Clonal nature of the immune response. II. The effect of immunization on clonal commitment

An inbred strain can produce several hundred different anti-group A carbohydrate (GAC) antibodies, as analyzed by isoelectric focusing. However, each individual mouse produces the bulk of its anti-GAC antibody as only one or two different spectrotypes, which appear to be randomly chosen. By using adoptive transfer techniques, we have observed that clonal commitment occurs very early in immunization, sometimes even before immunization, and thus does not result from competition among B cells for antigen. X