Characterization of proteins of chicken infectious anemia virus with monoclonal antibodies

Eight monoclonal antibodies (MAbs) against chicken infectious anemia virus (CIAV) were developed. These MAbs identified three isolates adapted to grow in the Marek's disease chicken cell line MSB1 (Cux-1, GA-1, and Conn-B) and the chicken-propagated CIA-1 isolate. All MAbs stained MSB1 in the same way with mostly perinuclear staining, although larger nuclear inclusions and cytoplasmic staining were also detected. None of the MAbs neutralized Cux-1. All MAbs reacted in a direct enzyme-linked immunosorbent assay with Cux-1 antigen treated with 0.5% sodium dodecyl sulfate followed by extraction with chloroform, but not with MSB1 cells infected with Cux-1 or chloroform-extracts of these cells. Three viral proteins--VP1, VP2, and VP3--with estimated sizes of 45, 30, and 16 kilodaltons (kd), respectively, were immunoprecipitated using the MAbs and Cux-1-infected cell lysates. The 16-kd protein was the major VP. In addition, a 79-kd protein was detected in infected cell lysates by immunoprecipitation with CIAV-antibody-positive and -negative chicken serum, and CIAV-specific and non-specific MAbs.