Vaccines

• Describe generation of memory B cells

  Memory B cells have already undergone antibody class switching and affinity maturation. They can re-enter germinal centres during secondary immune responses to undergo additional somatic hypermutation and affinity maturation. However, they are not yet differentiated into plasma cells and therefore require help from CD4+ Th cells for secretion of antibody.
• Describe memory T cells and their maintenance

  Most activated effector T cells are programmed to die via activation induced cell death and memory cell survival and maintenance is mediated by IL15 and IL7. Memory T cells express high levels of IL7 receptors, adhesion molecules ( CD44 ). T memory cells can be tissue resident or adapted for recirculation through lymphoid ( central memory ) or re-enter inflamed tissues ( effector memory)
• Compare features of naive B cells and memory B cells 


  Naive B cells and memory cells