Characterisation of stocks of Theileria parva by monoclonal antibody profiles.

Sixteen monoclonal antibodies, raised against macroschizonts of Theileria parva, were tested against 10 different stocks of the parasite. The indirect fluorescent antibody test was used to demonstrate that these antibodies showed different binding affinities to macroschizonts of the various stocks. A profile of antibody binding could thus be prepared for each stock. For a given stock the profile was consistently the same irrespective of culture passage level, host cell background and method of antigen preparation. Monoclonal antibody profiles thus appear to provide a means of characterisation of stocks of T parva in vitro, and preliminary evidence suggests that profiles may be used to differentiate strains. The best source of antigen for testing theilerial stocks was macroschizont infected cells raised in culture, but suitable preparations could also be made from lymph node biopsies of cattle infected with East Coast fever. In a field outbreak of disease it might thus be possible rapidly to characterise the strains of T parva involved and plan immunisation and control measures accordingly.