Bacterial endotoxin-immunocompetent cells interaction: newer aspects.

Bacterial endotoxin or LPS are constituents of the outer membrane of the cell wall of Gram-negative bacteria. When they invade human or mammalian organisms, they induce many biological effects. Lipid A represents the toxic part of the molecule. In the present communication, the AA. review some of the actions of LPS on immunocompetent cells, with particular reference to mitogenicity, adjuvanticity and tumor regression. Newer aspects of LPS immunobiology are emerging from the collected data. Of particular interest seems to be the relationship among T cells, Macrophages and B cells in LPS-induced adjuvanticity. These cells play a primary role in the potentiation of antibody production and their effects are mostly mediated via LK or MK. About possible mechanisms of tumor regression LPS-dependent, TNF and TNS features are illustrated. Because of the great extent of the present subject, the AA. are not able to include in this context some novel effects of endotoxin on immunocompetent cells as PGs release, SAA protein induction and colony forming activity.