Amplification of B cell clones forming antibody to the 2,4‐dinitrophenyl group

Abstract

Abstract The selection of several single cell clones forming anti‐2,4‐dinitrophenyl (DNP) antibody in mice enabled us to study the life span of B memory cells, and to estimate the number of DNP‐binding cells belonging to a single clone, as well as their amplification into anti‐DNP plaque‐forming cells. B memory cells belonging to clone E9 were found to survive for several weeks in the absence of antigen. Memory cells for this clone were transferred into recipient mice; antigen challenge after 2 or 4 weeks led to E9 anti‐DNP formation at the same or half the level resulting from immediate antigen challenge. DNP‐binding cells were labeled with 125 I‐DNP on a heterologous carrier protein ( Maia Squinudo hemocyanin); for 3 different DNP‐clones the incidence of DNP‐binding cells in spleen (2nd transfer generation, 8 weeks after cell transfer) was 1000 – 1900 per 10 6 cells. This compares with 900/10 6 spleen cells in a multiclonal mouse primed with DNP‐ovalbumin; a proportion of these cells may represent T cells with specificity for DNP. Anti‐DNP‐forming cells in spleens of irradiated mice, receiving clonal memory cells and antigen, appeared after a lag of 4 – 5 days, reached a peak of 12000 – 18000 PFC between day 8 and 11 and then declined rapidly despite continued high levels of antibody production in recipient mice; this suggests antibody formation at sites other than spleen. The data are consistent with around 1 % effective homing of B precursor cells in spleen.