Immunochemistry of the Streptococcal Group R Cell Wall Polysaccharide Antigen

Abstract

The group R streptococcal group antigen has been shown to be a polysaccharide located at the surface of the cell wall of the organism. The antigen was extracted from cell walls in 0.05 N HCI or 5% trichloracetic acid at 100 C, from whole cells at room temperature in 0.85% NaCl or 0.1 M acetate (pH 5.0), and by sonic oscillation. The antigen is largely destroyed when extracted from whole cells in 0.05 N HCI at 100 C. Acetate is recommended for routine extraction. The antigen extracted by sonic treatment was separated into six immunologically active fractions on diethylaminoethyl-Sephadex. The fractions were found to possess a common antigen which exhibited similar properties on immunodiffusion and immunoelectrophoresis. The purified antigen did not react with any other streptococcal group antisera. Adsorption of group R serum with the antigen removed all antibodies against whole cell antigen extracts of R cells. Chemical and enzymatic analysis of three fractions showed that the antigen was composed of D-glucose, D-galactose, rhamnose, and glucosamine. No significant quantities of phosphorus, glycerol, ribitol, or muramic acid were present. Significant inhibition of the quantitative precipitin determination by D-galactose and stachyose indicated that galactose in terminal alpha linkage was the immunodominant hexose in the antigen. D-Glucose and D-glucosamine possessed a partial inhibitory activity. N-acetyl-D-glucosamine and L-rhamnose did not produce significant inhibition. The results indicate that the R antigen is an immunologically specific structure which serves as a reliable means of identification of these streptococci as a serological group. The cells were grown for 17 hr at 37 C in Todd-Hewitt broth (Difco) supplemented with glucose and salts (12), removed from the medium by centrifugation, and, in some cases, washed with distilled water and lyophilized. Growth was estimated by optical density measurements at 550 nm. Lyophilized cells were extracted with either 0.01, 0.05, or 0.2 N HCl (2 mg/ml) at 100 C for 10 min and

Extraction, Purification, and Chemical and Immunological Properties of the Streptococcus mutans Group “a” Polysaccharide Cell Wall Antigen

“…The present data strongly indicate that the HS6 antigen-antibody combining site is located on the cell wall surface. Similar data for the S. mutans group "b" antigen (17) and the streptococcal group E (21), 0 (15), and R (22) antigens, and immunofluorescence of the S. mutans group "d" (2), and group A (3) and group F (25) whole cells, indicates that these sites of the group, and in some cases the type (25), polysaccharide antigens of the streptococci are on the surface of the cell. A polysaccharide antigen and a protein antigen could, in the same cell, (S. pyogenes for example [3]) both have such a location.…”

“…Disaccharides of glucose were much more effective inhibitors than D-glucose alone. Another example is that of streptococcal group R antiserum which shows a twofold inhibition by a trisaccharide (stachyose) as compared to galactose, a terminal sugar in stachyose (22). Antisera to those groups of streptococci which possess ,B-D-glucose specificity, E (21) and F (26), N-acetylglucosamine specificity, 0 (17), and ,B-D-galactose specificity, R (22), did not react to group anti-"a" serum.…”

“…It would be important to determine if the S. mutans group "a" and "b" antigens, although immunologically distinct (1), share any common features in chemical composition, structure, and location in the S. mutans cell. The cell wall surface location of streptococcal polysaccharides (15,17,21,22) may, in the case of S. mutans, be an important factor in the cariogenic activity of these microorganisms. The present study deals with the isolation, purification, characterization, and immunological properties of the group "a" antigen.…”

Purification and immunological characterization of a rhamnose-glucose antigen from Streptococcus mutans 6517-T2 (serotype g)

“…The serotype antigens of S. mutans serotypes c, e, and f are rhamnose-glucose polymers; the serotype antigen of S. mutans serotype b is a rhamnose-galactose polymer (reviewed in reference 17). Among the ,8-hemolytic streptococci, group antigens A, B, C, E, F, G, L, and R and type antigens of groups D and F all contain rhamnose (2,3,5,15,22,(26)(27)(28)(29). Although rhamnose is a major constituent, the antigenic specificity usually resides in the oligosaccharide side chains of rhamnose.…”

Synthesis of Glucan on the Cell Surface of Streptococcus mutans: Chemical and Scanning Electron Microscopic Studies

“…Anti-GS5 (S. mutans serotype c) serum, which was obtained by injecting dextrancoated whole cells into a rabbit (23), was used as the source of anti-dextran globulin. The titer of the antiserum against Dextran T 2000 (Pharmacia Fine Chemicals AB, Uppsala, Sweden) was 1: 512 by the capillary precipitin test (16).…”