PubMed Health⌕ Search

Biomedical subjects

F Nagase

Publications and source records attributed to F Nagase.

At least 37 records · Page 2Linked to original sources
PubMed1990

Demonstration of lipid A-binding proteins on murine lymphoma cells using R-mutant gram-negative bacteria as a detector.

Some R-mutant Escherichia coli and Salmonella heavily adhered to murine lymphoma cells of B cell and T cell lineages. This adhesion was primarily mediated by membrane-localized proteins on tumor cells, which bind the polymyxin B-reactive hydrophilic structure of lipis A on bacteria. SDS-PAGE analysis of tumor cell membranes showed that proteins or glycoproteins of MW = around 45Kd, 25-35Kd and around 15Kd preferentially bind lipid A. Various lymphoma cell lines binding the bacteria at different levels possessed lipid A-binding proteins of slightly different compositions. We conclude that lymphoma cells carry not a single but a group of lipid A-binding proteins in their membranes.

Animals↗
PubMed1990

Modulation by glycyrrhizin of the cell-surface expression of H-2 class I antigens on murine tumour cell lines and normal cell populations.

Glycyrrhizin (GL), a saponin fraction of licorice with defined chemical structure, was shown to display a definite action in vitro augmenting the cell-surface expression of H-2 class I antigens as well as class I gene transcription on various tumour cell lines. The magnitude of augmentation was varied among eight different cell lines tested, but reached more than three times. It was also found that GL enhanced the expression of H-2Dd antigens in some normal cell populations in vivo. The augmentation of H-2 class I antigens on tumour cell lines in vitro was probably not mediated by the interferon, which might have been produced by the cultured cells. These findings may suggest a new immunopharmacological action of GL.

Animals↗
PubMed1988

Induction of high-grade tumor-specific immunity in a host using a cytotoxic T-lymphocyte clone specific for a stable tumor antigen on murine leukemia L1210.

T-cell clone K4L, the cell surface phenotypes of which were Thy-1+, Lyt-1-, Lyt-2+, and L3T4-, was established from the spleen cells of a murine leukemia L1210-immune mouse. Clone K4L was specific for antigen B on L1210, and this antigen was different from antigen A for which the previously reported T-cell clone K7L was specific. K4L possessed cytotoxicity and tumor growth-inhibitory activity against both L1210 and antigen A loss variant, L1210-K7L-, but not against syngeneic tumor P388 or L5178Y. Previously we showed that antigen A was lost frequently for generation of antigen loss variants. In contrast, antigen B was barely found to be lost. When mice were inoculated with L1210 plus a moderate dose of K4L, the tumor grew after initial suppression but this newly emerging tumor was K4L sensitive and was ultimately rejected. The mice initially given L1210 plus K4L attained a high-grade tumor-specific immunity for rejecting the subsequently challenged high-dose (10(7) cells) L1210. This immunity did not involve any bystander antitumor activity against the third party P388 lymphoma that was injected together with L1210 but accompanied the increase in the L1210-specific cytotoxic T-lymphocyte activity. Evidence was provided that the live L1210, the outgrowth of which was inhibited by K4L, induced an effective immune response of radiation-sensitive host lymphocytes including L3T4+ helper T-cells. Taken together, our results show a novel strategy for inducing high-grade host-dependent antitumor immunity by use of a cytotoxic T-lymphocyte clone specific for a stable tumor-specific transplantation antigen.

Animals↗
PubMed1988

Induction and characterization of minor histocompatibility antigens. Specific primary cytotoxic T lymphocyte responses in vitro.

A definite cytotoxic activity was developed in a BALB/c (H-2d) anti-DBA/2 primary mixed leukocyte culture (MLC), which received interleukin 2 (IL-2) on day 3 of culture. This cytotoxic activity was minor histocompatibility antigens (MIHA)-specific at the stimulator level, and was not developed in a syngeneic (BALB/c anti-BALB/c) MLC. The addition of IL-2 on day 3 of culture was crucial; no or very weak cytotoxic activity was developed in MLC receiving IL-2 on day 0 or on both day 0 and day 3. Only appropriate MIHA-allogeneic tumor cells were lysed as the target of the cytotoxic activity. The cytotoxic activity seemed MIHA-specific also at the target level; it lysed tumor cells of DBA/2 mouse origin but not those of BALB/c (syngeneic) origin. Phenotypes of the cytotoxic effector cell were Thy-1+ Lyt-2+. We concluded from these results that MIHA-specific cytotoxic T lymphocytes (CTL) were generated in the MIHA-allogeneic primary MLC. In this newly developed system, we studied genetic and antigenic requirements for primary anti-MIHA CTL responses in vitro. We demonstrated; among spleen cells (SC) of seven B10 H-2-congenic strains only SC of B10.D2 strain whose major histocompatibility complex (MHC) (H-2d) was compatible with the responder MHC effectively stimulated responder BALB/c (H-2d) SC for an anti-MIHA (DBA-C57BL-common) CTL response. Similarly, only SC of two out of seven C x B recombinant inbred strains (C x B.H and C x B.D), which were compatible at the MHC with responder SC, activated responder BALB/c SC for the response. The possibility that cells responding to H-2 alloantigens suppressed the anti-MIHA response was ruled out. Additional experiments showed that compatibility at the H-2K-end or the H-2D-end of the MHC was sufficient for a definite anti-MIHA response. These provided formal evidence that primary anti-MIHA CTL responses in vitro were MHC-restricted at the stimulator level. We then showed that sonication-disrupted SC or Sephadex G-10 column-passed nonadherent SC failed to stimulate responder SC for a primary anti-MIHA CTL response, whereas G-10-passed nonadherent SC responded well to adherent stimulator cells. Further study demonstrated that Ia+ adherent cells were the most active cell type as stimulator. Finally, we confirmed that the primary anti-MIHA CTL responses to adherent stimulator cells was MHC-restricted.

Animals↗
PubMed1988

Further evidence for H-2-unrestricted induction of minor histocompatibility antigens-specific T cell immunity in vivo.

Antigenic requirements for inducing minor histocompatibility antigens (MIHA)-specific T cell immunity for second set rejection (SSR) of a MIHA-allogeneic tumor were studied. An intravenous injection of surprisingly small numbers (10(4)-10(5] of live allogenetic spleen cells (SC) effectively primed mice for SSR of the allogeneic tumor, and this immunity was developed as early as 2-3 days after injection of the SC. In contrast, sonication-disrupted allogeneic SC, which should be readily processed by host antigen presenting cells (APC), were not active as immunogens, even at a dose 1000 times higher than the minimum effective dose of live SC. The possibility that host APC preferentially receive MIHA antigens shed by live allogeneic SC for T cell activation was ruled out. These results demonstrated that antigen processing via conventional pathways is very little involved in the mechanism of T cell activation. Under such restricted experimental conditions, the induction phase but not the effector phase of the MIHA-specific T cell immunity was shown to be H-2-unrestricted.

Animals↗
PubMed1988

Biphasic radiation-sensitivity of the transplantation immunity for rejection of an allogeneic ascites tumor.

Transplantation immunity for second-set rejection of an allogeneic ascites tumor was induced by sensitizing mice with H-2-identical allogeneic spleen cells, and radiation-sensitivity of this immunity was studied. The immunity was not severely affected by 400 rads whole-body X-ray irradiation given at one day before the initial antigenic stimulation. In contrast, it was totally inactivated by 300-400 rads irradiation that was given one day before tumor challenge. An adoptive cell transfer experiment showed that alloreactive memory cells responsible for the immunity were unexpectedly highly radiosensitive. The immunity (memory), however, became resistant to 400 rads irradiation soon (one day) after challenge with the allogeneic tumor, and was resistant to 1500 rads for rejection of the tumor that was challenged at the second time when the initially challenged tumor was rejected. Corresponding to these observations, cells for allospecific CTL responses in peritoneal cavity of mice showed corresponding biphasic radiation-sensitivity.

Animals↗
PubMed1988

Augmentation by Corynebacterium liquefaciens of erythrocyte surface H-2 expression and alloimmunogenicity for antibody responses.

Intravenous injection of killed Corynebacterium liquefaciens induced a population of red blood cells that expressed both H-2K and H-2D antigens at exceptionally high density and displayed augmented immunogenicity for H-2 alloantigen-specific B cell activation. Injection of killed Escherichia coli or E. coli lipopolysaccharide was ineffective for the generation of such RBC. RBC that express H-2 antigens at high density first appeared at 7 days after injection of C. liquefaciens. These RBC persisted for more than 50 days, although they lost H-2 antigens gradually with time. The observed phenomenon was not due to enhanced erythropoiesis and peripheral release of immature RBC (reticulocytes); populations of both mature and immature RBC of mice injected with C. liquefaciens expressed H-2 antigens at high density, whereas those from normal mice or mice injected with phenyl hydrazine did not. Appearance of RBC expressing H-2 antigens at high density was preceded by a temporal increase in H-2 expression of bone marrow cells that included precursors of RBC. It was concluded that RBC expressing H-2 antigens at high density were descendants of bone marrow cells whose H-2 expression was augmented by C. liquefaciens. The present communication would be the 1st report of the bacteria-mediated augmentation of cell surface expression and activity of major-histocompatibility-complex class I antigens on host cells in vivo.

Animals↗
PubMed1988

Dynamics of cytotoxic T lymphocyte precursors in vivo assessed by change in the radiation sensitivity. Evidence for development of radiation-sensitive memory cells without clonal expansion.

The dynamics of cytotoxic T lymphocyte precursors (CTL-p) in mice injected with allogeneic spleen cells (SC) was studied with special reference to changes in their radiation sensitivity. Whole-body 400 rad X-ray irradiation of allo-SC-primed and unprimed mice virtually abolished the capacity of their SC to proliferate and to generate CTL in primary or secondary mixed leucocyte culture (MLC). However, the impaired ability of SC to generate CTL in the primary MLC was restored by interleukin 2 (IL-2). This showed that helper cells whose activity was replaceable with IL-2 (IL-2-producing cells) were functionally more radiation-sensitive than CTL-p in unprimed mice. In contrast, the radiation-impaired activity in secondary MLC was not restored by IL-2, suggesting that memory CTL-p in allo-SC-primed mice were unexpectedly sensitive to radiation. The D37 values determined from the percentage of residual CTL-p activity of SC in bulk cultures 1 day after irradiation were 525 rad for virgin CTL-p and 75 rad for memory CTL-p. Further studies demonstrated that the radiation-sensitive memory CTL-p were generated from relatively radiation-resistant precursors, largely independent of radiation-sensitive IL-2-producing cells and of cellular proliferation. The mean frequency of CTL-p in SC measured by limiting dilution assay was not significantly increased by the priming. This supports our conclusion that the development of the memory CTL-p activity in allo-SC-primed mice did not depend on clonal expansion. Whole-body 400 rad-irradiation reduced the frequency of CTL-p in SC from unprimed mice to 1/2-1/3 and that in SC from allo-SC-primed mice to 1/8-1/15. This supports the view that the majority of radiation-resistant virgin CTL-p functionally mature to radiation-sensitive memory CTL-p without cellular proliferation in allo-SC-primed mice.

Animals↗
PubMed1988

Genetic and stimulator cell requirements for generation and activation of minor histocompatibility antigen-specific memory cytotoxic T-lymphocyte precursors.

By adding IL-2 (supernatant of culture of concanavalin A-activated rat spleen cells) on Day 3 of mixed leucocyte cultures (MLC) we managed to fully activate multiple minor histocompatibility antigen (MIHA)-specific cytotoxic T-lymphocyte precursors (CTLp). In this newly developed system we studied genetic and stimulator cell requirements for the generation and activation of MIHA-specific memory CTLp. Memory CTLp were activated to generate effector CTL in MLC only when major histocompatibility complex (MHC)-compatible MIHA-allogeneic cells were used as stimulators. In contrast, memory CTLp were generated in mice that were primed by injection of either MHC-compatible or incompatible MIHA-allogeneic spleen cells. A surprisingly small number (10(4] of MHC-disparate cells cross-primed mice effectively. For priming, no special accessory cell types were required as stimulators, and 10(4) adherent cell-depleted spleen cells primed mice as well. These results contrasted to another finding that sonication-disrupted 10(6) stimulator cells did not prime mice effectively, and antigens shed from 10(7) live stimulator cells failed to sensitize host antigen-presenting cells for priming. It is suggested from these results that the mode of recognition of MIHA by virgin CTLp is unique or that an as yet unknown unusual stimulation pathway works for the priming.

Animals↗
PubMed1987

Expression of chimeric receptor composed of immunoglobulin-derived V regions and T-cell receptor-derived C regions.

Chimeric genes composed of immunoglobulin (Ig)-derived variable (V) regions and T-cell receptor (TCR)-derived constant (C) regions were constructed. The VL and VH genes showing anti-phosphorylcholine (PC) activity were used in this study. Two pairs of chimeric genes, VL-C beta and VH-C alpha genes, and VL-C alpha and VH-C beta genes, were inserted into an expression vector containing both Ecogpt and neo genes, and transfected into EL4 cells. Cells which express both chimeric receptor molecules were established. The activity of the transformants to the antigen was examined by using stopped-flow fluorometry. An increase in the concentration of cytoplasmic calcium ion was observed after addition of Staphylococcus pneumoniae R36A bacteria grown in the choline-containing medium which express PC molecules, but not after the PC-negative bacteria grown in the ethanolamine-containing medium.

Amino Acid Sequence↗
PubMed1987

Dynamics of generation of antigen loss variants from L1210 murine leukemia clones detected by a tumor-specific T-cell clone.

Originally T-cell clone K7L-sensitive L1210 murine leukemia clones were tested for their capacity to generate K7L-insensitive variants at various times after cloning. All of the L1210 clones (L1210/1, -2, -4, and -7) maintained in vitro for 1 month were severely inhibited in their growth in the culture in which K7L was added and in mice given injections of K7L at the initial stage. This indicated that any L1210 clone tested was not a mixture of K7L-sensitive and K7L-insensitive clones at the time of cloning. By both in vivo and in vitro K7L-mediated tumor suppression assays, K7L-insensitive antigen loss variants were then found to be generated from some (L1210/4, L1210/7) but not other (L1210/1, L1210/2) originally K7L-sensitive L1210 clones during 1 month of maintenance. Ratios of variant cells to total clone cells 1 month after cloning were estimated around 0.1% for L1210/7, 0.01% for L1210/4, and less than 0.001% (undetectable) for L1210/1 and L1210/2. Neither L1210/1 nor L1210/2 generated detectable K7L-insensitive variant cells during long-term (14-month) maintenance. All of the ten subclones of L1210/7 which were obtained 7 or 11 months after the initial cloning of L1210/7 were K7L sensitive, and not all the subclones generated K7L-insensitive variants in 1-2 months of maintenance after recloning. However, all of the subclones of L1210/7 which were maintained for 7 months generated antigen loss variants. All eight clone cells obtained from original L1210 and K7L-insensitive L1210 expressed H-2Kd and H-2Dd antigens detected by H-2Kd or Dd-specific cytotoxic T-lymphocyte clones or monoclonal antibodies. These results suggest that the antigen loss variants arise in originally K7L-sensitive L1210 clones at different times after cloning, and the probability of generation of the variants is clonally determined. The antigen loss variants seem to be generated by rare (once per 1 to 2 months or less frequent) chance with unproportionally rapid growth rather than by more frequent development for simple accumulation. The ratio of K7L-insensitive variant cells to total L1210/7 cells did not increase progressively during long-term (13 months or more) maintenance in vivo or in vitro and was always below 0.1%. It was suggested that the population size of antigen loss variants was controlled biphasically.

Animals↗
PubMed1987

Production of the constant domain of murine T-cell receptor beta-chain in Escherichia coli.

T-cell antigen receptor is a heterodimer of disulfide-linked alpha- and beta-chains. Although the essential features of T-cell receptor seem to be rather similar to those of immunoglobulin, the amount of T-cell receptor expressed on the surface of a T-cell is not large enough to be analyzed physcio-chemically. In this study, the DNA fragment encoding 120 amino acids from the 116th to the 235th of the murine beta-chain which corresponds to the presumed constant domain was inserted into an expression vector in E. coli. A large amount of this 18 kDa protein was observed to be synthesized in E. coli, and might be a good source for the three dimensional analysis of the T-cell receptor molecule.

Amino Acid Sequence↗
PubMed1987

Development of host-dependent high-grade tumor-specific immunity through a novel mechanism triggered by the Lyt-2+ tumor-specific T cell clone (K7L) that induces temporal growth of L1210 leukemia-K7L-variant.

When a murine leukemia L1210-specific Lyt-2+ T cell clone, K7L, was injected i.p. into CD2F1 mice together with L1210, the normal growth of L1210 in the peritoneal cavity of the mice at the early stage (days 0 to 5) was strongly inhibited, but L1210 grew progressively at the middle-stage (days 5 to 10), and then was rejected at the late stage (days 10 to 20). The mice thus survived for long times (more than 60 days), whereas the normal control injected with L1210 alone died within 14 days. The L1210 that grew at the middle stage in mice initially inoculated with L1210 together with K7L was a K7L-insensitive (K7L-) variant. All of eight tumor clones established from L1210-K7L- by limiting dilution was insensitive to the antitumor activity of K7L, and this property of tumor clones was stable after repeated in vitro passage. The initial depression of the L1210 growth by K7L followed by growth and rejection of the variant L1210-K7L- by the host T cell activity was then found to prepare a strong, long-lasting (more than 3 mo) immunity to protect mice against the high-dose (10(7) cells per mouse) challenge of original L1210. Corresponding to this result, definite tumor (L1210)-specific cytotoxic T lymphocyte (CTL) activity against both variant and original L1210 targets was developed by antigen (L1210) restimulation in the culture of spleen cells from these mice, but was not increased to a detectable level before L1210-K7L- variant started to grow. It was suggested that the 1210-K7L- variant and the original L1210 should have the common tumor-specific antigen that was independent of the K7L-reactive antigen, and that original L1210, whose growth was retarded by K7L, primed the host with the common antigen to be enormously boosted by the subsequently growing L1210-K7L- variant.

Animals↗
PubMed1987

Identification and characterization of a unique tumor-associated surface antigen on L1210 leukemia cells recognized by semisyngeneic antisera.

The tumor-associated surface antigen on L1210 leukemia cells was studied by immunofluorescence staining and immunoprecipitation. Anti-L1210 serum was prepared in BALB/c X DBA/2 F1 mice by priming with a hybrid of L1210 and human Lesch-Nyhan fibroblast cells and hyperimmunizing with L1210 leukemia cells. This hyperimmune serum was able to demonstrate specific surface fluorescence on L1210 cells, while the antiserum did not react with various mouse tumor cell lines, normal lymphoid tissues, or mitogen-activated lymphoid cells. The anti-L1210 serum immunoprecipitated a single polypeptide with a molecular weight of 90,000 from 125I-labeled L1210 cells. The expression of this antigen was enhanced by tumor-promoting agent and heat shock treatment. The biological significance of the L1210-specific cell surface antigen is discussed.

Animals↗
PubMed1986

Establishment of a murine leukemia L1210-specific T-cell clone displaying novel in vivo anti-tumor activity.

The murine leukemia L1210-specific cytotoxic T-cell clone K7 was established by repeated antigenic stimulation of spleen cells of L1210-immune CD2F1 mice in long-term culture. K7 possessed L1210-specific cytolytic activity detectable by the 51Cr-release test, but lost its cytolytic activity about 100 days after initiation of culture (designated as clone K7L). Clone K7L retained its L1210-specific tumor-growth-inhibitory activity independently of culture supplementation with IL-2. K7L possessed the cell-surface antigenic phenotype of cytotoxic T cells, Thy-1+, Lyt-1-, Lyt-2+. This clone K7L displayed surprisingly strong activity in specifically inhibiting in vivo tumor growth of L1210 by day 5 in the peritoneal cavity of CD2F1 mice when injected together with 10(5) tumor cells (more than 90% inhibition at E/T = 5), and prolonged survival times of most of the mice for more than 60 days, whereas control mice inoculated with L1210 alone died on day 9-17. This unique in vivo anti-tumor activity was not correlated to the in vitro cytolytic activity. Nevertheless, bystander inhibitory effect on the growth of third-party tumor cells (P388) was not seen in mice injected with a mixture of L1210 and P388 together with K7L, suggesting that K7L inhibited L1210 growth by direct cell-to-cell interaction. Host cells such as X-irradiation (800R)-sensitive lymphocytes and Carrageenan-sensitive macrophages were not involved in the early growth inhibition of L1210 by K7L.

Animals↗
PubMed1986

Aberrancy in immunogenicity and cell-surface expression of H-2 antigens on erythrocytes.

Immunogenicity for T cell-independent B-cell response assessed by splenic plaque-forming cell (PFC) response and cell-surface expression measured by laser flow cytometry of various class I H-2 antigens on mouse red blood cells (RBC) were compared. It was found that the order of magnitude of both immunogenicity and cell-surface expression on RBC is H-2Dd much greater than H-2Db greater than H-2Kd, H-2Kb. Furthermore, H-2d public antigens and H-2Ld antigens were neither immunogenic nor easily demonstrable on RBC. These findings contrasted with poor immunogenicity for PFC response (Nakashima et al. 1982, 1983) and proportionally strong expression of H-2 antigens on lymphoid cells. Immunogenicity and cell-surface expression of H-2Dd antigen on RBC were not shown to be controlled by the action of genes outside H-2D. It was therefore suggested that a number of H-2 antigens, including H-2Kd private, H-2Kb private, and H-2d public specificities are at least functionally defective on RBC. This is possibly due to the structural characteristics of the antigens. Since immunogenicity and cell-surface expression were in parallel, the expression of H-2 antigens on RBC must be dictated by a subset of B cells whose activity was assessed by PFC response. This finding supports the view that the H-2 molecules display a new category of activity which is different from their ability to activate T cells and depends on their expression on RBC.

Animals↗
PubMed1986

Augmentation of antibody responses of mice to inhaled protein antigens by simultaneously inhaled bacterial lipopolysaccharides.

Serum antibody responses of mice to repeatedly inhaled protein antigens such as bovine serum albumin and ovalbumin, plus or minus bacterial lipopolysaccharide (LPS) in the form of an aerosol were studied. Results showed that the levels of responses to inhaled protein antigens varied, depending on the mouse strain-antigen combination and that LPS inhaled simultaneously with the antigens definitely augmented the responses which were not otherwise very high. LPS extracted from Klebsiella O3 (LPS-K) but not LPS from Escherichia coli O55 (LPS-E), which was inhaled at the time of initial inhalation of antigen, significantly intensified the priming for the secondary antibody response to the antigen subsequently inhaled. Both LPS-K and LPS-E, however, definitely acted to augment the response when they were inhaled repeatedly together with the antigen. Oral administration of antigen or antigen plus LPS-K did not induce any detectable antibody response in our experiment, ruling out the possibility that the antigen and LPS stimulated the immune system via alimentary canal rather than via lung. Tissue distribution of the radioactivity soon after inhalation of 131I-labeled antigen and decay speed of the radioactivity were not significantly changed by LPS-K inhaled simultaneously. This suggested that the augmentation of responses was not mediated by the action of LPS to modulate the air-blood barrier against the entry of antigen via lung. All the results prove for the first time that inhaled LPS displays a definite adjuvant action on antibody responses to inhaled antigens.

Adjuvants, Immunologic↗