Production of antibody to lipopolysaccharide (LPS) after immunization with a LPS-polymyxin B-agarose immunogen.

A method was devised to produce antibodies to lipopolysaccharide (LPS) in guinea-pigs following a single immunization. The antigen was prepared by mixing polymyxin B-agarose with LPS from Escherichia coli O55:B5. Use of the agarose support allowed purification of the complex by simple washing procedures. Twenty-nine days after a single injection of the immunogen mixed with Freund complete adjuvant all animals demonstrated antibody to the LPS portion of the complex. No antibodies were detected to the polymyxin B component. Typical titres of LPS as measured by ELISA were 2(11). After, a booster immunization, titres of LPS antibody were further increased and a greater avidity was noted. In contrast to other methods which have been employed for production of antibody to LPS, use of the polymyxin B-agarose complex has the following advantages: ease of antigen preparation, ready purification of the complex, potent immunostimulation, and under the conditions employed here, LPS-specific antibody production, without accompanying antibody to polymyxin B.