Serum and mucosal antibody responses to pneumococcal protein antigens in children: relationships with carriage status

Research output: Contribution to journalArticle

Authors

  • Qibo Zhang
  • Jolanta Bernatoniene
  • Linda Bagrade
  • Andrew J Pollard
  • James C Paton
  • Adam Finn

Colleges, School and Institutes

Abstract

Streptococcus pneumoniae causes significant morbidity and mortality especially in children. Some pneumococcal protein antigens can protect mice against infection. Little information is available concerning the nature of naturally acquired protective immunity to pneumococci in humans induced by these antigens. This study investigates the relationships between systemic and local antibody production and carriage in children. Children undergoing adenoidectomy (n=112, ages 2-12 years) were studied. Nasopharyngeal swabs were collected for pneumococcal culture. Serum and saliva were assayed for antibodies to several pneumococcal proteins: choline binding protein A (CbpA), pneumolysin (Ply), pneumococcal surface adhesin A (PsaA) and pneumococcal surface protein A (PspA). Adenoidal mononuclear cells (MNC) were cultured with pneumococcal culture supernatants or recombinant proteins. Cell culture supernatants were analyzed for antigen-specific antibodies. Carriage rates fell with age and serum levels of anti-CbpA, Ply and PspA rose. Anti-CbpA and -Ply serum and salivary IgG antibody levels were higher in children who were culture negative than those who were colonized. Antigen stimulation increased respective antigen-specific IgG production by adenoidal MNC and these responses were greater in those who were colonized than in culture-negative children. Antibodies to CbpA and Ply may protect children aged 2 years and older against pneumococcal colonization. Adenoids may be important local induction and effector sites for both mucosal and systemic antibody production to pneumococcal proteins in children.

Details

Original languageEnglish
Pages (from-to)46-57
Number of pages12
JournalEuropean Journal of Immunology
Volume36
Issue number1
Publication statusPublished - Jan 2006

Keywords

  • Adenoids, Age Factors, Antibodies, Antibodies, Bacterial, Antigens, Bacterial, Blotting, Western, Child, Child, Preschool, Female, Flow Cytometry, Humans, Leukocytes, Mononuclear, Male, Nasopharynx, Respiratory Mucosa, Saliva, Streptococcus pneumoniae