title: Bactericidal antibody response against P6, protein D, and OMP26 of nontypeable Haemophilus influenzae after acute otitis media in otitis-prone children.
abstract: The bactericidal antibody response to three nontypeable Haemophilus influenzae (NTHi) outer membrane proteins (D, P6, and OMP26) was studied in 24 otitis-prone children (aged 7-28 months) after an acute otitis media (AOM) caused by NTHi. The study was carried out to understand the contribution of antigen-specific bactericidal antibody responses in the class of children who are most vulnerable to recurrent otitis media infections. Levels of protein D (P = 0.005) and P6 (P = 0.026) but not OMP26 antibodies were higher in bactericidal sera compared with nonbactericidal sera. For five (24%) and 16 (76%) of 21 bactericidal sera tested, removal of anti-protein D and P6 antibody, respectively, resulted in a two- to fourfold drop in bactericidal antibody. Antibodies to OMP26 did not make any contribution to the overall bactericidal activity in any serum samples. Eleven of 21 sera (52%) had bactericidal activity against a heterologous NTHi (86-028 NP) strain but the titers were significantly lower (P < 0.05) as compared to the homologous strains. Future studies of protein D, P6, OMP26, and other potential NTHi vaccine antigens should include studies of bactericidal antibody in children who are otitis prone as a possible correlate of protection.
authors.affiliation: Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, NY, USA.
authors.forename: M Nadeem
authors.initials: MN
authors.lastname: Khan
authors.forename: Ravinder
authors.initials: R
authors.lastname: Kaur
authors.forename: Michael E
authors.initials: ME
authors.lastname: Pichichero
mesh_terms: D000208:Acute Disease; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000097:blood / Q000276:immunology*; D001426:Bacterial Proteins / Q000097:blood / Q000276:immunology*; D001826:Body Fluids / Q000276:immunology / Q000382:microbiology; D002352:Carrier Proteins / Q000097:blood / Q000276:immunology*; D002675:Child, Preschool; D004432:Ear, Middle / Q000276:immunology / Q000382:microbiology; D006192:Haemophilus Infections / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D018073:Haemophilus Vaccines / Q000097:blood / Q000276:immunology*; D006193:Haemophilus influenzae / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007072:Immunoglobulin D / Q000097:blood / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D008074:Lipoproteins / Q000097:blood / Q000276:immunology*; D010033:Otitis Media / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D011994:Recombinant Proteins / Q000097:blood / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D018073:Haemophilus Vaccines; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D008074:Lipoproteins; C118414:OMP26 protein, Haemophilus influenzae; C069990:P6 outer membrane protein, Haemophilus; D011994:Recombinant Proteins; C067989:glpQ protein, Haemophilus influenzae