A specific cell surface antigen of Streptococcus gordonii is associated with bacterial hemagglutination and adhesion to alpha2-3-linked sialic acid-containing receptors

Infect Immun. 1997 Dec;65(12):5042-51. doi: 10.1128/IAI.65.12.5042-5051.1997.

Abstract

A Ca2+-independent lectin activity for alpha2-3-linked sialic acid-containing receptors is associated with Streptococcus gordonii DL1 (Challis) but not with a spontaneous mutant, strain D102, that specifically lacks hemagglutinating activity. Comparison of crossed-immunoelectrophoresis patterns of parent and mutant sonicated cell extracts identified a unique antigen (Hs antigen) in the parent cell extract that was purified by DEAE Sephacel column chromatography and by a wheat germ agglutinin (WGA) lectin affinity column. The purified antigen formed a single arc in crossed immunoelectrophoresis with anti-DL1 serum and migrated as a diffuse band above the 200-kDa marker in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunoelectron microscopy with specific anti-Hs antibody revealed labeling of structures in the fibrillar layer of strain DL1 and no labeling of fibrillar structures on strain D102. Rabbit anti-DL1 serum and anti-Hs Fab inhibited the hemagglutinating activity of strain DL1, and the inhibition was specifically neutralized by purified Hs antigen. Anti-Hs Fab did not inhibit the hemagglutinating activities of several heterologous S. gordonii strains; however, these bacteria were agglutinated by anti-Hs immunoglobulin G and also by WGA. In contrast, two S. gordonii strains that lacked hemagglutinating activity did not react with anti-Hs antibody or with WGA. These findings associate the sialic acid-binding lectin activity of S. gordonii DL1 with a specific fibrillar antigen, which is composed of protein and WGA reactive carbohydrate, and indicate that cross-reactive antigens occur on other strains of this species that possess hemagglutinating activity.

MeSH terms

  • Animals
  • Antigens, Bacterial / metabolism*
  • Bacterial Adhesion*
  • Hemagglutination*
  • N-Acetylneuraminic Acid
  • Rabbits
  • Receptors, Cell Surface / metabolism*
  • Streptococcus / metabolism*

Substances

  • Antigens, Bacterial
  • Receptors, Cell Surface
  • N-Acetylneuraminic Acid