Transfer of cell migration inhibition in vitro with xenogeneic RNA in experimental allergic orchitis.

Experimental allergic orchitis (EAO) was induced in rats following the injection of homologous testicular homogenate (THr) emulsified in Freund's complete adjuvant. Immune RNA (iRNA) was extracted from the spleen and lymph nodes. Normal guinea-pig peritoneal exudate cells (GP-PEC), when incubated in vitro with iRNA, were able to specifically recognise and respond to the immunising antigens (THr and PPD) as assessed by the direct migration inhibition reaction (MIR). Positive MIR's were also observed when incubated peritoneal exudate cells were tested against testicular homogenates from mice and guinea-pigs. This would confirm the presence of a common testicular antigen(s) in the three species studied. The reaction would appear to be organ-specific, kidney homogenate being unable to cause migration inhibition. GP-PEC incubated with iRNA which had been pretreated with RNAse did not show antigen-specific migration inhibition. Similarly, GP-PEC treated with RNA extracted from non-immunised donor rats did not respond.