Immunochemistry of adenoviruses: limitations and new horizons of gene therapy

Adenovirus Isolated From a Cat Is Related to Human Adenovirus 1

An adenovirus (AdV) has been isolated from the rectal swab of a domestic cat (Felis catus) and named feline adenovirus (FeAdV) isolate. It replicates and causes cytopathological effects in many human, feline, other mammalian cell lines that have both Coxsackie-adenovirus-receptor and integrins. Its antigens cross-react with anti-human adenovirus antibodies in immunofluorescence and immunocytochemistry assays. Electron microscopy revealed typical extracellular icosahedral particles and pseudo arrays inside cells. Sequence analysis of hexon and fiber genes indicates that this virus might belong to human adenovirus (HAdV) C species and might be a variant of type 1. In the fiber protein, three altered amino acids occur in the shaft; four altered residues are found in the knob region as compared to a European HAdV might be type 1 isolate (strain 1038, D11). One alteration affects amino acid 442 forming an RGS motif in an alanine rich region that might be an alternative way to bind integrins with subsequent internalization. Substitutions in the hexon sequence are silent. As compared to published HAdV sequences, the fiber is related to the original American prototype and recently described Taiwanese HAdV 1 isolates, but the hexon sequences are related to adenovirus isolates from France, Germany, Japan, and Taiwan. Serology carried out on FeAdV infected M426 cells indicates a prevalence of IgG in 80% of domestic cats in Delaware, United States. FeAdV isolate seems to be a recently recognized virus with possible pathogenic effects and, simultaneous human and feline infections are possible. Further molecular and biological characterization of this feline adenovirus isolate, as well as studies on both human and feline epidemiology and pathomechanisms, especially in endangered big cats, are warranted. FeAdV might have further practical advantages. Namely, it could be utilized in both human and feline AIDS research, developed into diagnostic tools, and gene therapy vectors in the near future.

The prevalence of IgG and IgA against adenoviruses in serum of children aged 11-26 months, hospitalised in the Clinical Paediatric Hospital in Warsaw, Poland

Adenoviruses are widely spread viruses causing infections related mainly to children. Contact with the pathogen may result in the presence of either immunoglobulin (Ig) A or IgG antibodies in the serum. The aim of this study was to assess the prevalence of IgA and IgG antibodies against adenoviruses in serum of children aged 11-27 months, hospitalised at the Public Children's Clinical Hospital in Warsaw. Immunoassay tests DRG Adenovirus IgA ELISA and IgG DRG Adenovirus ELISA detecting antibodies against all pathogenic serotypes of adenoviruses were performed in 128 sera samples. A low percentage of positive results for both immunoglobulins, 17 cases (13.28%) for IgA and 16 cases (12.50%) for IgG antibodies respectively were reported. We conclude, that the prevalence of antibodies against adenoviruses does not coincide with epidemiological data on the spread of infections among young children. The assays performed may be more useful in distinguishing the active form of the infection from seropositivity due to prior infection.