Successful vaccination relies almost completely on the long-term production of high affinity, neutralising antibody. The plasma cells secreting this antibody typically originate in germinal centers, transient structures that also give rise to recirculating memory B cells, which in turn can supplement the number of plasma cells if required. The rate with which B-lineage cells emigrate from the GC, the duration of the migration period and the capacity of these cells to survive in a competitive environment will ultimately determine whether an immunization is considered successful.
We have examined factors considered important in determining attributes of humoral memory. For memory B-cells this has included the relationship between antigen dose and memory frequency, GC-origin and persistence, and the requirements of particular survival proteins during memory development. For plasma cells, the study has included analysis of their maturation, turnover in relation to production and identifying the relationship between external survival factors, survival and the survival program ultimately enacted, including the identification of the survival proteins required for plasma cell persistence. Collectively these studies provide insight into the formation and maintenance of immune memory, suggesting how favourable outcomes for vaccination may be achieved.