Radioactive antigen suicide of an anti-DNP (2,4-dinitrophenyl) clone. II. Follow-up of clones relatively resistant to radioactive antigen suicide when initially selected.

After suicide of the anti-dinitrophenyl (DNP) clone E21 in a previous experiment (Eur. J. Immunol. 1975. 5:58) several new clones (S clones) appeared promptly in the recipients. There was compelling evidence that they were then resistant to suicide, relative to E21. We now report further studies on these S clones and their antibodies. The antibodies of half of the S clones had affinities ten to one hundred times higher than E21 (3 x 10(-7) M); none was lower. The four tested were also able to bind DNP on the particular conjugate used for the suicide procedure. Three of the S clones were serially propagated, they showed a very great capacity for proliferation, transferring into 510, 85 and 110 recipients each. When their cells were tested at subsequent passages, they recovered early after inhibition by radioactive antigen. Two S clones may still have been somewhat refractory to suicide but, probably in all three, rapid proliferation was largely responsible for the recovery of the few cells escaping suicide, and helped them to appear suicide resistant.