[Protective artificial polysaccharide-protein antigens made from the O-specific polysaccharides of Pseudomonas aeruginosa bacteria of the immunotypes 1, 2 and 7].

O-specific polysaccharide (PS) obtained from P. aeruginosa lipopolysaccharide (LPS), immunotypes 1, 2 and 7, were condensed in the presence of aminated bovine serum albumin (amBSA). As a result, artificial polysaccharide-protein antigens were synthesized and their protective properties were studied by the subcutaneous immunization of mice with their subsequent challenge with the cells of the homologous strain injected intraperitoneally in a dose of 3-5 LD50. The most effective immunization was achieved by using homologous LPS, taken in a subimmunogenic dose, as adjuvant. Heterologous LPS, taken in the same doses, showed no stimulating effect. The protective properties of the conjugates were also found to depend on the length of the PS chain. The conjugate of amBSA and PS of immunotype 2 with a molecular weight of about 10 KD was found to possess the highest protective potency. The decrease of the molecular weight of PS of immunotype 7 from 50 KD to 10 KD by selective acid hydrolysis led to obtaining the conjugate with high protective potency. The possibility of using the structurally linked pair antigen-adjuvant for the development of artificial vaccines is discussed.