Jin-ichi Sasaki

Isolation of Line 10 Hepatoma‐Cell Membrane by the Water Extraction Method and Immunochemical Analysis

Water extraction method was applied to isolate the cell membrane from line 10 hepatoma cells and normal liver cells in strain 2 guinea pig. The materials isolated by this method were further analyzed by different immunochemical techniques including SDS‐PAGE, crossed immunoelectrophoresis and crossed affino immunoelectrophoresis to demonstrate the major components and their antigenicities. Five major glycoproteins of apparent molecular weights of 44, 46, 62, 64, and 68 kDa were prominent in line 10 tumor cell materials, whereas one band of molecular weight of 82 kDa was prominent in the materials from normal liver cells. Also four minor components from line 10 tumor cells were found to be glycoprotein in nature.

Antigenic Analysis between BCG and Tumor Cells by BCG-Monoclonal Antibodies

Antigenic relation between Mycobacterium bovis strain BCG and experimental animal tumor cells was analyzed with BCG monoclonal antibodies (BCG‐MoAbs). Four BCG‐MoAbs of 602, 603, 609, and 612 were successfully established and applied for the antigenic analysis of Meth A, RL ♂ 1, colon tumor 26 of mouse, and line 10 of guinea pig tumor. MoAb 602 showed broad reactivity against all types of tumor cells. BCG antigen(s) was clearly recognized as small granules on the tumor cell surface under the fluorescence microscope, indicating that the animal tumor cells shared the common antigen(s) with BCG.

Antitumor Peptidoglycan with New Carbohydrate Structure from Squid Ink

Squid ink, which has little commercial use and is usually discarded, was extracted with Tris-HCl buffer (pH 6.8). The extract was fractionated using DEAE Sephacel ion-exchange chromatography and Sephacryl S-300gel filtration to give a peptidoglycan fraction that exhibited strong antitumor activity against Meth-A fibrosarcoma in BALB/c mice following intraperitoneal injection. The fraction contained 17.8% peptide, 51.2% polysaccharide moiety, and 30.3% pigment. Furthermore three fucose (Fuc)-rich glycosaminoglycans (GAGs), illexin (ILX)-A, -B, and -C (MW 50000, 50000–80000, and 80000), were isolated from the peptidoglycan fraction, using Actinase E digestion, DEAE Sephadex A-50 ion-exchange chromatography, and Sephacryl S-300gel filtration. They gave a single band on the electrophoresis using cellulose acetate membrane and contained equimolar ratios of Fuc, glucuronic acid (GlcA), and N-acetylgalactosamine (GalNAc). These GAGs were not digested with any glycosaminoglycanases, but each gave tri- and hexasaccharides with mild acid hydrolysis. On the basis of spectral data, chemical compositional analysis, and chemical and enzymatic degradation analyses of GAGs and the pyridylaminated (PA) oligosaccharides, the unique repeating branched-structure of the GAGs was determined to be [-3GlcAβl-4(GalNAcαl-3)Fucαl-]n.

The Mycobacterium bovis BCG 64-kDa surface protein is antigenically shared with different mouse tumor cells and has anti-tumor activity in immunized mice

The Mycobacterium bovis BCG 64-kDa surface protein, which was found to share antigenic determinants with line 10 hepatoma cells and showed anti-line 10 tumor activity in immunized guinea pigs, has also been found to share common antigenic determinants with Meth A, CT-26 and RL female 1 mouse tumor cells. The 64-kDa protein also demonstrated anti-tumor activity in immunized mice and 37% of the animals challenged with Meth A tumor cells and 50% of those challenged with CT-26 tumor cells completely rejected further tumor growth in the immunized mice. All these data clearly suggest that BCG 64 kDa protein is probably identical with the tumor specific antigen.

Idiotype vaccine for tumor by anti-idiotypic antibody prepared against anti-(bacillus Calmette Guèrin)BCG monoclonal antibody

SummaryThe anti-idiotypic antibody (Ab2) prepared against the anti-BCG monoclonal antibody (mAb) (Ab1) exhibited potential vaccine activity against Meth A fibrosarcoma that shared a common antigen(s) withMycobacterium bovis strain bacillus Calmette Guèrin (BCG). Mice vaccinated with the anti-idiotypic antibody (Ab2) were protected significantly against growth of the transplanted Meth A tumor (66%), and the presence of anti-(anti-idiotypic antibody) (Ab3) was proved in the Ab2-vaccinated mice by enzyme-linked immunosorbent assay and indirect immunofluorescence analyses using unabsorbed or absorbed sera against the BCG antigen(s) and Meth A tumor cells. This indicated that the anti-idiotypic antibody (Ab2) mimicked the structures of the BCG antigen(s) and behaved as the BCG antigen(s) to induce the Abl-like antibody (Ab3) in vivo. Presumably the Ab2-induced Ab3 plays a significant role in preventing growth of the transplanted tumor in animals. By contrast, the control mice treated with normal mouse serum failed to inhibit the tumor growth. These results suggest the possible development of a tumor vaccine from the anti-idiotypic antibody (Ab2) prepared against the anti-BCG monoclonal antibody, for tumors sharing a common antigen(s) withMycobacterium bovis strain BCG.

Macrophage activating property of bean-lecithin

Abstract The phospholipid, lecithin, isolated from beans was studied for its effect on peritoneal exudate macrophages of BALB/c mice. Superoxide anion (O 2 − ) production of lecithin-induced peritoneal exudate cells increased remarkably as compared with phosphate buffered saline-induced control cells. It was also found that bean-lecithin enhanced the expression of Fc receptors for antibody on macrophages, when co-cultured with bean-lecithin. Further, bean-lecithin induced chemotactic activity in macrophages. From these results, it was concluded that bean-lecithin has a macrophage activating potency which play an important role in systemic defence mechanism in vivo.