Cellular reprogramming is an interplay between the original starting cell’s plasticity and the (epi)genetic mechanisms used to drive this cell towards a new fate. Our capacity to reprogram mature cells into progenitors thus greatly depends on the inherent physiological plasticity of the initial cell. B lymphocytes possess a high degree of plasticity revealed both during their normal development and under experimental conditions in the laboratory. In this chapter, we discuss the biology of B cell plasticity in the context of physiology and pathology and we provide a specific practical example of this plasticity in a protocol describing the dedifferentiation of mature B cells into multipotential progenitors that can afterwards be reprogrammed into alternative lineages like T cells or macrophages.
