RETROVIRUS-INDUCED LYMPHOPROLIFERATIVE DISEASE IN MICE - ROLE OF HUMORAL IMMUNITY IN PERINATALLY EXPOSED MICE

The mice born to female mice infected with LP-BM5 MuLV, the etiologic agent for lymphoproliferative disease and nursed for 4-6 weeks by them were less susceptible upon reinfection by i.v. transfusion of blood o r plasma from infected donors with fully developed disease. Sera of 7 week or older perinatally exposed mice were capable of a complete in v itro neutralization of virus in plasma or blood from mice with fully d eveloped disease. In contrast, sera from 3-week old perinatally expose d mice were ineffective. The neutralizing ability of the sera was dras tically reduced or abrogated after their absorption with anti-mouse Ig M. These observations are consistent with the notion that perinatally exposure results in a moderate form of the disease of the offspring. T his perinatal infection is followed by a production of neutralizing an tibodies of predominantly the IgM class that significantly alters the course of the lymphoproliferative disease and, in some instances, even prevents its development.