Specificity of Hapten‐Reactive T and B Mouse Lymphocytes

Immunization of mice with hapten‐protein conjugates leads to the appearance of increased numbers of hapten‐specific antigen‐binding cells of both T and B origin. as well as to the formation of anti hapten antibody‐secreting cells. The affinity of cellular receptors of hapten‐reactive T and B cells was studied after immunization with different antigen doses at different time intervals. It was found that the affinity of secreted antibodies of the IgG class as well as of B‐cell receptors for hapten was dose‐ and time‐dependent. The affinity of hapten‐reactive T cells for the hapten itself was low, irrespective of dose and time. Binding strength of T‐and B‐cell receptors was also investigated with the aid of mono‐ and multivalent homologous and heterologous hapten‐carner complexes. The affinity of T cells for the homologous monovalent ligand was considerably higher than for the hapten itself or a heterologous monovalent ligand. indicating carrier contribution to T‐receptor affinity. The contribution of carrier to the affinity of 7S antibodies or B‐cell receptors was relatively small The avidity of hapten‐specific cells for multi valent ligands was high in both T and B cells, but the increment in avidity with such ligands compared to monovalent ligands was less pronounced in T cells