ABSTRACT
This chapter discusses the antagonistic properties of Rhodobacter sphaeroides (RsDPLA), other nontoxic lipopolysaccharide (LPS) and their lipid A derivatives, as well as synthetic lipid A analogs. RsDPLA is a potent antagonist of toxic LPS in both human and murine cells. The chapter also discusses the potent antagonist of toxic LPS and the effect of RU 486 on the protective effect of RsDPLA in galactosamine-sensitized mice challenged with toxic ReLPS. The chapter shows that RsDPLA blocks the induction of TNF-a by toxic LPS and induces a corticosteroid response. It establishes that RsDPLA clearly induces corticosteroids in mice, and examines the time course of this induction as well as the induction of the related ACTH. LPS is an amphipathic glycolipid found on the outer surface of the outer membrane of gram-negative bacteria. The interaction of toxic LPS with macrophages results in the induction of a cascade of cytokines.
