Structural Control of Immunogenicity IV. RELATIVE SPECIFICITY OF ELICITATION OF CELLULAR IMMUNE RESPONSES AND OF LIGAND BINDING TO ANTI-HAPTEN ANTIBODY AFTER IMMUNIZATION WITH MONO-ε-DNP-<em>NONA</em>-L-LYSINE.

An evaluation of the specificity of antigen binding receptors possessed by cells involved in cellular immune responses and by cells in the antibody synthesizing line was made in order to determine to what extent each cell type could distinguish between closely related mono-ε-DNP-oligo-L-lysines. The antigen binding receptors of cells involved in cellular immune responses were studied by the elicitation of delayed hypersensitivity reactions in vivo and by the stimulation of DNA synthesis by lymph node cells in vitro using 1-ε-DNP-nona-L-lysine and 9-ε-DNP-nona-L-lysine. These experiments demonstrated that closely related compounds could be distinguished by this cell population. On the other hand, serum antibody from animals immunized with 1-ε-DNP-nona-L-lysine did not regularly distinguish between various mono-ε-DNP-oligo-L-lysines of differing immunogenicity or between 1-ε-DNP-nona-L-lysine and 9-ε-DNP-nona-L-lysine. Serum antibody specificity is assumed to reflect the specificity of the receptors possessed by the precursors of antibody producing cells. Thus, it appears likely that the cells involved in cellular immune responses or functioning as &#39;helper&#39; cells in the stimulation of antibody synthesis by other cells are capable of determining the immunogenicity of a compound. On the other hand, precursors of antibody producing cells, at least in primed animals and in the mono-ε-DNP-oligo-L-lysine response, do not appear to make distinctions between peptides of differing immunogenicity. [ABSTRACT FROM AUTHOR]