INDUCTION OF LYMPHATIC LEUKAEMIA IN BALB/C MICE FROM ORIGINAL ISOLATE OF RAUSCHER VIRUS

The reported dual ability of Rauscher virus to induce early splenic (reticulum cell) disease followed by lymphatic leukaemia in BALB/c mice, was investigated. Virus from the 16th-18th passage induced only splenic disease. When inoculated into newborn C57BL/6 mice and rats only lymphatic leukaemia occurred. Ratpassaged virus also induced only lymphatic leukaemia upon inoculation back into BALB/c mice. When Rauscher's original 1st passage isolate was later inoculated into newborn BALB/c mice, both splenic disease and lymphatic leukaemia occurred, but generally not in the same animals. Each type of disease was then readily reproduced separately upon serial passage in BALB/c mice. Transplantable lymphomas were induced from lymph nodes of mice with lymphatic leukaemia. These lymphomas were shown to be related to lymphomas induced by the lymphatic leukaemia virus associated with Friend virus. It was concluded that Rauscher virus is probably a mixture of at least 2 viruses, one of which induces the early splenic response, and the other lymphatic leukaemia. The latter, although present in later passages of the virus, could not produce overt disease because of its relatively long latent period as compared with that of the quick-acting splenic disease virus. We are most grateful to Dr. Frank J. Rauscher whose co-operation made this work possible. We are indebted to Mrs. Anna Lisa Arecco and Mrs. Jean McClellan for skilled technical assistance. This investigation was supported by USPHS Grant No. CA-07868 from the National Cancer Institute. © 1969, The British Empire Cancer Campaign for Research. All rights reserved.