Virus-specific polypeptides of caprine arthritis-encephalitis virus recognized by monoclonal antibodies to virion proteins p24 and p14

The proteins of an isolate of caprine arthritis-encephalitis virus (CAEV) were analysed by SDS-PAGE and Western blotting. Monoclonal antibodies (MAbs) produced to the main core protein p24 and the small structural protein p14 also recognized two major polypeptides of Mr 41K and 55K in infected cell material, consistent with a precursor role for these gag polypeptides. In addition, the p24 MAbs detected a 33K polypeptide in extracellular virus preparations, while the p14 MAbs reacted strongly with a polypeptide of 18K (corresponding to structural protein p18) and weakly with another of 21K. The use of these MAbs in an indirect fluorescent antibody method revealed an intracytoplasmic location of these viral antigens in both mononucleated and multinucleated (syncytial) infected cells. Cross-reactivity with several other isolates indicated that these MAbs may be useful for diagnosis of CAEV infection.