Immunopathology of BCG infection in genetically resistant and susceptible mouse strains.

Natural resistance to Mycobacterium bovis (BCG) is under the control of a single gene, designated Bcg. Resistant (Bcgr) mice prevent multiplication of an i.v.

Human melanoma cells can be killed in vitro by an immunotoxin specific for melanoma-associated antigen p97.

Conjugates (immunotoxins) comprising ricin A-chain and monoclonal antibody 96.5, which is specific for human melanoma-associated antigen p97, inhibited protein synthesis and colony formation of cultured human melanoma cells that expressed more than 80,000 molecules of p97 per cell. Cells expressing fewer than 5,000 molecules of p97 were not killed.

[Immunotoxins (author's transl)].

Immunotoxins are hybrid molecules made up of an antibody and of the toxic subunit of a polypeptidic toxin. They act on the principle that the antibody binds the molecule to a cellular antigen which it specifically recognizes, so that the cytotoxic component only kills those cells that bear the antigen. Cell hybridizations obtained by fusion now produce monoclonal antibodies specific enough to bind the antigens present on certain malignant cells.

Genetic control of natural resistance to Mycobacterium bovis (BCG) in mice.

Mice of 12 inbred strains infected i.v. with Mycobacterium bovis (BCG) exhibited 2 distinct patterns of response as determined by the degree of BCG burden in the spleens of animals at 3 wk after infection with 10(4) viable bacilli: susceptible (C57BL/6J and related sublines, BALB/c and DBA/1J) and resistant (A/J, C3H/HeCr, DBA/2J, CBA/J, C57Br, AKR).

Differences in response among inbred mouse strains to infection with small doses of Mycobacterium bovis BCG.

Intravenous infection of six inbred mouse strains with small doses of dispersed cells of Mycobacterium bovis BCG (15.5 x 10(3) or 15.5 x 10(4) colony-forming units) separated them into resistant (C3H/HeCr, A/J, and DBA/2) and sensitive (B10.

Immunotoxins: hybrid molecules of monoclonal antibodies and a toxin subunit specifically kill tumour cells.

Several attempts to attack tumours in experimental systems have been made using conjugates of chemotherapeutic agents or potent toxins with antibodies (immunotoxins). In vitro studies have been highly successful, showing target specificity of a high order in some cases. However, so far, such conjugates have been inadequate in vivo, probably for two main reasons.

Modulating effect of passive immunization with anti-Mycobacterium tuberculosis antibodies on humoral response in BCG-infected mice.

Previous work has shown that the passive immunization with rabbit anti-Mycobacterium tuberculosis H37Rv antiserum of Mycobacterium bovis BCG-infected mice promotes the growth of bacilli in their spleen and induces a late production of antimycobacterial antibodies in their serum. The effect of the passive immunization on the early antibody response in infected mice has now been investigated. It was found that passive immunization with H37Rv antiserum of BCG-infected mice depressed the early humoral response as determined by the plaque-forming cell response to BCG extract when compared with BCG-infected mice treated with the antiserum freed from its mycobacterial antibodies as controls.