Naive B cell
Once exposed to an antigen, the naive B cell either becomes a memory B cell or a plasma cell that secretes antibodies specific to the antigen that was originally bound. Plasma cells do not last long in the circulation, this is in contrast to memory cells that last for very long periods of time. Memory cells do not secrete antibody until activated by their specific antigen. 
Notes and references
- Airoldi I, Raffaghello L, Cocco C, et al. (January 2004). "Heterogeneous expression of interleukin-18 and its receptor in B-cell lymphoproliferative disorders deriving from naive, germinal center, and memory B lymphocytes". Clin. Cancer Res. 10 (1 Pt 1): 144–54. doi:10.1158/1078-0432.CCR-1026-3. PMID 14734463.
- Lang ML (Aug 2009). "How do natural killer T cells help B cells?". Expert Rev Vaccines. 8 (8): 1109–21. doi:10.1586/erv.09.56. PMC 2747240. PMID 19627191.