Immune RNA-mediated transfer of tumor antigen responsiveness to unresponsive peritoneal exudate cells from tumor-bearing animals.

Peritoneal exudate cells (PEC) from mice inoculated 5 to 7 days previously with 1 X 10(6) MOPC-315 plasmacytoma cells exhibit in vitro migration-inhibitory factor reactivity to soluble tumor-associated antigens. By 10 to 14 days of tumor growth, PEC from MOPC-315-bearing mice did not elicit migration-inhibitory factor when stimulated with MOPC-315 tumor-associated antigens but were still capable of migration-inhibitory factor production when stimulated with nontumor antigens. RNA-rich extracts prepared from 5- and 6-day postgrafting tumor bearers were capable of transferring tumor antigen reactivity to both normal PEC and PEC from unresponsive MOPC-315-bearing mice. On the other hand, RNA from unresponsive tumor bearers was incapable of transferring tumor antigen reactivity to normal mouse cells.