Wild-Type Gross Leukemia Virus. III. Serological Tests as Indicators of Leukemia Risk

Summary

Progeny of the cross AKR♀ × C3Hf/Bi ♂ and of the reciprocal cross C3Hf/Bi♀ × AKR ♂ were individually typed at various ages for Gross soluble antigen (GSA) in the blood and observed throughout their life. There was a high correlation between the occurrence of GSA in the blood and development of leukemia. All AKR × C3H progeny were GSA+ at the earliest age tested and the incidence of spontaneous leukemia was 96%. The overall incidence of spontaneous leukemia in progeny of the reciprocal C3H × AKR cross was 56% and the average age of onset was considerably later. The pedigrees of the C3H × AKR progeny revealed two types of families: 1) those in which most members became GSA+ and in which the incidence of leukemia was high, and 2) those in which most members remained GSA− and in which the incidence of leukemia was much lower. The difference in leukemia incidences in these two family types may reflect either maternal immunization or different degrees of virus transmission by various G+ males. When caged or mated with G+ mice, some C3Hf/Bi mice became GSA+ and some C57BL/6 mice produced G antibody. Thus the appearance of GSA in the blood may be attributable to congenital infection, infection in later life, or both.