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Biomedical subjects

Y Kumazawa

Publications and source records attributed to Y Kumazawa.

At least 145 records · Page 8Linked to original sources

Mitogenic andadjuvant activities of polysaccharides from the cellular slime mold, Dictyostelium discoideum NC-4.

Cell surface and extracellular polysaccharide fractions obtained from Dictyostelium discoideum NC-4 cultured in bacteria-free medium showed strong B-cell mitogenic activities. Upon periodate treatment of the extra-cellular polysaccharide fraction this activity completely disappeared. The extracellular polysaccharide fraction could also enhance the antibody response in vitro against sheep red blood cells.

Adjuvants, Immunologic↗

Suppression of delayed type hypersensitivity induction to sheep red blood cells by concanavalin A in mice.

An examination was carried out on the in vivo effect of concanavalin A (Con A) on the induction of delayed-type hypersensitivity (DTH) to heterologous erythrocytes in mice. DTH induction was suppressed by an intravenous injection of 100 microng of Con A 1 day before, or simultaneously with immunization. This suppression was mediated by Con-A-activated spleen cells, and also by their cell-free extracts. However, this suppressive effect was abrogated by absorption of cell-free extracts with immunoadsorbent composed of rabbit anti-mouse thymocyte serum (ATS), indicating that suppressive factors for DTH induction make up one of the components extractable from Con-A-activated T cell population.

Animals↗

Separation of a water-soluble adjuvant (MAF3) from delipidated cells of Mycobacterium tuberculosis strain Aoyama B by hydrogenolysis and gel filtration.

A water-extract from hydrogenolyzed cells of Mycobacterium tuberculosis strain Aoyama B was separated into four portions (F-1 to F-4 fractions) by gel filtration with a Sephadex G-100 column. The third peak (called MAF3) eluted from the column was the most adjuvant-active fraction. The molecular weight determined by gel filtration was around 16 000 daltons. MAF3 consisted of heteropolymer(s) composed of approximately 76 to 79% neutral sugars (Ara, Gal, Man, and Glc) and 19% mucopeptide (MurN, GlcN, Glu, Ala, Dpm, Gly, Asp, Thr, Ser, Leu, Lys, Arg, His, Pro, Tyr, and Phe). The adjuvanticities of MAF3 and other fractions in water-in-oil emulsion were estimated by the enhancing effect on immune response to egg albumin (EA) in guinea pigs. MAF3 stimulated the production of humoral antibodies, particularly IgG2 antibody specific to the antigen, and induced delayed type hypersensitivity against EA in the skin and cornea of antigen-primed guinea pigs. These adjuvanticities of MAF3 were similar to the characteristics of mycobacterial cell wall in Freund's complete adjuvant.

Adjuvants, Immunologic↗

Modulation of mouse anti-trinitrophenyl plaque-forming cell affinity by adjuvants or lectins.

The efffects of several kinds of adjuvants or lectins, such as Corynebacterium parvum, dextran, poly AU, poly IC, dibutyryl cAMP, concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM) on anti-trinitrophenyl (TNP) direct plaque-forming cells (PFC) in the spleen of mice and the affinity of antibodies produced by these PFC were examined. The numbers of anti-TNP PFC in the spleens of mice which had been injected with C. parvum 7 days in advance were greater than those in controls after immunization with TNP-coupled heterologous erythrocytes, while the affinity of antibodies released by these PFC. Copolymers of nucleotides, poly AU and poly IC, were capable of enhancing splenic anti-TNP PFC responses, but showed almost no altering of PFC affinity. Dibutyryl cAMP did not have any effect on this system. Con A had potencies to both augment the number of anti-TNP PFC and heighten the PFC affinity, while PHA seemed to lack these potencies. Injection of PWM in the presence of antigen increased the number of anti-TNP PFC and heightened slightly the PFC affinity. These results indicate that the heightening of the affinity at the cellular level is regulated in ways different from the augmenting effects on the number of anti-TNP PFC by adjuvants or lectins. These results are discussed in the light of the mode of action of the substances used.

Adjuvants, Immunologic↗