sentences:  Clone (B-cell)
  
  The process of immunological B-cell maturation involves transformation from an undifferentiated B cell to one that secretes antibodies with particular specificity.This differentiation and activation of the B cell occurs most rapidly after exposure to antigen by antigen-presenting cells in the reticuloendothelial system, and under modulation by T cells, and is closely intertwined with affinity maturation.