Accurate identification of neutralizing antibodies to adenovirus Ad36, -a putative contributor of obesity in humans

Abstract

BackgroundIn children and adults, human adenovirus serotype 36 (Ad36) is linked with increased adiposity, and important metabolic alterations. Since this property is not shared by many other human adenovirus serotypes, it is imperative to specifically identify exposure to Ad36. Although serum neutralization assay (SNA) is the gold standard to specifically detect neutralizing antibodies (NA) to Ad36, it requires 2-weeks to complete and considerable training to interpret the results. Whereas, an enzyme-immuno assay (EIA) may provide a quicker and objective determination. ObjectivesEvaluate the accuracy of commercially available EIA kits to detect NA to Ad36. Modify SNA to reduce time and increase objectivity. Study DesignSera of 15 seropositive or 16 seronegative subjects confirmed by SNA were used to test: 1) reproducibility of SNA to detect Ad36 exposure, by repeating assays twice; 2) an EIA that detects antibodies to all human adenovirus serotypes (NS-EIA) (Abcam-108705); 3) an EIA supposedly specific for Ad36 antibody (Ad36-EIA) (MyBioSource,#MBS705802), and 4) the concordance of SNA with a novel combination of SNA and immune-staining (SN-IS) kit (Cell BioLabs,#VPK-111). ResultsThe SNA showed exact reproducibility. NS-EIA detected adenovirus antibodies in 94% samples, confirming the non-specificity of the assay for Ad36 serotype. All seronegative samples (as determined by SNA) were false positive by Ad36-EIA. In 97% samples, SN-IS showed fidelity with Ad36-antibody status as determined by SNA. ConclusionsThe available EIA kits are not specific for detecting NA to Ad36. The modified SNA with immune-staining reduces assay time and increases accuracy of detecting by reducing subjectivity.