vitro.

We have developed a model system for studying angiogenesis in which microvascular fragments and myofibroblasts (Mf) isolated from lipid tissues are grown in co-culture. We have found that Mf induce capillary formation by producing an endothelial cell growth factor and by secreting an extracellular matrix that causes endothelial cells to form a cordlike structure. This system appeared to be well suited for examining the effects of vasoactive substances such as the TNF and INF-gamma on capillary growth. TNF-alpha,beta, and IFN-gamma not only significantly inhibited capillary growth induced by Mf, but also blocked capillary development induced by fibroblast growth factors (FGF), well-known potent angiogenic factors. Recently, we have found that platelet-derived growth factor (PDGF) enhances in vitro capillary formation, probably at least in part by acting on Mf. Just as with FGF, capillary growth in the presence of PDGF was almost completely blocked by IFN-gamma. We examined the mode by which IFN-gamma inhibits angiogenesis and found that IFN-gamma inhibits both the proliferation of endothelial cells and collagen(s) synthesis by Mf. These actions of TNF or IFN-gamma could limit vascular formation in solid tumors.

Animals↗

[A case of refractory anemia with excess of blasts (RAEB) having weakened expression of B blood group antigen].

A 52 year-old male was admitted to our hospital with the complaint of the hypochondrial pain after meal in February 1989. He was diagnosed to be RAEB and to have common bile duct stone. His red blood cells (RBC) could not be agglutinated with anti-A, anti-B, or anti-A, B. The agglutinability of the cells to Ulex europaeus (anti-H) was the same to the normal type B RBC, and his serum contained anti-I, anti-E, and anti-c. In his saliva, both B and H antigens were detected. The glycosyl B transferase in his serum showed similar activity to that of normal individual with type B RBC. When his RBC were treated with normal type B transferase, the cells obtained the reactivity to anti-B but they agglutinated much weaker than the type O cells treated with the enzyme. These results indicated that the low agglutinability of his RBC could not be due to the low transferase activity but the qualitative or quantitative changes of the precursor molecules of the type B substance of the cells.

ABO Blood-Group System↗

Analysis of endotoxin fever in rabbits by using a monoclonal antibody to tumor necrosis factor (cachectin).

A murine monoclonal antibody to rabbit tumor necrosis factor (TNF; cachectin) was injected intravenously into an endotoxin-treated rabbit to examine the role of endogenous TNF in fever. Both early and late peaks of biphasic fever evoked by the endotoxin injection were suppressed by the antibody. TNF activity was detected in an endotoxin dose-dependent manner in the blood 1 h after the endotoxin injection, which was coincident with the early-peak fever. Although the late-peak fever responded to the antibody, no significant TNF activity was detected in the blood obtained 1 h before the peak response. The blood was found to contain endogenous pyrogen activity, which was stable after heating at 70 degrees C for 30 min and resistant to in vitro treatment with the antibody. Rabbit TNF injection also elicited biphasic fever in rabbits, the second phase of which was found to be mediated by the similar endogenous pyrogen. These results suggest that endogenous TNF plays an important role in eliciting a febrile response to endotoxin.

Animals↗

[Boron neutron capture therapy using 10B entrapped anti-CEA immunoliposome].

A new murine monoclonal antibody (2C-8) was prepared by immunizing mice ip with CEA producing human pancreatic cancer cell line, AsPC-1.SDS-PAGE and Western blot analysis showed that 2C-8 monoclonal antibody recognized CEA and NCA. This anti-CEA monoclonal antibody was conjugated with large multilamellar liposomes incorporated 10B compound (Cs2 10B12H11SH). This immunoliposomes applicated to boron neutron capture therapy. AsPC-1 cells were incubated with the 10B-Lip-MoAb(CEA) for 8 hours. After the irradiation with thermal neutron (1 x 10(11)-1 x 10(13) n/cm2), boronated AsPC-1 cells were showed decreasing uptake of 3H-TdR compared with control group. The numbers of 10B atoms in liposomes bound to an antibody were in proportion to the dose of 10B compounds added and maximum number of 10B atoms was approximatory 1.2 x 10(4)/Ab. These data indicated that the immunoliposomes could deliver highly amount of 10B atoms to the tumor cells and exert cytotoxic effect by thermal neutron. BNCT with immunoliposome may be useful to the non resectable malignant tumors in clinical application.

Animals↗

Molecular analysis of the dissociation between IL-2 production and proliferation in a response of a T cell clone to the antigen presented by B cells.

Using B cells as APC, antigen specific responses of two murine T cell clones, 34-7F and 35-8H, were analyzed. 34-7F cells produced IL-2 but failed to proliferate, whereas 35-8H cells both produced IL-2 and proliferate. The antigenic stimulation increased intracellular free Ca2+ concentration in both clones, but enhanced inositol phospholipid metabolism only in 35-8H cells. The treatment of 34-7F cells with PMA, an activator of protein kinase C, synergized with the antigenic stimulation to induce the proliferation of the T cells. Thus, the failure of 34-7F cells to proliferate in the Ag response appears to result from the absence of an increase in inositol phospholipid metabolism. The absence is likely due to the defect in B cells as APC, inasmuch as the antigenic stimulation of 34-7F cells with whole spleen cells induced increases in inositol phospholipid metabolism and proliferation. The PMA treatment synergized with the Ag on B cells to enhance IL-2R expression, which was not inhibited by the addition of nifedipine, a calcium channel blocker. The agent inhibited the IL-2 production. Taken together, the results in the present experiments suggest the association of IL-2 production with increases in intracellular free Ca2+ concentration but not in inositol phospholipid metabolism, and that of IL-2R expression with increases in the metabolism but not in intracellular free Ca2+ concentration.

Animals↗

Possible role of neuraminidase in activated T cells in the recognition of allogeneic Ia.

In a primary MLR, predominant stimulators in spleen cells are adherent cells and not B cells, although B cells are one of the cell types expressing a large amount of Ia molecules. Our previous experiments showed that T cells treated with neuraminidase (Nase) responded to an allogeneic Ia on B cells. In our experiments, the relationship between the responsiveness to the allogeneic Ia molecules on B cells and Nase activity of T cells was examined. The results showed that T cells increased in Nase activity with the acquisition of the reactivity to Ia on B cells. T cells from normal mice increased in Nase activity after the incubation for 3 days or more in MLR, and these T cells responded to allogeneic Ia on B cells. However, T cells from mice genetically deficient in Nase responded poorly to the Ia on allogeneic B cells even after the incubation in MLR for 3 days. T cells incubated for 3 days in MLR decreased in electrophoretic mobility, indicating the decrease of net negative charge of the cells, and increased in their binding of peanut agglutinin which has been reported to bind to galactosyl residues exposed on T cell surface by removing sialic acids. These results suggest that Nase in T cells was activated by the cultivation in MLR for 3 days, and sialic acids of some molecules on T cell surface were removed by the enzyme and, in turn, T cells acquired the responsiveness to allogeneic B cells in a secondary MLR. Thus, Nase was suggested to play a regulatory role in the recognition of Ia molecules in T cells.

Animals↗

Interleukin secretion by B cell lines and splenic B cells stimulated with calcium ionophore and phorbol ester.

A B cell lymphoma A20.2J and splenic B cells produced an active material to support the proliferation of an interleukin 2 (IL-2)-dependent T cell line, CTLL-2, by stimulation with both calcium ionophore A23187 and phorbol myristate acetate (PMA). Although the production of the active material was induced by stimulation with A23187 alone in A20.2J cells, both A23187 and PMA were essential for the stimulation of splenic B cells. Neither A20.2J cells nor splenic B cells produced the active material by stimulation with PMA alone. The production was inversely proportional to the concentration of fetal calf serum in culture medium. The active material produced by B cells was indicated to be IL-2 and not B cell-stimulating factor 1 (BSF-1) for the following reasons: 1) the proliferation of CTLL-2 cells in the presence of active material was inhibited by the inclusion of anti-IL-2 receptor or anti-IL-2 in culture medium but not by anti-BSF-1; 2) the material showed no co-mitogenic activity to purified splenic B cells with anti-immunoglobulins and did not support the proliferation of FDC-P2 which are known to grow in the presence of BSF-1; and 3) IL-2 mRNA could be detected in A20.2J and splenic B cells stimulated with A23187 and PMA in Northern blot analysis. Some B cell hybridomas were also shown to produce IL-2 by similar stimulation to A20.2J. Splenic B cells as well as A20.2J cells were able to produce IL-2 by stimulation with anti-immunoglobulins. These results suggest that under certain conditions IL-2 can be produced by splenic B cells, at least some subsets of B cells, and B cell lines.

Animals↗

Dissociation between the expression of IL 2 receptor and IL 2 receptor mRNA in the antigen-specific T cell clone stimulated by the specific antigen with B cell APC.

An antigen-presenting capacity of B cells was analyzed in comparison with that of whole spleen cells in terms of IL 2R expression of a human IgG-specific T cell clone, 24-2C.3. When the clone was stimulated with the antigen and irradiated spleen cells, the clone expressed an adequate amount of IL 2R on the surface in flow cytometric analysis. On the other hand, the clone expressed the receptor only poorly, being stimulated with B cell APC. The findings were confirmed by Western blot analysis on the clone solubilized by Nonidet P-40 and also by fluorescent antibody technique on the fixed clone. 24-2C.3 clone stimulated with B cell APC was also suggested not to secrete IL 2R in culture medium. In dot blot hybridization analysis performed with cDNA probe, however, 24-2C.3 clone stimulated with B cell APC was shown to express a comparable amount of IL 2R mRNA to the clone stimulated with whole spleen cells as APC. The mRNA expressed in the clones stimulated with B cells and with spleen cells could not be distinguished from each other in Northern blot analysis. The culture supernatant of 24-2C.3 clone incubated with the antigen and irradiated spleen cells was shown to enhance the expression of IL 2R on the clone stimulated with B cell APC. These results suggest that there is some defect in the antigen-presentation capacity of B cells in terms of the elicitation of the intracellular signal for IL 2R expression in T cells and that the humoral factor(s) produced in the presence of splenic adherent cells could supply the defect.

Animals↗

Accessory cell function in a Con A response: role of Ia and interleukin 1.

Accessory cell (A-cell) function in a Con A response was analyzed. Irradiated P388D1 cells efficiently induced a proliferative response to Con A of T cells purified from spleen cells, whereas paraformaldehyde-fixed P388D1 cells failed to serve as A cells. Although IL-1 containing culture supernatant (SN) of a macrophage hybridoma induced the Con A response of the T-cell preparations, the depletion of Ia+ cells by the treatment with anti-Ia antibody and complement abrogated the response in the presence of IL-1. Fixed P388D1 cells and the hybridoma SN synergized in the reconstitution of the response. A 15,000-Da fraction of the hybridoma SN or human recombinant IL-1 alpha was able to substitute the hybridoma SN for the response. The reconstitution of the response by IL-1 and fixed P388D1 cells was inhibited by the addition of monoclonal anti-Ia antibody. These results indicate that IL-1 or fixed P388D1 cell does not exert a sufficient signal by itself and both of them are required for the reconstitution of a Con A response of highly purified T cells, and that Ia on fixed P388D1 cells play an important role.

Animals↗

B cells as antigen-presenting cells: antigen-specific IL-2 production by cloned T cells without expression of IL-2 receptors.

A murine T cell clone, 24-2C, responds specifically to human IgG (HGG) in the context of I-Ab. B cells purified from mouse spleen cells were examined for their function as antigen-presenting cells (APC) in the response of 24-2C cells to HGG. B cells functioned as APC for IL-2 production but not for proliferation, whereas spleen cells or spleen-adherent cells functioned as APC for both IL-2 production and proliferation. LPS-activated B cells also failed to induce the proliferative response. The addition of the culture supernatant of 24-2C cells stimulated with HGG presented by irradiated spleen cells to the culture of 24-2C cells, irradiated B cells, and HGG induced the proliferative response of 24-2C cells, whereas IL-1, IL-3, and/or interferon-gamma did not reconstitute the proliferation. The expression of IL-2 receptors (IL-2R) on 24-2C cells was examined using a monoclonal anti-mouse IL-2R antibody AMT 13 or 7D4. 24-2C cells cultured with spleen cells as APC expressed IL-2R. Those cultured alone or with B cells as APC did not express IL-2R. Enlargement of 24-2C cells in response to HGG was also examined, and the relative cell size of those cultured with B cells or spleen cells as APC was larger than that of those cultured alone. These results demonstrate that B cells as APC induce IL-2 production and cell size enlargement in the response of 24-2C cloned T cells to HGG, but not IL-2R expression nor proliferation.

Animals↗

B cells as accessory cells in a Con A response of a T cell clone.

Accessory cell (AC) function of B cells was examined in Con A response of a cloned T cell line, 22-9D, which is Thy 1+,L3T4+,Lyt2-,H-2KbDb+ and I-Ab-.22-9D cells produced IL 2 in the presence of Con A without participation of AC. For the initiation of a proliferative response to Con A, the addition of spleen cells or spleen adherent cells was required. B cells as AC were unable to induce the proliferative response. In the presence of culture supernatant of spleen cells stimulated with Con A (CAS), 22-9D cells showed proliferative response to Con A with B cell AC. The response was inhibited by a relevant monoclonal anti-I-A antibody. Although irradiated spleen cells as AC induced IL 2 receptor expression of 22-9D cells in the presence of Con A, B cells were shown to require the addition of unknown factor(s) in CAS, which was suggested to be different from IL 1, IL 2, IL 3, or IFN-gamma, for the induction of the receptor expression on 22-9D cells.

Animals↗