Cyclic appearance of antibody-producing cells in the peripheral blood in response to a chemically-defiend polyglycerophosphate antigen.

Cyclic production of serum antibody and of plaque-forming cells (PFC) of polyglycerophosphate (PGP) specificity was observed in the peripheral blood of rabbits following a single injection of antigen. Individual animals were examined at 4-day intervals up to 28 days post-injection. Direct and indirect PFC displayed initial peaks at 4 days post-injection with an 8-day lag between the first and second peaks and a 12-day lag between the second and third peaks. Serum IgM rose to a peak 4 days after the initial PFC peak and gradually dropped to baseline levels. Serum IgG rose sharply to a peak at 4 days following the initial PFC peak and generally remained at elevated levels for the duration of the experiment. Cycling of background sheep erythrocyte PFC was also observed, but cycles were out of phase with the PGP cycles and with each other.