[Adjuvant and mitogenic effects of detoxified lipopolysaccharides].

McIntire and al. have observed that a lipopolysaccharide (LPS) extracted from E. coli could be detoxified by succinylation or phtalylation and remained capable of enhancing the immune respose to serum albumins. The data reported here confirm that several LPS preparations after treatment by phtalylation retained their adjuvant activity when injected with bovine serum albumin or influenza vaccine. Yet their toxicity (as measured in adrenalectomized mice) was at least 10 000-fold smaller. Furthermore it was observed that after phtalylation LPS could still induce blastic transformation of murine B-derived lymphocytes. Thus it was possible to dissociate the toxicity of LPS from both its adjuvant and mitogentic activities.