Production and initial characterization of monoclonal antibodies against channel catfish virus

Monoclonal antibodies (MAbs) were developed against the CA80-5 isolate of channel catfish virus (CCV) from an epizootic among juvenile channel catfish Ictalurus punctatus in California in 1980. These MAbs were tested for their binding and neutralization activities against isolates of CCV from California (CA80-5), Alabama (AL82-1), Louisiana (LA87-1), and Oklahoma (OK88-1). In the indirect fluorescent antibody test, all seven MAbs demonstrated punctate cytoplasmic and perinuclear staining of infected cells, which indicated similar specific anti-viral binding. Four of the MAbs were capable of neutralizing all CCV isolates. A comparison of the neutralization patterns of the four neutralizing MAbs with the four CCV isolates indicated that two of the MAbs (41 and 62) were less efficient in neutralizing the AL82-1 isolate. This comparison suggests that certain CCV strains may not possess all of the type-common antigenic determinants found in the CA80-5, LA87-1, and OK88-1 isolates.