Abstract
The 51 serotypes of human adenoviruses (HAdVs) of the genus Mastadenovirus are classified into the six species HAdV-A to HAdV-F. For the detection of genus- and species-specific antibodies in human sera an immunoblot assay was developed. The recombinant long fiber of HAdV-41[F] (Ad41Fi) and the native hexon of HAdV-5[C] were used as genus-specific antigens. The recombinant capsid protein IX (pIX) of HAdV-2 (Ad2pIX[C]) and HAdV-41 (Ad41pIX[F]), the C-terminal pIX part of HAdV-3 (Ad3pIXC[B]), and the fiber knob of HAdV-8 (Ad8FiKn[D]) were evaluated as representative species-specific antigens. Hence, the pIX amino acid sequences of numerous serotypes of all HAdV species were compared, and the cross-reactivities of pIX antigens with rabbit hyperimmune sera among HAdV-A to -F were analyzed. In an epidemiological study, 667 human patient sera, not selected for viral infection, were screened for adenovirus seroprevalence. The genus-specific antibody prevalences directed against the Ad41Fi and HAdV-5 hexon were 82.8 and 98.8%, respectively. The species-specific antibody prevalence of 44.7% against Ad2pIX[C], 36.6% against Ad41pIX[F], 26.4% against Ad8FiKn[D], and 18% against Ad3pIXC[B] showed an age-dependent distribution and correlated well with the frequency of isolated serotypes of the respective species in earlier studies (except HAdV-D). In conclusion, the immunoblot assay using pIX, fiber, and hexon antigens represents a valuable and new serological tool for refined adenovirus diagnosis as shown in an epidemiological study.