title: Variation of the specificity of the human antibody responses after tick-borne encephalitis virus infection and vaccination.
abstract: Tick-borne encephalitis (TBE) virus is an important human-pathogenic flavivirus endemic in large parts of Europe and Central and Eastern Asia. Neutralizing antibodies specific for the viral envelope protein E are believed to mediate long-lasting protection after natural infection and vaccination. To study the specificity and individual variation of human antibody responses, we developed immunoassays with recombinant antigens representing viral surface protein domains and domain combinations. These allowed us to dissect and quantify antibody populations of different fine specificities in sera of TBE patients and vaccinees. Postinfection and postvaccination sera both displayed strong individual variation of antibody titers as well as the relative proportions of antibodies to different domains of E, indicating that the immunodominance patterns observed were strongly influenced by individual-specific factors. The contributions of these antibody populations to virus neutralization were quantified by serum depletion analyses and revealed a significantly biased pattern. Antibodies to domain III, in contrast to what was found in mouse immunization studies with TBE and other flaviviruses, did not play any role in the human neutralizing antibody response, which was dominated by antibodies to domains I and II. Importantly, most of the neutralizing activity could be depleted from sera by a dimeric soluble form of the E protein, which is the building block of the icosahedral herringbone-like shell of flaviviruses, suggesting that antibodies to more complex quaternary epitopes involving residues from adjacent dimers play only a minor role in the total response to natural infection and vaccination in humans.
  
  
  OBJECTIVE
  Tick-borne encephalitis (TBE) virus is a close relative of yellow fever, dengue, Japanese encephalitis, and West Nile viruses and distributed in large parts of Europe and Central and Eastern Asia. Antibodies to the viral envelope protein E prevent viral attachment and entry into cells and thus mediate virus neutralization and protection from disease. However, the fine specificity and individual variation of neutralizing antibody responses are currently not known. We have therefore developed new in vitro assays for dissecting the antibody populations present in blood serum and determining their contribution to virus neutralization. In our analysis of human postinfection and postvaccination sera, we found an extensive variation of the antibody populations present in sera, indicating substantial influences of individual-specific factors that control the specificity of the antibody response. Our study provides new insights into the immune response to an important human pathogen that is of relevance for the design of novel vaccines.
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Johanna
authors.initials: J
authors.lastname: Jarmer
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Zlatkovic
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsouchnikas
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Oksana
authors.initials: O
authors.lastname: Vratskikh
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Judith
authors.initials: J
authors.lastname: Strauß
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Judith H
authors.initials: JH
authors.lastname: Aberle
authors.affiliation: Hospital Ceske Budejovice, Department of Infectious Diseases, Ceske Budejovice, Czech Republic.
authors.forename: Vaclav
authors.initials: V
authors.lastname: Chmelik
authors.affiliation: Institute of Environmental Health, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Kundi
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria.
authors.forename: Karin
authors.initials: K
authors.lastname: Stiasny
authors.affiliation: Department of Virology, Medical University of Vienna, Vienna, Austria franz.x.heinz@meduniwien.ac.at.
authors.forename: Franz X
authors.initials: FX
authors.lastname: Heinz
mesh_terms: D000328:Adult; D000368:Aged; D057134:Antibodies, Neutralizing / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood*; D015331:Cohort Studies; D004669:Encephalitis Viruses, Tick-Borne / Q000276:immunology*; D004675:Encephalitis, Tick-Borne / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014759:Viral Envelope Proteins / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000939:Epitopes; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C065696:glycoprotein E, Flavivirus