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Biomedical subjects

T Taniyama

Publications and source records attributed to T Taniyama.

At least 73 records · Page 4Linked to original sources
PubMed1987

I-Ad antigen expression of pyran copolymer-induced peritoneal cells in tumor vaccine-primed mice and its association with the host antitumor response.

Mice inoculated IP with L1210 murine leukemia vaccine and subsequently with pyran copolymer-induced macrophages (pyran-M phi) lived for a prolonged time after live L1210 inoculation IP. Pyran-M phi as tentatively identified by anti-AcM.1 monoclonal antibody expressed I-Ad antigen in tumor vaccine-primed recipient mice and contributed to maintaining I-Ad antigen positive (I-Ad+) macrophages at high cell density in the peritoneal cavity of recipient mice. The relevance of these I-Ad+ cells to the host antitumor response was examined by experiments in which I-Ad+ cell density in the peritoneal cavity and host antitumor response behaved in a parallel fashion. Human interferon-alpha A/D, an agent selectively inhibiting Ia antigen expression, and silica, a general antimacrophage agent, strongly suppressed I-Ad antigen expression of peritoneal macrophages of tumor vaccine-primed and pyran-M phi-inoculated mice and, consistently with this, the antitumor response was nullified in these mice. Tumor vaccine-primed mice inoculated with sodium caseinate or thioglycollate-induced peritoneal cells did not survive L1210 inoculation and, in these mice, I-Ad+ peritoneal macrophages were suppressed in number as compared with those of tumor vaccine-primed and pyran-M phi-inoculated mice. These results warrant further study on the contribution of I-Ad+ macrophages to pyran copolymer-induced augmentation of the antitumor response in tumor vaccine-primed mice.

Animals↗
PubMed1984

Phospholipases of Leptospira. I. Presence of phospholipase A1 and lysophospholipase in Leptospira biflexa.

The hydrolysis of phosphatidylethanolamine, phosphatidylcholine, lysophosphatidylcholine, and trioleoylglycerol by Leptospira biflexa strain Urawa was studied in vitro. Phospholipase A1 was identified by the formation of 32P- and 14C-labeled lysoderivatives from 32P-phosphatidylcholine, 32P-phosphatidylethanolamine, or 1-acyl-2-[1-14C]oleoyl-sn-glycero-3-phosphorylcholine. Phospholipase A1 activity was independent of lipase in the microorganism since 14C-labeled trioleoylglycerol was scarcely attacked under the same conditions in which the phospholipids were hydrolyzed. Lysophospholipase activity was also demonstrated using 32P- and non-labeled lysophosphatidylcholine. The activity of phospholipase A1 was found in a broad range of pH but no optimal pH was determined. The pH optimum of lysophospholipase was 8.0. Both enzymes were labile to heat. Phospholipase C activity, however, could not be detected because no radioactive di- and monoacylglycerol was found in the experiment with 1-acyl-2-[1-14C]-oleoyl-sn-glycero-3-phosphorylcholine as the substrate. It was inferred that phosphatidylethanolamine, which was the major component of phospholipids in leptospirae, was hydrolyzed serially by phospholipase A (A1 and/or A2?) and lysophospholipase to glycerophosphorylethanolamine via 2-acyl-type-lyso-derivative as one metabolic pathway of the substrate.

Hot Temperature↗
PubMed1983

Physicochemical properties of T-cell-activating monokines in guinea pigs.

T-cell-activating monokines of guinea pigs with interleukin 1-like activity were produced in protein-free medium by stimulation of peritoneal macrophages with synthetic muramyl dipeptide (MDP). Gel filtration of the culture supernatant of MDP-stimulated macrophages revealed that most of the activity to potentiate the responses of thymocytes and lymph node T cells to phytohemagglutinin were found in the high-molecular-weight (40,000-80,000) fraction. By isoelectric focusing, the monokine in the high-molecular-weight fraction was focused at a pI of around 4.7 forming a somewhat broad band, indicating some heterogeneity. In the analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the high-molecular-weight fraction, the peak of the activity was found at an approximate Mr of 60K under unreduced as well as reduced conditions. Accordingly, it is likely that the monokine in this fraction is a polypeptide of 60K, but a possibility still remains that the 60K component is an aggregate of low-molecular-weight monokine which requires more rigorous conditions for dissociation.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1983

Monoclonal antibody against human macrophages/monocytes and granulocytes.

A monoclonal antibody of the IgG2a isotype directed against lymphokine-activated human macrophage cell line (U937) was produced and characterized. By indirect immunofluorescence microscopy or binding assay, this antibody (MaG-1) reacted with human peripheral monocytes, peritoneal macrophages, alveolar macrophages, and peripheral granulocytes but not with lymphocytes, erythrocytes, and platelets. MaG-1 antigen was also expressed by 34% of bone-marrow cells which includes monocytic and granulocytic precursors, whereas lymphoid and erythroid precursor cells were found on MaG-1 negative population. Immunoprecipitation of 125I-labeled U937 cell extract with the Mag-1 antibody under nonreducing and reducing conditions yielded a specific band of 66 kD. Thus, this antibody defines a new human macrophage/monocyte and granulocyte-specific antigen and may be useful for studying differentiation of human macrophages/monocytes.

Antibodies, Monoclonal↗
PubMed1983

Monoclonal antibodies directed against mouse macrophages in different stages of activation for tumor cytotoxicity.

Three rat monoclonal antibodies against mouse peritoneal macrophages in different stages of activation were produced and characterized. One of these (AcM.1) bound to activated macrophages induced by pyran and Corynebacterium parvum, but not to resident and thioglycollate medium- (TGC) or proteose peptone- (PP) elicited macrophages. On the contrary, the antigen identified by MM9 monoclonal antibody was expressed only on resident and TGC- or PP-elicited macrophages. WE15 monoclonal antibody, on the other hand, reacted with all of the macrophages described above. In the assay for function, AcM.1 and WE15 monoclonal antibodies in the presence of complement (C) abolished the capacity of activated macrophages induced by pyran or C. parvum but not the capacity of killer T cells and natural killer (NK) cells to kill tumor target cells. On the other hand, MM9 and anti-Thy-1.2 monoclonal antibodies in the presence of C, as expected, did not affect the cytotoxicity of activated macrophages. However, none of the four monoclonal antibodies in the absence of C had any blocking effect on macrophage-mediated cytotoxicity. AcM.1 antibody reacted with two polypeptides with m.w. of 70,000 and 45,000 on pyran-activated macrophages; however, the antigens recognized by WE15 and MM9 have not been determined yet. These results indicate that the three rat monoclonal antibodies define different antigens present on macrophages at different stages of activation for tumor cytotoxicity, and that these antibodies should prove to be useful probes for analyzing the mechanism of activation of macrophages for tumor cytotoxicity.

Animals↗
PubMed1982

Establishment of a hybridoma secreting a monoclonal antibody specific for activated tumoricidal macrophages.

New activated macrophage-specific antigen (AcM.1) detected by a monoclonal antibody has been described. The AcM.1 antigen was only detectable on activated macrophages induced by pyran and Corynebacterium parvum but not on resident or thioglycollate medium (TGC), proteose-peptone, and mineral oil-elicited macrophages, and not on blood monocytes and neutrophils. Activated macrophages induced by pyran and C. parvum, as expected, exhibited tumor cytotoxicity, whereas TGC-elicited macrophages did not show any cytotoxicity. Moreover, pretreatment of pyran-activated peritoneal exudate cells with AcM.1 antibody plus complement abolished approximately 80% cytotoxicity. Thus, this AcM.1 antigen detected by a monoclonal antibody is the first unique marker of activated tumoricidal macrophages and should provide a useful probe for investigating the mechanisms of activation or differentiation of macrophages.

Animals↗
PubMed1980

Cytolytic activity against tumor cells by macrophage cell lines and augmentation by macrophage stimulants.

Previous studies have shown that macrophage cell lines retained the ability to phagocytize, to secrete lysosomal enzymes, and to function as effector cells in antibody-dependent cellular cytoxicity. In this paper, the cytolytic activity of murine macrophage cell lines against tumor target cells was assessed using an 18-h 51Cr release assay. Of the macrophage cell lines tested, RAW 264, PU5-1.8 and IC-21 had intermediate to high levels of spontaneous cytolytic activity, P388D, and J774 had low to intermediate levels, while /WEHI-3 showed little or no cytolytic activity against RBL-5, MBL-2 and TU-5 target cells. Tumor-cell killing by macrophage cell lines could be augmented by the addition of macrophage stimulants, such as bacterial lipopolysaccharide and poly I:C, indicating that the activation of macrophages by these stimulants does not require the participation of other cell types. Treatment with interferon also augmented the tumor-cell killing by macrophage cell lines. Although the mechanism by which these cell lines exert their spontaneous or boosted cytotoxic activity is not clear, it does not appear to be due to depletion of nutrients since cell lines with high metabolic and proliferative activities, such as WEHI-3 and RBL-5, showed little or no cytotoxicity and supernatants from the macrophage cell lines did not exert any cytotoxic effects in their essay. Thus, it appears that the different macrophage cell lines represent different levels of activation and/or differentiation and may be useful for studying the development of these processes as well as providing a useful tool for analyzing the mechanisms of macrophage-mediated cytolysis.

Adjuvants, Immunologic↗
PubMed1979

In vitro induction of T-lymphocyte-mediated cytotoxicity by infectious murine type C oncornaviruses.

We have developed a system to induce oncornavirus-specific secondary cytotoxic response in vitro. When Moloney strain of murine sarcoma virus-immune spleen cells were cultivated with purified infectious Moloney murine leukemia virus (M-MuLV) or with supernates of tissue culture cells containing infectious virus, a virus-specific secondary cytotoxic response directed against type-specific determinant(s) of M-MuLV was generated in vitro, as determined by a 4-h 51Cr-release assay. The effector cells were susceptible to the treatment with anti-Thyl.2 plus complement, but were unrelated to natural killer cells (NK), because they could not lyse some target cells specific for M-MuLV in both the induction phase and the interaction between effector cells and target cells. Furthermore, a product of the env gene of M-MuLV, perhaps gp70, appeared to be responsible for this response, because viruses with recombinations in the env gene between ecotropic M-MuLV and a xenotropic virus failed to induce a response. When infectious M-MuLV was exposed to UV-light at different doses, the ability of UV-treated M-MuLV to induce a secondary cytotoxic response decreased in parallel with infectivity, indicating that infectivity was necessary for the induction of this response.

Animals↗
PubMed1979

Cytolytic activity of macrophages isolated from primary murine sarcoma virus (MSV)-induced tumors.

Macrophages isolated from regressing or progressing tumors induced by murine sarcoma virus (MSV) were tested for cytolytic activity in a 18-h 51Cr release assay. Macrophages from the tumors of mice injected 14 days earlier with stocks of MSV-producing regressor or progressor tumors had comparable levels of cytotoxicity. However, macrophages from the progressively growing tumors, 50--65 days after the inoculation with the progressor virus, had lower levels of cytotoxicity than those from the regressing tumors (day 14). On the other hand, macrophages from progressively growing MSV tumors (day 14) in nude mice had little or no detectable cytolytic activity. In a fractionation study, using the 1-g velocity sedimentation technique, cells from regressing tumors (day 14) showed at least two peaks of cytolytic activity, one at about 4 mm/h and another at 6--7 mm/h. In contrast, none of the cell fractions of tumors from nude mice (day 14) showed cytolytic activity. Since bacterial lipopolysaccharide (LPS) has been shown to augment the cytolytic activity of primed macrophages, its effect on cells from MSV tumors was evaluated. Cytolytic activity of the cells from regressing or progr-ssing tumors that had pre-existing cytolytic activity was augmented by the addition of LPS during the assay period, but LPS treatment did not activate inactive fractions or change the distribution patterns of the cytolytic activity in fractions from 1-g velocity sedimentation.

Animals↗