Induction of Functional Secretory IgA Responses in Breast Milk, by Pneumococcal Capsular Polysaccharides

• Published in: The Journal of infectious diseases Vol. 186; no. 10; pp. 1422 - 1429
• Main Authors: Finn, Adam, Zhang, Qibo, Seymour, Lynn, Fasching, Claudine, Pettitt, Emily, Janoff, Edward N.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 15.11.2002; University of Chicago Press; Oxford University Press
• Subjects: Antibodies; Antigens; Bacterial Adhesion - drug effects; Biological and medical sciences; Breast milk; Conjugate vaccines; Epidemiology. Vaccinations; Female; General aspects; Humans; Immunization; Immunoglobulin A - immunology; Immunoglobulin A - pharmacology; Infant, Newborn; Infant, Newborn, Diseases - prevention & control; Infectious diseases; Major Articles; Medical sciences; Milk, Human - chemistry; Neutrophils; Phagocytes; Pneumococcal Infections - prevention & control; Pneumococcal Vaccines - administration & dosage; Polysaccharides; Polysaccharides, Bacterial - immunology; Room temperature; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - immunology; Vaccination; Human; IgA; Vaccination; Infant; Capsule; Polyvalent vaccine; Biological activity; Bactericidal effect; Streptococcus pneumoniae; Infection; Prevention; Streptococcaceae; Immunoprophylaxis; Streptococcal infection; Bacteriosis; Bacteria; Micrococcales; Female; Polysaccharide; Breast milk
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/344356

Capsule-specific secretory IgA (s-IgA) in breast milk may enhance protection against pneumococcal disease in infants. After immunization of 3 lactating mothers with 23-valent polysaccharide vaccine, specific s-IgA, but not IgG, increased by >2-fold in milk of at least 1 subject for 6 of 7 serotypes. The s-IgA was predominantly IgA1, in secretory form, and highly specific with avidity distinct from serum IgA and IgG. Milk whey from 2 immunized women supported dose- and complement-dependent killing of Streptococcus pneumoniae serotypes 19F and 14 by human neutrophils, as did purified s-IgA to serotype 19F. These data reveal that capsule-specific human s-IgA in breast milk can initiate killing of S. pneumoniae providing proof of concept that vaccine-induced human mucosal s-IgA can support functional bactericidal activity. Determining the biologic role for s-IgA in killing and inhibiting adherence of S. pneumoniae in vivo will contribute to the development of mucosal vaccines against S. pneumoniae