Antibody-Producing Cells in Rabbits Injected with Soluble BSA: II. Kinetics and Dose Response¹ Free

Using a modified hemolytic plaque assay, the kinetics of antibody-producing cells were followed in both spleens and mesenteric lymph nodes of rabbits receiving either primary or secondary injections of soluble BSA. Direct plaques, developed by complement alone, were distinguished from amplified plaques, requiring an incorporated antiglobulin. In the primary response spleen cells were much more active than lymph node cells, while identical responses were observed in spleen and nodes during the secondary response, probably because of a redistribution of memory cells. Peak numbers of antibody-producting cells preceded highest serum antibody levels by several days, but correlated with the appearance of circulating antigen-antibody complexes and their rapid immune elimination. In both primary and secondary responses, injection of large doses of soluble BSA were shown to result in fewer antibody-producing cells than did injection of moderate doses.