Detection of Hamster Type-C Virus Antigens by the Passive Hemagglutination Technique

Summary

An assay for antigen(s) of the type-C virus (D-9) of Syrian hamsters has been developed using the passive hemagglutination technique. Rabbits immunized with density gradient purified type-C virus (from plasma of Syrian hamsters bearing the D-9 lymphoma) developed antibodies that specifically hemagglutinated sheep erythrocytes sensitized with the hamster virus. The passive hemagglutination reaction was inhibited by density gradient purified type-C particles, tumor extracts, plasma, and organ extracts from hamsters bearing the D-9 lymphoma. Inhibition of passive hemagglutination was not obtained with density gradient material from normal hamster plasma. Both ether-soluble external viral antigens and water-soluble internal viral components inhibited the agglutination of sensitized cells. Extracts of normal Syrian hamster tissues or hamster embryos harvested during the last 5 days of gestation exhibited low levels of antigenicity. After sedimentation of type-C virions from infected plasma, large amounts of “soluble” viral antigens remained. These antigens could be removed by prolonged centrifugation at 115,000Xg. In some experiments, low levels of antigenicity were demonstrated in sera of newborn or weanling hamsters given injections of hamster type-C virus.