Applications of monoclonal antibodies in aquaculture

Monoclonal antibodies (MAbs) currently are being applied to the study of fish immunology and fish infectious diseases. MAbs to fish immunoglobulins (Igs) have helped isolate fish Igs, identify heavy and light chain variants in fish Ig, study the ontogeny of B lymphocytes, and improve techniques for the measurement of fish Ig and specific antibodies (Abs). MAbs have been obtained against several leucocyte surface antigens and are being used as markers for different subsets of fish leukocytes: neutrophils, non-specific cytotoxic cells and cells responsible for the mixed leucocyte reaction. The sensitivity and specificity of many immunoassays for identifying fish pathogens have been improved by the use of MAbs. Further improvement of these tests is currently being attempted by the use of MAbs together with the polymerase chain reaction (PCR). Epizootiological studies of fish diseases are beginning to emerge from the use of these reagents and techniques. In the near future these new methods should detect low levels of pathogens in adult carriers and perhaps in eggs, thus helping to prevent the dissemination of fish diseases. MAbs to fish pathogens are also being used for passive immunization studies as well as for conformational probes in the development of genetically engineered vaccines.