[Immunological properties of an artificial antigen possessing the specificity of Salmonella O-factor 3]. / Immunologicheskie svoistva iskusstvennogo antigena, obladaiushchego spetsifichnost'iu O-faktora 3 sal'monell.

For the first time the method of obtaining synthetic protein-free antigen with the specificity of Salmonella O-factor by the radical copolymerization of the synthetic trisaccharide 3-0 [4-0-(beta-D-mannopyranosyl)-alpha-L-rhamnopyranosyl]-beta-allyl-D- galactopyranoside with acrylamide was developed. The synthetic antigen thus obtained possessed the narrow specificity of serogroup E Salmonella O-factor 3. The serological activity of the antigen, studied in the precipitation and passive hemagglutination tests, was considerably higher than that of lipopolysaccharides isolated from S. anatum and S. newington. This synthetic antigen proved to be nontoxic and possessed immunogenic properties, inducing the formation of antibodies to Salmonella O-factor 3 in immunized animals.

[Interaction of antibodies of different immunoglobulin classes with specific O-antigens and Salmonella haptens]. / Vzaimodeístvie antitel razlichnogo klassa immunoglobulinov so spetsificheskimi )-antigenami i gaptenami sal'monell.

A study was made of the neutralizing properties of antisalmonella antibodies belonging to different immunoglobulin classes in respect to specific O-antigen (Lipopolysaccharide S. anatum) and haptens of salmonellae. In comparison with IgM-antibodies, IgG-antibodies were more stable bound not only with the univalent trisaccharide determinant, but also with the polysaccharide. However, in regard to the lipopolysaccharide complex the neutralizing activity of IgM- and IgG-antibodies was about the same; IgA-antibodies possessed the greatest neutralizing activity with respect to all the antigenic preparations used. The minimal neutralizing dose of the antigen and haptens increased with the reduction of the size of their molecule. A marked heterogeneity of antibodies of each of the immunoglobulin classes by their antigen-neutralizing properties was revealed in individual sera.

[Formation of antibodies of different classes in salmonelloses and typhoid fever]. / Osobennosti obrazovaniia antitel razlichnykh klassov pri sal'monellezakh i briushnom tife.

A modified method of chromatographic analysis was used to obtain fractions of immunoglobulins classes M, G, and A from the sera of patients suffering from salmonelloses, typhoid fever, and carriers; with the aid of passive hemagglutination test O-, H- and Vi-antibodies were determined in the fractions. In food poisoning of salmonella etiology in adults the antibody formation as a rule occurred by the type of secondary immune response, whereas its intensity depended on the severity of the clinical course of the disease. In case of an uncomplicated affection there was an increase of antibodies of all the three immunoglobulin classes. In formation of prolonged carrier state a deficiency of O-antibodies of the IgM-class was noted; this was, however, combined with the normal production of immunoglobulins of class M of H-antibodies. Immune humoral reaction was practically absent in the transitory carriers.