Detection of anti-reticuloendotheliosis virus antibody by blocking enzyme-linked immunosorbent assay with expression envelope protein.

Abstract

The current reticuloendotheliosis virus (REV) antibody detection kit that uses enzyme-linked immunosorbent assay (ELISA) needs concentrated virus, which is difficult to obtain due to its poor propagation in cells. In addition, this kit detects only chicken antibody but not other species. To overcome these disadvantages, we cloned and expressed REV env gene to develop monoclonal antibodies (mAbs), which we used for antibody detection in ELISA. Three mAbs were prepared from mice. These three mAbs could recognize REVs from ducks and geese by immunodot assay. In addition, the epitopes that the three mAbs recognized were determined by using three different env protein fragments by western blotting. One mAb was used to develop a blocking ELISA (bELISA) coated with expressed env protein to detect anti-REV antibody in chicken serum. This assay had a 98.8% (79/80) agreement with a commercial ELISA kit. Another 146 chicken sera with known neutralization antibodies were used as positive controls to evaluate this bELISA. The sensitivity and specificity this bELISA were 88.9% (40/45) and 94.8% (91/96), respectively. Thus, this bELISA could be used for anti-REV antibody detection in birds.