Isolation of line 10 hepatoma-cell membrane by the water extraction method and immunochemical analysis

A 64 kDa protein from Mycobacterium bovis BCG shares the same antigenic determinants with line 10 hepatoma cells and has anti-line 10 tumor activity

A 64 kilodalton (kDa) surface protein was isolated from the water-extracted materials from Mycobacterium bovis strain BCG, the determinants of which are antigenically shared by a 64 kDa major surface antigenic component of line 10 hepatoma cells. The 64 kDa protein showed anti-line 10 tumor activity in pre-immunized guinea pigs, and this suggest that the 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

The 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) with Mycobacterium 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 Ab1-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) with Mycobacterium bovis strain BCG.

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 male 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.