title: The immune response to pneumococcal proteins during experimental human carriage.
abstract: Colonization of the nasopharynx is the initial step in all infections caused by Streptococcus pneumoniae. The antibody response to carriage was examined in an experimental model of human colonization in healthy adults. Asymptomatic colonization was detected in 6/14 subjects and continued for up to 122 d. Susceptibility to carriage did not correlate with total serum immunoglobulin (Ig)G to the homotypic capsular polysaccharide. All of the colonized subjects, in contrast, developed a serum IgG and secretory IgA response to a 22 kD protein, whereas 7 of 8 subjects who did not become colonized had preexisting antibody to this protein. Analysis of the 22 kD protein identified it as the NH(2)-terminal region of pneumococcal surface protein A (PspA). Our findings provide evidence for the role of antibody to this protein fragment in preventing pneumococcal carriage by humans.
authors.affiliation: Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA. .
authors.forename: Tera L
authors.initials: TL
authors.lastname: McCool
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Cate
authors.forename: Gregory
authors.initials: G
authors.lastname: Moy
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Weiser
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D002353:Carrier State / Q000276:immunology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D000939:Epitopes / Q000235:genetics; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000097:blood; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology; D011008:Pneumococcal Infections / Q000276:immunology* / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D000939:Epitopes; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D010446:Peptide Fragments; D022242:Pneumococcal Vaccines; C051592:pneumococcal surface protein A