Inhibition of Streptococcus mutans adherence to saliva-coated hydroxyapatite by human secretory immunoglobulin A (S-IgA) antibodies to cell surface protein antigen I/II: reversal by IgA1 protease cleavage.
The effect of human secretory immunoglobulin A (S-IgA) and serum antibodies to surface protein antigen (Ag) I/II on the adherence of Ag I/II-bearing Streptococcus mutans and of free Ag I/II to saliva-coated hydroxyapatite (SHA) was investigated. The inhibition by S-IgA of binding of both S. mutans and free Ag I/II to SHA was dependent on antibody to Ag I/II. Essentially no difference was found between S-IgA1 and S-IgA2 with respect to antibody-dependent inhibition of Ag I/II binding to SHA, but S-IgA1 inhibited S. mutans adherence more effectively than did either serum immunoglobulin A1 (IgA1) or IgG antibodies. The antiadherence effect of S-IgA was abrogated after cleavage by IgA1 protease. Purified Fab alpha fragments containing Ag I/II-binding activity enhanced the binding of free Ag I/II to SHA and showed greater binding to SHA than did intact S-IgA1. Despite its relative inability to interact with precoated SHA, S-IgA1 containing antibody to Ag I/II was readily incorporated into the salivary pellicle during coating, but this did not promote Ag I/II binding. These data suggest that S-IgA antibodies can inhibit the initial adherence of S. mutans to salivary pellicle-coated tooth surfaces in an adhesin-specific fashion, but the presence in the oral cavity of bacterial IgA1 proteases would potentially interfere with this antiadherence mechanism.
Hajishengallis
G
G
Department of Microbiology, University of Alabama, Birmingham 35294.
Nikolova
E
E
Russell
M W
MW
D000907:Antibodies, Bacterial / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000276:immunology*; D044622:Dental Pellicle; D017886:Durapatite; D006801:Humans; D006882:Hydroxyapatites; D007070:Immunoglobulin A / Q000502:physiology; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D007140:Immunoglobulin Fab Fragments / Q000502:physiology; D007074:Immunoglobulin G / Q000502:physiology; D008562:Membrane Glycoproteins; D010447:Peptide Hydrolases / Q000494:pharmacology*; D012463:Saliva / Q000502:physiology*; D012697:Serine Endopeptidases; D013295:Streptococcus mutans / Q000502:physiology*
D000907:Antibodies, Bacterial; D000954:Antigens, Surface; D001426:Bacterial Proteins; D006882:Hydroxyapatites; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; C055764:S-layer proteins; D017886:Durapatite; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C021433:IgA-specific serine endopeptidase