Reaction of Heterozygous Swiss Mice to Implantation of C 3 H Myeloma X5563. ∗

Abstract

Summary and Conclusions

Random-bred Swiss mice reacting to implants of C₃H myeloma X5563 showed 46% takes, of which 40% were rejected after reaching a size of 0.5 to 4.5 ml, while 60% grew progressively. In C₃H mice, progressive growth of 99+% of the implants was noted and rejection was never seen. Adaptation apparently did not occur after 5 transplant generations in Swiss mice. When tumor tissue was returned from Swiss to C₃H mice, progressive growth always occurred. Most of the Swiss rejecters, though free from tumor, synthesized greatly elevated levels of 7S gamma globulins, and died in a few weeks from “wasting syndrome.” Some mice in which palpable tumors did not develop also showed fatal runting. Three rejecters developed massive atypical lymphoid hyperplasia. It is suggested that these variable reactions may result, in part, from the heterozygous nature of the Swiss colony.