Immunogenicity of deoxycholate-disrupted endotoxins.

A comparison of the immunogenicity of sodium deoxycholate-disrupted lipopolysaccharides from Escherichia coli cell walls revealed that these fragments, which are nonimmunogenic in the rabbit, have some activity in the mouse. This relationship was independent of the route of immunization and sex, but in both species immunogenicity was restored by dilution or dialysis. Adsorption of disrupted lipopolysaccharides onto bentonite particles or administration with methylated bovine serum albumin and Freund's adjuvant did not appreciably augment activity in vivo. It is postulated that in the mouse the requirements for immunogenicity of these lipopolysaccharides are either less stringent with regard to the three-dimensional structure of the antigen, or that a reaggregation to toxic, native lipopolysaccharides may occur in vivo.