Anti-EF-Tu IgG titers increase with age and may contribute to protection against the respiratory pathogen Haemophilus influenzae

Research output: Contribution to journalArticle


Non-typeable Haemophilus influenzae (NTHi) is a pathogen that commonly colonizes the nasopharynx of preschool children, causing opportunistic infections including acute otitis media (AOM). Patients suffering from chronic obstructive pulmonary disease (COPD) are persistently colonized with NTHi and occasionally suffer from exacerbations by the bacterium leading to increased morbidity. Elongation-factor thermo unstable (EF-Tu), a protein critical for bacterial protein synthesis, has been found to moonlight on the surface of several bacteria. Here, we show that antibodies against NTHi EF-Tu were present in children already at 18 months of age, and that the IgG antibody titers increased with age. Children harboring NTHi in the nasopharynx also displayed significantly higher IgG concentrations. Interestingly, children suffering from AOM had significantly higher anti-EF-Tu IgG levels when NTHi was the causative agent. Human sera recognized mainly the central and C-terminal part of the EF-Tu molecule and peptide-based epitope mapping confirmed similar binding patterns for sera from humans and immunized mice. Immunization of BALB/c and otitis-prone Junbo (C3H/HeH) mice promoted lower infection rates in the nasopharynx and middle ear, respectively. In conclusion, our results suggest that IgG directed against NTHi EF-Tu may play an important role in the host immune response against NTHi.


External organisations
  • Sahlgrenska University Hospital
  • MRC Harwell Institute
  • Rochester General Hospital
  • University of Gothenburg
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Microbiology in the medical area
  • Respiratory Medicine and Allergy


  • Bacterial infections, Chronic obstructive pulmonary disease, Epitope mapping, Mucosal immunity, Surface antigen
Original languageEnglish
Pages (from-to)490-499
JournalEuropean Journal of Immunology
Issue number3
Early online date2018 Dec 19
Publication statusPublished - 2019
Publication categoryResearch

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