Passive acquired mucosal immunity to group A streptococci by secretory immunoglobulin A.
We present a model in which animals are passively immunized at a mucosal site, allowing one to evaluate immunological protection at the mucosal level only. Affinity-purified, anti-M protein sIgA administered intranasally protected mice against systemic infection after intranasal challenge with group A streptococci. In contrast, anti-M protein serum Ig administered intranasally was not protective at this site, although it neutralized the antiphagocytic property of M protein and promoted phagocytosis. Protection by sIgA occurred despite the lower immunoreactivity of sIgA to purified M protein compared with serum Ig. The data suggest that sIgA can protect at the mucosa and may preclude the need for opsonic IgG in preventing streptococcal infection.
Bessen
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Laboratory of Bacteriology and Immunology, Rockefeller University, New York, New York 10021.
Fischetti
V A
VA
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D007116:Immunization, Passive; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D051379:Mice; D009092:Mucous Membrane / Q000276:immunology*; D013290:Streptococcal Infections / Q000517:prevention & control*; D013297:Streptococcus pyogenes / Q000276:immunology*
D000907:Antibodies, Bacterial; D007071:Immunoglobulin A, Secretory