Biological activities of lipoteichoic acid and peptidoglycan—teichoic acid of Bacillus subtilis 168 (Marburg)

To evaluate the suitability of Bacillus subtilis as a production host of heterologous proteins for pharmaceutical purposes, we assessed the biological activity of this bacterium and its major cell envelope components, lipoteichoic acid (LTA) and peptidoglycan–teichoic acid complex (PG–TA) in several eukaryotic effector assays. LTA and PG–TA were found to be non-toxic for mice and guinea-pigs in a short-term toxicity assay. PG–TA was weakly pyrogenic and weakly mitogenic. Both LTA and PG–TA acted as immunologic adjuvants in mice and when injected in mice, also caused an increase in the number of granulocyte–monocyte colony-forming cells in the bone marrow probably via stimulation of production of granulocyte–macrophage colony-stimulating factor.