[Studies on the in vitro formation of antibodies. III. Induction of primary and secondary immune response in vitro].

Peritoneal cells from normal, unimmunized mice (female NMRI, 28-32 gr) produced in vitro primary and secondary immune response after induction with the bacteriophage T2 6 hours or 7 day resp. after establishing the cultures. We confirmed the induction of a primary and secondary immunological response in vitro in the very same culture by the following data: 1. In vivo the donor animals were not in contact with the antigen used. We found neither the phage nor its host E. coli B in the gut of 97 mice investigated and no humoral antibodies against T2. The kinetics of humoral antibody production in vivo by different doses of T2 also showed that there are no related or identical antigen structures incorporated in our animals. 2. The T2 neutralizing activity in the culture medium after the first induction had the sedimentation constant of 19.7 +/- 2.3 S (n = 9) but the activity found after the second induction sedimented with 8.1 +/- 0.7 S (n = 10). 3. The primary activity was more sensitive to mercaptoethanol than the secondary. 4. Complement was bound by the complex T2 + neutralizing activity.