Generation of antibody diversity. I. Kinetics of production of different antibody specificities during the course of an immune response

摘要

AbstractThe plaque‐forming cells (PFC) produced by mice immunized with erythrocytes from one sheep could be divided into different specificity subgroups by testing their ability to cross‐react with erythrocytes from other individual sheep or from other species. Using this marker system, we investigated the kinetics of production of different specificities during primary and secondary immune responses.The main findings were: (a) PFC of certain specificities were entirely absent from the spleen during the first 2 days of a primary response, but present from the start in a secondary response; (b) more than half of the early plaques were so specific that they lysed red cells from the immunizing sheep, but not from other sheep. In addition, significant numbers of heteroclitic antibody‐forming cells were found. These results do not support the conventional idea that all B cells exist before antigenic stimulation. Instead, they provide some evidence for the view that antigen stimulates the proliferation of an initial population of B cells with low affinity receptors from which it generates cells producing entirely new antibody specific