title: Intranasal immunization with recombinant outer membrane protein P6 induces specific immune responses against nontypeable Haemophilus influenzae.
abstract: OBJECTIVE
  Nontypeable Haemophilus influenzae (NTHi) is one of the leading causative pathogens for otitis media. The outer membrane protein P6 of NTHi is highly conserved among the strains and is an attractive candidate for a preventive vaccine. However, for the production of a relatively small amount P6 containing lipopolysaccharides, the development of a recombinant version of this protein is required. This study was designed to investigate the specific mucosal immunity induced by intranasal immunization of recombinant P6 (rP6) with cholera toxin (CT).
  
  
  METHODS
  BALB/c mice were immunized with of rP6 (30 microg) and CT (2 microg) intranasally every 2 days for 2 weeks. Anti-rP6 specific IgG, IgA and IgM antibodies and the subclass of anti-rP6 specific IgG antibody were determined by enzyme linked immunosorbent assay (ELISA). Anti-rP6 specific IgA in nasopharyngeal washings were also determined by ELISA. Nasopharyngeal clearance of inoculated NTHi after the intranasal immunization were assessed. All statistical differences between the two groups were assessed by ANOVA parametric test.
  
  
  RESULTS
  Intranasal immunization with rP6 and CT evoked rP6-specific mucosal IgA immune response as well as the systemic IgG immune response against rP6 and enhanced nasopharyngeal clearance of inoculated live NTHi.
  
  
  CONCLUSIONS
  These results indicate the good immunogenicities of rP6 to induce specific immune responses against NTHi. Intranasal immunization with rP6 will be an effective approach to protect infections of NTHi.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Wakayama Medical University, Kimiidera 811-1, Wakayama-shi, Wkayama 641-0032, Japan. mhotomi@wakayama-med.ac.jp
authors.forename: Muneki
authors.initials: M
authors.lastname: Hotomi
authors.forename: Noboru
authors.initials: N
authors.lastname: Yamanaka
authors.forename: Jun
authors.initials: J
authors.lastname: Shimada
authors.forename: Masaki
authors.initials: M
authors.lastname: Suzumoto
authors.forename: Yorihiko
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sakai
authors.forename: Jun
authors.initials: J
authors.lastname: Arai
authors.forename: Bruce
authors.initials: B
authors.lastname: Green
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis; D001422:Bacterial Adhesion / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology* / Q000494:pharmacology*; D002772:Cholera Toxin / Q000276:immunology / Q000494:pharmacology; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000276:immunology* / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000276:immunology*; D018928:Immunity, Mucosal / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D017817:Nasal Lavage Fluid / Q000276:immunology; D010033:Otitis Media / Q000382:microbiology / Q000517:prevention & control; D011897:Random Allocation; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D018073:Haemophilus Vaccines; C069990:P6 outer membrane protein, Haemophilus; D002772:Cholera Toxin