In vitro transfer of cellular immunity in experimental allergic orchitis by means of immune RNA.

Ribonucleic acid (RNA) extracts were obtained from lymph nodes of guinea-pigs that had previously been immunized with a purified testicular antigen emulsified in Freund's complete adjuvant. The RNA extracts were incubated with normal guinea-pig peritoneal exudate cells (NGP-PEC). After treatment, the NGP-PEC cells showed specific inhibition of migration when tested with the specific antigen. No inhibition of migration was observed when cells were tested with an unrelated antigen or when the cells were incubated with RNA obtained from animals immunized with adjuvant alone. Failure of inhibition of migration was also observed when the 'immune' RNA was degraded with RNAse. The appearance of this I-RNA in the immunized guinea-pigs correlates with the appearance of delayed hypersensitivity in vivo.