IMMUNOLOGICAL REACTIONS BETWEEN DEXTRAN POLYSACCHARIDE AND SOME BACTERIAL ANTISERA.

Area of Science:

• Immunology
• Microbiology
• Carbohydrate Chemistry

Background:

• Dextran is a synthetic polysaccharide derived from saccharose by Leuconostoc mesenterioides.
• Bacterial polysaccharides from certain pathogens like pneumococci, Salmonella, and Streptococcus viridans exhibit complex immunological profiles.

Purpose of the Study:

• To investigate the immunological cross-reactivity between synthetic dextran and bacterial antisera.
• To determine if this cross-reactivity is mediated by specific antipolysaccharide antibodies or a distinct antibody class.

Main Methods:

• Immunological assays were performed using dextran and antisera from various bacterial species.
• Analysis focused on differentiating antibody responses to the polysaccharide structure versus other potential antigenic determinants.

Main Results:

• Dextran demonstrated significant immunological reactions with antisera from pneumococci, some Salmonella serotypes, and certain Streptococcus viridans strains.
• This cross-reactivity was found to be independent of the specific antipolysaccharide antibodies present in the tested sera.

Conclusions:

• A distinct antibody likely exists that targets a common structural element shared between dextran and specific bacterial polysaccharides.
• The active group of the dextran polysaccharide appears similar or identical to the active group responsible for the observed cross-reactivity in bacterial polysaccharides.