PC require changes in RNA processing so that secretory Heavy chain is synthesized rather than mIg. Rate of H and L chains are significantly higher in PC than B-cells 3. MC is generated from few selected Hi affinity centrocytes in light zones of germinal centers. Transcriptional factors binds to the promoters or enhancers of genes and increase or decrease transcription of genes. Antigen competition can effect immune response to an related antigen.
Injected antibody competes for antigen and reduces clonal expansion.