TRANSFER AGENT OF IMMUNITY .2. CONVERSION OF NONIMMUNE SPLEEN CELLS INTO ANTIBODY-FORMING CELLS BY TRANSFER AGENT IN RIBONUCLEIC ACID FRACTION OF IMMUNIZED MICE

Using erythrocytes as antigen particles, number of antibody‐forming cells was enumerated by immunocytoadehesion technique, in which formation of rosette was shown to be inhibited by anti‐mouse immunoglobulin sera. This number increased in vitro after treatment of spleen cells of mice for 60 min with RNA fraction extracted from spleen of mice immunized with erythrocytes used in the enumeration, and incubation of cells for 12 hr at 37 C. Response of cells treated with immune RNA fraction was immunologically specific and was inhibited by puromycin or cycloheximide. The activity of immune RNA capable of converting nonimmune cells to antibody‐forming cells was shown to be sensitive to ribonucleases but resistant to deoxyribonuclease and proteolytic enzyme. © jointly owned by Japanese society for Bacteriology and Society of Japanese Virologists