[Cytotoxic properties of the splenocytes of C3HA mice following treatment with exogenous RNA].

The influence of fractions of exogenous RNA, isolated from spleens of C3HA mice and of rats, both intact (control--cRNA) and immunized with homogenate of normal syngenic, allogenic and xenogenic tissues (immune--immRNA), on the cytotoxic properties of splenocytes of C3HA intact mice was compared in the in vitro cytotoxic experiments. The splenocytes treated with different RNA fractions were used as effector-cells. In vitro cultivated MGXXIIa cells of strain specific C3HA mice hepatoma, and K562 cells of human erythroleukemia, both labeled with 3H-uridine, served as target cells. Thus, it is only the cytoplasmic fraction of immRNA isolated from the spleens of rats immunized with tissue antigens of C3HA mice that induced a more pronounced stimulation of cytotoxic activity of splenocytes.