Radioactive antigen suicide of an anti-DNP (2,4-dinitrophenyl) clone. I. Recovery and escape from clonal dominance by suicide resistant precursors.

An anti-2,4-dinitrophenyl (DNP) clone line, maintained in vivo by serial passage through irradiated syngeneic recipients, was exposed to 125I-labeled dinitrophenylated L-Tyr-L-Glu-L-Lys copolymer antigen of high specific activity. Hapten-specific suicide was obtained, though with more difficulty than for a heterogeneous secondary response. The recovery was followed and was shown to occur either with the same clones or with new clones, depending on conditions. After suicide at a late passage of the clone, recovery by new clones occured very rapidly. This indicated that there was a background heterogeneity in the clone system, normally suppressed by clonal dominance and that some of these new clones were suicide resistant.