Purification of Lipopolysaccharide from Pseudomonas Aeruginosa and Conjugation of it's a-polysaccharide with Tetanus Toxoid: Evaluation of Antibody Production

Pseudomonas aeruginosa lipopolysaccharide(LPS) is one of the most important and immunogenic antigens of this microorganism, that is used in construction of conjugated vaccines against it's infections.In this study the LPS of Pseudomonas aeruginosa CIP 1310 strain, was extracted by heating the bacterial pellet in phenolic solution, followed by elimination of proteins and nucleic acids. After extraction of a-polysaccharide by heating in weak acidic solutions the toxicity of LPS and a-polysaccharide was studied in mice. None-toxic a-polysaccharid was conjugated with tetanus toxoid to increase it's immunogenecity and the ability of none-cojugated and cojugated a-polysaccharide in induction of humoral immune response was compared in rabbit.The obtained results indicates that the antibody titer against LPS increases by conjugation. Our results showed that by eliminating the lipid-A from the structure of LPS and conjugation of it with appropriate carriers we can detoxify it as well as increase it's immunogenecity.Conjugation of gram negative bateria a-polysaccharides with appropriate proteins can be considered as a probable route of vaccine production against their infections, in our country like some other counteries, although it needs complementary researchs and confimation of it's efficiency.