Igm And Igd Differential Cll Bcrs Organization And Interaction With Co-Receptors Before And During Ibrutinib Therapy

Studies of the B cell receptor (BCR) on normal B lymphocytes indicate that membrane IgM and IgD (respectively mIgM and mIgD) are organized in independent protein islands containing different BCR co-receptors that then reorganize as B cells transition from resting (CD19 and CD20 associated with IgD) to activated (CD19 and CD20 associated with IgM). In this way the signaling balance between IgM and IgD regulates B cell fate. Since BCR signaling is a key factor for chronic lymphocytic leukemia (CLL), as evinced by the efficacy of the signaling inhibitory drug ibrutinib, we decided to evaluate the membrane organization of the BCR-complex on primary CLL cells in an isotype dependent fashion.