In vitro generation of CD20⁺CD27⁺CD43⁺CD70⁻CD69⁻cells from CD43⁻B cells. (A) On day 0, CD19⁺-enriched B cells were sorted into CD3⁻CD19⁺CD20⁺CD27⁺CD43⁻IgD⁺IgM⁺ (natural effector), CD3⁻CD19⁺CD20⁺CD27⁺CD43⁻IgD⁻IgM⁺ (IgM only memory), and CD3⁻CD19⁺CD20⁺CD27⁺CD43⁻IgD⁻IgM⁻ (switched memory) B cells. Subsequently, sorted cells were put in culture in the presence of R-848 and IL-2. Cells were analyzed by flow cytometry on day 5. Live CD3⁻CD19⁺CD20⁺CD27⁺ cells of the 3 cultured populations were gated as shown. (B) Plots showing expression of CD43 and CD70 of live CD3⁻CD19⁺CD20⁺CD27⁺ cells starting from natural effector (left), IgM only memory (middle), and switched memory B cells (right). (C) Plots showing expression of CD43 and CD69 of live CD3-CD19⁺CD20⁺CD27⁺ cells starting from natural effector (left), IgM only memory (middle), and switched memory B cells (right). Plots from a representative experiment of 3 are shown.