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Biomedical subjects

M Torii

Publications and source records attributed to M Torii.

At least 127 records · Page 7Linked to original sources
PubMed1985

Cell wall preparation consisting of group A carbohydrate and peptidoglycan moieties from Streptococcus pyogenes activates murine B lymphocytes.

Cell walls from Streptococcus pyogenes strain Sv (Group A, M type 3) were lysed with M1 endo-N-acetylmuramidase, and the group A-specific carbohydrate antigen was purified by Sephadex G-100 gel filtration. The initial eluting antigen (M1gA) peak was assessed for mitogenic and polyclonal lymphocyte-activating properties in murine spleen cell cultures. Good mitogenic responses were induced over a broad dose range (1-100 micrograms) with M1gA in both BALB/c and C3H/HeJ splenic cultures. Similar mitogenic responses were induced in nude (nu/nu) and nu/+ splenic cultures, suggesting that M1gA is a B cell mitogen. The M1gA induced anti-trinitrophenyl, anti-sheep erythrocytes, and anti-horse erythrocytes polyclonal plaque-forming cell responses in splenic cell cultures. Studies with purified splenic B cells and M1gA suggest that the mitogenic responses were indeed thymic independent. These studies clearly indicate that native group A carbohydrate antigen is a B cell mitogen and polyclonal B cell activator.

Animals↗
PubMed1984

Effects of dibutyryl adenosine 3'-5' cyclic monophosphate on the ultrastructure of rat ascites hepatoma cells and on the intracellular localization of alpha-fetoprotein.

The growth of rat ascites hepatoma cells (AH 66) in vitro was inhibited and the amount of alpha-fetoprotein (AFP) in the culture medium was increased in the presence of dibutyryl adenosine 3'-5' cyclic monophosphate (DBc-AMP). Electronmicroscopically, AH 66 cells that had been incubated with DBc-AMP showed an increase in polysomes on rough endoplasmic reticulum (RER), and some mitochondria appeared to be completely surrounded by RER. AFP in untreated cells was found to be localized on ribosomes of RER, free ribosomes and occasionally also on microvilli of cell membranes by electronmicroscopic and immunohistochemical analysis. After DBc-AMP treatment, increased staining of AFP was identified on ribosomes of RER and microvilli of cell membranes as well as on nuclear membranes. These results suggest that DBc-AMP accelerates the production and release of AFP in cultured rat ascites hepatoma cells.

Animals↗
PubMed1983

A plaque assay for assessment of immune responses to Streptococcus mutans cell wall carbohydrate.

A plaque-forming cell (PFC) assay has been developed for measurement of single cell responses to the serotype carbohydrate antigen of the Streptococcus mutans cell wall. Serotype g carbohydrate was purified from a mutanolysin (M1) enzyme digest (and designated M1g) of S. mutans 6715 cell walls by ion exchange and gel filtration chromatography. M1g carbohydrate was esterified by stearoylization (sM1g), and subsequently coated to sheep erythrocytes (sM1g-SRBC). This coating antigen was then used for enumeration of IgM anti-M1g PFC responses from spleens of either mice or rats immunized with S. mutans 6715 antigen. Good splenic IgM anti-M1g PFC responses were seen in either mice or rats given S. mutans whole cells or cell walls, while cell wall lysates or M1g were lowly immunogenic. Of interest was the finding that sM1g induced good IgM anti-M1g PFC responses in mice and in murine spleen cell cultures, in vitro. This study describes a method for assessment of individual antibody-producing cells to a major S. mutans cell wall determinant which should facilitate studies directed to determine mechanisms involved in the induction of immune responses to this important bacterium.

Animals↗
PubMed1983

Combining site specificities of mouse hybridoma antibodies to dextran B1355S.

The combining sites of 12 mouse hybridoma antibodies to dextran B1355S have been characterized by quantitative precipitin assay. All antibodies preferentially bind the immunizing antigen B1355S and two other class I dextrans, B1498S and B1501S, but show substantial differences in the extents to which they cross react with class I dextrans, suggesting their clustering into five groups. Three myeloma proteins, CAL20 TEPC1035, J558, and MOPC104E, which bind dextran B1355S, each fall into a different group. There appears to be a substantial, but imperfect, correlation of DH region structure and individual idiotypic determinants with dextran binding patterns. Proteins with RY DH segments and IdI (J558) idiotypes are in groups 1 or 3, and proteins with YD DH segments and IdI (MOPC104E) idiotypes are exclusively in group 5. However, identical patterns of precipitin curves accompany very different sequences in CDR3. Antibodies of group 1, which react only with class II dextrans, differ the most in primary sequence, a finding suggesting that subsites responsible for cross reactivity with class I dextrans may be blocked and that this may be effected by side chains of different amino acids. This finding delineates a new aspect of the relationship of variability in amino acid sequence to antibody complementarity.

Amino Acid Sequence↗
PubMed1983

Biological effects of Spirometra erinacei plerocercoids in several species of rodents.

Observations were made of the biological effects on infection with plerocercoids of Spirometra erinacei on normal female Snell mice, male chinese hamsters, golden hamsters, normal and hypox rats. Plerocercoid infection caused the strongest growth-promoting effect on normal Snell mice. In mice, this effect appears to be independent of strain. Chinese hamsters infected with these larvae showed similar growth. The infected normal rats and golden hamsters, however, showed a weight increase in the skeletal muscle only, while the hypox rats exhibited no effect at all. The elevation in the concentration of serum triglyceride was observed in all the animals investigated except for rats. Golden hamsters, in particular, exhibited a marked increase in the concentration of serum free fatty acids and total cholesterol. There was close correlation between the concentrations of serum triglyceride and free fatty acids, and the regression coefficient of the resulting linear regression equation for the experimentals was higher than that for the controls. This suggests that serum triglyceride results from an increased concentration of serum free fatty acids derived from stimulated lipolysis. The total cholesterol concentration in the serum decreased in chinese hamsters infected with larvae. The serum glucose concentration increased in normal Snell mice but decreased in chinese and golden hamsters. No difference in glycerol and free fatty acid concentration was observed in infected animals except for golden hamsters.

Animals↗
PubMed1983

An enzyme-linked immunosorbent assay (ELISA) for quantification of antibodies to Streptococcus mutans surface antigens.

An ELISA was developed to quantitate the level of antibodies to various cell surface antigens of the Gram positive bacterium, Streptococcus mutans. Whole cells and purified cell wall components of S. mutans, lipoteichoic acid (LTA) from Streptococcus pyogenes, and dextran T 2000 were employed as coating antigens in this study. Cell walls of S. mutans were purified by mechanical disruption of whole cells followed by differential centrifugation and proteolytic enzyme treatment. Serotype-specific carbohydrate was purified from an autoclaved, lyophilized S. mutans whole cell preparation by column chromatography. LTA was prepared by Sepharose 4B chromatography of a phenol-water extract of S. pyogenes and used for detection of anti-polyglycerophosphate (PGP) antibodies. A rabbit antiserum to S. mutans 6715 (serotype g), which precipitated with purified carbohydrate antigen (RR g), gave good reactions with purified cell walls and whole cells of S. mutans 6715, less activity with RR g and low activity to LTA and dextran when tested by ELISA. Adsorption of this antiserum with whole cells of S. pyogenes resulted in antibody activity with specificity only to the serotype carbohydrate. The specificity of the antibody for homologous coating antigen was RR g greater than cell wall greater than whole cells. An antiserum to S. mutans MT573 (serotype e) contained antibody predominantly to LTA, whereas, anti-S. mutans MT703 (serotype e) reacted with both dextran and LTA; however, the activity to LTA was removed by prior adsorption of the antiserum with S. pyogenes cells. This treatment did not alter the antibody activity to dextran. To establish the sensitivity of ELISA, a purified IgG anti-serotype carbohydrate antibody was prepared by adsorption of anti-S. mutans 6715 antiserum with a mutant of S. mutans which lacks serotype carbohydrate followed by adsorption and elution of specific antibodies from S. mutans 6715 whole cells. The minimum level of sensitivity of ELISA was 12.5 ng of IgG anti-serotype carbohydrate.

Antibodies, Bacterial↗
PubMed1983

Effects of Spirometra erinacei plerocercoids on the growth of Snell dwarf mice.

Snell normal and dwarf mice were infected with Spirometra erinacei plerocercoids collected in Japan, to investigate the relationship between the growth-promoting effects of plerocercoids and the growth hormone releasing factor and the somatostatin--growth hormone--somatomedin axis in the host. Infection with plerocercoids caused increases in body weight and weights of muscle, liver, spleen and heart in the normal male mice, and increases in the head--body length, body weight and weights of muscle, liver, spleen, kidney and heart in the normal female mice, but did not increase the weight of the fat pad. Infection with plerocercoids caused increases in body weights and weights of muscle, liver and spleen in the male dwarf mice, and increases in the head--body length, body weight and weights of muscle, liver, spleen and kidney in the female dwarf mice. These observations suggest that plerocercoids promote the growth of dwarf mice as well as normal mice. As the dwarfism of Snell mice is due to a defective anterior pituitary gland, it seems that plerocercoids do not stimulate secretion of growth hormone from the pituitary. Accordingly, it seems to be more probable that the larvae secrete a growth hormone-like substance.

Animals↗
PubMed1983

Isolation and characterization of the serotype g carbohydrate moiety from an enzyme lysate of Streptococcus mutans 6715 cell walls.

The serotype-specific carbohydrate moiety of Streptococcus mutans was isolated by mild degradation of purified cell walls with a cell-wall lytic enzyme. Cell walls of serotype g S. mutans strain 6715 were digested with M1 enzyme, an endo-N-acetylmuramidase purified from culture supernatants of Streptomyces globisporus strain 1829. The enzyme lysate of the cell walls was applied to a CM Sephadex C-25 column to remove the M1 enzyme from the cell wall lysate and then subjected to Sephadex G-100 column chromatography. Carbohydrate antigens with serotype g specificity, designated M1g, and a peptidoglycan--polysaccharide complex lacking serotype specificity (M1PG) were separated. Purified serotype g antigen was also obtained by autoclaving the S. mutans 6715 whole cells in saline at 120 C for 30 min. The extract was applied to a DEAE Sephadex A-25 column to remove nucleic acids and teichoic acids. The unbound peak fraction was concentrated and re-chromatographed on a Bio-Gel P-100 column. The void volume fraction contained serotype g carbohydrate and was designated RRg antigen. M1g and RRg antigens formed a band of identity with anti-serotype g serum by immunodiffusion. These antigens were composed mainly of galactose, glucose, and rhamnose at an approximate weight ratio of 8 : 4: 1, while constituent sugars of M1PG consisted of rhamnose and glucose, with no detectable galactose. M1g also contained peptidoglycan residues other than threonine, an interpeptide bridge component of the native cell wall peptidoglycan. Marked inhibition of the quantitative precipitin reaction between M1g and anti-serotype g serum was obtained with melibiose and galactose, which suggests that the immunodeterminant of the serotype g carbohydrate is an alpha-linked galactose-glucose terminal linkage.

Amino Acids↗
PubMed1983

Lymphoid cell responses to bacterial cell wall components: murine B-cell responses to a purified cell wall moiety of Actinomyces.

A mitogenic component, designated fraction C (Fr C), has been purified from a mutanolysin enzyme digest of Actinomyces cell walls by CM Sephadex C-25 ion-exchange and G-100 gel filtration chromatography. Good mitogenic responses were obtained with Fr C over a broad dose range with peak mitogenesis seen with 500 micrograms/culture. Fraction C (mol. wt. = 35,000-40,000) consists of 75% carbohydrate and 23% protein, is non-dialysable, resistant to heat, lysozyme or protease treatment, and partially sensitive to base, and all mitogenic activity is destroyed by either periodate or acid treatment. Fraction C is a B-cell mitogen since it induced responses in nude (nu/nu) and nu/+ BALB/c spleen cell cultures and purified splenic B-cell cultures, but did not stimulate purified splenic T-cell cultures. Similar mitogenic fractions for B cells have been obtained from cell walls of A. naeslundii and from a human isolate of A. viscosus. Good polyclonal IgM synthesis and plaque-forming cell responses to hapten or erythrocytes were obtained in vitro with the purified cell wall fractions derived from all three Actinomyces strains studied. These results indicate that the Actinomyces cell wall possesses a carbohydrate-rich component which activates B cells and may represent a common determinant of this genus.

Actinomyces↗
PubMed1983

Effective immunity to dental caries: enhancement of salivary anti-Streptococcus mutans antibody responses with oral adjuvants.

In the present study, we compared the ability of the soluble adjuvants concanavalin A (ConA), muramyl dipeptide (MDP), and peptidoglycan (PG) to enhance immune responses to orally administered particulate antigens of Streptococcus mutans 6715 in gnotobiotic rats. The isotype and levels of antibody in saliva and in serum from experimental rats were determined by an enzyme-linked immunosorbent assay using S. mutans whole cells (WC) as the coating antigen. The specificities of salivary and serum immunoglobulin A (IgA) antibodies to particulate S. mutans antigens, lipoteichoic acid, S. mutans serotype g carbohydrate, and dextran were also determined. When 50 micrograms of ConA was used as the oral adjuvant with S. mutans 6715 WC immunogen, a slight enhancement of immune responses was obtained. A higher dose of ConA suppressed humoral responses to the immunogen. Enhanced immune responses, especially of the IgA isotype, in both serum and saliva were induced in gnotobiotic rats given MDP and either S. mutans 6715 WC or purified cell walls (CW) by gastric intubation. Elevated IgA antibody levels to CW, lipoteichoic acid, and carbohydrate were observed in rats given S. mutans WC and MDP by gastric intubation, whereas oral immunization with S. mutans CW and MDP resulted in higher antibody levels to CW and carbohydrate and lower levels to lipoteichoic acid when compared with the antibody levels in rats given antigen alone. Rats orally immunized with either S. mutans WC or CW and MDP and challenged with virulent S. mutans 6715 exhibited significantly (P less than or equal to 0.05) lower plaque scores, numbers of viable S. mutans in plaque, and caries scores than did rats immunized with antigen alone or in infected-only controls. In another series of experiments, a PG fraction derived from S. mutans 6715 CW was assessed for adjuvant properties. The oral administration of PG and either S. mutans WC or CW induced good salivary and serum IgA antibody responses. The specificity of the antibodies was similar to that obtained in rats given antigen and MDP. Rats receiving either S. mutans WC or CW and PG and challenged with virulent S. mutans 6715 had lower plaque scores, fewer numbers of viable S. mutans in plaque, and lower caries activity than did infected rats receiving S. mutans WC or CW immunogen alone. These results provide evidence that soluble adjuvants derived from the gram-positive bacterial CW, e.g., MDP and PG, are effective oral adjuvants and augment IgA immune responses to particulate S. mutans antigens which are protective against the mucosally associated disease, dental caries.

Adjuvants, Immunologic↗
PubMed1983

Idiotype-specific T lymphocytes. I. Regulation of antibody production by idiotype-specific H-2-restricted T lymphocytes.

Cytotoxic T lymphocytes (CTL) specific for MOPC-104E myeloma cells of BALB/c origin could be induced in BALB/c, (BALB/c X BALB.B)F1, and (BALB/c X BALB.K)F1 mice. (BALB/c X BALB.B)F1 CTL activity specific for MOPC-104E was effectively inhibited by anti-H-2d but not by anti-H-2b alloantiserum. However, the activity was hardly blocked by specific anti-idiotypic antibodies to MOPC-104E. For further analysis of the recognition of idiotype on target cells by CTL, the effect of those lymphocytes on anti-dextran B1355S antibody-producing B lymphocytes, which have a cross-reactive idiotype to MOPC-104E, was investigated. Lymphocytes from the CTL population did inhibit antibody production by dextran-immune spleen cells, but those from the CTL population specific for irrelevant myeloma cells (MOPC-167) did not. The (BALB/c X BALB.K)F1 CTL population suppressed the antibody production of BALB/c but not of BALB.K. This indicates that F1 cells can preferentially see H-2 antigens of immunizing myeloma cells on target B lymphocytes. The inhibition of antibody production was antigen specific and was only restricted to the PFC that were inhibitable by anti-idiotypic antibodies. The surface phenotypes of the cells that inhibited the antibody production were Thy-1+, Lyt-1-, Lyt-2+, and I-J-. These results strongly suggest that CTL specific for MOPC-104E recognize self H-2 antigens simultaneously with idiotypic determinants on B lymphocytes. Possible immunoregulatory roles of idiotype-specific CTL on antibody production systems are also suggested.

Animals↗