ANTITUMOR EFFECT OF SPLENOCYTES TREATED WITH RNA FROM ANIMALS IMMUNIZED WITH BOVINE MYELIN BASIC-PROTEIN

Chemically and immunologically, myelin basic protein (MBP) is very sim ilar with the basic protein extracted from animal and human tumors. Th e results of this study demonstrated that splenocytes from C57BL/6 mic e bearing B16 melanoma cells are sensitized to MBP, suggesting that th is protein may share common antigenic determinants with antigens from B16 melanoma cells. The RNA preparations isolated from lymphoid tissue s of normal or immunized guinea pigs with bovine MBP are referred to a s N-RNA or MBP-RNA, respectively. It was also found that MBP-RNA is ac tive in transferring MBP reactivity to normal splenocytes whereas N-RN A had no effect. To investigate whether this transfer of MBP immunorea ctivity could result in a protective immunity, C57BL/6 mice transplant ed with B16 melanoma received normal splenocytes treated with N-RNA or MBP-RNA. Two weeks after injection of B16-F10 cells, the mice were sa crified and the tumor of each animal was removed and weighed. A signif icant inhibition of B16 melanoma growth was only achieved in C57BL/6 m ice treated by splenocytes incubated with MBP-RNA which acts as an ant i-tumor RNA. In this context, MBP could be considered as a tumor antig en.