A specific cell surface antigen of Streptococcus gordonii is associated with bacterial hemagglutination and adhesion to alpha2-3-linked sialic acid-containing receptors.
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.
Takahashi
Y
Y
Oral Infection and Immunity Branch, National Institute of Dental Research, Bethesda, Maryland 20892, USA.
Sandberg
A L
AL
Ruhl
S
S
Muller
J
J
Cisar
J O
JO
D000818:Animals; D000942:Antigens, Bacterial / Q000378:metabolism*; D001422:Bacterial Adhesion; D006384:Hemagglutination; D019158:N-Acetylneuraminic Acid; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013291:Streptococcus / Q000378:metabolism*
D000942:Antigens, Bacterial; D011956:Receptors, Cell Surface; D019158:N-Acetylneuraminic Acid