title: Serum antibodies to putative proteinase maturation protein A in children with acute otitis media.
abstract: The pneumococcal genes encoding for the surface associated proteins have been proposed to be important for pneumococcal protein vaccine development. We cloned the full-length putative proteinase maturation protein A gene SP098l/ppmA (as published by Tettelin et al. in 2001) and produced the encoded protein in high levels in E. coli. The purified recombinant PpmA was used as an antigen in Western blotting to study systemic antibody responses to PpmA in animals and in children with acute otitis media (AOM). In children, the geometric mean titers of serum IgG antibodies against PpmA increased with age and differed significantly in relation to pneumococcal findings in middle ear fluid and/or nasopharyngeal aspirate. The serum IgG antibody titers against PpmA were low in children with Streptococcus pneumoniae cultured in the middle ear, and the highest in children with pneumococci in the nasopharynx, without them being found in the middle ear fluid. We conclude that PpmA is immunogenic in humans, and therefore an interesting antigen to study further in developing pneumococcal multicomponent protein vaccines.
authors.affiliation: Department of Bacterial and Inflammatory Diseases, National Public Health Institute (KTL), Mannerheimintie 166, FIN-00300 Helsinki, Finland.
authors.forename: Anni
authors.initials: A
authors.lastname: Vainio
authors.forename: Riku
authors.initials: R
authors.lastname: Fagerlund
authors.forename: Krister
authors.initials: K
authors.lastname: Melén
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Lehtinen
authors.forename: Ilkka
authors.initials: I
authors.lastname: Julkunen
authors.forename: Anni
authors.initials: A
authors.lastname: Virolainen
mesh_terms: D000367:Age Factors; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D006168:Guinea Pigs; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D009305:Nasopharynx / Q000382:microbiology; D010033:Otitis Media / Q000276:immunology*; D010034:Otitis Media with Effusion / Q000382:microbiology; D011008:Pneumococcal Infections / Q000276:immunology*; D011817:Rabbits; D013223:Statistics as Topic; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G