Preparation of an adjuvant-active, tuberculin-free peptidoglycolipid from human tubercle bacilli

Bacillus Calmette-Guérin Immunotherapy for Cancer

Bacillus Calmette–Guérin (BCG), an attenuated vaccine from Mycobacterium bovis, was initially developed as an agent for vaccination against tuberculosis. BCG proved to be the first successful immunotherapy against established human bladder cancer and other neoplasms. The use of BCG has been shown to induce a long-lasting antitumor response over all other forms of treatment against intermediate, non-invasive muscle bladder cancer Several types of tumors may now be treated by releasing the immune response through the blockade of checkpoint inhibitory molecules, such as CTLA-4 and PD-1. In addition, Toll-Like Receptor (TLR) agonists and BCG are used to potentiate the immune response against tumors. Studies concerning TLR-ligands combined with BCG to treat melanoma have demonstrated efficacy in treating mice and patients This review addresses several interventions using BCG on neoplasms, such as Leukemia, Bladder Cancer, Lung Cancer, and Melanoma, describing treatments and antitumor responses promoted by this attenuated bacillus. Of essential importance, BCG is described recently to participate in an adequate microbiome, establishing an effective response during cell-target therapy when combined with anti-PD-1 antibody, which stimulates T cell responses against the melanoma. Finally, trained immunity is discussed, and reprogramming events to shape innate immune responses are addressed.

Adjuvant activity of mycobacterial fractions. III. Adjuvant effect of cell wall of Mycobacterium bovis BCG on cell-mediated cytotoxicity in mice

A quantitative assay and characterization of oil-attached cell wall of Mycobacterium bovis BCG (BCG-CWS) which stimulates cell-mediated immunity of spleen cells to alloantigens in mice were carried out by an in vitro cell-mediated cytotoxicity test using 51Cr-labeled target cells. C57BL/6J mice (H-2b) were immunized intraperitoneally with mastocytoma cells (H-2d) with or without oil-attached BCG-CWS. The cytotoxicity, comparable to that of spleen cells from mice immunized with mastocytoma cells (3 X 10(7)), could be induuced in spleens of mice immunized with a mixture of mastocytoma cells (10(4)) and oil-attached BCG-CWS. The enhancing effect persisted from 55 days or more after the alloantigenic immunization. Oil-attached BCG-CWS enhanced cell-mediated cytotoxicity of T cells in the spleen and the mesenteric lymph node, but not in the thymus. The cytotoxicity showed specificity toward the alloantigen used for immunization. In addition to BCG-CWS, the cell walls of Nocardia rubra and Corynebacterium diphtheriae PW8 and the peptidoglycolipids of Mycobacterium tuberculosis Aoyama B were found to be potent stimulants of cell-mediated cytotoxicity in mice. Oil-attached BCG-CWS did not enhance humoral response to mastocytoma cells but enhanced cell-mediated cytotoxicity when viable mastocytoma cells were used as antigen. The above result was supported by the fact that anti-hapten antibody response induced by viable trinitrophenyl (TNP)-mastocytoma cells (10(4)) plus oil-attached BCG-CWS did not increase to the maximum levels as was observed in mice immunized with a larger number of mastocytoma cells (3 X 10(7)) alone, while cell-mediated cytotoxicity induced by the same treatment increased to the maximum level obtained by immunization with mastocytoma cells (3 X 10(7)) alone.