[The immunogenic and serological properties of the O-specific polysaccharide (L-hapten) in Shigella].
O-specific polysaccharide (L-hapten) was isolated earlier (Zh. mikrobiol. epidemiol. immunobiol., 1989, No. 11, pp. 8-11). In this paper L-hapten was shown to be unable, even at high concentrations (up to 2,000 micrograms/ml), to sensitize sheep red blood cells for passive hemagglutination by O-antibodies. At the same time classical LPS and heat-activated LPS were active at concentrations ot 32 and 8 micrograms/ml respectively. The O-antibody-neutralizing activity of L-hapten was lower than that of LPS 10(3)-10(4) times in the passive hemagglutination test and 25-50 times in competitive ELISA. The immunogenicity of isolated L-hapten was very weak: primary response in mice to the i.v. injection of 1-10 micrograms of L-hapten was similar to the effect produced by 10(-3)-10(-4) micrograms of LPS. No protective activity of L-hapten was noted in mice when the challenge dose of virulent shigellae was 16 LD50 or more, and only a weak protective effect was observed with a low challenge dose (8 LD50). The molecular basis of low serological and biological activity of L-hapten is discussed. The most probable explanation of the results obtained in this study is that L-hapten contains some nonspecific carbohydrates, inserted in or complexed with the O-side chain. Despite its low immunogenicity, L-hapten can be an important component of effective bacterial vaccines provided it is included into a suitable delivery system as is the case with Shigella ribosomal vaccine.
Levenson
V I
VI
Belkin
Z P
ZP
Egorova
T P
TP
Liubinskaia
M M
MM
Sazykina
S Iu
SIu
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D000939:Epitopes / Q000276:immunology* / Q000302:isolation & purification; D006241:Haptens / Q000276:immunology* / Q000302:isolation & purification; D007114:Immunization; D008070:Lipopolysaccharides / Q000276:immunology / Q000302:isolation & purification; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D019081:O Antigens; D011135:Polysaccharides, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D012764:Shigella sonnei / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000939:Epitopes; D006241:Haptens; D008070:Lipopolysaccharides; D019081:O Antigens; D011135:Polysaccharides, Bacterial
Immunogennye i serologicheskie svoĭstva O-spetsificheskogo polisakharida (L-gaptena) shigell.